Schistosomiasis, a neglected tropical disease, is caused by the blood fluke that resides in the blood vessels of the human hosts. It presents as an acute, but mostly chronic, illness and is commonly found in the least developed countries having water resource development projects, like dams and irrigation system, and lacking good basic facilities as well as good healthcare systems. Forty countries in sub-Saharan Africa (SSA) were endemic for schistosomiasis in 2010. Of the five known species, Schistosoma haematobium, S. mansoni, S. japonicum, S. intercalatum, and S. mekongi, that can infect humans, it is S. haematobium which causes urogenital schistosomiasis and S. mansoni which causes intestinal schistosomiasis that have been responsible for most of the disease and a substantial public health and economic burden in SSA. Children, women, and farmers in rural communities who depend on water contact for recreational, domestic, or occupational activities are most vulnerable to the infection. Cross-border movements from unstable and conflict zones in SSA have contributed to the spread of the disease to previously non-endemic foci, and emigration from rural areas into the cities for economic opportunities has introduced the disease into some urban areas. In 2019, schistosomiasis caused around 1.64 million and 1.23 million disability-adjusted life years (DALYs) and years lived with disability (YLDs), respectively, with at least 80% of the burden concentrated in SSA. Annual loss from disability due to schistosomiasis in Africa was estimated to be nearly half a billion US dollars, approximately 70% of the global cost. The life cycle involves intermediate planorbid freshwater snail hosts—Bulinate species and Biomphalaria species—in the transmission of the infection with sexual and asexual stages. Man is the definitive host. Pathology and clinical morbidity of schistosomiasis are caused by eggs trapped in tissues of various organs and may present as hematuria in urogenital schistosomiasis and abdominal pain, diarrhea, and bloody stool in intestinal schistosomiasis. Long-term complications from schistosomiasis include urinary tract infections, bladder calcification, hydronephrosis/hydroureter, kidney failure, lesions of the liver, portal vein, and spleen, leading to periportal fibrosis, hepatomegaly, splenomegaly, pipe-stem portal fibrosis, ascites, nodules in the vulva, and bladder cancer. Microscopic examination for parasite eggs in the urine or stool is considered definitive for the diagnosis of the infection. Control of schistosomiasis involves health education, safe water supply, mollusciding, environmental management, chemotherapy (praziquantel as drug of choice) or combination of these measures. Currently, schistosomiasis control is mainly by mass drug administration (MDA) with anthelminthics, and the ongoing debate is whether it can be controlled or eliminated using the current approach.
BT - Neglected Tropical Diseases - Sub-Saharan Africa DO - 10.1007/978-3-031-53901-5_13 LA - ENG M3 - Book N2 -Schistosomiasis, a neglected tropical disease, is caused by the blood fluke that resides in the blood vessels of the human hosts. It presents as an acute, but mostly chronic, illness and is commonly found in the least developed countries having water resource development projects, like dams and irrigation system, and lacking good basic facilities as well as good healthcare systems. Forty countries in sub-Saharan Africa (SSA) were endemic for schistosomiasis in 2010. Of the five known species, Schistosoma haematobium, S. mansoni, S. japonicum, S. intercalatum, and S. mekongi, that can infect humans, it is S. haematobium which causes urogenital schistosomiasis and S. mansoni which causes intestinal schistosomiasis that have been responsible for most of the disease and a substantial public health and economic burden in SSA. Children, women, and farmers in rural communities who depend on water contact for recreational, domestic, or occupational activities are most vulnerable to the infection. Cross-border movements from unstable and conflict zones in SSA have contributed to the spread of the disease to previously non-endemic foci, and emigration from rural areas into the cities for economic opportunities has introduced the disease into some urban areas. In 2019, schistosomiasis caused around 1.64 million and 1.23 million disability-adjusted life years (DALYs) and years lived with disability (YLDs), respectively, with at least 80% of the burden concentrated in SSA. Annual loss from disability due to schistosomiasis in Africa was estimated to be nearly half a billion US dollars, approximately 70% of the global cost. The life cycle involves intermediate planorbid freshwater snail hosts—Bulinate species and Biomphalaria species—in the transmission of the infection with sexual and asexual stages. Man is the definitive host. Pathology and clinical morbidity of schistosomiasis are caused by eggs trapped in tissues of various organs and may present as hematuria in urogenital schistosomiasis and abdominal pain, diarrhea, and bloody stool in intestinal schistosomiasis. Long-term complications from schistosomiasis include urinary tract infections, bladder calcification, hydronephrosis/hydroureter, kidney failure, lesions of the liver, portal vein, and spleen, leading to periportal fibrosis, hepatomegaly, splenomegaly, pipe-stem portal fibrosis, ascites, nodules in the vulva, and bladder cancer. Microscopic examination for parasite eggs in the urine or stool is considered definitive for the diagnosis of the infection. Control of schistosomiasis involves health education, safe water supply, mollusciding, environmental management, chemotherapy (praziquantel as drug of choice) or combination of these measures. Currently, schistosomiasis control is mainly by mass drug administration (MDA) with anthelminthics, and the ongoing debate is whether it can be controlled or eliminated using the current approach.
PB - Springer International Publishing PY - 2024 SN - 9783031539008/2194-8275, 2194-8283 SP - 333 EP - 375 T2 - Neglected Tropical Diseases - Sub-Saharan Africa TI - Schistosomiasis ER -