Crimean-Congo hemorrhagic fever in South Africa

Abstract

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonosis which occurs widely in Africa, eastern Europe, and Asia within the distribution range of ticks of the genus Hyalomma. A disease named Crimean hemorrhagic fever was first observed in the Crimean Peninsula in 1944, and the causative agent which was isolated in 1967, was found to be identical to Congo virus isolated in 1956 from a febrile child in the Belgian Congo (now Democratic Republic of Congo - DRC); hence the names Crimean and Congo are used in combination [8, 10, 11, 49]. By 1979, the virus was known to occur in many countries in eastern Europe and Asia, but the furthest south that evidence of infection had been found in Africa was the detection of antibodies in cattle sera in Tanzania [21]. Case fatality rates recorded in Eastern Europe and Asia varied from 15% to 40%, but in Africa only 1/15 known human infections had been fatal. Nevertheless, suggestions that African strains of the virus were less pathogenic for humans than Eurasian strains were rejected on the grounds that observations had been too limited [21].