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A combined school- and community-based campaign targeting the entire school-age population of Burkina Faso with drugs against schistosomiasis (praziquantel) and soil-transmitted helminthiasis (albendazole) was implemented in 2004-2005. In total, 3,322,564 children from 5 to 15 years of age were treated, equivalent to a 90.8% coverage of the total school-age population of the country. The total costs of the campaign were estimated to be US 1,067,284 dollars, of which 69.4% was spent on the drugs. Delivery costs per child treated were US 0.098 dollar, in the same range as school-based only interventions implemented in other countries; total costs per child treated (including drugs) were US 0.32 dollar. We conclude that a combined school- and community-based strategy is effective in attaining a high coverage among school-age children in countries where school enrolment is low and where primary schools cannot serve as the exclusive drug distribution points. The challenge for Burkina Faso will now be to ensure the sustainability of these disease control activities.

The recent emergence of a mixed focus of Schistosoma haematobium-Schistosoma mansoni, in the lower delta of the Senegal river, requires adapted control programmes. A mass treatment with praziquantel was organised in April 1994 by local authorities in three villages where populations had been examined. A total of 2042 subjects participated. In Savoigne S. haematobium prevailed (53% for prevalence), in Diagambaly S. haematobium (64%) and S. mansoni (76%) were both abundant, and in Boundoum S. mansoni prevailed (53%). Therapeutic coverage (80%) was assessed on a representative sample. A cohort of 968 treated subjects were followed-up 40, 100, 200 and 300 days after treatment. Six weeks after treatment, the average of egg excretion decreased by 95% for S. haematobium, ranging from 23 to one egg(s)/10 ml at Savoigne and from 14 to one egg(s)/10 ml at Diagambal. Conversely, egg excretion only decreased by 75% for S. mansoni, from 23 to six eggs/g at Boundoum and from 69 to 16 eggs/g at Diagambal, showing evidence of the low susceptibility of S. mansoni local strain to praziquantel. Ten months after treatment, reinfections with S. haematobium remained weak at Savoigne (two eggs/10 ml) while those with S. mansoni were so high at Boundoum (24 eggs/g) that they compensated the reduction of load induced by the treatment. At Diagambal, where the two parasites were present before treatment, the disappearance of the urinary schistosomiasis after treatment concurred with a dramatic increase of intestinal schistosomiasis. S. manoni egg excretion was seven times higher than before treatment (478 eggs/g). These different effects of treatment are discussed according to the ecology of transmission in the three villages.

The construction of large dams has been shown to increase the prevalence and intensity of human schistosomiasis. However, until now no study had been carried out to assess the impact of such a project in Côte d'Ivoire. For Kossou and Taabo, two large dams which became operational in the 1970s, baseline data are available on schistosomiasis prevalence in the surrounding area before dam construction, so that the changes in schistosomiasis levels can be assessed. We re-evaluated the prevalence of Schistosoma haematobium and S. mansoni in November 1992, by analysing 548 urine and 255 stool samples, respectively, from schoolchildren from five villages around each lake. A marked increase in the overall prevalence of S. haematobium was observed, from 14% to 53% around Lake Kossou and from 0 to 73% around Lake Taabo. Baseline data for S. mansoni are only available for Lake Taabo, where a prevalence of 3% was found in 1979 and where the prevalence in 1992 was still low at 2%. The construction of these two large dams therefore led to little change in S. mansoni prevalence but to a significant increase in that of S. haematobium.

The authors present the results of a survey with ultrasonography conducted to evaluate the prevalence of hepatic fibrosis as a complication of infection by Schistosoma mansoni. Because of the specific images it yields, ultrasonography appears to be highly valuable for the diagnosis of Symmer's fibrosis. It allows the assessment of morbidity from Schistosoma mansoni, which has previously only been performed indirectly by physical examination.

An epidemiological survey was made in 4 villages of the recently discovered Schistosoma mansoni focus of Bana (Niger). The total prevalence of intestinal schistosomiasis is 15%. The highest prevalences are noted in the age-group from 20 to 38 years old. The mean egg load is moderate: 11.3 eggs/g of stools. Several hypothesis are discussed to explain the low endemicity of this focus.