In HIV infected individual , Gram stain of lung aspirate shows yeast like morphology. All of the following are the most likely diagnosis except –
**Core Concept**
In HIV-infected individuals, the compromised immune system increases the susceptibility to opportunistic infections, including fungal pathogens that can cause respiratory infections.
**Why the Correct Answer is Right**
The presence of yeast-like morphology in the lung aspirate suggests a fungal infection. In HIV-infected individuals, the most likely diagnosis is Pneumocystis jirovecii pneumonia (PCP), caused by the fungus Pneumocystis jirovecii. This fungus is a common opportunistic pathogen in immunocompromised patients, particularly those with HIV/AIDS. PCP typically presents with symptoms such as cough, dyspnea, and hypoxemia.
**Why Each Wrong Option is Incorrect**
**Option A:** Histoplasmosis - This fungal infection can also present with respiratory symptoms, but it typically shows a more typical yeast-like morphology with narrow-based budding, not yeast-like morphology.
**Option B:** Candida pneumonia - While Candida species can cause respiratory infections, they are not typically associated with yeast-like morphology in lung aspirates.
**Option C:** Aspergillosis - This fungal infection can cause respiratory symptoms, but it typically shows hyphae or septate hyphae, not yeast-like morphology.
**Clinical Pearl / High-Yield Fact**
PCP is a classic opportunistic infection in HIV-infected individuals, and its diagnosis is often made based on clinical presentation and radiographic findings, as well as the presence of yeast-like morphology in respiratory specimens.
**Correct Answer: C. Aspergillosis. Aspergillosis is caused by Aspergillus species, which typically shows hyphae or septate hyphae, not yeast-like morphology.**