Nosocomial outbreak of viral hemorrhagic fever caused by Crimean Hemorrhagic fever-Congo virus in Pakistan, January 1976.

This paper describes the clinical, epidemiological, and laboratory investigations undertaken to isolate and identify the etiological agent of a nosocomial cluster of hemorrhagic fever cases due to Crimean hemorrhagic fever (CHR)-Congo virus. Since this virus is usually transmitted by ticks it was surprising that the index case, in a nomadic shepherd, occurred during the winter season when ticks are relatively inactive. These are the first cases of CHF-Congo virus found in humans in Pakistan. Investigations on other biological properties, particularly strain differences and virulence, are being continued at the Islamabad laboratory.