Background Coccidioides spp. an endemic dimorphic fungi is present in the north and south of Mexico. The Ministry of Health report in Mexico between 1988 and 1994 0.5 to 1.3 cases per 100,000 habitants. The clinical picture ranges from asymptomatic to disseminated disease. They should be classified according to the EORTC/MSG criteria in proven and probable disease, in Mexico there is no study about clinical characteristics and outcomes in hospitalized patients according to this classification.ObjectiveEvaluate the clinical characteristics and outcomes in hospitalized patients with proven and probable coccidioidomycosis according to EORTC/MSG criteria.Methods The National Institute of Respiratory Diseases in Mexico City is the national referral center for complicated pulmonary infectious diseases. This retrospective cohort from 2010 to 2016 included proven and probable Coccidioidomycosis hospitalized patients classified according to EORTC/MSG 2008 criteria. We collected data about clinical characteristics on admission and outcomes.ResultsFifty-seven patients were evaluated, 26 proven and 31 probable, mean age was 43 years. The proven group was associated with DM2 OR 2.8 (IC95% 1.1–7, P = 0.014) and hemoptysis OR 3.2 (IC95% 1.1–9, P = 0.013), the probable group with dyspnea OR 3.5 (IC 95% 1.08–11, P = 0.024), high respiratory rate 27.2 ± 13 vs. 22 ± 3.3 (P = 0.05), and low O2 saturation 83.97% ± 11.1 vs. 91.8% ± 4.31 (P < 0.001). In the proven group, multiple cavities in CT scan were more frequent. The probable had association with severe ARDS (P 0.011), use of invasive mechanical ventilation (P 0.025), and increase in mortality 14% vs. 1.8% OR 1.2 (IC95% 1.03–1.6 P = 0.025) with lower survival in Kaplan–Meier (P < 0.02). In the proven group, there was more disseminated disease (P <0.001), HIV was associated with lower survival (P <0.001) and they received more days of antifungal treatment 109.5 ± 127 vs. 59.8 ± 93 days. Amphotericin B was the most prescribed in both groups.Conclusion At present, we do not use the EORTC/MSG criteria due to lack of tests in our country, in this study the probable group referred usually from community centers had worse outcome and clinical characteristics, that is why we cannot underestimate this group of patients. We need to have better diagnostic tests in order to identify promptly these patients and avoid a late disease presentation.Disclosures All authors: No reported disclosures.