Schistosomiasis Sustained Control Program in Ethnic Groups Around Ninefescha (Eastern Senegal)

Abstract

Schistosomiasis is the second most significant parasitic disease in children in several African countries. For this purpose, the "Programme National de Lutte contre les Bilharzioses" (PNLB) was developed in partnership with the World Health Organization (WHO) to control this disease in Senegal. However, geographic isolation of Bedik ethnic groups challenged implementation of the key elements of the schistosomiasis program in eastern Senegal, and therefore, a hospital was established in Ninefescha to improve access to health care as well as laboratory support for this population. The program we have implemented from 2008 in partnership with the PNLB/WHO involved campaigns to 1) evaluate schistosomiasis prevalence in children of 53 villages around Ninefescha hospital, 2) perform a mass drug administration following the protocol established by the PNLB in school-aged children, 3) monitor annual prevalence, 4) implement health education campaigns, and 5) oversee the building of latrines. This campaign led to a drop in schistosomiasis prevalence but highlighted that sustainable schistosomiasis control by praziquantel treatment, awareness of the use of latrines, and inhabitants' voluntary commitment to the program are crucial to improve Schistosoma elimination. Moreover, this study revealed that preschool-aged children, for whom praziquantel was not recommended until 2014 in Senegal, constituted a significant reservoir for the parasite.

Figure 1.

Location of the villages included in the program. (A) Bedik's territory was depicted on Senegal map (hatched square). (B) Location of all the 53 villages around Ninefesha area in Kedougou District.

Figure 2.

Scheme of the study. For each year, the monitoring of schistosomiasis prevalence and the treatment program were depicted for children 6–14 years of age and for children under 6 years of age in Assoni village.

Figure 3.

Average prevalence of Schistosoma mansoni and Schistosoma haematobium in children 6–14 years of age. For each year, the prevalence of S. mansoni (black bars) and S. haematobium (grey bars) was evaluated in school-aged children of the 53 villages.

Figure 4.

Schistosoma mansoni and Schistosoma haematobium prevalence course of reported in villages that have at least one positive case between 2009 and 2014. (A) Schistosoma mansoni prevalence was assessed in each village from 2009 to 2014. Only the 16/53 villages which had positive at least once between 2009 and 2014 are represented. The continuous line linking empty squares represents S. mansoni prevalence in Assoni only. The dashed line linking the gray spots represents the average prevalence of S. mansoni in 15 other villages (i.e., excepted Assoni). (B) Schistosoma haematobium prevalence was assessed in each village from 2009 to 2014. Only 35/53 villages that had at least one positive case between 2009 and 2014 are represented. The dashed line linking the gray spots represents the average prevalence for all the 35 villages.

Figure 5.

Latrine model and building. (A) Standard eastern-Senegalese-school-latrine model rejected by school-aged children was made with concrete blocks with a corrugated iron roof and inadequate waste pipes. (B) Latrine model accepted by inhabitants was made of a pit covered with a reinforced concrete slab, which was poured by a bricklayer. A fence around the latrine makes it possible to use it day and night.