Treatment Effects and Integrated Morbidity Control of Schistosomiasis

Schistosomiasis is caused by the blood fl uke and leads to signifi cant ill-health and economic burden. The disease is common in the tropics and subtropics and acquired through contact with freshwater bodies infested with the infective cercariae shed from the intermediate host snail. From a public health perspective, the three most important species are Schistosoma mansoni and S. japonicum (causing intestinal schistosomiasis) and S. haematobium (causing urinary schistosomiasis). Schistosomiasis is endemic in 76 countries and territories worldwide (Engels et al. 2002; Steinmann et al. 2006) with around 85% of the infections confi ned to sub- Saharan Africa (Savioli et al. 1997; Chitsulo et al. 2000). Schistosomiasis is largely confi ned to rural dwellings and exacerbates poverty (Hotez et al. 2008; Wang et al. 2008). In some areas of sub-Saharan Africa there is an overlap in distribution of S. mansoni and S. haematobium resulting in mixed infections (WHO 2002). This thesis focuses on urinary schistosomiasis due to S. haematobium and intestinal schistosomiasis due to S. mansoni. Schistosomiasis is largely related to poverty, and efforts to alleviate poverty through development of water-related projects tend to increase transmission of the infection (Poda et al. 2004; Steinmann et al. 2006). Mostly children, women and farmers in poor rural areas who depend on water contact for recreational, domestic or occupational activities are affected. Peri-urban schistosomiasis is on the increase (Kloetzel et al. 1994; Chimbari & Chirundu 2003; Njiokou et al. 2004), and movement of displaced people from confl ict zones has contributed to the spread of the disease to previously non-endemic areas (Chitsulo et al. 2000).