Opportunistic infection improvements level off

Six diseases have shown no decrease at all

Coverage of the 2001 IDSA Conference

One of the greatest achievements of protease inhibitor (PI) therapy and highly active antiretroviral therapy (HAART) has been the dramatic decrease in the incidence of opportunistic infections (OIs) related to AIDS. In the first couple of years after the advent of PI therapy, clinicians found that fewer HIV/AIDS patients developed some of the more common OIs, such as Kaposi’s sarcoma and pneumocystosis. However, new research shows the decline in OI rates has ended. The declines experienced between 1995 and 1998 did not continue through 1999 for all except for two OIs, according to a study by researchers with the Centers for Disease Control and Prevention. The exceptions to the new trend are the OIs cerebral toxoplasmosis and CMV retinitis, both of which showed lower rates among men in 1999 than in 1998.

"Possible reasons for the leveling incidence include the achievement of the maximum benefits of HAART among this cohort," says A.D. McNaghten, PhD, MHSA, an epidemiologist with the CDC. "Medication side effects, poor patient compliance, the development of resistant strains of HIV, and late presentation and diagnosis may diminish the effects of HAART," McNaghten says. "These possibilities need to be investigated further."

The CDC study, which was presented at the 39th Annual Meeting of the Infectious Diseases Society of America (IDSA), held Oct. 25-28, 2001, in San Francisco, also found that six OIs did not decrease at all between 1995 and 1999. These included disseminated histoplasmosis, pulmonary candidiasis, Burkitts lymphoma, disseminated coccidioidomycosis, and recurrent salmonella septicemia. The sixth, cervical cancer, actual had an increasing trend during this time period, McNaghten says.

OIs decreased less for women

When the incidence trends were analyzed by gender, it was found that men had significant decreases for 19 of 25 OIs, while women had decreasing trends for only 11 of 26 OIs.1 "These women may be diagnosed with HIV later and enter care later than men," McNaghten says. "There may also be differences in treatment." For example, a recent ASD analysis showed that among patients eligible for antiretroviral therapy according to treatment guidelines in 1999, female gender was associated with a decreased likelihood of HAART prescription, McNaghten says.

CDC investigators will continue to study the incidence of OIs, including conducting an analysis of OI incidence in 2000 and 2001 to determine if specific OIs are increasing, decreasing, or remaining level, McNaghten says. Meanwhile, clinicians should keep these findings in mind as they initiate and adjust antiretroviral treatment for HIV patients. "These findings reinforce the importance of antiretroviral therapy and OI prophylaxis, which are vital to preventing OIs," McNaghten says. "It is important for clinicians to be aware of the recommendations in the Guidelines for the Use of Antiretroviral Agents in HIV-Infected Adults and Adolescents and the USPHS/IDSA Guidelines for the Prevention of OIs in Persons Infected with HIV."


1. McNaghten AD, Hanson DL, Nakashima AK, Swerdlow DL. Incidence of AIDS-defining opportunistic infections in the US may be leveling from 1998-1999. Presented at the 39th Annual Meeting of the Infectious Diseases Society of America. San Francisco: Oct. 25-28, 2001. Abstract 751.