Once a year school-based deworming with praziquantel and albendazole combination may not be adequate for control of urogenital schistosomiasis and hookworm infection in Matuga District, Kwale County, Kenya

Abstract

Background: Neglected tropical diseases (NTDs) predominantly occur in resource poor settings where they often present a serious public health burden. Sustained global advocacy has been important in raising awareness of NTDs and the relatively low cost for control of helminthic NTDs using preventive chemotherapy. This enthusiasm was boosted at the London declaration on NTDs in 2012 through commitments by different partners to avail resources required for control of NTDs particularly those that employ preventive chemotherapy as the major intervention strategy. Subsequently, national NTD programmes are responding to these new opportunities by implementing preventive chemotherapy including school-based deworming (SBD). Further, with the availability of increased resources, both financial and pharma, the optimal strategies for implementing preventive chemotherapy in highly endemic settings are under debate and this paper goes some way to addressing this issue in a specific setting in coastal Kenya.

Methods: We conducted a repeated cross-sectional study in Matuga District, Kwale County, Kenya to evaluate the effect of school-based co-administration of praziquantel and albendazole against urogenital schistosomiasis and soil-transmitted helminth (STH) infections. A total of 1022 school children in 5 study schools were tested for the infections in urine and stool samples during a baseline survey in September 2009. The presence of Schistosoma haematobium infection was determined by the urine filtration method while STH infections were determined by Kato-Katz technique.

Results: Urogenital schistosomiasis and hookworm infection were the major parasitic infections among the children in the study area. There was significant decrease in both prevalence and intensity of S. haematobium infection after treatment but varying levels of rebound were observed during the period between the treatments. The school-based treatment, however, did not have any significant effect on both the prevalence and intensity of hookworm infection.

Conclusions: Once per year SBD programmes may not be adequate for controlling hookworm infection and urogenital schistosomiasis in rural areas of Kwale County. There is a need to consider expanded preventive chemotherapy strategies that will allow inclusion of the adult populations. Community-based health education campaigns focusing on increasing household latrine ownership and use, as a complementary measure to control STH and urogenital schistosomiasis in similar settings, may also be useful.

Figure 1

Map of study area. A map showing the location of the five study schools in Mwaluphamba Location, Matuga District, Kwale County, Kenya.

Figure 2

Changes in prevalence of S. haematobium infection by school and year in Mwaluphamba Location, Mutuga District, Kwale County. Overall, 505 (49.4%) of the 1022 children examined at baseline were found to have S. haematobium infection with Mlafyeni school having the highest rates (77.4%). The treatment significantly reduced the prevalence of S. haematobium infection in all schools. However, rebound in prevalence of S. haematobium infection was observed in most schools.

Figure 3

Prevalence of STH infections in study schools at baseline and follow-up surveys in Mwaluphamba Location, Mutuga District, Kwale County. The major STH infection in the area was hookworm but the once per year school-based deworming did not have a significant effect on the infection.