Cercopithifilaria species in dogs and ticks from Greece

Filarioids of the genus Cercopithifilaria (Spirurida, Onchocercidae) are parasites of wild and domestic animals in tropical and subtropical regions being transmitted by ixodid ticks. Though this filarioid species have been studied in canine and tick populations in Europe, data on their species diversity and geographical distribution in Greece is scant. Thus, the aims of this study were to investigate the presence of Cercopithifilaria spp. in dogs and ticks across Greece and to assess the possible risk factors. A total of 500 skin biopsies were collected from dogs, while 508 ticks were collected from 180 infested animals and examined. Sediments from skin biopsies were microscopically screened for detection of dermal microfilaria (mfs). Skin samples (n = 115) and tick specimens (n = 153) were molecularly subjected by PCR. Overall, 70 samples (14%) scored positive for mfs. Specifically, 68 samples (13.6%) were positive for Cercopithifilaria bainae and two (0.4%) were co-infected with C. bainae and Cercopithifilaria sp. II. Molecular analyses revealed that all sequences obtained belong to C. bainae. Haplotype I was the most frequent (92.6%), followed by haplotype XVIII (3%) and haplotypes II and IX (1.5%). Three new haplotypes of C. bainae, named XIX, XX, and XXI, were also identified. Among the risk factors examined, habitat, dog use, body weight, tick infestation history, and the use of acaricides were associated with the presence of C. bainae. The estimated prevalence of Cercopithifilaria spp. demonstrates that these filarioids are common in dogs and ticks in Greece. Finally, the identification of 7 haplotypes for C. bainae confirms their genetic variability.