[An outbreak of Shigella dysenteriae type 1 dysentery in a refugee camp in Rwanda]

As a consequence of the civil war that devastated Burundi in October 1993, more than 300,000 refugees settled in the neighboring country of Rwanda. We describe the outbreak of dysentery due to Shigella dysenteriae type 1 (Sd1) that developed in Nzangwa, a camp hosting some 20,000 Burundese refugees. Between November 17, 1993 and March 10, 1994, 6,122 cases of bloody diarrhea were notified by the health information system of the camp. The overall attack rate was 32.3%, and the fatality rate was 3.8%. Children under five years of age were the most affected group of the population. All dysentery cases were treated with nalidixic acid for 5 days. The compliance assessment showed that less than 50% of the ambulatory patients completed the 5-day regimen. From 35 stool samples obtained from the refugees, seven Sd1 strains were isolated, of which three were multi-resistant to nalidixic acid. These results confirmed the morbidity and mortality of Sd1 outbreaks in the displaced populations of Central Africa. We also emphasize the difficulties in implementing effective prevention measures and appropriate case management strategies in this environment. To improve the management of patients in large Sd1 outbreaks with limited resources, we devised a clinical classification of cases according to the risk of dying.