On July 28, 2009, the World Health Organization was notified that 21 AMISOM soldiers in Mogadishu had become sick, and three had died, with acute peripheral edema, difficulty in breathing, palpitations, and fever. The WHO, together with the U.S. Center for Disease Control, AMISOM, and the Aga Khan University Hospital in Nairobi began an investigation. From April 26, 2009 to May 1, 2010, 241 AU soldiers had lower limb edema and at least one additional symptom; four patients died. At least 52 soldiers were airlifted to hospitals in Kenya and Uganda. Four of 31 hospitalized patients had right-sided heart failure with pulmonary hypertension. The illness was associated with exclusive consumption of food provided to troops (not eating locally acquired foods). Because the syndrome was clinically compatible with wet beriberi, thiamine was administered to affected soldiers, resulting in rapid and dramatic resolution.