Dirofilariasis

Human dirofilariasis typically manifests as either subcutaneous nodules or lung parenchymal disease, in many cases asymptomatically. The zoonotic filariae of Dirofilaria immitis and Dirofilaria (Nochtiella) repens have become increasingly recognized worldwide as inadvertent human pathogens,The dirofilarial life cycle, like that of all filarial and helminthic nematodes, consists of 5 developmental or larval stages in a vertebral host, an arthropod (mosquito) intermediate host, and a vector. Adult female worms produce thousands of first-stage larvae (microfilariae), which are ingested by a feeding insect vector. After ingestion, microfilariae eventually transform into third-stage larvae within the mosquito and migrate from the abdomen to the thorax and finally to the salivary glands, allowing transmission of infection to a new host upon a subsequent blood meal. with the usual hosts of these infective nematodes being domestic and wild carnivores.