Clinical and laboratory features of human dirofilariasis in Russia

The article presents the results of the prospective study of 266 patients with dirofilariasis who received medical and diagnostic assistance in Rostov Scientific Research Institute of Microbiology and Parasitology in Rostov-on-Don, Russia from 2000 to 2016. We have assessed the features of the dynamics of epidemiology of this infection in several territories of the Russian Federation, depending on the social structure of patients. Immature females of dirofilaria were found most commonly in humans (82.9 ± 2.6%), the proportion of maturity females and adult males of worms respectively was 10.5 ± 2.1% and 0.9 ± 0.6%. All mature worms were localized inside a capsule. Peripheral blood eosinophilia was detected only in patients with the migration of helminths (19 of 116 persons – 16.4%). Blood samples of patients examined by the method of concentration in 3% acetic acid for detection of microfilariae, showed negative result in all patients. Our data are consistent with the opinion of KI Skriabin about that human as «dual facultative host» for dirofiliaria. It is rare that parasite in human body is able to develop to the imago stage (according to our observations – 11.4%). The immune response to invasion by dirofiliaria in human is manifested as dense connective tissue which forms a capsule. According to our study the rare cases (22) of detection the sexual mature D. repens (10.4%) were localized inside the capsule. Observations of patients with D. repens infection allowed concluding that human for this helminth is «a biological deadend».