Epidemiology of Pneumocystis carinii pneumonia in an era of effective prophylaxis: the relative contribution of non-adherence and drug failure

AIDS. 2000 Nov 10;14(16):2559-66. doi: 10.1097/00002030-200011100-00019.


Objective: To determine the relative contribution of patient non-adherence, provider failure to prescribe prophylaxis, and drug failure to the continued occurrence of Pneumocystis carinii pneumonia (PCP), and to determine correlates of non-adherence.

Design: Retrospective case-control study.

Methods: Patients with confirmed or presumptive PCP from May 1995 to September 1997 who had at least 6 months of prior HIV care (cases) were compared to controls matched for initial CD4 cell count and date of initial HIV care.

Results: The incidence of PCP declined by 85% in the 28 months of the study. Of the 118 cases of PCP identified, 59 (50%) were in HIV care for > 6 months prior to PCP diagnosis. In a multivariate logistic regression model, risk factors for PCP among patients in HIV care were patient non-adherence [odds ratio (OR), 12.4; 95% confidence interval (CI), 6.4-23.5], use of prophylaxis other than trimethoprim-sulfamethoxazole (OR, 27.0; 95% CI, 13.8-52.9), and absence of antiretroviral use (OR, 7.5; 95% CI, 4.5-12.5). Provider non-adherence occurred in one out of 59 cases (2%), and five out of 106 controls (5%). Of the patients who developed PCP on prophylaxis, 18 cases (30%) appeared due to drug failure; there were no cases of apparent drug failure among patients on trimethoprim-sulfamethoxazole. In multivariate analysis, non-adherence was more common among patients of non-white race, those with a history of injecting drug use, and those with active substance abuse or psychiatric illness.

Conclusions: Patient non-adherence was the most common reason for the occurrence of PCP among patients in HIV care; provider non-adherence was uncommon. Drug failure occurred only among patients on prophylaxis other than trimethoprim-sulfamethoxazole.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AIDS-Related Opportunistic Infections / epidemiology
  • AIDS-Related Opportunistic Infections / microbiology
  • AIDS-Related Opportunistic Infections / prevention & control*
  • Adult
  • Anti-Infective Agents / therapeutic use*
  • Case-Control Studies
  • Chemoprevention
  • Female
  • Humans
  • Male
  • Multivariate Analysis
  • Pneumonia, Pneumocystis / epidemiology*
  • Pneumonia, Pneumocystis / prevention & control*
  • Retrospective Studies
  • Risk Factors
  • Treatment Failure
  • Treatment Refusal*


  • Anti-Infective Agents