Review on an Epidemiology of Schistosomiasis in Ethiopia and its Public Health Importance
Author(s):
Banchigizie Fetene Akililu
Schistosomiasis or Bilharziasis is a disease caused by trematodes of the genus Schistosoma with different species. Schistosomes are dioecious (separate sex) trematodes or flukes with flat bodies which live in the vascular systems (mesenteric vein, portal vein), bladder and typically in other organs of their definitive hosts. The distribution of Schistosoma infection varies from place to place. Schistosomiasis is common in many tropical and sub tropical areas as well as in Africa, Asia and India. Schistosomabovis S.mattheei, S.intercalatum, S. spindale, S.nasalis and S.indicumhave significant veterinary important in livestock production in Africa, Asia, and south Europe. The distribution of Schistosoma infection varies from place to place. Schistosomabovis is the commonest species in Africa and Mediterranean region. The definitive hosts of Schistosoma species are mammals. Mainly, cattle and sheep, as well as human being serve as final host for Schistosomiasis. worms, Schistosoma parasites have an indirect life cycle, while water snail act as an intermediate host belong to the genera Bullinus and Physopsis. Embryonated eggs of Schistosoma are excreted through faeces, urine and nasal discharge from definitive host, depending on the localization of the species. Infection hosts occur through skin penetration typically when they are watering, grazing, swimming, or washing with in contaminated water in which certain types of snails that can carry the parasite are present. Schistosomiasis is one of the most prevalent parasitic diseases and an important public health problem in many developing countries. It is prevalent in tropical and sub-tropical areas, especially in poor communities that had low access to safe drinking water and adequate sanitation. The drug of choice for all species of Schistosomiasis is praziquantel. Control measures of Schistosomiasis are applying based on interrupting the epidemiological cycle of the parasite by removing the adult parasites with chemotherapy, by eliminating the intermediate host (snail) with molluscicides and habitat modification and preventing access of definitive hosts to natural water course contaminated with cercariae.
