The epidemiology of Crimean-Congo hemorrhagic fever in Turkey, 2002-2007

Abstract

Background: Crimean-Congo hemorrhagic fever (CCHF) is a serious disease caused by the CCHF virus of the Bunyaviridae family. The disease has been reported in 30 countries in Africa, Asia, Eastern Europe, and the Middle East. It has been present in Turkey since 2002. In this study we present and discuss the epidemiological features, clinical and laboratory findings, treatment, and outcome of cases diagnosed with CCHF between 2002 and 2007 from the surveillance results of the Turkish Ministry of Health (MoH).

Methods: According to the surveillance system of the MoH, data for patients with clinical, laboratory, and epidemiological findings compatible with CCHF are recorded on case reporting forms. These forms are submitted to the General Directorate of Primary Health Care of the MoH by the city health directorates. All the surveillance data regarding CCHF were recorded on a database (SSPS 11.0) established in the Communicable Diseases Department of the MoH.

Results: According to the surveillance reports of the Turkish MoH, between 2002 and 2007, 1820 CCHF cases occurred (150 in 2002-2003, 249 in 2004, 266 in 2005, 438 in 2006, and 717 in 2007). The crude fatality rate was calculated to be 5% (92/1820). Two thirds of the CCHF cases were reported from five cities located in the Mid-Eastern Anatolia region; 69.4% of the cases were from rural areas. The male to female ratio was 1.13:1. Of all the reported cases, 68.9% had a history of tick-bite or tick contact and 84.1% were seen in the months of May, June, and July. Of 1820 CCHF cases, three (0.16%) were nosocomial infections.

Conclusions: CCHF appears to be a seasonal problem in the Mid-Eastern Anatolia region of Turkey. The possible risk factors for transmission and the clinical and laboratory findings of patients with a diagnosis of CCHF were found to be similar to those reported in the literature. The mean fatality rate for Turkey is lower than the rate reported for other series from other parts of the world.