Canine Dirofilaria infections in Lithuania

Abstract

Dirofilariasis is a group of zoonotic parasites infection caused by species of the genus Dirofilaria and transmitted by mosquitoes. Dirofilaria infections in Europe caused by D. immitis and D. repens. Parasites can infect wild and domestic canines, felines, and humans. Dogs are the main reservoirs. Climatic changes and an increase in the movement of reservoirs have an impact on the spread of dirofilariasis into previously non-endemic areas. However, the data on this zoonotic infection in Lithuania are still scare. Blood samples of 2180 randomly selected dogs presented in small animal clinic during 2014-2015 were investigated for filarial parasites. The species of the microfilariae and adult worm were determined on the basis of their morphometrical characteristics and the Diff-quick staining technique applied to blood smears and using Modified Knott’s test. For accurate identification of the filarial species we used PCR with panfilarial primers that amplify fragments of ITS2 region of rDNA from six different filariae species and species specific primers for amplification of COI gene of D. repens. Microfilariae were detected in blood smears of 42 (1.6%) dogs, adult worm were found in subcutaneous tissue from 4 dogs. Sequence analysis confirmed D. repens in all of investigated samples. This is the first detection of D. repens in Lithuania.