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François Mouchet

Bio: François Mouchet is an academic researcher. The author has contributed to research in topics: Schistosoma haematobium & Schistosomiasis. The author has an hindex of 6, co-authored 14 publications receiving 102 citations.

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Journal ArticleDOI
TL;DR: The emergence pattern of Schistosoma curassoni cercariae from Bulinus umbilicatus, whose adult worms parasitize bovine, caprine, and ovine ungulates in Niger, is of a circadian type with a mean emission time at 0855 hr 1 hr 6 min, characteristic of the schistosome species parasitizing domestic or wild cattle as mentioned in this paper.
Abstract: The emergence pattern of Schistosoma curassoni cercariae from Bulinus umbilicatus, whose adult worms parasitize bovine, caprine, and ovine ungulates in Niger, is of a circadian type with a mean emission time at 0855 hr 1 hr 6 min, characteristic of the schistosome species parasitizing domestic or wild cattle. The comparison of this cercarial emergence pattern with those of the other 3 sympatric species of schistosomes (Schistosoma haematobium, Schistosoma bovis, and Schistosoma mansoni) shows a significant difference between the chronobiology of the cercariae infective for human and those infective for bovine hosts. This difference may improve epidemiological surveys based on snail prevalences by allowing the distinction between bulinids infected with human and bovine parasites.

29 citations

Journal ArticleDOI
TL;DR: The results of this study establish and determine the natural role of B. senegalensis in the transmission of urinary schistosomiasis and indicate that the chronobiology of cercarial emergence can be used as a reliabie character for distinguishing between S. haematobium on one hand and S. bovis andS.
Abstract: The transmission in West Africa of Schisto&&a haematobium by Bulinus truncatus and B. globosus is well known (BROWN, 1980). On the contrary, B. senegalensis, widely distributed in the sub-desert and sahelian zone and associated principally with a temporary environment (BETTERTON et al., 1983), has been found naturally infected in Senegal and The Gambia only (VERCRUYSSE et al., 1985). In Niger, snail-schistosome infection experiments have proved that B. senegalensis is an excellent potential vector of S. haematobium originating from the sahelian zone (VERA et al., 1990). The purpose of this study was to establish and determine the natural role of B. senegalensis in the transmission of urinary schistosomiasis. The survey was carried out in 1988 in temporary rain-fed pools near the village of Bomberi, in the western part of Niger, 120 km north-east of Niamey in the south sahelian zone. A parasitological survey of schoolchildren in that village showed a prevalence of urinary schistosomiasis of 83% (77/92). A fortnightly hand collection of snails (lasting 20 min) was conducted from the time when the ponds filled until their drying up. The schistosomes were characterized by determining the emergence rhythms of cercariae under standardized laboratory conditions by means of a chronocercariometric apparatus (PAGÈS & THÉRON, 1990). The survey showed that B. senegalensis was the only snail species present in the ponds near the village which were used by human populations. That species was also the only one present in ponds located within a range of 10 km around the village. The populations of B. senegalensis developed after the filling of the ponds, in late June, and survived until their drying up between October and December. Only 3 of 600 snails (0.5%) collected in October 1988 released cercariae, characterized by peak emergence between 1200 h and 1400 h. Studies in our laboratory on several strains from different localities in Niger have shown that the mean shedding time (MST) was between 1200 h and 1400 h for S. haematobium and between 0800 h and 1000 h for S. bovis and S. curassoni (MOUCHET et al., 1990). Our results agree with those obtained by previous workers. For S. haematobium, the MST was between 1200 h and 1400 h, whether under natural outdoor conditions in South Africa (PITCHFORD & DU TOIT, 1976) or under experimental conditions identical to ours in Niger (PAGÈS & THÉRON, 1990). Different African strains of S. bovis were characterized by an MST between 0800 h and 1000 h under similar experimental conditions (MOUAHID et al., 1987; PAGÈS & THÉRON, 1990). These results indicate that the chronobiology of cercarial emergence can be used as a reliabie character for distinguishing between S. haematobium on one hand and S. bovis andS. curassoni on the other hand. Furthermore, in Niger, S. curassoni is present only in the eastern part of the country (MOUCHET et al., 1989). These results consequently allow us to affirm the natural infection of B. senegalensis by S. haematobium in the focus of

9 citations

Journal ArticleDOI
TL;DR: IgG and IgE circulating immune complexes, total serum IgE and parasite related IgE in patients with monoor mixed infection with Schistosoma mansoni andor S. haematobium and the influence of therapy.
Abstract: Santoro, F., Prata, A., Silba, A. E. & Capron, A. (1981). Correlation between circulating antigens detected by the radio-immunoprecipitation polyethylene glycol assay (RIPEGA) and Clq binding immune complexes in human schistosomiasis mansoni. American Journal of Tropical Medicine and Hygiene, 30, 1020-1025. Smith, M. D., Verrousr, P. J., Morel-Maroger, L. M., Genitau, M. & Couland, J. P. (1977). A study of the a, 42, 219-225. presence of circulating immune complexes in schistosomiasis. Transactions of the Royal Society of Tropical Medicine and Hygiene, 71, 343-348. Stevens, W. J., Feldmeir, H., Bridts, C. H. & Daffalla, A. A. (1983). IgG and IgE circulating immune complexes, total serum IgE and parasite related IgE in patients with monoor mixed infection with Schistosoma mansoni andor S. haematobium. Influence of therapy. Clinical and Experimenral Immunology, 52, 144-152. Voller, A., Bidwell, D. E. & Bartlett, A. (1976). Enzyme immunoassays in diagnostic medicine. Theory and practice. Bulleiin of ihe World Health Organization, 53, 55-65.

8 citations

Journal Article
TL;DR: If schistosomiasis increases the risk of chronic pyelonephritis, that increase could not be accounted for with the measures of these two variables, but the mean blood pressure and the creatininemia showed no difference between the two populations.
Abstract: In order to assess the relation between urinary schistosomiasis and urinary tract infections (U.T.T.), a study of two villages in the surroundings of Niamey (Rep. of Niger) was undertaken. In the first village located near a rice plantation irrigation scheme, the global prevalence of S. haematobium infection was 77%. Boys between 5 to 14 years of age were all infected and their mean egg output was 500 eggs/10 ml of urine. In the second village, where water is supplied from wells, schistosomiasis was almost absent. Urinary tract infections were diagnosed upon the cytologic count of the urinary sediment and the urine culture. Comparison between S. haematobium infected and non-infected villages showed that the prevalence of U.T.I. was 3.8 times higher among the females of the infected village. This was also noticed for old men and especially for boys aged 5 to 14 (5.2% U.T.I.) for whom urinary infection is usually uncommon. However the mean blood pressure and the creatininemia showed no difference between the two populations. If schistosomiasis increases the risk of chronic pyelonephritis, that increase could not be accounted for with the measures of these two variables.

6 citations


Cited by
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Journal ArticleDOI
TL;DR: It is found that people with safe water and adequate sanitation have significantly lower odds of a Schistosoma infection and future research directions in this area are highlighted.
Abstract: Schistosomiasis is a disease caused by infection with blood flukes of the genus Schistosoma. Transmission of, and exposure to, the parasite result from faecal or urinary contamination of freshwater containing intermediate host snails, and dermal contact with the same water. The World Health Assembly resolution 65.21 from May 2012 urges member states to eliminate schistosomiasis through preventive chemotherapy (i.e. periodic large-scale administration of the antischistosomal drug praziquantel to school-aged children and other high-risk groups), provision of water, sanitation and hygiene (WASH) and snail control. However, control measures focus almost exclusively on preventive chemotherapy, while only few studies made an attempt to determine the impact of upgraded access to safe water, adequate sanitation and good hygiene on schistosome transmission. We recently completed a systematic review and meta-analysis pertaining to WASH and schistosomiasis and found that people with safe water and adequate sanitation have significantly lower odds of a Schistosoma infection. Importantly though, the transmission of schistosomiasis is deeply entrenched in social-ecological systems, and hence is governed by setting-specific cultural and environmental factors that determine human behaviour and snail populations. Here, we provide a comprehensive review of the literature, which explores the transmission routes of schistosomes, particularly focussing on how these might be disrupted with WASH-related technologies and human behaviour. Additionally, future research directions in this area are highlighted.

196 citations

Journal ArticleDOI
TL;DR: Cercariae, like miracidia, are non-parasitic larval stages implicated in the life cycle of all trematodes for the host-to-host parasite transmission.
Abstract: Cercariae, like miracidia, are non-parasitic larval stages implicated in the life cycle of all trematodes for the host-to-host parasite transmission. Almost all cercariae are free-living in the external environment. With a few exceptions (cercariae of Halipegus occidualis (Halipegidae) can live several months, Shostak & Esch, 1990a), cercariae have a short active life during which they do not feed, living on accumulated reserves. Most cercariae encyst as metacercariae in second intermediate hosts which are prey of the definitive host; in certain species, the interruption of the active life is achieved by an encystment in the external environment (or a simple immobile waiting strategy in a few species). In some two-host life cycles, the cercariae develop into adults after penetration (this is the case for various species causing human schistosomiasis). Some cercariae do not leave the mollusc which must then be ingested by the definitive host.

180 citations

Journal ArticleDOI
TL;DR: How early phenotypic identification and recent confirmation through molecular studies on naturally occurring infections, combined with experimental manipulations, have revealed evidence of viable hybridization and introgressions within and between human and animal schistosome species is reviewed.
Abstract: Hybridization of parasites is an emerging public health concern in our changing world. Hybridization and introgression in parasites and pathogens can have major impacts on the host and the epidemiology and evolution of disease. Schistosomiasis is a Neglected Tropical Disease of profound medical and veterinary importance across many parts of the world, with the greatest human burden within sub-Saharan Africa. Here we review how early phenotypic identification and recent confirmation through molecular studies on naturally occurring infections, combined with experimental manipulations, have revealed evidence of viable hybridization and introgressions within and between human and animal schistosome species. Environmental and anthropogenic changes in selective pressures following, for instance, new dam constructions, altered agricultural practices, together with mass drug administration programmes, may all be predicted to further impact the availability of suitable definitive and intermediate hosts for schistosomes. It is therefore imperative to understand the distribution and role of such novel zoonotic hybrid schistosomes on host range, drug efficacy, and hence ultimately transmission potential, if we are to achieve and maintain sustainable control.

112 citations

Journal ArticleDOI
TL;DR: Evidence of drugs active against the infection with parasitic Schistosoma haematobium worms is summarized and dichotomous data as risk ratios (RR), and continuous data as mean difference (MD) are presented, alongside their 95% confidence intervals (CIs).
Abstract: Background Urinary schistosomiasis causes long-term ill-health This review examines the various treatment options and newer drugs Objectives To evaluate antischistosomal drugs, used alone or in combination, for treating urinary schistosomiasis Search strategy In August 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2007, Issue 3), MEDLINE, EMBASE, LILACS, mRCT, and reference lists of articles We also contacted experts in schistosomiasis research Selection criteria Randomized and quasi-randomized controlled trials of praziquantel, metrifonate, artemisinin derivatives, or albendazole, alone or in combination, versus placebo, different doses, or other antischistosomal drugs for treating urinary schistosomiasis Data collection and analysis One author extracted data, and assessed eligibility and methodological quality, which were cross-checked by a second person Dichotomous outcomes were combined using risk ratio (RR), and continuous data were combined using weighted mean difference (WMD); both presented with 95% confidence intervals (CI) Main results Twenty-four trials (6315 participants) met the inclusion criteria Compared with placebo, participants receiving metrifonate had fewer parasitological failures at follow up at one to three months (1 trial) and three to 12 months (3 trials) Egg reduction rate was over 90%, and no adverse events were reported (1 trial) One metrifonate dose was inferior to three doses given fortnightly (both used 10 mg/kg) Praziquantel (standard single 40 mg/kg oral dose) was more effective than placebo at reducing parasitological failure at one to three months' follow up and three to 12 months Egg reduction rates were improved with praziquantel (over 95% versus 53% to 64% with placebo) Mild to moderate adverse events were recorded in two trials A comparison of metrifonate (10 mg/kg x 3, once every 4 months for one year) with praziquantel (standard dose) showed little difference in parasitological failure For praziquantel, there was no significant difference in effect between 20 mg/kg x 2, 30 mg/kg x 1, and 20 mg/kg x 1, and the standard dose for all outcomes One small trial of artesunate showed no obvious benefit compared with placebo, and the artesunate-praziquantel combination was similar to praziquantel alone Authors' conclusions Praziquantel and metrifonate are effective treatments for urinary schistosomiasis and have few adverse events Metrifonate requires multiple administrations and is therefore operationally less convenient in community-based control programmes Evidence on the artemisinin derivatives is currently inconclusive, and further research is warranted on combination therapies We suggest metrifonate be reconsidered for the WHO Model List of Essential Medicines

110 citations