Dirofilaria repens in dogs and humans in Lithuania

Abstract

Background: In Lithuania, the frst case of canine subcutaneous diroflariosis was recorded in 2010. Since then, an increasing number of cases of canine diroflariosis have been documented in diferent veterinary clinics throughout the country. Human diroflariosis was diagnosed in Lithuania for the frst time in September 2011. However, to the authors’ knowledge, there are no published data on the presence and prevalence of autochthonous diroflariosis in dogs and humans in the country. The present study provides information about the predominant species and prevalence of Diroflaria in dogs and describes the cases of human diroflariosis in Lithuania. It also outlines PCR detection of the bacterial endosymbiont Wolbachia that contributes to the infammatory features of flarioid infection. Results: A total of 2280 blood samples and six adult worms from pet and shelter dogs were collected in the central and eastern regions of Lithuania in 2013–2015. Based on their morphological appearance, morphometric measurements and molecular analysis, all the adult nematodes were identifed as Diroflaria repens. The diagnosis of microflariae in blood samples was based on blood smear analysis and Knott’s test. The PCR and sequence analysis of the ribosomal DNA ITS2 region and cox1 gene confrmed the presence of D. repens. Overall, 61 (2.7%) of the 2280 blood samples were found to be positive for the presence of D. repens. The infection rate of D. repens was signifcantly higher in shelter dogs (19.0%; 19/100) than in pet dogs (1.9%; 42/2180) (χ 2=100.039, df=1, P<0.0001). Forty-nine DNA samples of D. repens-infected dogs were tested for the presence of the bacterial endosymbiont Wolbachia and, of these, 40 samples (81.6%) were found to be positive. Three ocular and six subcutaneous cases of human diroflariosis were diagnosed in Lithuania in the period 2011–2018.[...]