Volume 9 Number 2 August 1995
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Epidemic prone diseases in Ethiopia EPHA Expert Group reportMelakeberhan Dagnew1, Mesganaw Fantahun1 and Shabbir Ismail1 Review of the global situation Infectious agents have caused disease and death in human populations throughout history . Some of the most devastating epidemics ever recorded have been caused by uncontrollable spread of dangerous human pathogens. The plague epidemic of the middle ages was responsible for the death of 13 million people in Europe during a four-year period (1). More recently, in the first part of the century , pandemic influenza swept the world by killing 20 million people in less than a Year's time (1). At present the world population is affected by devastating epidemics that have resulted in high morbidity and mortality. Repeated epidemics of the same disease and the emergence of new once are attributed to t.uman demographics and behaviour, economic development and land use, international travel and commerce, technology and industry and the breakdown of public health measures (1). Among the epidemic prone diseases, AIDS is moving up in several countries as a leading cause of death. According to estimates over 2.5 million cases and over 13 million infected persons are likely to be affected globally (2). Malaria epidemic is causing millions of deaths (3). Diarrhoeal diseases are widely recognized as major causes of morbidity and mortality particularly in Africa. Vibrio Cholera and Shigella have caused widespread epidemics throughout the world. In 1968, Shigella epidemic affected half a million people and killed 20,000 people. In Burundi, it took the lives of 2000 people in 1981/82 (4).In recent times Cholera epidemics have ravaged many parts of Africa (5). Another epidemic prone disease that has caused high mortality at different periods of human history is Epidemic Meningitis. In Sub-Sal1ara Africa repeated major outbreaks have occurred. During the 1988/89 epidemics millions of people were affected (6). Common outbreaks which resulted in high mortality have also occurred as a result of acute febrile illnesses. These diseases are widely spread in developing countries. For example in 1980 the number of typhoid cases occurring in Africa was four million (7). Yellow fever is still a potential threat in many areas of tropical Africa (5). In general, the incidence of a number of these diseases is escalating globally including those that were once under control in many parts of the world. These diseases if not eliminated at least can be significantly moderated. The response to fight these diseases needs a more aggressive and timely action at local, national, regional and international levels. The national situationThe most common diseases in Ethiopia are communicable and nutrition deficiency diseases. Outbreaks of some communicable disease have caused morbidity, mortality and disability in a large number of people. In recent years outbreaks of diseases have been observed in areas where they were not reported before. Some of the reasons attributed to the epidemic situation in the country at present are movement of large numbers of people, poorly planned settlements and irrigation schemes, poor control of disease transmitting vectors, overcrowding, poor personal and environmental hygiene, deforestation, displacement because of social, political and economic problems (8). Increase in health service coverage (though slow) has been suggested as one reason for the appearance of endemic and epidemic diseases in areas where such diseases were not reported before. ________________ 1 From the Department of Community Health, Gondar College of Medical Sciences, P.O. Sox 196, Gondar. The Ministry of Health of Ethiopia has identified the following Epidemic Prone Diseases (8). 1 .Those that are often encountered a. Malaria b. Relapsing Fever c. Typhus d. bacillary dysentery f. Typhoid fever 2. Those that are infrequently or sometimes encountered a. Measles b. whooping cough d. Rabies 3. Those that infrequently or are rarely encountered a. cholera b. Yellow fever Malaria About three fourths of the total area of the country is estimated to be malarious and two thirds of the population are at risk of infection (5). In 1958 in Dembia, Gondar, and other regions of the country, malaria epidemic claimed about 150,000 lives (9). About four episodes of severe epidemics at 7 -8 years of interval have occurred since then (9) .Malaria and other Vector Borne Diseases are dealt with by another working group and hence will not be further discussed here. Meningococcal meningitisEthiopia lies within the so called "Meningitis Belt" which stretches across the continent south of the Sahara(10). Epidemic Meningitis occur every eight to ten years during the dry season. Smaller outbreaks occur more frequently. The reasons for such trends are not well understood, but herd immunity, climatic factors, especially high temperatures and low humidity, poor hygiene and crowding have been implicated (5). In this country Epidemic Meningitis is mostly caused by the sero-group A followed by C. Meningococcal meningitis was first mentioned in the country in 1901. Later epidemics were reported in 1935, in the 1959-63, 1964,1972,1977,1981-83, 1988-89(5,11). The largest number of recorded cases and deaths were reported in 1981-83 and 1988-89. About 50,000 cases and 990 deaths were reported in 1981-83. Forty five thousand cases and 1685 deaths were reported in 1988-89 (5). Starting from 1981 the epidemic had spread from N . West to the south and east and hence has increased the boundaries of the" Meningitis Belt"(8). More than 70% of the cases in the 1981-83 epidemic were reported from Gondar , 18% from Wello, 9% from Gojam and fewer cases from Tigray(5). In 1988-89, 28% of all cases were reported from Shewa, 22% from Wello, 14% from Gojam, 6% from Sidamo and 5% from Gamo Gofa. More than 50% of all cases were among children up to 14 years and slightly over 40% in the 15-44 group. Of the reported cases in 1981-83, 54.4% were male and 45.6% females (11). A similar ratio was observed in the 1988-89 epidemic. Epidemics were not reported from low land pastoralist areas and this has been attributed to low population density and less crowded living. The current criteria of epidemic threshold rate in Ethiopia is recommended to be 15 cases/100,000 inhabitants per week or higher averaged over two consecutive weeks (12). The strategy for control of the epidemic currently adopted is case management using intravenous crystalline penicillin infusion or, in difficult situations, oil suspension of chloramphenicol; immuno-prophylaxis with A and/or C poly saccharides to high risk groups, closed communities and close contacts at home and work for ages between 2-30 years; and chemoprophylaxis with rifampicin to close contacts when vaccine is not available (12). Uninterrupted and efficient surveillance and control systems and coordinated efforts with countries in the region are recommended to effectively prevent and control the disease. |