Parasitic Infections of the Lung

¹ Chairman, Division of Medicine, Professor of Preventive Medicine, The Bowman Gray School of Medicine.

Although diseases of the respiratory tract due to infection by protozoan and metazoan parasites are not common in the conventional practice of medicine they have been encountered with sufficient frequency to merit consideration. It is probable that such conditions will be recognized more frequently in the future since several million men and women have had overseas service in areas of the world where some of the more important parasites are heavily endemic. The increasing interest of American business in foreign countries implies a constant flow of personnel to these regions, and foreigners are coming to the United States in increasing numbers from many parts of the world. These individuals therefore constitute a very large number of persons who potentially at least may have been exposed to infections which are not endemic in this country.

Investigation of clinical problems in such a group necessitates the application of geographical medicine—the interpretation of clinical data in the light of the travels of the particular patient and the geographic distribution of particular parasites. The infections, therefore, may be grouped from this point of view. Amebiasis, malaria, ascariasis, strongyloidiasis and cysticercosis may be acquired in the United States as well as in many other parts of the world. On the other hand paragonimiasis and schistosomiasis cannot be acquired on the North American continent, and endemic hydatid disease is so rare in this area as to be virtually nonexistent.

In the consideration of future medical problems among veterans it is of the utmost importance that these implications of geographical medicine be given due consideration. It is equally important to recognize the fact that there may be a prolonged latent period, in some instances years in duration, between infection and the development of the resultant clinical syndrome.