Epidemiological Survey of Crimean-Congo Hemorrhagic Fever (CCHF), a Fatal Infectious Disease in Khuzestan Province, Southwest Iran, During 1999 - 2015

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) is an arboviral zoonotic disease transmitted to humans mainly through the bite of blood-sucking Ixodidae ticks and also via contact with the blood and tissues of infected livestock. OBJECTIVES: This study is a retrospective descriptive survey based on data collected from the health center of Khuzestan province, Iran, during 1999 - 2015. PATIENTS AND METHODS: Patients with symptoms of severe headache, high fever, and bleeding were evaluated. Laboratory tests and serological or molecular assays were used to detect probable and confirmed cases, respectively. The epidemiological parameters of this study were analyzed on the basis of probable cases. RESULTS: A total of 42 patients were diagnosed as probable cases, and 17 of these (42.5%) were confirmed serologically. Two peaks of the disease occurred in Khuzestan province, in 2003 and 2010, with seven cases each of those years, leading to the deaths of five and two patients, respectively. Men and women comprised 57.1% and 42.9% of the patients, respectively. Of all probable cases, 64.3% were from urban areas and 35.7% were from rural areas. The age groups of 10 - 19 and 20 - 29 years, with a frequency of 26.2% in each group, were exposed to the most infections. Farmers and housewives were the highest at-risk occupational groups with a frequency of 28.6% and 26%, respectively. Fever, bleeding, and thrombocytopenia were reported in 95% of the patients, and the case-fatality ratio was calculated to be 28.6% (12 of 42 cases). CONCLUSIONS: Continuous training is necessary to improve the knowledge and awareness of the highest-risk groups with regard to the transmission modes, prevention, symptoms, and treatment of this disease.