Seroprevalence and entomological study on chikungunya virus at the Croatian littoral

During 2011-2012, a total of 1008 serum samples from randomly selected inhabitants of seven Croatian counties located on the Adriatic Coast were tested for the presence of chikungunya virus (CHIKV) IgG antibodies using indirect immunofluorescence assay. Nine participants (0.9%) from four counties were found to be seropositive to CHIKV. Seroprevalence varied from 0.5% to 1.8% between counties. Additionally, a total of 3,699 mosquitoes were captured in 126 localities from August 16 to September 24, 2011. Three mosquito species were found: Ae. albopictus (3010/81.4%), Cx. pipiens (688/18.6%) and only one specimen of the Cs. longiareolata. Female mosquitoes (N = 1,748) were pooled. All pools tested negative for CHIKV RNA using a real-time RT-PCR.