Improving analysis of the size and dynamics of AIDS epidemics

Country HIV and AIDS estimates have been published by the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) every two years since 1998,1 and the 2006 Global Report is the fifth release of country estimates.2 Since 1998 much has changed in the approaches and methods used to produce national estimates using data from surveillance systems and research studies. In recent years, these estimates have become more accurate, owing much to the availability of results from national population based surveys in countries with generalised epidemics, and to the use of an explicit analytic framework and the greater availability of data on the size of groups with high risk behaviour in countries with low level or concentrated epidemics.3,4 The focus of these analyses has also been shifting from the global level to the national and increasingly to the subnational level. This is a trend that parallels a shift in the use of these analyses from global advocacy to improved national planning of prevention and treatment as programmes are scaled up towards universal access.5

Two years ago, a supplement on the methods underlying the 2003 estimates was published.6 The current supplement aims to provide information on the approaches, methods, and tools that were used to produce the 2005 estimates featured in the 2006 Global Report,2 as well as two specific country examples. Following a successful first round in 2003, UNAIDS, WHO, and a large number of …