Use of the polymerase chain reaction in the diagnosis of unsuspected herpes simplex viral pneumonia: report of a case.

A 30-year-old apparently immunocompetent woman presented with acute respiratory failure (acute respiratory distress syndrome). No etiologic agent was found, and she died 2 weeks later despite antibiotic therapy. Postmortem examination of the lungs showed diffuse organizing alveolar damage with superimposed focal necrotizing peribronchiolar pneumonia. Cultures obtained from lung tissue were negative for virus, fungi, and bacteria. Histopathologic and electron microscopic studies showed that the necrotizing changes were consistent with herpesvirus infection. With the use of a new diagnostic tool, the polymerase chain reaction, a specific diagnosis of herpes simplex virus pneumonia was made, and other viral agents were excluded. The polymerase chain reaction is a sensitive, specific, and rapid technique that may greatly facilitate establishing an infectious etiology in cases of pneumonia.