Some aspects of the epidemiology, clinical manifestations, and diagnosis of human dirofilariasis caused by Dirofilaria repens.
In recent years, zoonotic filariae Dirofilaria immitis and Dirofilaria (Nochtiella) repens are gaining popularity as incidental human parasitic pathogens. The usual hosts for these nematodes are domestic and wild carnivorous animals. The medical significance of human dirofilariasis is due to frequent misdiagnosis as malignancy and in many cases diagnosis is made after invasive surgical procedures. The aim of this study was to ascertain the geographical distribution and clinical manifestations of a relatively rare among people zoonotic disease such as dirofilariasis, whose epidemiological features depends on prevalence of the parasite among usual hosts, presence of suitable vector, and human activities favoring exposure. Data for a 39-year period were analyzed, during which, in Bulgaria, were recorded 47 cases of human dirofilariasis with various organ localizations. Morphological methods were also used for species identification of Dirofilaria (N.) repens and serological diagnostic tests for filariasis. Some epidemiological parameters such as annual incidence, prevalence for different geographic areas in Bulgaria, distribution by gender (28 females and 19 males) and age (from 19 to 77 years of age) of the diseased were identified, and aspects of the clinical manifestations, diagnosis, and treatment of the disease were discussed. Comparison was made between the number of cases in Bulgaria and those in other European countries. Although the climatic and faunal conditions in Bulgaria are favorable for disease transmission between animal reservoir hosts and humans, the diagnosis of dirofilariasis is often omitted.