ABSTRACT
BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) is a viral disease with fatality rate up to 30%. Up to date, only one CCHF case has been reported in Greece, while a distinct virus strain (AP92) had been isolated in 1975 from ticks in Imathia prefecture, northern Greece. The aim of the present study was to estimate the CCHF virus (CCHFV) seroprevalence among humans residing in the prefecture of Imathia, and the neighboring prefecture of Pella, and to investigate the risk factors associated with the seropositivity. MATERIAL AND METHODS: A total of 277 persons randomly selected from the general population were tested for the presence of CCHFV IgG antibodies. Additional 51 persons belonging in groups with risk for acquisition of CCHFV infection (19 slaughterhouse workers and 32 hunters) were also tested. All participants filled in a questionnaire related to demographics and probable risk factors (e.g. occupation, former tick bite, animal contact). RESULTS: Six of the 277 (2.2%) persons were found to carry CCHFV IgG antibodies: 3 in Imathia and 3 in Pella prefecture, resulting in seroprevalence of 1.7% and 2.9%, respectively. History of tick bite, residence in a hilly territory and increased age were significantly associated with CCHFV seropositivity. None of the slaughterers was found IgG-positive, while CCHFV IgG antibodies were detected in a 67-year old hunter who reported agricultural activities and a former tick bite. CONCLUSIONS: A relatively low seroprevalence is observed in the area where the AP92 strain has been isolated, with tick bite being significantly associated with CCHFV seropositivity. Further studies in ticks in the area will show whether are they infected by the AP92 strain or other more pathogenic CCHFV strains and at which rate.
ABSTRACT
To estimate endemic areas for Crimean-Congo haemorrhagic fever (CCHF) in Greece, a country-wide seroepidemiological study was conducted, and 1611 human sera were prospectively collected along with data regarding possible risk factors for acquisition of infection, and tested for CCHF virus IgG antibodies by ELISA. The overall seroprevalence was 4.2%, with significant differences among prefectures, ranging from 0 to 27.5%. Multivariate analysis revealed that slaughtering and agricultural activities were significant risk factors for CCHFV seropositivity. The significantly high seroprevalence in specific prefectures, together with the extremely low number of CCHF cases, suggest that this phenomenon might be strain-related.
