PROJECT BODY:
Chapter one
Introduction
1.1Background of the study
Lassa fever is an acute viral hemorrhagic illness caused by Lassa virus, a member of the virus family Arenaviridae. The disease is endemic in Sierra Leone, Guinea, Liberia, and Nigeria (Bowen et al. 2000) where The number of Lassa Fever virus infections per year is estimated at 100,000 to 300,000 with approximately 5,000 deaths (Bowen et al., 2000; Gunther et al., 2000; World Health Organisation (WHO), 2005, WHO, 2000). Outbreaks have been reported in Ghana, and serological evidence of human infection has been found in Ivory coast , Senegal and Mali. (Richmond and Baglole, 2003). The virus has also been imported into countries where it is not endemic, for example, by returning travelers (Gunther et al., 2000). The virus exhibits persistent, asymptomatic infection, with profuse urinary virus excretion in Mastomys natalensis, the ubiquitous and highly commensal rodent host Keenlyside et al., 1983; Monath et al., 1974). The virus is shed in their excreta (urine and feces), which can be aerosolized and inhaled by humans (Viral haemorraghic fever consortium, 2011). Primary mode of spread is from rodent to man through contact with rodent excreta or urine in food or during hunting and processing of rats for consumption. The virus has the capacity for person-to-person spread, either within households during care for sick relatives or in health care settings (Fischer-Hoch, 2005). Percutaneous or per-mucosal exposure to blood and other infected body fluids, especially if the fluids contain blood, can result in secondary human spread. This type of transmission is the most likely route in health care settings (Aranoff et al., 1997). This nosocomial hazard can be minimized by proper and timely infection-control measures, careful management of infected patients, and, in some cases, administration of prophylactic therapy to health care workers after exposure (Weber and Rutala 2001; Morbidity and Mortality Weekly Review (MMWR) 1988). Lassa fever presents at it’s early stage with symptoms and signs indistinguishable from those of other viral, bacterial or parasitic infections common in the tropics such as malaria, typhoid and other viral haemorrhagic fevers (Richmond and Baglole, 2003). Laboratory testing is required for confirmation. Untreated, Initial flu-like and gastrointestinal symptoms give way to bleeding, organ failure and neurological complications (Bausch et al., 2001). The drug ribavirin is effective if administered early following infection (McCormick et al., 1986). When the disease is in an advanced stage, even state-of-the-art intensive care cannot prevent a fatal outcome. A suspect must be rapidly excluded or verified to facilitate appropriate case management, including treatment, the implementation of isolation measures, or the tracking of contact persons (Haas et al., 2003) Late diagnosis and treatment also increases the likelihood of secondary transmission, including nosocomial transmission. It is therefore imperative that health care workers in endemic communities are adequately sensitized on the disease, it’s clinical features and diagnosis.