Diagnosis and Clinical Importance of Human Dirofilariosis

The dog parasites Dirofilaria immitis (D. immitis) and Dirofilaria repens (D. repens), well known as zoonotic agents, can infect humans with immature forms. Human dirofilarioses in many asymptomatic patients are undiagnosed because physicians do not consider this etiology, and because it is impossible to apply non-invasive diagnostic procedures. So far, in Serbia, about 28 cases with parasite determination of human dirofilariosis have been reported. It is possible that the majority of cases are undiagnosed, considering the fact that systemic investigation, at the territory of our country, shows that there are endemic zones for dirofilarioses in dogs. Clinical spectrum of human dirofilariosis includes superficial infections (subcutaneous, subconjuntival), which are easy to detect, and pulmonary nodules. Most pulmonary cases are asymptomatic infections, especially in cases of transitory or residual small calcified nodules. In humans, parasites do not usually reach the adult stage and micro-filariae are absent. The scheme that D. repens enables subcutaneous infections and D. immitis pulmonary infections is an oversimplification.