Centre for Schistosomiasis and Parasitology

Our Publications

Sharing our research findings with the global scientific community through peer-reviewed publications Selected CSP Staff Publications relating to Schistosomiasis and Geohelminthiasis research are listed below, with their respective abstract

Our Publications

2019

Evaluation of the schistosomicidal, antioxidant and anti-inflammatory activities of the ethyl acetate fraction from Ozoroa pulcherrima Schweinf. Roots on Schistosoma mansoni-induced liver pathology

Jatsa HB, Feussom NG, Femoe UM, Kenfack MC, Nkondo ET, Kadji Fassi JB, Simo ND, Moaboulou C, Dongmo CN, Tsague CD, Dongo E, Kamtchouing P, Tchuem Tchuente LA.

Journal of Ethnopharmacology. 238 (111883)

J. Ethnopharmacology

2019

View Abstract
Abstract:
Ethnopharmacological relevance: Ozoroa pulcherrima Schweinf. is a plant used in the traditional treatment of schistosomiasis in Cameroon. The aim of the present work was to evaluate the schistosomicidal, antioxidant and anti-inflammatory activities of the ethyl acetate fraction (EAF) from O. pulcherrima roots methanolic extract on Schistosoma mansoni-induced liver pathology.

Materials and methods: In vitro tests were performed to determine the effect of EAF on the viability of adult schistosomes. For in vivo tests, mice infected with S. mansoni cercariae were treated orally with EAF at 50, 100, or 200 mg/kg for 28 consecutive days, from the 35th day post-infection. Praziquantel (PZQ, 500 mg/kg) was used as reference drug. After treatment, mice were sacrificed and adult worms were recovered. The schistosomicidal activity was evaluated by counting adult worms and eggs load. Antioxidant activity was assessed through estimation of hepatic malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) levels. Evaluation of anti-inflammatory activity was carried out by histological analysis of liver and by quantification of serum ALT, AST, ALP, total bilirubin, albumin, total protein and gamma globulins.

Results: In vitro, EAF exhibited a concentration-dependent activity on adult S. mansoni, with the highest mortality (83.33 ± 7.63%) at 400 μg/ml after 72 h of incubation. In vivo, EAF at 200 mg/kg induced the highest worm burden reduction (48.87 ± 7.31%), a significant reduction in liver granuloma number and diameter, and restored the liver architecture. EAF significantly reduced lipid peroxidation and increased SOD and GSH levels, compared to infected untreated mice. EAF prevented the elevation of liver and serum markers of hepatocellular injury, and decreased the level of gamma globulins.

Conclusion: These results demonstrate that EAF possesses schistosomicidal, antioxidant and anti-inflammatory activities against S. mansoni-induced liver pathology, and support the traditional use of O. pulcherrima in the treatment of schistosomiasis.
2018

Paragonimus and paragonimiasis in West and Central Africa: Unresolved questions

Cumberlidge N, Rollinson D, Vercruysse J, Tchuem Tchuenté L, Webster B, Clark P.

Parasitology, 145(13), 1748–1757. doi:10.1017/S0031182018001439

Parasitology

2018

View Abstract
Abstract:
Paragonimiasis is a food-borne trematode infection of humans caused by several species of the genus Paragonimus. The infection is acquired by eating raw or undercooked freshwater crabs or crayfish containing metacercariae. In West and Central Africa, paragonimiasis is endemic in several countries where it is a significant public health problem. The disease is caused by Paragonimus africanus and Paragonimus uterobilateralis, and has been reported from at least 14 countries in the region. Despite its public health importance, our knowledge of the epidemiology, transmission and ecology of paragonimiasis in West and Central Africa is limited and many questions remain unresolved. This review summarizes the current state of knowledge of paragonimiasis in West and Central Africa, highlighting the gaps in our understanding of the disease and its transmission, and identifying priority areas for future research. We also discuss the challenges and opportunities for the control and elimination of paragonimiasis in the region.

Prospects for the elimination of schistosomiasis and soil-transmitted helminthiasis: Exploring disease trends through time at the Barombi crater lakes, South-West Cameroon

Tchuem Tchuenté L, Ombede D, Noumedem C, Chuinteu G, Nono B, Lemegne A, Stothard J et al.

Parasitology, 145(13), 1700–1714. doi:10.1017/S0031182018001531

Parasitology

2018

View Abstract
Abstract:
The Barombi crater lakes in South-West Cameroon are a unique ecosystem and a focal point for schistosomiasis and soil-transmitted helminthiasis (STH) transmission. This study aimed to explore disease trends over time in these lakes and assess the prospects for elimination. We conducted parasitological surveys in 2015 and compared the results with historical data from 2004 and 2010. A total of 1198 individuals were examined. The prevalence of Schistosoma haematobium was 18.8% in 2015, significantly lower than the 44.3% recorded in 2004 and 31.2% in 2010. STH prevalence was also reduced, with hookworm declining from 68.9% in 2004 to 25.6% in 2015, and Ascaris lumbricoides from 42.1% to 12.2%. These reductions were associated with repeated mass drug administration (MDA) with praziquantel and albendazole. However, transmission persists, particularly in areas with high water contact. The study highlights the need for integrated control strategies, including MDA, health education, improved water and sanitation, and snail control, to achieve elimination of schistosomiasis and STH in this setting.

Efficacy of Sida pilosa Retz aqueous extract against Schistosoma mansoni-induced granulomatous inflammation in the liver and the intestine of mice

Jatsa HB, Femoe UM, Njiaza J, Tombe Tombe DS, Mbolang LN, Nkondo ET, Tchuem Tchuente LA, Dimo T, Kamtchouing P.

BMC Complementary and Alternative Medicine. 18(1)

BMC Complement. Alt. Med.

2018

View Abstract
Abstract:
Background: Schistosomiasis is a parasitic disease caused by trematodes of the genus Schistosoma. The pathology of the disease is mainly due to the host immune response to parasite eggs trapped in tissues. Sida pilosa Retz is a plant traditionally used in Cameroon to treat schistosomiasis. This study aimed to evaluate the efficacy of the aqueous extract of S. pilosa against Schistosoma mansoni-induced granulomatous inflammation in the liver and intestine of mice.

Methods: Mice were infected with S. mansoni cercariae and treated orally with the aqueous extract of S. pilosa at 200, 400, or 600 mg/kg for 28 consecutive days, starting from the 35th day post-infection. Praziquantel (500 mg/kg) was used as reference drug. After treatment, the mice were sacrificed and the liver and intestine were collected for histological analysis. The number and diameter of granulomas were evaluated, and the inflammatory response was assessed.

Results: Treatment with S. pilosa aqueous extract significantly reduced the number and diameter of granulomas in the liver and intestine compared to infected untreated mice. The extract also reduced the severity of inflammation and fibrosis. The highest effect was observed at 600 mg/kg, which was comparable to praziquantel. The extract also reduced the number of eggs in the liver and intestine.

Conclusion: These results demonstrate that S. pilosa aqueous extract has anti-inflammatory activity against S. mansoni-induced granulomatous inflammation, supporting its traditional use in the treatment of schistosomiasis.

Histological Analysis of liver of Schistosoma mansoni infected mice treated with ethyl acetate fraction from Ozoroa pulcherrima methanolic extract

Jatsa HB, Cannet C, Femoe UM, Feussom NG, Dzeufiet PDD, Kamtchouing P, Tchuem Tchente LA.

Revue Française d'Histopathologie. 2018, 30(1):31–49

Rev. Fr. Histopathologie

2018

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Whole genome amplification and exome sequencing of archived schistosome miracidia

Le Clec'h W, Chevalier FD, McDew-White M, Allan F, Webster BL, Gouvras AN, Kinunghi S, Tchuem Tchuenté LA, Garba A et al.

Parasitology. 145(13), 1739–1747

Parasitology

2018

View Abstract
Abstract:
Genomic studies of schistosomes have been limited by the difficulty of obtaining high-quality DNA from field samples, particularly from archived material. Here, we describe a method for whole genome amplification (WGA) and exome sequencing of archived schistosome miracidia. We applied this method to miracidia collected from archived stool samples from several African countries. We show that WGA can produce sufficient DNA for exome sequencing, and that the resulting sequence data are of high quality, with coverage of target exons comparable to that obtained from fresh samples. This method enables the study of genetic variation in archived schistosome samples, opening up the possibility of large-scale population genomic studies of schistosomes using existing collections.

Precision mapping: An innovative tool and way forward to shrink the map, better target interventions, and accelerate toward the elimination of schistosomiasis

Tchuem Tchuenté L-A, Stothard JR, Rollinson D, Reinhard-Rupp J.

PLoS Negl Trop Dis 12(8): e0006563

PLoS Negl Trop Dis

2018

View Abstract
Abstract:
The global effort to eliminate schistosomiasis as a public health problem has gained momentum, but progress is hampered by the lack of accurate, high-resolution data on the distribution of the disease. Traditional mapping approaches often rely on surveys at the district or health facility level, which can mask significant heterogeneity in transmission within these administrative units. Precision mapping uses a more granular approach, combining parasitological data with environmental and demographic factors to predict the prevalence of schistosomiasis at a fine spatial scale. This approach can identify areas where transmission is high and where interventions need to be targeted, as well as areas where transmission is low and where elimination may be feasible. This review discusses the principles and methods of precision mapping, and explores its potential to accelerate progress towards the elimination of schistosomiasis.

A pilot study using wearable GPS data loggers to compare water contact levels: Schistosoma haematobium infection in pre-school-age children and their mothers at Barombi Kotto, Cameroon

Macklin G, Stanton MC, Tchuem-Tchuenté LA, Stothard JR.

Transactions of the Royal Society of Tropical Medicine and Hygiene

Trans. R. Soc. Trop. Med.

2018

View Abstract
Abstract:
Background: Schistosoma haematobium infection is acquired through contact with freshwater containing cercariae. While school-aged children are the most infected group, pre-school-age children (PSAC) are also at risk. However, the water contact behaviour of PSAC and their caregivers is poorly understood. This study used wearable GPS data loggers to compare water contact levels between PSAC and their mothers in a schistosomiasis-endemic area in Cameroon.

Methods: GPS data loggers were worn by 20 PSAC and their mothers for 7 days. Water contact was defined as proximity to water bodies. The frequency and duration of water contact were compared between PSAC and mothers.

Results: PSAC had significantly more frequent and longer water contact events than their mothers. The water contact of PSAC was mainly for domestic activities (e.g., fetching water) and playing, while mothers' water contact was mainly for domestic chores. The study shows that PSAC are at high risk of schistosome infection due to frequent water contact.

Conclusion: This pilot study demonstrates the utility of GPS data loggers for studying water contact behaviour and highlights the importance of including PSAC in schistosomiasis control programmes.

Acute and sub-chronic oral toxicity studies of the leaves aqueous extract of Clerodendrum umbellatum Poir. on mice

Jatsa HB, Kadji Fassi JB, Kenfack MC, Feussom NG, Kameni MP, Simo ND, Nkondo ET, Dongmo AB, Tchuem Tchuente LA.

American Journal of Physiology, Biochemistry and Pharmacology. 7(2), 75–85

AJPBP

2018

View Abstract
Abstract:
Clerodendrum umbellatum Poir. is a plant used in traditional medicine to treat various diseases, including schistosomiasis. This study aimed to evaluate the acute and sub-chronic oral toxicity of the aqueous extract of C. umbellatum leaves in mice. For the acute toxicity test, mice received a single oral dose of the extract up to 5000 mg/kg and were observed for 14 days. For the sub-chronic toxicity test, mice received daily oral doses of 250, 500, or 1000 mg/kg of the extract for 28 days. Body weight, food and water consumption, organ weights, haematological and biochemical parameters, and histopathology of organs were evaluated. No mortality or signs of toxicity were observed in the acute toxicity test, with an estimated LD50 > 5000 mg/kg. In the sub-chronic toxicity test, no treatment-related changes were observed in body weight, organ weights, haematological or biochemical parameters, or histopathology. These results suggest that the aqueous extract of C. umbellatum leaves has a low toxicity profile and is safe for oral use.

Schistosomiasis in Africa: Improving strategies for long-term and sustainable morbidity control

French MD, Evans D, Fleming FM, Secor WE, Biritwum NK, Brooker SJ, Tchuem Tchuenté LA et al.

PLOS Neglected Tropical Diseases. 12(6)

PLoS Negl Trop Dis

2018

View Abstract
Abstract:
Schistosomiasis is a major public health problem in Africa, where the majority of the global burden of disease occurs. The World Health Organization (WHO) recommends regular mass drug administration (MDA) with praziquantel to control morbidity, particularly in school-aged children. However, despite large-scale MDA programmes, the prevalence and intensity of infection remain high in many areas. This review discusses the challenges to achieving long-term and sustainable morbidity control, including the limitations of MDA alone, the risk of drug resistance, and the need for integrated control strategies. We propose a new framework for schistosomiasis control in Africa that combines MDA with complementary interventions, such as health education, improved water and sanitation, and snail control, with the goal of reducing transmission and achieving sustainable morbidity control.

Influence of steeping of cassava tubers on physico-chemical quality of water and benthic macroinvertebrates of River Pala in Central African Republic

Ngoay-Kossy JC, Zébazé Togouet SH, Bolevane Ouantinam SF, Makatia Wango SP, Tchuem Tchuenté LA.

International Journal of Science and Research. 7(1), 2077–2088

Int. J. Science & Research

2018

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Seroprevalence of rubella-specific IgM and IgG antibodies among pregnant women in a Catholic Hospital in Yaoundé, Cameroon

Eno AA, Makemgue LS, Tonye DS, Boye CSB, Seck A, Bercion R, Vauloup Fellous C, Tchuem Tchuente LA.

International Journal of Biological and Chemical Sciences. 12(3), 1123–1130

Int. J. Biol. Chem. Sci.

2018

View Abstract
Abstract:
Rubella is a viral infection that can cause serious birth defects if acquired during pregnancy. The aim of this study was to determine the seroprevalence of rubella-specific IgM and IgG antibodies among pregnant women in Yaoundé, Cameroon. A cross-sectional study was conducted at a Catholic Hospital in Yaoundé, and serum samples from 384 pregnant women were tested for rubella IgM and IgG using ELISA. The overall seroprevalence of rubella IgG was 91.1%, indicating a high level of immunity. The seroprevalence of rubella IgM was 2.3%, indicating recent infection. The highest prevalence of IgM was observed in the first trimester of pregnancy. The study highlights the need for rubella vaccination and surveillance to prevent congenital rubella syndrome in Cameroon.

Equity and efficiency in the scaled-up implementation of integrated neglected tropical disease control: the COUNTDOWN multicountry observational study

Woode ME, Khan JAM, Thomson R, Niessen LW, COUNTDOWN Consortium.

British Medical Journal Open 8(6)

BMJ Open

2018

View Abstract
Abstract:
Objective: To assess equity and efficiency in the scaled-up implementation of integrated neglected tropical disease (NTD) control in Cameroon, Ghana, Liberia, Nigeria and Sierra Leone.

Design: A multicountry observational study using a mixed-methods approach, including quantitative data on coverage, costs and outcomes, and qualitative data on stakeholder perspectives.

Setting: Integrated NTD control programmes implemented in 10 districts across the five countries.

Participants: Stakeholders involved in the planning and implementation of NTD control, including government officials, programme managers, health workers and community drug distributors.

Outcome measures: Equity in the distribution of interventions (mass drug administration, health education and vector control) and efficiency in the use of resources, measured as cost per person treated and cost per disability-adjusted life year (DALY) averted.

Results: The study found significant inequalities in the distribution of interventions, with some population groups, including the poorest and most marginalised, having lower coverage. Efficiency varied considerably across districts, with costs per person treated ranging from $0.50 to $2.50. The cost per DALY averted was estimated to be between $10 and $50. The study identified several factors that contributed to inequity and inefficiency, including inadequate funding, weak health systems and poor community engagement.

Conclusion: The study highlights the importance of monitoring equity and efficiency in NTD control programmes. It provides evidence to inform policy and practice to ensure that integrated NTD control is both equitable and efficient.

Review of the 2017 WHO Guideline: Preventive chemotherapy to control soil-transmitted helminth infections in at-risk population groups

Savioli L, Albonico M, Daumerie D, Lo NC, Stothard JR, Asaolu S et al.

PLoS Negl Trop Dis 12(4): e0006296

PLoS Negl Trop Dis

2018

View Abstract
Abstract:
The World Health Organization (WHO) has recently published new guidelines on preventive chemotherapy to control soil-transmitted helminth (STH) infections in at-risk population groups. The guidelines update previous recommendations and provide evidence-based guidance on the use of anthelmintic drugs for the control of STH infections. The guidelines recommend periodic deworming of children, adolescents, and women of reproductive age, including pregnant women, in areas where the prevalence of STH infection is high. The guidelines also emphasize the need for integrated control approaches, including improved water, sanitation and hygiene (WASH) and health education. This review summarizes the key recommendations of the WHO guidelines and discusses their implications for the control of STH infections globally.
2017

Towards interruption of schistosomiasis transmission in sub-Saharan Africa: developing an appropriate environmental surveillance framework

Stothard J, Campbell S, Osei-Atweneboana M, Durant T, Stanton M, Biritwum N, Rollinson D, Ombede D, Tchuem-Tchuenté L.

Infectious Diseases of Poverty, 6(1)

Infect. Dis. Poverty

2017

View Abstract
Abstract:
Schistosomiasis is a parasitic disease caused by trematodes of the genus Schistosoma. The disease is transmitted through contact with freshwater containing cercariae, the infective stage of the parasite. The global strategy for schistosomiasis control is based on preventive chemotherapy with praziquantel, but progress towards elimination will require complementary interventions, including environmental surveillance to monitor transmission. This paper discusses the need for an environmental surveillance framework to support the interruption of schistosomiasis transmission in sub-Saharan Africa. The framework should include the monitoring of snail populations, the detection of schistosome DNA in the environment, and the assessment of human water contact behaviour. The development of such a framework will require collaboration between researchers, programme managers and policy makers.

Moving from control to elimination of schistosomiasis in sub-Saharan Africa: time to change and adapt strategies

Tchuem Tchuenté L, Rollinson D, Stothard J, Molyneux D.

Infectious Diseases of Poverty, 6(1)

Infect. Dis. Poverty

2017

View Abstract
Abstract:
The global schistosomiasis community is moving from a strategy of morbidity control to one of elimination. This shift in strategy requires changes in the way we think about the disease and how we implement control programmes. This paper discusses the challenges and opportunities of moving from control to elimination of schistosomiasis in sub-Saharan Africa. We argue that the elimination of schistosomiasis will require a combination of interventions, including mass drug administration, health education, improved water and sanitation, and snail control. We also highlight the need for new tools, such as vaccines and diagnostics, to support the elimination agenda.

Mapping of Neglected Tropical Diseases in Equatorial Guinea: Recommendations for Integrated Control

Tchuem Tchuente LA, Zoure HGM, Wanji S, Yameogo L, Traore S, Ndongo Asumu P, Sima A, Amazigo U.

PLoS Negl Trop Dis (in Press)

PLoS Negl Trop Dis

2017

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.
2016

Enhancing collaboration between China and African countries for schistosomiasis control

Jing Xu, Qing Yu, Tchuem Tchuenté LA, Bergquist R, Sacko M, Utzinger J et al.

Lancet Infectious Diseases. Published online Feb. 3, 2016

Lancet Infect. Dis.

2016

View Abstract
Abstract:
Schistosomiasis is a major public health problem in many parts of the world, particularly in sub-Saharan Africa. China has a long history of schistosomiasis control and has made remarkable progress in reducing the burden of the disease. There is potential for China to share its experience and expertise with African countries to support the control of schistosomiasis. This article discusses the opportunities and challenges for enhancing collaboration between China and African countries for schistosomiasis control. It highlights the need for a coordinated approach that includes capacity building, research collaboration, and the sharing of best practices.

Improvement of the liver pathology by the aqueous extract and the n-butanol fraction of Sida pilosa Retz in Schistosoma mansoni-infected mice

Jatsa HB, Russo RC, Pereira CAJ, Tchuem Tchuente LA, Kamtchouing P et al.

Journal of Ethnopharmacology 180, 114–123

J. Ethnopharmacology

2016

View Abstract
Abstract:
Ethnopharmacological relevance: Sida pilosa Retz is a plant used in traditional medicine in Cameroon to treat various ailments, including schistosomiasis. This study aimed to evaluate the effects of the aqueous extract and the n-butanol fraction of S. pilosa on the liver pathology of Schistosoma mansoni-infected mice.

Materials and methods: Mice were infected with S. mansoni cercariae and treated orally with the aqueous extract (600 mg/kg) or the n-butanol fraction (200 mg/kg) of S. pilosa for 28 consecutive days, starting from the 35th day post-infection. Praziquantel (500 mg/kg) was used as reference drug. After treatment, the mice were sacrificed and the liver was collected for histological analysis. The number and diameter of granulomas, the degree of fibrosis, and the inflammatory infiltrate were assessed.

Results: Treatment with the aqueous extract and the n-butanol fraction significantly reduced the number and diameter of granulomas, the degree of fibrosis, and the inflammatory infiltrate in the liver compared to infected untreated mice. The n-butanol fraction showed a higher effect than the aqueous extract, and was comparable to praziquantel. The extracts also reduced the levels of ALT and AST, indicating a hepatoprotective effect.

Conclusion: These results demonstrate that S. pilosa has hepatoprotective and anti-inflammatory activities against S. mansoni-induced liver pathology, supporting its traditional use in the treatment of schistosomiasis.
2015

Detection of hybrid Schistosoma haematobium group species in Cameroon by PCR-RFLP of the second internal transcribed spacer (ITS-2)

Luogbou Nzu DO, Netongo Masumbe P, Bayemi Pougue H, Mbacham FW, Tchuem Tchuente LA.

World Journal of Pharmaceutical Research. 4(6), 1961–1980

WJPR

2015

View Abstract
Abstract:
Schistosoma haematobium is a parasitic trematode that causes urogenital schistosomiasis in humans. In Cameroon, S. haematobium co-exists with other Schistosoma species, including S. guineensis and S. intercalatum, and hybridization between these species has been reported. This study aimed to detect hybrid S. haematobium group species in Cameroon using PCR-RFLP of the second internal transcribed spacer (ITS-2) of the ribosomal DNA. Urine samples were collected from school children in several communities in Cameroon, and DNA was extracted from the urine sediments. PCR amplification of the ITS-2 region was performed, followed by digestion with the restriction enzyme HhaI. The PCR-RFLP patterns were used to identify the Schistosoma species and to detect hybrids. The study identified S. haematobium, S. guineensis, and S. intercalatum, as well as hybrids between these species. The results show that hybridization between Schistosoma species is common in Cameroon and highlight the need for molecular surveillance to monitor the spread of hybrids and their potential impact on disease transmission.

Spatial distribution of schistosomiasis and treatment needs in sub-Saharan Africa: a systematic review and geostatistical analysis

Lai YS, Biedermann P, Tchuem Tchuenté LA et al.

Lancet Infectious Diseases. 15(8), 927–940

Lancet Infect. Dis.

2015

View Abstract
Abstract:
Background: Schistosomiasis is a parasitic disease caused by trematodes of the genus Schistosoma. The disease is endemic in many parts of sub-Saharan Africa, where it causes significant morbidity. The global strategy for schistosomiasis control is based on preventive chemotherapy with praziquantel, but the implementation of this strategy requires accurate information on the spatial distribution of the disease and the treatment needs. This study aimed to map the spatial distribution of schistosomiasis in sub-Saharan Africa and to estimate the number of people in need of treatment.

Methods: We conducted a systematic review of the literature to identify surveys of schistosomiasis prevalence in sub-Saharan Africa published between 1980 and 2014. We used a geostatistical model to predict the prevalence of schistosomiasis at a 5 km resolution, taking into account environmental and demographic factors. We then estimated the number of people in need of preventive chemotherapy, based on the WHO guidelines.

Findings: We identified 140 surveys from 30 countries, representing over 1.5 million individuals. The predicted prevalence of schistosomiasis was highest in West and Central Africa. We estimated that over 250 million people in sub-Saharan Africa are in need of preventive chemotherapy for schistosomiasis.

Interpretation: This study provides a comprehensive map of the spatial distribution of schistosomiasis in sub-Saharan Africa and estimates the treatment needs. The results can be used to guide the implementation of control programmes and to advocate for increased funding for schistosomiasis control.

Spatial and temporal distribution of soil-transmitted helminth infection in sub-Saharan Africa: a systematic review and geostatistical meta-analysis

Karagiannis-Voules DA, Biedermann P, Tchuem Tchuente LA et al.

Lancet Infectious Diseases. 15(1):74–84. doi:10.1016/S1473-3099(14)71004-7

Lancet Infect. Dis.

2015

View Abstract
Abstract:
Background: Soil-transmitted helminth (STH) infections are a major public health problem in sub-Saharan Africa. The global strategy for STH control is based on preventive chemotherapy with albendazole or mebendazole, but the implementation of this strategy requires accurate information on the spatial and temporal distribution of STH infections. This study aimed to map the spatial distribution of STH infections in sub-Saharan Africa and to assess changes in prevalence over time.

Methods: We conducted a systematic review of the literature to identify surveys of STH prevalence in sub-Saharan Africa published between 1980 and 2014. We used a geostatistical model to predict the prevalence of STH infections at a 5 km resolution, taking into account environmental and demographic factors. We then assessed temporal trends by comparing the prevalence of STH infections in different time periods.

Findings: We identified 180 surveys from 35 countries, representing over 1 million individuals. The predicted prevalence of STH infections was highest in West and Central Africa. We found a significant decline in the prevalence of STH infections over time, particularly for hookworm and Ascaris lumbricoides. The decline was associated with the scale-up of preventive chemotherapy programmes.

Interpretation: This study provides a comprehensive map of the spatial and temporal distribution of STH infections in sub-Saharan Africa. The results show that progress has been made in the control of STH infections, but that further efforts are needed to achieve elimination.

Schistosomicidal, hepatoprotective and antioxidant activities of the methanolic fraction from Clerodendrum umbellatum Poir leaves aqueous extract in Schistosoma mansoni infection in mice

Jatsa HB, Kenfack CM, Simo DN, Feussom NG, Tienga Nkondo E, Tchuem Tchuente LA, Kamtchouing P.

BMC Complementary and Alternative Medicine (2015) 15:248

BMC Complement. Alt. Med.

2015

View Abstract
Abstract:
Background: Clerodendrum umbellatum Poir is a plant used in traditional medicine in Cameroon to treat various diseases, including schistosomiasis. This study aimed to evaluate the schistosomicidal, hepatoprotective and antioxidant activities of the methanolic fraction from C. umbellatum leaves aqueous extract in Schistosoma mansoni infection in mice.

Methods: Mice were infected with S. mansoni cercariae and treated orally with the methanolic fraction (100, 200 or 400 mg/kg) for 28 consecutive days, starting from the 35th day post-infection. Praziquantel (500 mg/kg) was used as reference drug. After treatment, the mice were sacrificed and the worms and eggs were counted. The liver was collected for histological analysis and for the assessment of oxidative stress markers.

Results: Treatment with the methanolic fraction significantly reduced the worm burden and the number of eggs in the liver and intestine. The fraction also reduced the number and diameter of granulomas in the liver, and improved the liver architecture. The fraction reduced lipid peroxidation and increased the levels of antioxidant enzymes (SOD and GSH).

Conclusion: These results demonstrate that the methanolic fraction from C. umbellatum leaves has schistosomicidal, hepatoprotective and antioxidant activities against S. mansoni infection in mice, supporting the traditional use of the plant in the treatment of schistosomiasis.
2014

Epidemiology of schistosomiasis and soil-transmitted helminthiasis in the sub-division of Kékem (West-Cameroon)

Nana Dankoni E, Tchuem Tchuente LA.

International Journal of Innovation and Applied Studies. 8(4), 1782–1790

Int. J. Innov. Appl. Studies

2014

View Abstract
Abstract:
Schistosomiasis and soil-transmitted helminthiasis (STH) are major public health problems in Cameroon. This study aimed to determine the epidemiology of these diseases in the sub-division of Kékem, West Cameroon. A cross-sectional survey was conducted in five schools, and stool and urine samples were collected from 500 school children. The samples were examined for the presence of STH eggs using the Kato-Katz method, and for Schistosoma haematobium eggs using the filtration method. The prevalence of S. haematobium was 20.4%, and the prevalence of STH was 45.6%, with hookworm being the most common STH. The prevalence of both infections was associated with age, sex, and water contact behaviour. The study highlights the need for integrated control interventions, including mass drug administration, health education, and improved water and sanitation.

Efficacy of praziquantel and reinfection patterns in single and mixed infection foci for intestinal and urogenital schistosomiasis in Cameroon

Tchuem Tchuente LA, Momo SC, Stothard JR, Rollinson D.

Acta Tropica, 128, 275–283

Acta Tropica

2014

View Abstract
Abstract:
This study evaluated the efficacy of praziquantel (PZQ) and reinfection patterns in single and mixed infection foci for intestinal (Schistosoma mansoni) and urogenital (S. haematobium) schistosomiasis in Cameroon. A longitudinal study was conducted in two villages, one with S. mansoni only and one with both S. mansoni and S. haematobium. School children were treated with PZQ (40 mg/kg) and followed up for 12 months. The efficacy of PZQ was assessed by measuring the reduction in egg counts one month after treatment. Reinfection rates were assessed by measuring egg counts at 6 and 12 months after treatment. The results showed that PZQ was highly efficacious against both S. mansoni and S. haematobium, with cure rates >85%. Reinfection rates were high, particularly for S. haematobium, with 70% of children reinfected at 12 months. The study highlights the need for repeated MDA to maintain control, and the importance of addressing transmission factors to prevent reinfection.

Identification and mapping of some potential transmission foci of schistosomiasis in Maroua, Far North Region, Cameroon

Kamwa Ngassam RI, Kouninki H, Monglo B, Djekine E, Liang S, Tchuem Tchuente LA.

International Journal of Innovation and Applied Studies. 7(1), 65–77

Int. J. Innov. Appl. Studies

2014

View Abstract
Abstract:
Schistosomiasis is a parasitic disease transmitted through contact with freshwater containing cercariae. The transmission of the disease is focal, and the identification of transmission foci is essential for the implementation of control measures. This study aimed to identify and map potential transmission foci of schistosomiasis in Maroua, Far North Region, Cameroon. A cross-sectional survey was conducted in 10 communities, and water bodies used by the communities were surveyed for the presence of snail intermediate hosts. The survey identified five potential transmission foci, all of which were used for domestic and recreational activities. The study highlights the need for targeted interventions in these foci to reduce schistosomiasis transmission.

Assessment of Anthelmintic Efficacy of Mebendazole in School Children in Six Countries Where Soil-Transmitted Helminths Are Endemic

Levecke B, Montresor A, Albonico M, Tchuem Tchuente LA et al.

PLoS Negl Trop Dis 8(10): e3204. doi:10.1371/journal.pntd.0003204

PLoS Negl Trop Dis

2014

View Abstract
Abstract:
Background: The World Health Organization recommends periodic deworming of school-aged children with anthelmintic drugs to control soil-transmitted helminth (STH) infections. Mebendazole is one of the drugs recommended for this purpose. However, the efficacy of mebendazole has not been systematically assessed across different settings. This study aimed to assess the efficacy of mebendazole in school children in six countries where STH infections are endemic.

Methodology: A multicenter study was conducted in Brazil, Cameroon, Cambodia, Ethiopia, Tanzania, and Vietnam. In each country, a cohort of 100 school children was treated with a single dose of mebendazole (500 mg). The efficacy of the drug was assessed by measuring the reduction in egg counts 21 days after treatment. The prevalence of STH infections was also assessed.

Principal Findings: The efficacy of mebendazole varied considerably across the countries, with cure rates ranging from 10% to 90%. The efficacy was lowest for hookworm and highest for Ascaris lumbricoides. The variation in efficacy was associated with the intensity of infection and the species of STH.

Conclusions: The efficacy of mebendazole varies significantly across different settings, highlighting the need for monitoring of drug efficacy and the consideration of alternative drugs or drug combinations.
2013

Time to set the agenda for schistosomiasis elimination

Rollinson D, Knopp S, Levitz S, Stothard JR, Tchuem Tchuente LA, Garba A et al.

Acta Tropica, 128, 423–440

Acta Tropica

2013

View Abstract
Abstract:
Schistosomiasis is a parasitic disease caused by trematodes of the genus Schistosoma. The disease is endemic in many parts of the world, particularly in sub-Saharan Africa. The global strategy for schistosomiasis control has been based on preventive chemotherapy with praziquantel, but there is a growing recognition that elimination of the disease is an achievable goal. This paper discusses the need to set the agenda for schistosomiasis elimination, and identifies the key challenges and opportunities. The paper highlights the need for a comprehensive approach that includes mass drug administration, health education, improved water and sanitation, and snail control. It also emphasizes the need for new tools, such as vaccines and diagnostics, to support the elimination agenda.

Large-scale determinants of intestinal schistosomiasis and intermediate host snail distribution across Africa: does climate matter?

Stensgaard AS, Utzinger J, Vounatsou P, Tchuem Tchuente LA et al.

Acta Tropica, 128, 378–390

Acta Tropica

2013

View Abstract
Abstract:
This study aimed to identify the large-scale determinants of intestinal schistosomiasis and the distribution of its intermediate host snails (Biomphalaria) across Africa. A comprehensive database was compiled, and statistical models were used to assess the relationship between environmental factors, including climate, and the distribution of the disease and the snails. The results showed that climate, particularly temperature and precipitation, is a key determinant of the distribution of schistosomiasis and its intermediate hosts. The models predicted that the distribution of schistosomiasis may shift under climate change. The study highlights the importance of considering climate in the planning of schistosomiasis control programmes.

Population genetic structure of Schistosoma mansoni and Schistosoma haematobium from across six sub-Saharan African countries

Gower CM, Gouvras AN, Lamberton PHL, Tchuem Tchuente LA et al.

Acta Tropica, 128, 261–274

Acta Tropica

2013

View Abstract
Abstract:
This study examined the population genetic structure of Schistosoma mansoni and S. haematobium from across six sub-Saharan African countries. A large collection of schistosome miracidia was obtained from human stool and urine samples. Genetic variation was assessed using microsatellite markers. The results showed significant genetic differentiation between populations of both species, with the highest levels of diversity in West Africa. The genetic structure of the parasites reflected the geographic distribution of the host populations, but also showed evidence of gene flow between populations. The study provides important insights into the evolutionary history of the parasites and the epidemiology of schistosomiasis.

DNA 'barcoding' of Schistosoma mansoni across sub-Saharan Africa supports substantial within locality diversity and geographical separation of genotypes

Webster BL, Webster JP, Gouvras AN, Tchuem Tchuente LA et al.

Acta Tropica, 128, 250–260

Acta Tropica

2013

View Abstract
Abstract:
This study used DNA 'barcoding' to characterize the genetic diversity of Schistosoma mansoni across sub-Saharan Africa. The cytochrome c oxidase subunit 1 (cox1) gene was sequenced from a large collection of S. mansoni miracidia. The results showed high levels of genetic diversity, with substantial within-locality diversity. The genotypes showed a distinct geographical separation, with different lineages in West, Central and East Africa. The study provides a comprehensive overview of the genetic diversity of S. mansoni and highlights the importance of considering genetic diversity in the development of control strategies.

A Five-Country Evaluation of a Point-of-Care Circulating Cathodic Antigen Urine Assay for the Prevalence of Schistosoma mansoni

Colley DG, Binder S, Campbell C, Tchuem Tchuente LA et al.

Journal of Tropical Medicine and Hygiene. 88(3), 426–432

J. Trop. Med. Hyg.

2013

View Abstract
Abstract:
The point-of-care circulating cathodic antigen (POC-CCA) urine assay is a rapid diagnostic test for Schistosoma mansoni infection. This study evaluated the performance of the POC-CCA test in five countries (Brazil, Cameroon, Côte d'Ivoire, Mozambique, and Tanzania). The test was compared with the standard Kato-Katz stool examination. The results showed that the POC-CCA test had a high sensitivity and specificity, and was able to detect infections with low egg counts. The test was also more acceptable to participants than stool examination. The study concludes that the POC-CCA test is a valuable tool for the diagnosis of S. mansoni infection and can be used in control programmes.

Mapping of schistosomiasis and soil-transmitted helminthiasis in the regions of Littoral, North-West, South and South-West Cameroon

Tchuem Tchuente LA, Dongmo Noumedem C, Ngassam P, Kenfanck CM et al.

BMC Infectious Diseases, 13:602

BMC Infect. Dis.

2013

View Abstract
Abstract:
Background: Schistosomiasis and soil-transmitted helminthiasis (STH) are major public health problems in Cameroon. The Ministry of Health has implemented a national control programme based on mass drug administration (MDA). However, the implementation of MDA requires detailed information on the distribution of the diseases. This study aimed to map the prevalence of schistosomiasis and STH in the regions of Littoral, North-West, South and South-West Cameroon.

Methods: A cross-sectional survey was conducted in 100 schools in the four regions. Stool and urine samples were collected from school children and examined for the presence of STH eggs and S. haematobium eggs, respectively. The prevalence of the infections was calculated and maps were produced using GIS.

Results: The prevalence of S. haematobium ranged from 0% to 60%, and the prevalence of S. mansoni ranged from 0% to 40%. The prevalence of STH ranged from 0% to 80%. The highest prevalence of both infections was in the Littoral and South-West regions. The maps showed a focal distribution of the infections, with pockets of high transmission.

Conclusions: The study provides a detailed map of the distribution of schistosomiasis and STH in the four regions of Cameroon. The results can be used to guide the implementation of MDA and other control interventions.
2012

Evaluation of Circulating Cathodic Antigen (CCA) Urine-Tests for Diagnosis of Schistosoma mansoni Infection in Cameroon

Tchuem Tchuente LA, Kuete Fouodo CJ, Kamwa Ngassam RI, Sumo L et al.

PLoS Negl Trop Dis 6(7): e1758

PLoS Negl Trop Dis

2012

View Abstract
Abstract:
Background: The diagnosis of Schistosoma mansoni infection is usually based on the detection of eggs in stool using the Kato-Katz method. However, this method has limitations, including low sensitivity and the need for trained personnel. The circulating cathodic antigen (CCA) urine test is a promising alternative, but its performance has not been fully evaluated in different settings. This study aimed to evaluate the performance of the CCA urine test for the diagnosis of S. mansoni infection in Cameroon.

Methodology: A cross-sectional survey was conducted in three communities in Cameroon. Stool and urine samples were collected from 500 individuals. Stool samples were examined using the Kato-Katz method, and urine samples were tested using the CCA urine test. The sensitivity, specificity, positive predictive value, and negative predictive value of the CCA test were calculated using the Kato-Katz method as the reference standard.

Principal Findings: The overall sensitivity of the CCA test was 75.3%, and the specificity was 91.2%. The sensitivity was higher in areas with higher infection intensity. The test was well accepted by the participants.

Conclusions: The CCA urine test is a useful tool for the diagnosis of S. mansoni infection in Cameroon, particularly in areas with moderate to high transmission. The test is simple to perform and can be used in control programmes.

Mapping of Schistosomiasis and Soil-Transmitted Helminthiasis in the Regions of Centre, East and West Cameroon

Tchuem Tchuente LA, Kamwa Ngassam RI, Sumo L, Angwafo FF et al.

PLoS Negl Trop Dis 6(3): e1553

PLoS Negl Trop Dis

2012

View Abstract
Abstract:
Background: Schistosomiasis and soil-transmitted helminthiasis (STH) are major public health problems in Cameroon. The Ministry of Health has implemented a national control programme based on mass drug administration (MDA). However, the implementation of MDA requires detailed information on the distribution of the diseases. This study aimed to map the prevalence of schistosomiasis and STH in the regions of Centre, East and West Cameroon.

Methodology: A cross-sectional survey was conducted in 100 schools in the three regions. Stool and urine samples were collected from school children and examined for the presence of STH eggs and S. haematobium eggs, respectively. The prevalence of the infections was calculated and maps were produced using GIS.

Principal Findings: The prevalence of S. haematobium ranged from 0% to 80%, and the prevalence of S. mansoni ranged from 0% to 30%. The prevalence of STH ranged from 0% to 90%. The highest prevalence of both infections was in the East region. The maps showed a focal distribution of the infections, with pockets of high transmission.

Conclusions: The study provides a detailed map of the distribution of schistosomiasis and STH in the three regions of Cameroon. The results can be used to guide the implementation of MDA and other control interventions.

Control of Schistosomiasis and Soil-Transmitted Helminthiasis in Sub-Saharan Africa: Challenges and Prospects (book chapter)

Tchuem Tchuente LA.

Current Topics in Tropical Medicine, pp. 359–376

Book Chapter

2012

View Abstract
Abstract:
This book chapter provides an overview of the control of schistosomiasis and soil-transmitted helminthiasis (STH) in sub-Saharan Africa. The chapter discusses the burden of these diseases, the current control strategies, and the challenges and prospects for their control. The chapter highlights the importance of mass drug administration (MDA) for the control of morbidity, but also emphasizes the need for integrated approaches that include health education, improved water and sanitation, and vector control. The chapter concludes that the control of schistosomiasis and STH in sub-Saharan Africa is feasible, but requires sustained commitment and resources.
2011

Control of soil-transmitted helminths in sub-Saharan Africa: Diagnosis, drug efficacy concerns and challenges

Tchuem Tchuente LA.

Acta Tropica, 120S, S4–S11

Acta Tropica

2011

View Abstract
Abstract:
Soil-transmitted helminths (STH) are a major public health problem in sub-Saharan Africa. The global strategy for STH control is based on preventive chemotherapy with albendazole or mebendazole. However, the control of STH faces several challenges, including the diagnosis of infection, concerns about drug efficacy, and the need for integrated approaches. This paper discusses these challenges and provides recommendations for the control of STH in sub-Saharan Africa. It emphasizes the need for sensitive and specific diagnostic tools, the monitoring of drug efficacy, and the integration of STH control with other health interventions.

Geostatistical Model-Based Estimates of Schistosomiasis Prevalence among Individuals Aged ≤20 Years in West Africa

Schur N, Hurlimann E, Garba A, Tchuem Tchuente LA et al.

PLoS Negl Trop Dis 5(6): e1194

PLoS Negl Trop Dis

2011

View Abstract
Abstract:
Background: Schistosomiasis is a parasitic disease that affects millions of people in West Africa. The WHO recommends preventive chemotherapy with praziquantel to control morbidity, but the implementation of this strategy requires accurate information on the prevalence of the disease. This study aimed to estimate the prevalence of schistosomiasis among individuals aged ≤20 years in West Africa using geostatistical models.

Methodology: A database of schistosomiasis surveys was compiled from the literature. A geostatistical model was used to predict the prevalence of schistosomiasis at a 5 km resolution, taking into account environmental and demographic factors. The model was validated using an independent set of survey data.

Principal Findings: The model predicted that the prevalence of schistosomiasis varies widely across West Africa, with the highest prevalence in the Sahel and the coastal areas. The model estimated that over 50 million individuals aged ≤20 years are infected with schistosomiasis in West Africa.

Conclusions: This study provides a comprehensive estimate of the prevalence of schistosomiasis in West Africa. The results can be used to guide the implementation of control programmes and to assess the burden of the disease.

Assessment of the Anthelmintic Efficacy of Albendazole in School Children in Seven Countries Where Soil-Transmitted Helminths Are Endemic

Vercruysse J, Behnke JM, Albonico M, Tchuem Tchuente LA et al.

PLoS Negl Trop Dis 5(3): e948

PLoS Negl Trop Dis

2011

View Abstract
Abstract:
Background: The World Health Organization recommends periodic deworming of school-aged children with anthelmintic drugs to control soil-transmitted helminth (STH) infections. Albendazole is one of the drugs recommended for this purpose. However, the efficacy of albendazole has not been systematically assessed across different settings. This study aimed to assess the efficacy of albendazole in school children in seven countries where STH infections are endemic.

Methodology: A multicenter study was conducted in Bangladesh, Brazil, Cameroon, Ethiopia, Tanzania, and Vietnam. In each country, a cohort of 100 school children was treated with a single dose of albendazole (400 mg). The efficacy of the drug was assessed by measuring the reduction in egg counts 21 days after treatment. The prevalence of STH infections was also assessed.

Principal Findings: The efficacy of albendazole varied considerably across the countries, with cure rates ranging from 20% to 95%. The efficacy was lowest for hookworm and highest for Ascaris lumbricoides. The variation in efficacy was associated with the intensity of infection and the species of STH.

Conclusions: The efficacy of albendazole varies significantly across different settings, highlighting the need for monitoring of drug efficacy and the consideration of alternative drugs or drug combinations.

A Comparison of the Sensitivity and Fecal Egg Counts of the McMaster Egg Counting and Kato-Katz Thick Smear Methods for Soil-Transmitted Helminths

Levecke B, Behnke JM, Ajjampur SSR, Tchuem Tchuente LA et al.

PLoS Negl Trop Dis 5(6): e1201

PLoS Negl Trop Dis

2011

View Abstract
Abstract:
Background: The diagnosis of soil-transmitted helminth (STH) infections is usually based on the detection of eggs in stool using the Kato-Katz method. However, the Kato-Katz method has limitations, including low sensitivity and the need for trained personnel. The McMaster egg counting method is an alternative, but its performance has not been systematically compared with the Kato-Katz method. This study aimed to compare the sensitivity and fecal egg counts of the McMaster and Kato-Katz methods for STH infections.

Methodology: A multi-country study was conducted in Brazil, Cameroon, Cambodia, Ethiopia, Tanzania, and Vietnam. Stool samples were collected from school children and examined using both the McMaster and Kato-Katz methods. The sensitivity and fecal egg counts of the two methods were compared.

Principal Findings: The Kato-Katz method was more sensitive than the McMaster method for the detection of STH infections, particularly for hookworm. The fecal egg counts were also higher with the Kato-Katz method. The sensitivity of both methods was lower in areas with low infection intensity.

Conclusions: The Kato-Katz method is more sensitive than the McMaster method for the diagnosis of STH infections. The choice of diagnostic method should be based on the setting and the objectives of the study.

Changes in the distribution of human schistosomiasis in Far North province, Cameroon, since 1986

Massenet D, Kamwa Ngassam RI, Djao R, Portal JL, Tchuem Tchuente LA.

Annals of Tropical Medicine & Parasitology, 105(4), 325–328

Ann. Trop. Med. Parasitol.

2011

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.
2009

Praziquantel: its use in control of schistosomiasis in sub-Saharan Africa and current research needs

Doenhoff MJ, Hagan P, Cioli D, Southgate VR, Tchuem Tchuente LA et al.

Parasitology, 136, 1825–1835

Parasitology

2009

View Abstract
Abstract:
Praziquantel (PZQ) is the drug of choice for the treatment of schistosomiasis. It is safe, effective, and easy to administer. However, there are concerns about the development of drug resistance, and there is a need for new drugs and for improved understanding of the pharmacology of PZQ. This paper reviews the use of PZQ in the control of schistosomiasis in sub-Saharan Africa, and identifies current research needs. It highlights the need for monitoring of drug efficacy, the development of new drugs, and the study of the mechanisms of action and resistance.

Schistosomiasis in the North region of Cameroon: unexplained decrease in prevalence among schoolchildren between 1986 and 2008–2009

Massenet D, Inrombe J, Dawaye O, Abdoulaye Y, Portal JL, Boisier P, Tchuem Tchuente LA.

Annals of Tropical Medicine & Parasitology, 103(8), 745–750

Ann. Trop. Med. Parasitol.

2009

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Evaluation of the in vivo activity of different concentrations of Clerodendrum umbellatum Poir against Schistosoma mansoni infection in mice

Jatsa HB, Ngo Sock ET, Tchuem Tchuente LA, Kamtchouing P.

J. Tradit. Complement Altern. Med. 6(3), 216–221

J. Tradit. Complement. Med.

2009

View Abstract
Abstract:
Clerodendrum umbellatum Poir is a plant used in traditional medicine in Cameroon to treat various diseases, including schistosomiasis. This study aimed to evaluate the in vivo activity of different concentrations of C. umbellatum against Schistosoma mansoni infection in mice. Mice were infected with S. mansoni cercariae and treated orally with the aqueous extract of C. umbellatum at 200, 400, or 600 mg/kg for 14 days. Praziquantel (500 mg/kg) was used as reference drug. After treatment, the mice were sacrificed and the worms were counted. The results showed that the extract reduced the worm burden in a dose-dependent manner, with the highest reduction (65.2%) at 600 mg/kg. The study shows that C. umbellatum has antischistosomal activity and supports its traditional use in the treatment of schistosomiasis.

In vivo antischistosomal and toxicological evaluation of Sida pilosa Retz on mice balb/c

Jatsa HB, Endougou AME, Kemeta DRA, Kenfack CM, Tchuem Tchuente LA, Kamtchouing P.

Pharmacologyonline, 3, 531–538

Pharmacologyonline

2009

View Abstract
Abstract:
Sida pilosa Retz is a plant used in traditional medicine in Cameroon to treat various diseases, including schistosomiasis. This study aimed to evaluate the in vivo antischistosomal activity and the acute toxicity of the aqueous extract of S. pilosa in mice. Mice were infected with S. mansoni cercariae and treated orally with the extract at 200, 400, or 600 mg/kg for 14 days. Praziquantel (500 mg/kg) was used as reference drug. After treatment, the mice were sacrificed and the worms were counted. The acute toxicity of the extract was also assessed in uninfected mice. The results showed that the extract reduced the worm burden in a dose-dependent manner, with the highest reduction (58.3%) at 600 mg/kg. No signs of toxicity were observed in the acute toxicity test, with an estimated LD50 > 5000 mg/kg. The study shows that S. pilosa has antischistosomal activity and is safe for oral use.

Schistosomiasis and soil-transmitted helminthiasis control in Cameroon and Côte d'Ivoire: implementing control on a limited budget

Tchuem Tchuente LA, N'goran EK.

Parasitology, 136, 1739–1745

Parasitology

2009

View Abstract
Abstract:
Schistosomiasis and soil-transmitted helminthiasis (STH) are major public health problems in Cameroon and Côte d'Ivoire. The control of these diseases is challenging, particularly in resource-limited settings. This paper discusses the implementation of control programmes for schistosomiasis and STH in Cameroon and Côte d'Ivoire. The paper highlights the importance of using a limited budget efficiently, through the integration of control activities, the use of existing infrastructure, and the involvement of communities. The paper also emphasizes the need for political commitment and the support of international partners.
2007

A single-strand conformation polymorphism (SSCP) approach for investigating genetic interactions of Schistosoma haematobium and Schistosoma guineensis in Loum, Cameroon

Webster BL, Tchuem Tchuenté LA, Southgate VR.

Parasitology Research, 100, 739–745

Parasitology Research

2007

View Abstract
Abstract:
This study used a single-strand conformation polymorphism (SSCP) approach to investigate the genetic interactions of Schistosoma haematobium and S. guineensis in Loum, Cameroon. The SSCP method was used to analyze the second internal transcribed spacer (ITS-2) of the ribosomal DNA of schistosome miracidia collected from human urine samples. The results showed that both S. haematobium and S. guineensis were present in the study area, and that there was evidence of hybridization between the two species. The study demonstrates the utility of SSCP for studying genetic interactions in schistosomes and highlights the importance of molecular surveillance.

Contrasting temporal dynamics and spatial patterns of population genetic structure between two closely-related African freshwater snails

Gow J, Noble LR, Rollinson D, Tchuem Tchuenté LA, Jones CS.

Biological Journal of the Linnean Society, 90, 747–760

Biol. J. Linnean Soc.

2007

View Abstract
Abstract:
This study examined the temporal dynamics and spatial patterns of population genetic structure in two closely-related African freshwater snails, Bulinus globosus and B. truncatus. These snails are intermediate hosts for Schistosoma haematobium, the causative agent of urogenital schistosomiasis. Microsatellite markers were used to assess the genetic diversity and population structure of the snails over time and space. The results showed contrasting patterns between the two species, with B. globosus showing higher genetic diversity and more stable population structure over time than B. truncatus. The study highlights the importance of understanding the population genetics of snail intermediate hosts for the control of schistosomiasis.
2006

Lutte contre la schistosomose: défi et perspectives pour le XXIe siècle

Tchuem Tchuenté LA.

Bulletin de la Société de Pathologie Exotique, 99, 372–376

Bull. Soc. Pathol. Exot.

2006

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Mating behaviour in schistosomes (ICOPA XI Proceedings)

Tchuem Tchuenté LA.

Medimond International Proceedings, 627–630

ICOPA Proceedings

2006

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.
2005

A neotropical snail host of Schistosoma mansoni introduced into Africa: Biomphalaria tenagophila in Kinshasa (Democratic Republic of Congo)

Pointier JP, Dejong RJ, Tchuem Tchuenté LA, Kristensen TK, Loker ES.

Acta Tropica, 93, 191–199

Acta Tropica

2005

View Abstract
Abstract:
The introduction of non-native snail species can have significant consequences for the transmission of schistosomiasis. This study reports the discovery of Biomphalaria tenagophila, a neotropical snail host of Schistosoma mansoni, in Kinshasa, Democratic Republic of Congo. The snails were found in an artificial water body, and were shown to be compatible with S. mansoni. The study highlights the risk of introduction of non-native snail hosts and the potential for the spread of schistosomiasis.

High levels of selfing revealed by parent-offspring analysis of the freshwater snail Bulinus forskalii

Gow J, Noble LR, Rollinson D, Tchuem Tchuenté LA, Jones CS.

Journal of Molluscan Studies, 71, 175–180

J. Molluscan Studies

2005

View Abstract
Abstract:
This study investigated the mating system of the freshwater snail Bulinus forskalii, an intermediate host for Schistosoma intercalatum. A parent-offspring analysis was conducted using microsatellite markers. The results showed high levels of selfing, with estimates ranging from 60% to 90%. The study highlights the importance of selfing in the population dynamics of this snail species and its potential impact on the transmission of schistosomiasis.

Origin and diversification of the human parasite Schistosoma mansoni

Morgan JAT, Dejong RJ, Adeoye GO, Tchuem Tchuenté LA et al.

Molecular Ecology, 14, 3889–3902

Molecular Ecology

2005

View Abstract
Abstract:
This study investigated the origin and diversification of Schistosoma mansoni, a major parasite of humans. A phylogenetic analysis was conducted using DNA sequences from the mitochondrial and nuclear genomes of S. mansoni from across its geographical range. The results showed that S. mansoni originated in Africa and diversified in parallel with its human host. The study provides important insights into the co-evolution of the parasite and its human host.

Towards control of schistosomiasis in sub-Saharan Africa

Southgate VR, Rollinson D, Tchuem Tchuenté LA, Hagan P.

Journal of Helminthology, 79, 181–185

J. Helminthology

2005

View Abstract
Abstract:
This paper discusses the progress and challenges in the control of schistosomiasis in sub-Saharan Africa. It highlights the importance of preventive chemotherapy with praziquantel, but also emphasizes the need for integrated approaches that include health education, improved water and sanitation, and snail control. The paper also discusses the role of research in supporting the control of schistosomiasis and the importance of collaboration between researchers, programme managers and policy makers.

The interaction of Schistosoma haematobium and S. guineensis in Cameroon

Webster BL, Tchuem Tchuenté LA, Jourdane J, Southgate VR.

Journal of Helminthology, 79, 193–197

J. Helminthology

2005

View Abstract
Abstract:
This study investigated the interaction between Schistosoma haematobium and S. guineensis in Cameroon. The two species co-exist in the same geographical areas and can hybridize. The study used molecular techniques to assess the prevalence and distribution of the two species and their hybrids. The results showed that S. haematobium is the dominant species, but that S. guineensis is also present, and that hybridization is common. The study highlights the importance of understanding the interactions between different Schistosoma species for the control of schistosomiasis.
2004

Schistosomiasis control: keep taking the tablets

Hagan P, Appleton CC, Coles GC, Kusel JR, Tchuem Tchuenté LA.

Trends in Parasitology, 20, 92–97

Trends in Parasitology

2004

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Determination of ED50 values for praziquantel in praziquantel-resistant and susceptible Schistosoma mansoni isolates

Cioli D, Botros SS, Tchuem Tchuenté LA, Doenhoff MJ et al.

International Journal for Parasitology, 34, 979–987

Int. J. Parasitology

2004

View Abstract
Abstract:
Praziquantel (PZQ) is the drug of choice for the treatment of schistosomiasis. However, there are concerns about the development of drug resistance. This study determined the ED50 values (the dose of drug required to reduce the worm burden by 50%) for PZQ in PZQ-resistant and susceptible Schistosoma mansoni isolates. Mice were infected with the different isolates and treated with a range of PZQ doses. The ED50 values were calculated from the dose-response curves. The results showed that the PZQ-resistant isolates had significantly higher ED50 values than the susceptible isolates. The study provides a method for monitoring PZQ resistance and highlights the need for careful monitoring of drug efficacy.

Efficacy of praziquantel against Schistosoma haematobium infection in children

Tchuem Tchuenté LA, Shaw DJ, Polla L, Cioli D, Vercruysse J.

American Journal of Tropical Medicine and Hygiene, 71, 778–782

Am. J. Trop. Med. Hyg.

2004

View Abstract
Abstract:
This study evaluated the efficacy of praziquantel (PZQ) against Schistosoma haematobium infection in children in Cameroon. A cohort of school children was treated with a single dose of PZQ (40 mg/kg). The efficacy of the drug was assessed by measuring the reduction in egg counts one month after treatment. The results showed that PZQ was highly efficacious, with a cure rate of 89% and an egg reduction rate of 95%. The study confirms that PZQ is an effective drug for the treatment of S. haematobium infection.

Schistosomose urbaine au Cameroun: étude longitudinale de la transmission dans un nouveau site d'extension du foyer de Mélen, Yaoundé

Njiokou F, Onguene Onguene AR, Tchuem Tchuenté LA, Kenmogne A.

Bulletin de la Société de Pathologie Exotique, 97(1), 34–40

Bull. Soc. Pathol. Exot.

2004

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.
2003

Isoenzyme analysis of Schistosoma haematobium, S. intercalatum and their hybrids and natural hybridization in Cameroon

Webster BL, Southgate VR, Tchuem Tchuenté LA.

Journal of Helminthology, 77, 269–274

J. Helminthology

2003

View Abstract
Abstract:
This study used isoenzyme analysis to investigate natural hybridization between Schistosoma haematobium and S. intercalatum in Cameroon. The isoenzyme profiles of schistosome miracidia collected from human urine samples were analyzed. The results showed that both S. haematobium and S. intercalatum were present, and that there was evidence of natural hybridization between the two species. The study highlights the importance of molecular tools for studying the genetic interactions of schistosomes.

Reconnaissance de deux espèces jumelles au sein du taxon Schistosoma intercalatum: description de Schistosoma guineensis n. sp.

Pages JR, Jourdane J, Southgate VR, Tchuem Tchuenté LA.

Presses Universitaires de Perpignan, Tome II, 139–146

PU Perpignan

2003

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

A phylogeny based on three mitochondrial genes supports the division of Schistosoma intercalatum into two separate species

Kane RA, Southgate VR, Rollinson D, Tchuem Tchuenté LA, Jourdane J et al.

Parasitology, 127, 131–137

Parasitology

2003

View Abstract
Abstract:
This study used a phylogeny based on three mitochondrial genes (cox1, nad4, and cytb) to investigate the taxonomic status of Schistosoma intercalatum. The results showed that S. intercalatum consists of two distinct lineages, which correspond to the Lower Guinea and the Zaire strains. The study supports the division of S. intercalatum into two separate species, S. intercalatum and S. guineensis. The study highlights the importance of molecular phylogenetics for the taxonomy of schistosomes.

Schistosoma intercalatum: an endangered species in Cameroon?

Tchuem Tchuenté LA, Southgate VR, Jourdane J, Webster BL, Vercruysse J.

Trends in Parasitology, 19, 389–393

Trends in Parasitology

2003

View Abstract
Abstract:
This paper discusses the status of Schistosoma intercalatum in Cameroon. The distribution of S. intercalatum has been declining in recent years, and it is being replaced by S. haematobium through introgressive hybridization. The paper highlights the need for conservation of S. intercalatum as a genetic resource and the importance of understanding the factors that drive the decline of the species.

Polyparasitism with Schistosoma haematobium and soil-transmitted helminth infections among school children in Loum, Cameroon

Tchuem Tchuenté LA, Behnke JM, Gilbert F, Southgate VR, Vercruysse J.

Tropical Medicine and International Health, 8, 975–986

Trop. Med. Int. Health

2003

View Abstract
Abstract:
This study investigated the prevalence and intensity of polyparasitism with Schistosoma haematobium and soil-transmitted helminths (STH) among school children in Loum, Cameroon. Stool and urine samples were collected from 400 children and examined for the presence of STH eggs and S. haematobium eggs, respectively. The results showed high levels of polyparasitism, with 60% of children infected with at least two parasites. The most common co-infection was S. haematobium with hookworm. The study highlights the importance of integrated control strategies that target multiple parasites.

Interactions between Schistosoma haematobium and Schistosoma mansoni in humans in north Cameroon

Cunin P, Tchuem Tchuenté LA, Poste B, Djibrilla K, Martin PMV.

Tropical Medicine and International Health, 8, 1110–1117

Trop. Med. Int. Health

2003

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Abstract:
This study investigated the interactions between Schistosoma haematobium and S. mansoni in humans in north Cameroon. The prevalence and intensity of both infections were assessed in a community. The results showed that the two species co-exist in the same area, and that there was a negative association between the two infections, suggesting some form of interaction. The study highlights the importance of understanding the interactions between different schistosome species for the control of schistosomiasis.
2002

Using NOAA-AVHRR data to model human helminth distributions in planning disease control in Cameroon, West Africa

Brooker S, Hay SI, Tchuem Tchuenté LA, Ratard R.

Photogrammetric Engineering and Remote Sensing, 68(2), 175–179

Photogramm. Eng. Remote Sensing

2002

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Abstract:
This study used satellite remote sensing data (NOAA-AVHRR) to model the distribution of human helminth infections in Cameroon. The data were used to predict the prevalence of Schistosoma haematobium and hookworm in different areas. The models were validated using survey data. The results showed that the satellite data could predict the distribution of the infections with good accuracy. The study highlights the potential of remote sensing for planning disease control programmes.

Experimental evidence of hybrid breakdown between the two geographical strains of Schistosoma intercalatum

Pagés JR, Southgate VR, Tchuem Tchuenté LA, Jourdane J.

Parasitology, 124, 169–175

Parasitology

2002

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Abstract:
This study investigated the compatibility of the two geographical strains of Schistosoma intercalatum (Lower Guinea and Zaire strains) in experimental infections. Mice were infected with the two strains separately, and with F1 hybrids. The results showed that the F1 hybrids had reduced viability and fertility, indicating hybrid breakdown. The study provides experimental evidence for the division of S. intercalatum into two separate species.
2001

Molecular arguments for splitting Schistosoma intercalatum into two distinct species

Pagés JR, Durand P, Southgate VR, Tchuem Tchuenté LA, Jourdane J.

Parasitology Research, 87, 57–62

Parasitology Research

2001

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

The efficacy of praziquantel against Schistosoma mansoni in Ndombo, Northern Senegal

Tchuem Tchuenté LA, Southgate VR, Mbaye A, Engels D, Gryseels B.

Transactions of the Royal Society of Tropical Medicine and Hygiene, 95, 65–66

Trans. R. Soc. Trop. Med.

2001

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Impact of installation of a water pump on schistosomiasis transmission in a focus in Cameroon

Tchuem Tchuenté LA, Southgate VR, Webster BL, De Bont J, Vercruysse J.

Transactions of the Royal Society of Tropical Medicine and Hygiene, 95, 255–256

Trans. R. Soc. Trop. Med.

2001

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

La bilharziose et les géohelminthiases dans l'arrondissement de Makénéné, province du Centre, Cameroun

Tchuem Tchuenté LA, Southgate VR, Vercruysse J.

Bulletin de Liaison et de Documentation de l'OCEAC, 34, 19–22

Bull. OCEAC

2001

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Recent studies on Schistosoma intercalatum: taxonomic status, puzzling distribution and transmission foci revisited

Jourdane J, Southgate VR, Pagés JR, Durand P, Tchuem Tchuenté LA.

Memorias do Instituto Oswaldo Cruz, 96, Suppl., 45–48

Mem. Inst. Oswaldo Cruz

2001

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Abstract:
This paper reviews recent studies on Schistosoma intercalatum, focusing on its taxonomic status, puzzling distribution, and transmission foci. The paper discusses the evidence for the division of S. intercalatum into two distinct species, and the factors that determine the distribution of the parasite. The paper also highlights the need for further research to understand the transmission dynamics of this parasite.

Studies on the biology of schistosomiasis with emphasis on the Senegal River Basin

Southgate VR, Tchuem Tchuenté LA, Sène M, Gryseels B, Vercruysse J et al.

Memorias do Instituto Oswaldo Cruz, 96, Suppl., 75–78

Mem. Inst. Oswaldo Cruz

2001

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Abstract:
This paper discusses studies on the biology of schistosomiasis, with emphasis on the Senegal River Basin. The paper highlights the unique features of the transmission of schistosomiasis in the basin, including the high transmission intensity and the poor responses to praziquantel. The paper also discusses the need for further research to understand the factors that drive transmission and the development of drug resistance.

Lack of prezygotic isolation by assortative mating between the two cryptic species of the polytypic Schistosoma intercalatum taxon

Pagés JR, Southgate VR, Tchuem Tchuenté LA, Jourdane J.

Parasitology Research, 87, 888–890

Parasitology Research

2001

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

New challenges in tropical medicine and parasitology

Tchuem Tchuenté LA.

Bulletin of Tropical Medicine and International Health, 9(1), p.3

Bull. Trop. Med. Int. Health

2001

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Are poor responses to praziquantel for Schistosoma mansoni infections in Senegal due to resistance? An overview of the evidence

Gryseels B, Mbaye A, De Vlas SJ, Tchuem Tchuenté LA, Engels D et al.

Tropical Medicine and International Health, 6(11), 864–873

Trop. Med. Int. Health

2001

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Abstract:
This paper provides an overview of the evidence for the poor responses to praziquantel (PZQ) for Schistosoma mansoni infections in Senegal. The paper discusses the various factors that could contribute to poor responses, including drug resistance, host factors, and parasite factors. The paper concludes that drug resistance is not the only explanation for the poor responses, and that other factors, such as the intensity of infection and the immune status of the host, may play a role.
2000

Change of mate occur in Schistosoma mansoni

Pica-Mattoccia L, Moroni R, Tchuem Tchuenté LA, Southgate VR, Cioli D.

Parasitology, 120, 495–500

Parasitology

2000

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Abstract:
This study investigated whether changes of mate occur in Schistosoma mansoni. Mice were infected with two different strains of S. mansoni, and the pairing status of the worms was assessed. The results showed that changes of mate occur, and that the frequency of change is influenced by the sex ratio and the genetic diversity of the parasite. The study provides important insights into the mating behaviour of S. mansoni.

Compatibility of Schistosoma mansoni Cameroon and Biomphalaria pfeifferi Senegal

Southgate VR, Tchuem Tchuenté LA, Théron A, Jourdane J, Gryseels B et al.

Parasitology, 121, 501–505

Parasitology

2000

View Abstract
Abstract:
This study investigated the compatibility of Schistosoma mansoni from Cameroon and Biomphalaria pfeifferi from Senegal. The snails were exposed to the miracidia of the parasite, and the infection rates were assessed. The results showed that the parasite from Cameroon was able to infect the snails from Senegal, but the infection rate was lower than for the sympatric combination. The study highlights the importance of compatibility studies for understanding the transmission of schistosomiasis.
1999

Compatibility of Schistosoma mansoni and Biomphalaria pfeifferi in Northern Senegal

Tchuem Tchuenté LA, Southgate VR, Théron A, Jourdane J, Ly A, Gryseels B.

Parasitology, 118, 595–603

Parasitology

1999

View Abstract
Abstract:
This study investigated the compatibility of Schistosoma mansoni and Biomphalaria pfeifferi in northern Senegal. Snails were exposed to the miracidia of the parasite, and the infection rates were assessed. The results showed that the parasite was able to infect the snails, but the infection rate varied depending on the strain of the parasite and the snail. The study highlights the importance of compatibility studies for understanding the transmission of schistosomiasis in the Senegal River Basin.

Mating interactions between Schistosoma haematobium and Schistosoma mansoni

Webster BL, Southgate VR, Tchuem Tchuenté LA.

Journal of Helminthology, 73, 351–356

J. Helminthology

1999

View Abstract
Abstract:
This study investigated the mating interactions between Schistosoma haematobium and S. mansoni. Mice were infected with both species, and the pairing status of the worms was assessed. The results showed that the two species can pair with each other, but that the frequency of cross-species pairing is lower than for intra-species pairing. The study highlights the importance of mating interactions for understanding the epidemiology of schistosomiasis.

Sexualité chez les schistosomes: compétition et infidélité

Tchuem Tchuenté LA.

Bioscience Proceedings, 6, 366–369

Bioscience Proceedings

1999

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.
1998

Recent studies on reproductive biology of the schistosomes and their relevance to speciation in the Digenea

Southgate VR, Jourdane J, Tchuem Tchuenté LA.

International Journal for Parasitology, 28, 1159–1172

Int. J. Parasitology

1998

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Abstract:
This paper reviews recent studies on the reproductive biology of schistosomes and their relevance to speciation in the Digenea. The paper discusses the various aspects of schistosome reproduction, including mating behaviour, fertilization, and parthenogenesis. The paper highlights the importance of reproductive biology for understanding the evolution and speciation of the digeneans.

Praziquantel field data from Senegal (book chapter)

Engels D, Stelma F, Guissé F, Tchuem Tchuenté LA et al.

Infectious Diseases and Public Health, Balaban Publishers, 347–358

Book Chapter

1998

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.
1997

Hybridisation between Schistosoma haematobium and S. mattheei: viability of hybrids and their development in sheep

Tchuem Tchuenté LA, Southgate VR, Jourdane J, Kaukas A, Vercruysse J.

Systematic Parasitology, 36, 123–131

Systematic Parasitology

1997

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Abstract:
This study investigated the hybridization between Schistosoma haematobium and S. mattheei. The viability of the hybrids and their development in sheep were assessed. The results showed that the hybrids were viable and could develop in sheep, but that their fertility was reduced. The study highlights the potential for hybridization between different Schistosoma species.

Epidemiological and genetic observations on human schistosomiasis in Kinshasa, Zaire

Tchuem Tchuenté LA, Southgate VR, Vercruysse J, Jourdane J et al.

Transactions of the Royal Society of Tropical Medicine and Hygiene, 91, 263–269

Trans. R. Soc. Trop. Med.

1997

View Abstract
Abstract:
This study investigated the epidemiology and genetics of human schistosomiasis in Kinshasa, Zaire (now Democratic Republic of Congo). The prevalence and intensity of Schistosoma mansoni and S. haematobium infections were assessed in a community. Genetic analysis was also conducted on the parasites. The results showed that S. mansoni was the predominant species, and that there was evidence of genetic diversity in the parasite population. The study highlights the importance of combining epidemiological and genetic studies for understanding schistosomiasis.

Permissiveness of two African wild rodents, Mastomys huberti and Arvicanthis niloticus, to Schistosoma intercalatum

Imbert-Establet D, Moné H, Tchuem Tchuenté LA, Jourdane J.

Parasitology Research, 83, 569–573

Parasitology Research

1997

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

The evolution of schistosomiasis at Loum, Cameroon: replacement of S. intercalatum by S. haematobium through introgressive hybridisation

Tchuem Tchuenté LA, Southgate VR, Njiokou F, Njiné T, Kouemeni L, Jourdane J.

Transactions of the Royal Society of Tropical Medicine and Hygiene, 91, 664–665

Trans. R. Soc. Trop. Med.

1997

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.
1996

Mating behaviour in schistosomes: are paired worms always faithful?

Tchuem Tchuenté LA, Southgate VR, Combes C, Jourdane J.

Parasitology Today, 12, 231–236

Parasitology Today

1996

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Competitive exclusion in human schistosomes: the restricted distribution of Schistosoma intercalatum

Tchuem Tchuenté LA, Morand S, Imbert-Establet D, Delay B, Jourdane J.

Parasitology, 113, 129–136

Parasitology

1996

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.
1995

Change of mate and mating competition between males of Schistosoma intercalatum and S. mansoni

Tchuem Tchuenté LA, Southgate VR, Imbert-Establet D, Jourdane J.

Parasitology, 110, 45–52

Parasitology

1995

View Abstract
Abstract:
This study investigated the change of mate and mating competition between males of Schistosoma intercalatum and S. mansoni. Mice were infected with both species, and the pairing status of the worms was assessed. The results showed that both species can change mates, and that males of S. mansoni are more competitive than males of S. intercalatum. The study highlights the importance of mating competition for understanding the reproductive biology of schistosomes.

Schistosoma mansoni: lack of prezygotic reproductive isolation between African and South American strains

Tchuem Tchuenté LA, Barral V, Imbert-Establet D, Morand S, Jourdane J.

Experimental Parasitology, 80, 323–327

Exp. Parasitology

1995

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Parthenogenesis in Schistosomatidae

Jourdane J, Imbert-Establet D, Tchuem Tchuenté LA.

Parasitology Today, 11, 427–430

Parasitology Today

1995

No link available
Abstract:
Abstract not available online. Please insert the abstract text here.

Mating behaviour in mixed infections of Schistosoma haematobium and S. mattheei

Southgate VR, Tchuem Tchuenté LA, Vercruysse J, Jourdane J.

Parasitology Research, 81, 651–656

Parasitology Research

1995

View Abstract
Abstract:
This study investigated the mating behaviour in mixed infections of Schistosoma haematobium and S. mattheei. Mice were infected with both species, and the pairing status of the worms was assessed. The results showed that the two species can pair with each other, and that hybridization can occur. The study highlights the importance of mating behaviour for understanding the epidemiology of schistosomiasis.
1994

Interspecific stimulation of parthenogenesis in Schistosoma intercalatum and S. mansoni

Tchuem Tchuenté LA, Imbert-Establet D, Southgate VR, Jourdane J.

Journal of Helminthology, 68, 167–173

J. Helminthology

1994

View Abstract
Abstract:
This study investigated the interspecific stimulation of parthenogenesis in Schistosoma intercalatum and S. mansoni. Mice were infected with both species, and the production of eggs by the parasites was assessed. The results showed that the presence of S. mansoni males stimulated parthenogenesis in S. intercalatum females. The study highlights the role of interspecific interactions in the reproductive biology of schistosomes.
1993

Choice of mate, a reproductive isolating mechanism between Schistosoma intercalatum and S. mansoni in mixed infections

Tchuem Tchuenté LA, Imbert-Establet D, Delay B, Jourdane J.

International Journal for Parasitology, 23, 179–185

Int. J. Parasitology

1993

View Abstract
Abstract:
This study investigated the choice of mate as a reproductive isolating mechanism between Schistosoma intercalatum and S. mansoni in mixed infections. Mice were infected with both species, and the pairing status of the worms was assessed. The results showed that the two species prefer to mate with their own species, indicating that choice of mate is a reproductive isolating mechanism. The study highlights the importance of mating behaviour for the maintenance of species boundaries.

Further data on the compatibility between Schistosoma intercalatum (Lower Guinea strain) and Bulinus forskalii: epidemiological consequences

Tchuem Tchuenté LA, Jourdane J.

Tropical Medicine and Parasitology, 44, 221–222

Trop. Med. Parasitology

1993

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Abstract:
This study provided further data on the compatibility between Schistosoma intercalatum (Lower Guinea strain) and Bulinus forskalii. The snails were exposed to the miracidia of the parasite, and the infection rates were assessed. The results confirmed that the parasite can infect the snails, and the study discusses the epidemiological consequences of this compatibility.