Pneumocystis jiroveci pneumonia (PCP) misdiagnosed as pandemic influenza H1N1 in a renal transplant patient.

Respiratory infections are of particular concern in transplant patients. However, there is a significant overlap in the symptoms caused by different pathogens. Here, we report a case of Pneumocystis jiroveci pneumonia (PCP) in a renal transplant patient which was initially misdiagnosed as pandemic influenza H1N1. The patient did not improve under oseltamivir treatment and bronchoscopy was performed five days later after hospitalization. PCP was diagnosed by microscoping evaluation of bronchoalveolar lavage (BAL) fluid. Besides, BAL and serum of the patient yielded a large amount of 1,3-beta-D-glucan, a cellwall compotent of medically important mycoses including P. jiroveci. The patient was successfully treated with intravenous trimethoprim-sulfamethoxazole. Due to the lack of sensitivity of influenza case definitions, the attending physicians should be careful about alternative diagnoses particularly in transplant patients with severe respiratory infections.