Pulmonary Infarct Secondary to Dirofilaria Larvae

Abstract

<i>Dirofilaria</i>is the generic name for long filiform nematodes that commonly infect dogs and other mammals. In<i>Dirofilaria immitis</i>infection, the adult parasite lodges in the right ventricular cavity and/or the pulmonary arteries and gives rise to circulating microfilaria. Despite its frequency in domesticated dogs,<i>D immitis</i>infection is rare, and subcutaneous or orbital infections by other species of<i>Dirofilaria</i>are uncommon. Faust¹reviewed the literature in 1957 and found only 37 cases of human infection; only three were<i>D immitis</i>(heart worm) infection. All of the other cases involved orbital or subcutaneous tissues and were classified as<i>D conjunctivae</i>or<i>D repens</i>infections. Other instances of subcutaneous infection have been reported by Sams and Beck,²Jung and Harris,³and Lenth.⁴Dashiele⁵reported the first instance of human pulmonary involvement by recognizing larval dirofilariae in branches of the pulmonary artery within a "coin lesion." We