Dirofilaria repens infection as a cause of intensive peripheral microfilariemia in a Polish patient: process description and cases review

Abstract

Dirofilariasis is a parasitic disease of dogs and other carnivores transmitted mainly by the mosquitoes of the genera Culex, Aedes, Anopheles. Full life cycle of the Dirofilaria nematodes in humans is extremely rarely observed, usually lacking species determination at the molecular level. We report fully documented unusual clinical manifestation of subcutaneous dirofilariasis with intensive microfilariemia in peripheral blood revealed by the Knott's concentration technique. The identification of the Dirofilaria repens nematode was based on typical morphological findings for adult gravid female nematode found in the histopathological preparations. The morphology of microfilariae obtained from patient's peripheral blood was also typical for D. repens. The final identification was confirmed by the molecular analysis of microfilariae collected from the blood.

Human dirofilariasis in Bulgaria between 2009 and 2018

“…In literature, recommendations are made to measure the total IgE level and eosinophilia if dirofilariasis is suspected (Kłudkowska et al, 2018; Ermakova et al, 2017). In all 18 patients, we analysed complete blood count, but only in the patient with a living larva extirpated from the oral cavity, we found elevated eosinophil levels reaching 31 %.…”

“…Microfilaraemic dogs are the most important reservoir of infection (Genchi & Kramer, 2017). In humans, the larvae rarely reach sexual maturity, and most often migrate into the subcutaneous tissue, rarely localizing in an organ (Poppert et al, 2009; Kłudkowska et al, 2018). In the past ten years, D. repens has been described as a typical example of an emerging pathogen, since it is affecting more and more regions in Europe.…”

Usual or unusual presentations of Dirofilaria repens in two sibling dogs: a case report

“…In a case of subcutaneous localization of D. repens with concurrent microfilaremia by D. immitis , a moderate eosinophilia (2.7·10 9 /L) was observed (Giori et al 2010 ). In human cases of dirofilariasis, eosinophilia is rarely observed (Joseph et al 2011 , Fontanelli-Sulekova et al 2016, Ermakova et al 2017 , Kłudkowska et al 2018 ). In a study on 266 patients with D. repens infection, peripheral blood eosinophilia was detected in 16.4% of cases and only in those patients showing migrating worms (Ermakova et al 2017 ).…”

“…In a study on 266 patients with D. repens infection, peripheral blood eosinophilia was detected in 16.4% of cases and only in those patients showing migrating worms (Ermakova et al 2017 ). Dirofilaria infection should be considered in the differential diagnosis of eosinophilia of unknown etiology (Kłudkowska et al 2018 ). In dogs, parasitic infections, particularly by ectoparasites or parasite with a migrating tissue phase (e.g., D. immitis , A. vasorum ), are the most common cause of eosinophilia.…”

Case Studies of Severe Microfilaremia in Four Dogs Naturally Infected With Dirofilaria repens as the Primary Disease or a Disease Complicating Factor

“…Humans are considered a dead-end, accidental host for D. repens, but a growing body of case reports suggests that humans may instead be a dual facultative host in which the parasite can achieve maturity and release microfilariae (Mf) into the bloodstream (2,3). Recently, there has been documentation in Poland of a human patient having microfilaremia (360 Mf/ml) (4). Furthermore, an ocular mucosa associated lymphoid tissue lymphoma (MALT) has been reported in a human patient in Poland as a possible consequence of dirofilariosis (5).…”