THE EPIDEMIC OF VISCERAL LEISHMANIASIS IN WESTERN UPPER NILE, SOUTHERN SUDAN - COURSE AND IMPACT FROM 1984 TO 1994

Background. Although endemic in parts of southern Sudan, visceral leis hmaniasis (VL) had not been reported in Western Upper Nile (WUN) until an epidemic was confirmed in 1989. A combination of circumstances cre ated conditions for transmission among a population of mainly Nuer and Dinka people who had no immunity. The civil war which restarted in 19 83 has been a major contributing cause and continues to hinder provisi on of treatment, data collection and control measures. Methods. Since the first of three clinics to treat VL was established in WUN in 1989, data on the epidemic and mortality have been collected in seven retro spective surveys of villages and among patients. Adults were interview ed about surviving family members and those who had died since the epi demic came. Survey death rates are used here to estimate mortality fro m VL and 'excess mortality' above expected levels. Results. The survey s found high mortality at all ages and suggest an overall death rate o f 38-57% since the epidemic started in 1984, and up to 70% in the most affected areas. Both methods of estimation suggest that around 100 00 0 deaths, among about 280 000 people in the epidemic area, might be at tributable to VL. Conclusions. This continuing epidemic has shown that VL can cause high mortality in an outbreak with astonishingly high in fection rates. Population movement has been a major factor in transmis sion and poor nutritional status has probably contributed to the risk of clinical infection. Although over 17 000 people have been successfu lly treated for VL at the clinics in WUN, the disease is likely to bec ome endemic there.