Seroprevalence of Crimean-Congo Hemorrhagic Fever Virus Infection in Humans and Domestic Ruminants, Democratic Republic of the Congo.

Crimean-Congo hemorrhagic fever virus (CCHFV) was first isolated in the Democratic Republic of the Congo (DRC) in 1956. To date, only 3 sporadic human cases have been reported in the DRC, and data on CCHFV infection in livestock, which are key players in transmission, are scant. We conducted a cross-sectional seroepidemiological study on archived human and animal serum samples collected from 25 provinces across the DRC. Samples were tested using an ELISA detecting CCHFV nucleoprotein-specific antibodies. The seroprevalence of CCHFV infection in humans was 4.4% (55/1,239) and in domestic ruminants was 28.9% (322/1,114). High seroprevalences tended to correlate with increased age, specific climate conditions (e.g., tropical monsoon) and vegetation (e.g., mountain savanna) types, and higher elevation (>600 m). Our findings suggest that CCHFV actively circulates in animals and sporadically transmits to humans in the DRC, highlighting the need for continued surveillance of CCHFV infection.