Crimean-Congo hemorrhagic fever: experience at a tertiary care hospital in Karachi, Pakistan.

Crimean-Congo hemorrhagic fever (CCHF) is endemic in certain rural areas of Pakistan. Since the discovery of CCHF virus (CCHFV) in the country in the 1960s, there have been 13 outbreaks in addition to sporadic cases. An outbreak during 2000 coincided with the movement of sacrificial animals from rural to urban areas for the festival of Eid-ul-Azha. Diagnosis was suspected in patients with fever and thrombocytopenia, and confirmed retrospectively using immunoassays and reverse transcriptase-PCR. Patients were given platelet, plasma and red cell infusions. Management varied due to unfamiliarity with the condition and its treatment, lack of availability of diagnostic laboratory tests and limited supply of ribavirin. Inadequate antiviral treatment and late presentation probably contributed to the death of six of the eight patients. Renal failure, disseminated intravascular coagulation and persistent high-grade fever were associated with mortality. The nucleotide sequence of the small genomic RNA segment of the CCHFV isolated in this outbreak was found to be very closely related to the CCHFV strains previously isolated in Pakistan.