The Laboratory Evaluation of Opportunistic Pulmonary Infections

15 March 1996 | Volume 124 Issue 6 | Pages 585-599

The patient population at risk for opportunistic pulmonary infections has increased during the last decade.The spectrum of organisms causing opportunistic infections has also grown. With an ever broader list of potential therapeutic options and a growing differential diagnosis, a specific diagnosis of the cause of pulmonary disease becomes more important. Recent microbiologic advances have helped to facilitate the laboratory diagnosis of some of these agents. Immunoassays are available for the detection of antigen in nasopharyngeal secretions (respiratory syncytial virus, influenza), in serum (Cryptococcus species), and in urine (Legionella or Histoplasma species). Rapid-culture techniques are available for the culture and detection of various viruses, including cytomegalovirus. Molecular probes can now assist in the rapid identification of Mycobacterium tuberculosis and some fungi. In the near future, polymerase chain reaction-based techniques may assist in the detection of Pneumocystis carinii and Legionella, Chlamydia, Mycoplasma, and mycobacteria species. An expeditious evaluation of pulmonary disease requires an understanding of the differential diagnosis of likely causes of pulmonary disease in specific immunosuppressed patient populations, an understanding of the most appropriate specimens to process for these diagnoses, and an understanding of the limitations (sensitivity and specificity) of these diagnostic tests. An understanding of the most appropriate specimens and tests in a given institution should allow for early, relatively specific treatment of many potentially life-threatening infections.

Author and Article Information

An updated, edited summary of a Combined Clinical Staff Conference held on 29 September 1994 at the National Institutes of Health, Bethesda, Maryland.
Authors who wish to cite a section of the conference and specifically indicate its author may use this example for the form of reference:
Gill VJ. Laboratory evaluation of specimens, pp 586-588. In: Shelhamer JH, moderator. The laboratory evaluation of opportunistic pulmonary infections. Ann Intern Med. 1996; 124:585-599.
Requests for Reprints: James H. Shelhamer, MD, Building 10, Room 7-D-43, National Institute of Health, Bethesda, MD 20892
Current Author Addresses: Drs. Shelhamer, Kovacs, Masur, and Ognibene: Critical Care Medicine Department, Clinical Center, Building 10, Room 7-D-43, National Institutes of Health, Bethesda, MD 20892.