Dirofilaria repens: emergence of autochthonous human infections in the Czech Republic (case reports)

Jana Matějů,Kristýna Hrazdilová,Barbora Mitková,Víta Žampachová,Libuše Kolářová,Marta Chanová,David Modrý

doi:10.1186/s12879-016-1505-3

Abstract

BackgroundHuman dirofilariasis is a zoonotic infection that continues to spread to previously unaffected areas of Europe. In the South Moravian Region of the Czech Republic (CR), imported as well as autochthonous canine infections were recorded in the last decade, and parasite DNA was detected in mosquitoes of Aedes vexans. In the present paper, human Dirofilaria infections are reported from the country for the first time.Case presentationThe samples from five patients with suspected tissue helminthiases were investigated. In particular cases, nematodes were isolated from various tissues including skin of lower leg, soft tissues of finger, subcutaneous tissue of hypogastrium, lymph node and peritoneum. The diagnosis was based on light microscopic morphology and/or DNA analysis of the worms. In addition, ELISA examination of patients’ sera for anti-filaria IgG antibodies was performed.ConclusionsIn the CR, five cases of human dirofilariasis caused by Dirofilaria repens were recorded during 2010–2014 (species determination for three of them was confirmed besides morphological also by DNA analysis). At least, three of the cases were of autochthonous origin (the patients are Czech citizens residing in South Moravian Region who have never travelled abroad). The findings confirm the natural setting of D. repens in South Moravian Region of the CR. Dirofilariasis should be therefore considered as endemic in this area where it may represent a significant risk factor for public health.

Highlights

Human dirofilariasis is a zoonotic infection that continues to spread to previously unaffected areas of Europe
In the Czech Republic (CR), five cases of human dirofilariasis caused by Dirofilaria repens were recorded during 2010– 2014
The findings confirm the natural setting of D. repens in South Moravian Region of the CR

Summary

Introduction

Human dirofilariasis is a zoonotic infection that continues to spread to previously unaffected areas of Europe. Immune-mediated formation of nodules surrounding the larvae is the most frequent pathologic finding associated with the infection The former strict relation between particular Dirofilaria species and Matějů et al BMC Infectious Diseases (2016) 16:171 its tissue-specific residence has recently been reconsidered, since many of the cases have rather atypical locations [2]. Ocular and pulmonary dirofilariases are reported the most frequently with subcutaneous dirofilariasis being by far the major clinical presentation among human cases in Europe. It is characterized by formation of gradually growing and sometimes migrating erythematous nodules and it is mostly caused by D. repens [2]. It is responsible for the formation of pulmonary nodules surrounding the larvae entrapped in the arterial lumen [2] and for the disruption of the arterial wall due to worm penetration with subsequent development of focal necrosis [4]

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Discussion

Conclusion