Survival of HIV-positive IDUs in the era of HAART

2 October 2007. Related: Treatment access.

Polly Clayden, HIV i-Base

Mortality rates among injection drug users (IDUs) have been historically high and are still significantly higher than the rates for the general population. HIV-positive IDUs have an additional increase in mortality risk.

A paper authored by Roberto Muga and coworkers from the Department of Internal Medicine, Hospital Universitari Germans Trias i Pujol, Badalona, and Department of Statistics and Operations Research, Universitat Polite`cnica de Catalunya, Barcelona, Spain, published in the 1 August 2007 edition of Clinical Infectious Diseases, looked at survival of HIV-positive IDU in the era of HAART.

In this study they evaluated the mortality rates for a cohort of HIV-positive and negative IDUs who were admitted to a substance abuse treatment programme in a tertiary hospital between January 1987 and December 2004. The investigators divided the follow up period into: 1987-1991 (the antiretroviral monotherapy era), 1992-1996 (the dual-combination treatment era and the introduction of methadone maintenance), and 1997-2004 (the era of HAART and established methadone programmes).

The investigators noted that during follow-up, several IDUs who were HIV-negative at admission became HIV-positive. They defined the time of infection by the midpoint of the interval from the last negative test result to the first positive test result.

People that seroconverted contributed survival times to both groups of HIV infection: as seronegative subjects, the (rightcensored) survival time lasted from admission until HIV infection; as seropositive subjects, the survival time lasted from the duration after admission to HIV infection, until either death or the end of follow-up.

During the study period,1209 IDUs were admitted for the first time to a substance use treatment programme. Twenty-eight (2.3%) of the total study group were excluded from the study cohort because their HIV status was unknown. The calendar periods of admission, for the remaining 1181 IDU included were as follows: 490 (41.5%) for 1987-1991, 393 (33.3%) for 1992-1996 and 298 (25.2%) for 1997-2004.

The majority (81.3%) of patients were men. The mean age was 27.8 (+/- 5.6) years, and the mean duration of injection drug use was 7.6 (+/-5.0) years. The prevalence of HIV infection and hepatitis C virus infections was 59.0% and 92.3%, respectively, and the total duration of follow-up was 10,116 person-years.

The investigators reported that although survival duration for HIV-negative IDUs in 1997–2004 was similar to the duration in earlier periods, the duration for HIV-infected IDUs improved significantly since 1997 (p=0.01). Additionally, among patients admitted in the last period, there was no significant difference between the survival durations for HIV-uninfected and HIVinfected IDUs (HR 0.89; 95%; CI 0.44–1.81).

They found that survival for HIV-positive IDUs improved substantially since 1997, reaching similar rates to those for HIVnegative IDUs who accessed the health care system in the era of HAART and methadone.

They noted that because only one-third of the HIV-positive IDUs in this study received HAART, other factors are likely to have contributed to their improved survival including: access to substitution therapy with methadone, prophylaxis for opportunistic infections, harm reduction interventions, and regular clinical care.

They wrote: “HAART has been proven to be an extremely effective therapy for HIV-infected individuals. We have shown that HIV-infected IDUs who received health care during the period 3 exhibited mortality rates comparable to those for IDUs who were not infected with HIV.”

Reference:

Muga R, Langohr K, Tor J et al. Survival of HIV-Infected Injection Drug Users (IDUs) in the Highly Active Antiretroviral Therapy Era, Relative to Sex- and Age-Specific Survival of HIV-Uninfected IDUs. Clinical Infectious Diseases 2007:45, 1 August 2007.