This is an observational study in 1,000 individuals aged 14 years or older, diagnosed with Community Acquired Pneumonia (CAP) who meet all eligibility criteria in Coccidioides endemic regions. This study is designed to provide data on the prevalence of primary pulmonary coccidioidomycosis among persons presenting with CAP in endemic regions. Among individuals diagnosed with primary pulmonary coccidioidomycosis, we aim to describe the clinical course, predictors of the clinical course and compare the response to prescribed antifungal therapy versus no antifungal therapy. The hypothesis for patients with primary pulmonary coccidioidomycosis is that early treatment with antifungal therapy is effective in reducing the frequency, severity and associated adverse outcomes of infection with recently acquired coccidioidomycosis pneumonia. The study will be divided into Step 1 and Step 2. Step 1 will identify which subjects have primary pulmonary coccidioidomycosis based on the case definition for the protocol and Step 2 will follow subjects who meet the case definition and will observe their clinical management and clinical outcomes. Subjects will enroll in Step 1 within 28 days of symptom onset. In Step 1, blood work for serologic determination of Coccidioides infection will be drawn at the time of enrollment (Day 1), and again 21 days later if a positive result is not reported at Day 1. Subjects with a diagnosis of primary pulmonary coccidioidomycosis confirmed by positive serologic testing during Step 1 will enter Step 2 within 14 days of a positive test result; subjects with a negative serology at Day 1 and Day 22 will not be followed further. Subjects referred to the study after a diagnosis of primary pulmonary coccidioidomycosis confirmed by positive serologic testing will also be allowed to enter Step 2 directly within 14 days of a positive test result and within 7 weeks of symptom onset, as long as they meet study enrollment criteria. The primary objective is to assess the prevalence of primary pulmonary coccidioidomycosis (PPC) in subjects with community acquired pneumonia (CAP) in coccidioidomycosis endemic areas.