Volume 9 Number 2 August 1995
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Bacillary dysenteryDysentery was one of the top ten 3iseases in children under five years of age as reported to the Ministry of Health among out-patients in 1988-89(13). The main causative agents of epidemic bacillary dysentery are the shigella. Four pathogenic species of shigella are generally identified. They are S. dysentraie (Shiga), S. flexneri, S. Boydi and S.Sonnei. S.dysentraie (shiga) causes epidemics with high mortality. Spread of infection occurs by contaminated food and water, flies or contact through unwashed hands after defecation. Shigella cause up to 10% of acute diarrhoea in children under five years of age (14). In recent years multiple antibiotic resistance has been observed. It was reported that up to 20% of patients die even after treatment (8). Education on personal hygiene, proper waste disposal, protection of water sources and prevention of water contamination, measures to reduce the fly population and hygienic preparation of food are important in the prevention and control of the disease. Typhoid feverTyphoid Fever is caused by infection with Salmonella typhi which are specific human pathogens. It is now rarely seen in developed countries because of sewage and water treatment facilities but remains a common problem in developing countries like Ethiopia. The disease is transmitted to healthy people through water and food contaminated with faeces and urine. The incidence peaks in the dry season when water supplies are concentrated but may also reach high levels at the onset of rains when the organisms are flushed into streams and wells. Even in the presence of clean water and good sanitation an epidemic could develop among refugees, prisoners and other groups of people in concentration camps, because organisms can spread from unclean fingers. Despite difficulties in confirming the disease in most of the laboratories of the country , a high number of cases are reported to the Ministry of Health. In 1976-79 and 1983 a total of about 5000 and 1500 cases, respectively, were reported(8). Prevention and control methods include treatment of patients, proper waste disposal, hand-washing after defecation, water treatment, hygienic food preparation and avoidance of food contamination by flies (8). Measles and pertussisMeasles and pertussis are included in the six childhood diseases of the expanded programme on Immunization (EPI). These diseases are characterized by high mortality and morbidity rates. At the same time they are preventable by immunization. According to reports of health facilities to the Ministry of Health, the number of measles cases reported in 1980 and 1983 was about 3000 (5). After 1983 the number of reported cases declined until 1989 at which time it came down to 1000 cases. In 1990 there was a rise to about 2000 cases. This was attributed to the epidemics in shelter populations displaced by war in Wello, Eritrea and Gondar (5). Measles epidemics were also reported from relief camps during 1983-85 famine. In Gamu Gofa, in 1982 during an epidemic mortality rates of between 7.1 % and 10.9% were reported for children under 10 years old. Cultural factors including avoidance of injections and visits of homes children who have died of measles by relatives and their children appeared to have facilitated transmission (15). Crowded conditions and loss of maternal antibodies have been considered major factors in the epidemiology of measles in Ethiopia. The number of pertussis cases reported to the Ministry of Health declined from nearly 6000 in 1982-83 to less than 1000 in 1990(5). The epidemiology of pertussis in Ethiopia has not been studied. National EPI coverage for measles and pertussis (OPT 3) vaccine in childre nunder one year of age in November 1990 was reported to be 59% in areas where vaccination takes place (5). However, some surveys have put such a coverage rate in question. High defaulter rates and missed opportunities were also noted by some investigators (16). The major reasons for immunization failure were lack of information and motivation, inadequate health infrastructure:, problems of communication and transport, the protracted civil war and deficiencies in the surveillance systems (5,17). Efficient and regular supervision, disease surveillance and increase in community involvement, development of health leadership were recommended to improve the EPI coverage and therefore minimize morbidity and mortality due to these diseases (5). Viral hepatitisInfection with hepatitis A (HA V) affects people with low socio economic status and poor hygiene. In Ethiopia it becomes universal by the early teens (5). Therefore it is reasonable to believe that HA V is unlikely to cause outbreaks in this country. Hepatitis B-infection (HBV) is a major cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma. The main mode of transmission of HBV is transfusion of infected blood and blood products. Major risk factors in this country are uvulectomy, traditional surgery, tattooing, ear piercing, sexual exposure, circumcision, scarification, presence of lice and jiggers and birth at home (5). Hepatitis B surface antigen (HBS Ag) carrier state is between 8% and 12% while the overall HBV marker prevalence is between 42% and 79% in the general population. Studies have shown hepatitis O, C, E and non A non B viruses to be endemic in Ethiopia. HEV was shown to have caused epidemics in military personnel stationed in Eritrea (18). The majority of acute viral hepatitis cases in this country are due to non A non B hepatitis (5,8). However, as diagnostic tests become more refined the number of acute viral hepatitis cases due to non A, non B virus is likely to decline. Control measures against hepatitis include health education on ways of disease transmission and prevention, improvement of personal and environmental hygiene and screening of blood donors. Immunization with a polyvalent vaccine by integrating with the national EPI programme has also been suggested (5). |