Objectives: To assess the prevalence and risk factors for HBV and HCV coinfection in the Australia HIV Observational Database (AHOD), and examine outcomes of HIV disease following initiation of highly active antiretroviral therapy (HAART).
Methods: Analyses were based on 2086 participants recruited to AHOD by September 2002. Of these, 1605 (77%) had been tested for HBV surface antigen, 1704 (82%) for anti-HCV antibody and 1453 (70%) for both. Demographic and clinical predictors of HBV and HCV coinfection were examined. The impact of HBV and HCV coinfection on HIV disease progression was assessed by Kaplan-Meier survival curves and Cox proportional hazard model of time to AIDS events and death.
Results: Among those tested, prevalence of HBV surface antigen and HCV antibody were 6.3% and 13.1%, respectively (4.8% and 10.7%, respectively, among the entire cohort). In multivariate analyses, the only independent risk factor for HIV/HBV coinfection was coinfection with HCV. Independent risk factors for HIV/HCV coinfection were HIV exposure category (with people who reported injecting drug use [MSM & IDU, IDU only] or receipt of blood or blood products at markedly increased risk) and HBV coinfection. HIV disease outcomes following first initiation of a HAART regimen were similar for HIV/HBV and HIV/HCV coinfected patients compared with HIV-only patients in terms of AIDS-free survival and detectable HIV virus during the first 12 months. However, patients coinfected with HIV/HCV appeared to have a poorer response to HAART in terms of CD4 count changes, with a CD4 count increase of 32 cells/microL (95% CI 1-67) less than HIV-only patients.
Conclusions: Coinfection with HBV or HCV is relatively common among HIV-infected participants in AHOD. HIV disease outcomes following HAART do not appear to be adversely affected by HBV/HCV coinfection, except for slightly poorer CD4 count responses in HIV/HCV coinfected patients.