Études et publications

Southgate VR, de Clercq D, Sène M, Rollinson D, Ly A, Vercruysse J.

Annals of tropical medicine and parasitology, 2000, 94(2):157-64 (PMID : 10827870)

Snail-infection experiments were carried out with a number of different species and populations of Bulinus and isolates of Schistosoma haematobium. The parasites came from six localities in the Senegal River basin (SRB), in the Lower Valley (Mbodiene), Middle Valley (Podor, Diatar and Nguidjilone), and Upper Valley (Aroundou and Galladé). Isolates of S. haematobium from the Middle and Upper Valleys all showed some compatibility with laboratory-bred B. truncatus from Mali, but none of these isolates was compatible with laboratory-bred B. truncatus originating from Senegal. Schistosoma haematobium from Diatar (Middle Valley) was compatible with B. senegalensis, whereas S. haematobium from Mbodiene (Lower Valley), which is naturally transmitted by B. globosus, was incompatible with B. senegalensis and B. truncatus. These data demonstrate that different isolates of S. haematobium from different regions of the SRB exhibit distinct intermediate-host specificities, which in turn will have an effect on the epidemiology of the disease, including the periods of transmission. It is apparent that, in addition to B. senegalensis and B. globosus, B. truncatus, the most widespread bulinid snail in the SRB, may be playing a role in the epidemiology of urinary schistosomiasis. This conclusion has obvious implications for the future spread of urinary schistosomiasis in the SRB. Chemical and physical measurements from assorted habitats along the SRB, including pH, temperature, salinity, conductivity, and resistivity, are also reported.

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de Bernis L, Dumont A, Bouillin D, Gueye A, Dompnier JP, Bouvier-Colle MH.

BJOG: International Journal of Obstetrics and gynaecology, 2000, 107(1):68-74 (PMID : 10645864)

OBJECTIVE: To compare maternal morbidity and mortality in two urban populations with contrasting availability of health care, and to test the hypothesis that differences in maternal outcome result mainly from the management of delivery in health facilities. DESIGN: A population-based study of a cohort of pregnant women which was part of a multicentre study of maternal morbidity in six countries of western Africa (MOMA). SETTING: Two different urban areas of Senegal (Saint-Louis and Kaolack). POPULATION: 3,777 pregnant women who were followed up throughout pregnancy, delivery and puerperium. MAIN OUTCOME MEASURES: Maternal morbidity and mortality: morbidity was assessed from women's recall at each visit by the investigator and from obstetric complications diagnosed by the birth attendant within health facilities. RESULTS: Maternal mortality was higher in the Kaolack area where women gave birth mainly in district health care centres, usually assisted by traditional birth attendants, than in Saint-Louis where women giving birth in health facilities went principally to the regional hospital and were usually assisted by midwives (874 and 151 maternal deaths per 100,000 live births, respectively, P < 0 x 01). Maternal morbidity, however, was higher in Saint-Louis than in Kaolack area, especially for births in health facilities (9 x 50 and 4 x 84 episodes of obstetric complications per 100 live births, respectively, P < 0 x 01). Univariate and multivariate analyses showed that morbidity was mainly associated with the training of the birth attendant in facility deliveries and that antenatal care had no effect. CONCLUSION: Midwives in health facilities appear to detect more obstetric complications than traditional birth attendants. Immediate detection leads to immediate care and to low fatality rates. This could explain differences in maternal outcome between two urban centres with contrasting health care availability. These results suggest that one of the strongest weapons in the fight against maternal mortality is the employment of the most qualified personnel possible for monitoring labour.

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Duplantier JM, Sène M.

Journal of helminthology, 2000, 74(2):129-35 (PMID : 10881283)

More than 2000 animals belonging to six different rodent species and one insectivore species were examined for infection with schistosomes in the region of Richard-Toll, Senegal. Two murid rodents, Arvicanthis niloticus and Mastomys huberti, were found infected with Schistosoma mansoni. Prevalences were about 5% for both rodent species with a mean worm burden of about 20 worms per host. The sex-ratios of S. mansoni worms were always biased towards males. Prevalences and worm burdens, although similar in both male and female rodents, increased significantly with age. The highest prevalences and worm burdens were found near habitations and decreased significantly with the distance from the town of Richard-Toll. Eggs were also observed in the liver and faeces of the two naturally infected rodent species. The results suggest that rodents participate in the transmission of intestinal schistosomiasis in Richard-Toll but the human population is the main source of infection. The genetic resemblance between human and murine isolates of S. mansoni suggests that further epidemiological studies are needed in this region of Senegal.

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