Estimation of cumulative HIV incidence in Australia, based on national case reporting

It has been recognised that the Australian National HIV Database may contain multiple reports for some individuals, mainly because of incomplete or inaccurate recording of name codes. The number of distinct individuals diagnosed with human immunodeficiency virus (HIV) was estimated from the dates of birth of cases of HIV infection reported to the database. There were 18,787 cases of HIV infection diagnosed by the end of 1994 and reported to the database by the end of April 1995. Based on the reported dates of birth, the total number of individuals was estimated to lie in the range 13,600 to 15,300. Corresponding analyses by state (or territory) estimated the total number of individuals diagnosed with HIV to lie in the ranges 8360 to 9760 in New South Wales, 1490 to 1540 in Queensland, 3010 to 3180 in Victoria and 1530 to 1600 in other states and territories combined. It was estimated that 5 per cent of individuals were diagnosed with HIV infection in more than one state. Allowing for people with HIV infection who have not yet been tested for HIV antibody and reported, the total number of people to have acquired HIV in Australia by the end of 1994 was estimated to lie in the range 15,500 to 17,700. This is consistent with back-projection estimates.