Seroepidemiological Study of Canine and Human Dirofilariasis in the Endemic Region of Northern Serbia

Abstract

Dirofilariasis is a vector-borne zoonotic disease caused mainly by <i>Dirofilaria immitis</i> and <i>Dirofilaria repens</i> that affect dogs and humans all over the world. Serbia is considered an endemic country to both forms of dirofilariasis, although most of the population is concentrated in the north of the country. The aims of this study were to show the prevalence of <i>D. immitis</i> and <i>D. repens</i> in dogs and the seroprevalence in humans compared to previous studies in Northern Serbia. In total, 346 dog sera samples and 265 human samples were analyzed. Dog blood samples were analyzed using the modified Knott's method to check whether there were <i>Dirofilaria</i> spp. microfilariae and serum samples were checked by a commercial <i>D. immitis</i> antigen test. Human serum samples were analyzed with a non-commercial ELISA for detection of specific anti-<i>D. immitis</i>, anti-<i>D. repens</i>, and anti-<i>Wolbachia</i> IgG antibodies, and confirmed by western blotting. The overall prevalence for <i>Dirofilaria</i> spp. in dogs was 29.19%. The overall prevalence for <i>D. immitis</i> was 26.30%. The percentages of <i>D. immitis</i> and <i>D. repens</i> microfilaremia in dogs were 25.72 and 1.45%, respectively, while <i>D. immitis</i>./<i>D. repens</i> microfilaremia co-infections were also 1.45%. The overall seroprevalence for <i>Dirofilaria</i> spp. in humans was 3.77%. The overall seroprevalence for <i>D. immitis</i> was 1.51, 1.13% for <i>D. repens</i>, and for <i>D. immitis</i>/<i>D. repens</i> co-infections was 1.13%. The results indicate that <i>D. immitis</i> and <i>D. repens</i> are present in dogs and humans in the province of Vojvodina, in the northern part of Serbia. It is most likely associated with the presence of many rivers, the climate, and presence of mosquitoes in the area, so there could be a real public health risk.