Quantitative techniques to improve monitoring and evaluation of HIV epidemics and transfusion-transmissible infections in Australia

This thesis aims to understand, assess and improve current strategies for monitoring and managing transfusion-transmissible infections (TTIs) among Australian blood donors and improve Australia’s HIV/AIDS data recording. A retrospective analysis of national donation testing data was conducted to examine recent trends in TTIs in Australia and to describe key attributes of infected blood donors. The study demonstrates that the prevalence and incidence of TTIs in Australian donors remained low in 2005-2010, with steady or declining trends. Prevalence of, and likely reasons for, non-compliance (i.e. failure to disclose truthful information during pre-donation screening using a Donor Health Questionnaire) in Australian donors to deferral criteria for TTI-related high-risk behaviours was examined by conducting an anonymous, online survey of a nationally representative sample of 30,274 Australian blood donors. The prevalence of overall non-compliance was estimated to be 1.65%. Non-compliance to individual deferral categories ranged from 0.05% (sex work) to 0.54% (sex with an injecting drug user). The selected high-risk behaviours are substantially less common in blood donors compared to the general population. The thesis provides the first rigorous estimate for the size of the national donor-eligible population in Australia. Using a refinement to a published method, this study estimates that 62% of the 16-80 year olds are donor-eligible in Australia. This thesis also maximized completeness of notification data for reported HIV/AIDS cases in Australia. Using a deterministic record linkage approach, the study merged the national AIDS and HIV registries; this increased the number of known diagnosed HIV cases by 1,183 (3.9%). This thesis provides evidence that the existing procedures employed by the Blood Service are effective in maintaining a low-risk but adequate blood supply in Australia. However, non-compliance to TTI-related deferrals, even at a minimal level, poses a potential safety threat to the blood supply. Focus on further minimization of non-compliance should therefore be considered. Finally, using a complex but comprehensive linkage process, completeness of records for HIV notifications have been achieved without compromising data quality. A single national registry with complete HIV and AIDS notification data should now improve understanding of past trends and future surveillance of HIV in Australia