Objective: To detect lung mycosis (Paracoccidioides brasiliensis, Aspergillus sp., and Histoplasma capsulatum) with chronic respiratory disease symptoms (Huanuco and San Martin departments forest). Design: Cross-sectional study. Setting: Peru's Alto Huallaga . Patients: Study done in six districts' (Rupa Rupa, Tocache, Uchiza, Santa Lucia, Aucayacu and Puerto Inca - Sungaro) subjects with diagnosis of chronic respiratory disease, three or more episodes of bronchitis per year and/or cough for over three months in whom pulmonary tuberculosis was screened by direct baciloscopy. Interventions: Each subject had a clinical epidemiological card filled and 10 mL of blood was collected for immunodiffusion test for Histoplasma capsulatum, Paraccocidiodes brasiliensis, and Aspergilus sp, between April and September 2004. Main outcome mesasures: Mycosis seroprevalence, including Histoplasma capsulat...