Related Experiment Videos
Therapy may explain recent deficits in AIDS incidence.
M H Gail1, P S Rosenberg, J J Goedert
1National Cancer Institute, Epidemiology and Biostatistics Program, Rockville, MD 20892.
Journal of Acquired Immune Deficiency Syndromes
|January 1, 1990
Summary
Zidovudine (AZT) prophylaxis likely explains the observed "AIDS deficit" in homosexual men. This therapy, combined with improved medical care, reduced reported AIDS cases, highlighting the impact of treatment on HIV/AIDS epidemiology.
Area of Science:
- Epidemiology
- Public Health
- Virology
Background:
- Fewer AIDS cases than expected were reported among homosexual and bisexual men in the US since mid-1987.
- This "AIDS deficit" was most pronounced in major cities but observed nationwide.
- Intravenous drug users (IVDUs) showed virtually no such deficit.
Purpose of the Study:
- To investigate the reasons behind the observed "AIDS deficit" among specific populations.
- To evaluate the role of zidovudine (AZT) prophylaxis in accounting for the reduced AIDS incidence.
- To examine alternative explanations for the observed trends in AIDS reporting.
Main Methods:
- Analysis of data from placebo-controlled trials.
- Review of pharmaceutical company reports on zidovudine (AZT) usage.
- Examination of data from the San Francisco Men's Health Study.
- Comparison of AIDS incidence rates across different risk groups (homosexual men vs. IVDUs).
Main Results:
- Prophylactic zidovudine (AZT) administration since March 1987 sufficiently explains most of the "AIDS deficit" in homosexual and bisexual men.
- Combined effects of AZT and other medical care advances likely contributed to the observed deficits.
- Alternative hypotheses, including changes in HIV infection rates, incubation periods, reporting delays, surveillance definitions, or HIV strain evolution, were insufficient to explain the deficits.
Conclusions:
- Therapeutic interventions, particularly zidovudine (AZT), significantly impact national AIDS rates.
- Failure to account for therapy effects can lead to underestimation of cumulative HIV infections and long-term AIDS incidence.
- Expanding access to AZT and advanced treatments for AIDS-free patients with advanced immunodeficiency could reduce AIDS incidence in underserved groups like IVDUs.