Despite the availability of effective chemoprophylaxis, Pneumocystis carinii pneumonia (PCP) continues to be the most frequently diagnosed opportunistic infection among persons with advanced HIV disease. Preliminary studies in Los Angeles and in other locales suggest that delayed HIV diagnosis is an important factor in many persons who develop PCP. However, relatively little is known about other potential risk factors for PCP. In particular, it is currently not known whether most cases of PCP result from person-to-person transmission or from reactivation of latent infection. The answer to this question has important implications for infection control practices in hospitals and other residential care facilities that care for patients with HIV infection.
- To identify risk factors for PCP in persons with advanced HIV disease.
- To determine if there is epidemiologic support for the hypothesis that P. carinii is transmitted from person-to-person.
- To provide laboratory specimens to the Centers for Disease Control and Prevention (CDC) for further analysis to identify P. carinii strain variation and markers for antibiotic resistance.
The study is being done in Seattle-King County and Los Angeles County with oversight by the Centers for Disease Control and Prevention (CDC). A case-control study design is being employed in both counties. In Los Angeles, cases are recruited from Harbor-UCLA Medical Center, Cedar- Sinai Medical Center, and LAC-USC Medical Center using laboratory reports of culture-confirmed PCP. Control subjects are recruited from the same sites, matched by CD4 count. Participants receive an approximately 45 minute interview and their medical records are reviewed. Available sputum and other lung fluid specimens from case-patients are sent to the CDC. Data collection activities were recently completed and data analysis is underway. A total of 120 cases and 120 controls were recruited into the study in Los Angeles.
Paul A. Simon, M.D., M.P.H.