[Endemic fungal pathogens in a rural setting of Argentina: seroepidemiological study in dogs].

BACKGROUND

Three fungal species causing human disease, namely Paracoccidioides brasiliensis, Histoplasma capsulatum and Coccidioides sp., are endemic in different areas of Argentina. Rates of infection in domestic dogs have been used in other Latin American countries as indicators of the presence of these pathogens in a given area. We used such an approach to investigate the epidemiological relevance of paracoccidiodomycosis, histoplasmosis and coccidioidomycosis in our country.

AIM

To investigate the presence of P. brasiliensis, H. capsulatum and Coccidioides sp. in a rural area of Argentina called Interfluvio Teuco-Bermejito, located in Chaco province.

METHODS

We applied Western Blotting to determine the presence of specific antibodies in sera from 89 domestic dogs inhabiting the area. Antibodies against the following extra-cellular fungal antigens were investigated: gP43 of P. brasiliensis, H/M of H. capsulatum and 120, 82 and 48kDa antigen bands of Coccidioides sp.

RESULTS

Specific antibodies against H. capsulatum were found in 9/89 (10%) sera: 8 reacted against both H and M antigens and 1 only reacted against antigen M. Of these 9 sera, one showed additional anti-gp43 activity and another reacted against all the fungal antigens tested.

CONCLUSIONS

This is the first study using dog infection to assess the presence of endemic fungal pathogens in Argentina. Our results suggest that H. capsulatum is the main dimorphic fungal pathogen in the Interfluvio Teuco-Bermejito area. Therefore, the diagnosis of histoplasmosis should be taken into account in patients living in this geographic region who show pulmonary or mucocutaneous symptoms compatible with the disease.