A patient suffering from AIDS presents with history of dyspnea and non- productive cough x-ray shows bilateral perihilar opacities without pleural effusion and lymphadenopathy. Most probable etiological agent is :

Ans. is 'd' ie Pneumocystis jiroveci The x-ray picture of this patient is characteristic of Pneumocystis jiroveci pneumonia (PCP) Pneumocystis jiroveci It is the most common* opportunistic infection in AIDS patient approximately 60-80% of all patients with AIDS suffer at least one episode of PCP during their course of illness. Symptoms pt presents with a dry cough and shortness of breath accompanied by pyrexia. X-ray picture - X-ray appearance is normal early in the disease or may show bilateral diffuse infiltrates in the perihilar region This later rapidly progresses to involve the entire lung. Let's also see other options- Cytomegalic virus X-ray picture shows bilateral interstitial or reticulonodular infiltrates which begin in the periphery of the lower lobes and spread centrally and superiorly. CMV is also ruled out as it's not a common cause of Pneumonia in AIDS patient. It is the most common cause of pneumonia in renal transplant patient* Remember it is the most common cause of chorioretinitis in AIDS patient* Tuberculosis X-ray picture in early stages a typical pattern of upper lobe infiltrates and cavitation is seen, as tuberculosis in any other disease. X-ray picture in late stages primary tuberculosis * like the pattern is seen with diffuse interstitial or miliary infiltrates little or no cavitation* intrathoracic lymphadenopathy Kaposi's Sarcoma X-ray picture of pulmonary involvement Ill-defined nodules sometimes associated with pleural effusions and lymphadenopathy.