Antibodies to Rift Valley fever virus in Swedish U.N. soldiers in Egypt and the Sinai.

Swedish United Nations Emergency Forces soldiers serving in Egypt and the Sinai peninsula were serologically tested for hemagglutination-inhibiting antibodies to Rift Valley fever (RVF) virus. Eight of 170 were positive. RVF has not been reported outside Africa, and a survey of 500 Swedish soldiers who had not served in the Middle East or Africa revealed no RVF virus antibodies. There were extensive RVF epidemics in Egypt in 1977 and 1978, and it is considered that these serologically positive soldiers contracted RVF disease while on duty in the Middle East.