Enterohaemorrhagic Escherichia coli in Central African Republic

A dysentery outbreak in the Central African Republic village of Zemio was diagnosed as "Shigella flexneri" by the Pasteur Institute in Bangui (IPB) in February 1996; 2 months later there was an outbreak of hemorrhagic colitis. 108 patients presented with bloody diarrhea; cramping abdominal pain fever nausea and vomiting were uncommon. The illness lasted between 5 days and 3 weeks (average 8 days). Antibiotics were ineffective. Four patients died and several developed hemolytic-uremic syndrome. Stool cultures done at IPB tested negative. PCR was used to detect enterohemorrhagic Shiga-like toxin (SLT) 1 and 2 the invasivity gene ipaH and the attaching and effacing gene eaeA. DNA fragments of 130 and 494 nucleotides corresponding to amplified SLT1 and eaeA were found in 80% of the specimens tested. No amplification was obtained for SLT2 or for ipaH in specimens collected during the second epidemic. These results suggest the presence of enterohemorrhagic Escherichia coli and the absence of Shigella. The number of reported cases of acute bloody diarrhea in infants and adults in Bangui has increased since 1996. E. coli O157:H7 was isolated from two fatal adult cases. Smoked zebu meat was suspected in several hospital cases (bloody diarrhea hemolytic anemia and renal insufficiency) in which non-fermenting sorbitol E. coli O157:H7 was not isolated. In two cases of acute diarrhea other serotypes of E. coli were indicated by retrospective PCR on stools which were positive for SLT1 and for eaeA and negative for invasivity. A study was conducted in Bangui on 290 cases (33 with bloody diarrhea) and 140 controls. Patients were not paired because of civil unrest in the city. The questionnaire included demographic and socioeconomic characteristics environmental factors and habitual food consumption. The major contributing factor was consumption of locally made meat pies (kanda) which were made with smoked zebu meat. Kanda is stored at ambient temperature often for days before it is sold in markets or along roads. Before 1996 E. coli was not reported as a cause of bloody diarrhea in the Central African Republic.