Mycological diagnosis of paracoccidioidomycosis in a hospital from a nonendemic area: classical and molecular methods

Introduction: Paracoccidioidomycosis is a systemic mycosis endemic in Latin America. Climate change and host migration emphasize the need to optimize this infection diagnosis.

Objective: To evaluate the implementation of Paracoccidioides spp. DNA detection in the mycological diagnosis of patients with suspected paracoccidioidomycosis.

Materials and methods: It is a retrospective study with laboratory data from patients with clinical suspicion of paracoccidioidomycosis, who consulted a university hospital from a non-endemic area.

Results: We analyzed the laboratory results of samples from 19 patients with suspected paracoccidioidomycosis. Seventeen out of 19 patients were born in or had visited an endemic area in Latin America. Fourteen adult male patients were confirmed to have paracoccidioidomycosis by conventional diagnosis: the direct examination was positive in 12 samples while fungal growth was found only in 4. Anti-Paracoccidioides spp. antibodies were detected in 10 patients, 8 of them with proven paracoccidioidomycosis. Nested PCR for Paracoccidioides spp. detection was performed on clinical samples from 14 patients, and positive results were obtained for 9 out of 10 patients with the conventional diagnosis of paracoccidioidomycosis.

Conclusions: The incorporation of molecular techniques to detect Paracoccidioides spp. DNA complements the conventional diagnosis of paracoccidioidomycosis. This tool allows the prescription of antifungal treatment in those cases where the fungus is not observed in the clinical samples.