[Paracoccidioides brasiliensis infection in a subtropical region with important environmental changes]

Paracoccidioidomycosis is a systemic mycoses caused by Paracoccidioides brasiliensis, a dimorphic fungus that infects man through respiratory ducts. It has been accepted that its ecological niche is located in the soil and plants of subtropical forests of Latin America. The Province of Corrientes is located at the northeastern border of Argentina, in a subtropical area where important environmental modifications have been introduced in the last decade as consequence of damming the Paranà river at Yacyretà, one of the biggest hydroelectric dams in the world. Since there are no data on human infection provoqued by this fungal agent in Corrientes, the purpose of this study was to obtain information at present time about infection indexes and to assess if environmental changes introduced in the area could impact on the epidemiology of the disease. Skin tests with paracoccidioidin and histoplasmin were performed on 455 persons of both sexes, from 1 to 73 years of age, who live permanently in the area and voluntarily accepted to be included in the study. Both antigens were employed at the same time in order to evaluate crossed type reactions. Of the 455 persons, 52 (39 males-13 females) were reactive to paracoccidioidin (11.4%), with an increasing prevalence with age. According to previous data, these results would indicate an increase in the index of human infection by P. brasiliensis, and this may be related to the important changes in climatic and environmental conditions introduced in the area in the last years.