Multiple viral infections in the immunocompromised host: recognition and interpretation

During the past decade, diagnostic virology has become an integral part of patient management. Concurrent infection with multiple viruses occurs in both the healthy and immunocompromised host. Many common viruses result in latent infection with the potential for reactivation throughout the life of the host. Superimposed on this are transient infections with yet other viruses.

To review multiple viral infections in immunocompromised hosts, focusing on laboratory recognition and interpretation of results.

A review of the literature, with case examples from the author's laboratory.

Viral infections are more likely to cause morbidity and mortality in immunodeficient hosts, and early recognition and treatment may be lifesaving. To detect two or more viruses shed concurrently from the same body site requires the use of multiple test modalities, which are now available in many clinical laboratories. Establishing the significance of a virus isolate is a complex process. Knowledge of the specimen source, virus quantitation and characteristics of the patient are helpful. Careful evaluation of the patient's clinical findings together with other laboratory test results, including histopathology, X-rays and the detection of other microorganisms, is also essential.

The recognition and interpretation of multiple virus infections requires heightened awareness as well as close cooperation and communication between the professionals in the laboratory and physicians at the bedside.