Increasing risks of human dirofilariasis in travelers

Abstract

Background: Dirofilariasis is a zoonotic nematode infection of domestic and wild carnivores that can be transmitted to man by infected mosquitoes.

Methods: Internet search engines were queried with the key words to examine case reports, series, and descriptive analyses of animal and human dirofilariasis to meet the objectives of this review to describe the increasing prevalence of animal and human dirofilariasis worldwide; to resolve misconceptions regarding the pathophysiology and outcomes of animal versus human dirofilariasis; and to recommend new strategies for the diagnosis, management, and prevention of human dirofilariasis in travelers.

Results: Descriptive epidemiological studies in the United States and Europe have now established dirofilariasis as an emergent parasitic disease of dogs and man. Global warming has extended the mosquito-vector-borne transmission cycles, enzootic distributions, and canine microfilarial prevalences of the disease to non-endemic regions.

Conclusions: Travel medicine clinicians must remain vigilant regarding the possibilities of human pulmonary dirofilariasis when solitary "coin lesions" appear on screening chest X-rays or abdominal neuroimaging studies in asymptomatic patients without peripheral hypereosinophilia. The least invasive diagnostic methods are recommended. Future investigations should focus on conducting active epidemiological surveillance for dirofilariasis in humans and animals; on improving canine dirofilarial chemoprophylaxis; and on developing new, rapid molecular methods for diagnosing and differentiating human dirofilarial infections.