Human infection with schistosomes and soil-transmitted helminths is the cause of clinical morbidity in many areas of the world. Human schistosomiasis is caused mainly by 3 schistosome species: Schistosoma haematobium, S. mansoni and S. japonicum. S. guineensis, S. intercalatum and S. mekongi have highly localized distribution in Central Africa and along the Mekong River in South-East Asia, respectively. Soil-transmitted helminthiases (STH) are infections caused by various parasite species, the main ones being: Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, Ancylostoma duodenale and Necator americanus. The 2 last species are indistinguishable microscopically and are usually reported together as “hookworms”. Schistosomiasis and STH are neglected tropical diseases (NTDs) that are transmitted mainly in areas with poor access to clean water and sanitation. Schistosomiasis occurs in focal areas and its presence is closely linked to the presence of water bodies that harbour susceptible species of snails. The presence of an intermediate snail host in water is essential for Schistosoma to complete their life cycle. Schistosomiasis and STH can cause significant morbidity, including anaemia, nutritional disturbances and, in the case of schistosomiasis, granuloma, organ pathology and cancer, and an increased risk of acquisition of HIV. In women, urogenital schistosomiasis may cause vaginal bleeding, pain during sexual intercourse and nodules in the vulva, now described as female genital schistosomiasis. Groups at risk for STH and schistosomiasis are people in need of micronutrients: preschool-aged children (pre-SAC, 1–4 years of age), school-aged children (SAC, 5–14 years), women of reproductive age (WRA) and, for schistosomiasis, entire communities in high-risk areas.
To control schistosomiasis and STH, WHO recommends access to clean water and sanitation, behavioural change interventions and preventive chemotherapy (PC), which is periodic treatment with anthelminthic medicines (albendazole or mebendazole for STH and praziquantel for schistosomiasis) to populations at risk. PC for all groups at risk is essential for preventing morbidity due to helminth infections and for sustained reduction of transmission. Additional preventive measures such as snail control and environmental management are suggested to control and eliminate schistosomiasis.