Crimean-Congo hemorrhagic fever: seroprevalence and risk factors among humans in Achaia, western Greece

Abstract

Background: The Crimean-Congo hemorrhagic fever virus (CCHFV) presents a wide distribution, with the Balkan Peninsula being among the endemic regions. To date, only one CCHF case has been reported in Greece; however, based on seroprevalence data, there is evidence that CCHFV circulates in the country. Achaia is a prefecture in western Greece that has not previously been studied for CCHFV.

Objectives: The aim of this study was to estimate the seroprevalence of CCHFV in humans in Achaia Prefecture, Greece, and to assess possible factors playing a role in seropositivity.

Methods: A total of 207 serum samples from people of all age groups, from both urban and rural areas, were prospectively collected and tested for IgG antibodies against CCHFV.

Results: The overall seroprevalence was 3.4%, with significant differences among municipalities. An agro-pastoral occupation, contact with sheep and goats, former tick bite, increasing age, and living at an altitude of ≥400 m, on specific land cover types, were significantly associated with CCHFV seropositivity.

Conclusions: A relatively high seroprevalence was detected in a previously unstudied region of Greece, where CCHFV infection seems to occur mainly through tick bites. Further investigations are needed to identify the circulating CCHFV strains in Greece, in order to gain a better understanding of CCHFV ecology and epidemiology in the country.

Keywords: Crimean-Congo hemorrhagic fever; Epidemiology; Greece; Risk factors; Seroprevalence.