Viral diseases in Ethiopia: a review

Abstract

Ethiopia is endemic for many viral diseases. Serosurveys have demonstrated the high prevalence rate of hepatitis B virus. There are also indications of high transmission for hepatitis C, hepatitis E and human immunodeficiency virus (HIV). The population is exposed to poliomyelitis, hepatitis A, measles, rubella and mumps early in life. Rotaviral diarrhoea is an important cause of infant morbidity and mortality. Vast areas of the country are endemic for yellow fever and rabies. The extent of many other viral diseases in the country is unknown. There is a need for a well organised national laboratory to assess the impact of vaccination efforts and to support control as well as surveillance measures within the country.

PIP: In Ethiopia during 1960-1962, more than 100,000 people in the Omo and Didessa river valleys acquired yellow fever and 30,000 died. There have been no yellow fever cases since 1966. Some other aboviruses that arise sporadically are Jos virus, dengue fever, Crimean-Congo hemorrhagic fever, and group A arboviruses. By age 15, all people in surveyed regions were positive for hepatitis A virus. Prevalence of hepatitis B virus increases with age ( 75% of adults in urban areas and many rural areas). The frequency of carriers of hepatitis Bs antigen is greatest in areas where people practice ceremonial tattooing. During 1988-1989, 93% of jaundiced patients in a military camp in Ethiopia had antibodies to hepatitis E virus as a result of a waterborne outbreak. Other hepatitis viruses in Ethiopia are delta and C viruses. All 3 serotypes of poliovirus exist, especially type III. 93% of 1-year-olds have already acquired immunity to it. Peak frequency of onset among paralytic cases is 2 cases. Measles epidemics are common in children. An outbreak in southwestern Ethiopia had a mortality rate of 20%. Immunity to rubella is around 85% for 14-year-olds. It increases with age. Rotavirus causes diarrhea in many children, especially among 7-12 month old infants and in June and November. Most children have been exposed to Epstein-Barr virus, which is responsible for mononucleosis and maybe for Burkitt's lymphoma. Officials do not conduct ongoing surveillance of influenza in Ethiopia. Influenza epidemics have occurred in 1957 and 1963. Rabies is endemic, with dogs being responsible for most cases. In November 1992, there were 3978 AIDS cases. 75% are less than 40 years old, with males more likely to be HIV infected than females. The Falashas of northwest Ethiopia have the world's second highest endemic rate of human T cell leukemia virus-1. Officials do not know the extent of viral diseases because there is no well organized national laboratory. One is needed to conduct surveillance and to evaluate the effectiveness of vaccination activities.