A normally healthy 9-year-old boy presents with a fever, cough, and lower respiratory symptoms (no upper respiratory tract symptoms). He has been ill for 4 days. His chest sounds are consistent with pneumonia, so a chest radiograph is obtained. The radiograph shows small, patchy infiltrates with hilar adenopathy. His blood smear shows small, nondescript yeast forms inside monocytic cells. What is the most likely causative agent?

Blood smear showing small, nondescript yeast forms inside monocytic cells is suggestive of Histoplasmosis The acute phase of histoplasmosis is characterized by non-specific respiratory symptoms, often cough or flu-like. Chest X-ray findings are normal in 40-70% of cases. Chronic histoplasmosis cases can resemble Tuberculosis Pneumocystis jiroveci infect m/c immunocompromised individuals. Coccidioides immitis also cause pulmonary infections but cant produce these x ray features. Sporotrichosis- cause subcutaneous skin lesion along lymphatics