Diagnosis of Measles Pneumonia from Bronchoalveolar Lavage Fluid by Reverse-Transcriptase Polymerase Chain Reaction: Case Report.

A 24-year-old male contracted measles during treatment with prednisolone for bronchial asthma and eosinophilic pneumonia. Five days after the appearance of skin eruptions, infiltration shadows were detected in the hilum of the left lung on a chest X-ray and a chest computed tomography revealed diffuse macular and infiltration shadows in both lungs and in the left S6 segment, respectively. Pneumonia complicating measles may be caused by either the measles virus itself or by a secondary bacterial infection. Since this patient had been treated with prednisolone, pneumonia caused by a pathogen other than bacteria, or recurrence of eosinophilic pneumonia were suspected, and bronchoalveolar lavage was performed. Culture of the bronchoalveolar lavage fluid (BALF) was negative for bacteria, acid-fast bacilli, and mycetes, and polymerase chain reaction (PCR) analysis did not detect cytomegalovirus, but reverse transcriptase PCR did detect the measles virus. There were increased lymphocytes in the BALF with a significantly reduced CD4/CD8 ratio. Histological findings revealed alveolitis. Based on conventional diagnostic criteria, pneumonia due to the measles virus was confirmed. Since the criteria of pneumonia due to measles virus includes histological, serological and bacteriological studies which require an extended period of time, RT-PCR using BALF may be useful for the rapid diagnosis of measles pneumonia.