PREVALENCE OF SCHISTOSOMIASIS IN RELATION TO THE OCCURRENCE OF INTERMEDIATE SNAIL HOST IN PARTS OF ZANGON-KATAF LOCAL GOVERNMENT AREA OF KADUNA STATE, NIGERIA
CHAPTER ONE
INTRODUCTION
1.1Â Â Â Â Â Â Â Â Background of the Study
Schistosomiasis is a parasitic disease of humans caused by parasitic fluke of the genus Schistosoma. There are five most common species that infect humans. These species include, S. mansoni, found in Africa and South America; S. haematobium, found in Africa and the Middle East; S. intercalatum, found in Central and West Africa; S. japonicum, found in China, Southeast Asia, and the Philippines; and S. mekongi, found in parts of Southeast Asia (Sturrock, 2001). Schistosoma guineensis has been recently discovered in as one of the common important schistosome species that infect humans (Webster et al., 2006). It was identified 2003 in the western Africa, mainly in Cameroon, Equatoral Guinea, Gabon, Nigeria etc (WHO 2010). Schistosomiasis is also referred to as Bilharziasis. This is because it was discovered by Theodore Bilharz (1951), a German surgeon working in Cairo who first identified the etiological agent, Schistosoma haematobium (Ross et al., 2006).
Schistosomes are helminth parasites whose adult forms live in the blood stream of humans, hence, the name blood flukes. The two species present in Africa are Schistosoma haematobium and Schistosoma mansoni (Cunin et al., 2003). Their life cycle involves two hosts (a definitive host and an intermediate host). The definitive host for both species is man, while the intermediate host for S. mansoni and S. haematobium are snails of the genus Biomphalaria and Bulinus species respectively. The species differ as follows: their predilection site (i.e.final location) in the human host, the species of the intermediate (snail) host involved in their life cycle, the pathology they induce and the number, size and shape of the eggs they produce.
The presence of Schistosoma haematobium and Schistosoma mansoni in Africa had brought about two major forms of schistosomiasis affecting humans in Africa. These are the urinary and intestinal schistosomiasis, which are caused by Schistosoma haematobium and Schistosoma mansoni respectively (Colley et al., 2014).
Schistosomiasis usually manifests as a chronic and debilitating disease in humans. It is the most prevalent of the waterborne diseases and one of the greatest risks to health in rural areas of developing countries. The disease is common in tropical and sub-tropical areas, especially in poor communities that have low access to usable water bodies and adequate sanitation (Ogbe, 2002). Urinary schistosomiasis affecting the urinary tract involves Schistosoma haematobium with an appropriate aquatic snail intermediate host called Bulinus species. The worms live in the blood vessels of the bladder and rectum.
DOWNLOAD COMPLETE PROJECT MATERIALS
PREVALENCE OF SCHISTOSOMIASIS IN RELATION TO THE OCCURRENCE OF INTERMEDIATE SNAIL HOST IN PARTS OF ZANGON-KATAF LOCAL GOVERNMENT AREA OF KADUNA STATE, NIGERIA
