PULMONARY MANIFESTATIONS OF PARASITIC INFESTATIONS

Parasitic infestations in man may cause transient or permanent pulmonary lesions. The lesions occur during migration and evolution of the parasites, during parasitemia, or during the final habitat. These manifestations, though infrequent in Canadian medical practice, present difficulties in diagnosis. Life cycles, mode of entry, and migration of parasites in the human body are described and illustrative case histories presented. In this series, transient pulmonary changes were associated with Ascaris lumbricoides, Ankylostoma duodenale, filariasis, Giardia lamblia and Trichinella spiralis; permanent lesions were produced by Entameba histolytica and Tenia echinococcus. Other parasites which may produce pulmonary changes are Strongyloides stercoralis and several types of Filaria (transient); Schistosoma, Paragonimus westermani (permanent). A case of amebiasis is presented illustrating the latent stage of infestation which lasted several decades before the organism spread from bowel to para-aortic nodes, to the lumen of the inferior cava, thence to the radicles of the portal vein and lung.