Background: Before 2003, little was known about the scale of China's HIV/AIDS epidemic. In 2003, the Chinese government produced national estimates with support from the Joint United Nations Programme on HIV/AIDS, the World Health Organization and the United States Centers for Disease Control and Prevention. Subsequent national estimation exercises were carried out in 2005, 2007 and 2009. We describe these estimation processes and present the results of China's HIV/AIDS estimation exercises from 2003 to 2009.
Methods: The Workbook Method was used to generate national HIV/AIDS estimates. Data from the provincial level were used in 2003, data from the prefecture level were used in 2005 and data from the county level were used in 2007 and 2009. Data at the lowest level of aggregation were used to estimate risk group population size and HIV prevalence. Data from lower levels were combined into national estimates.
Results: At the end of 2003, 2005, 2007 and 2009, there were an estimated 0.84, 0.65, 0.70 and 0.74 million people living with HIV/AIDS in China, respectively, with an overall HIV prevalence of 0.05-0.06%. The number of new HIV infections decreased from 70 000 in 2005, to 50 000 in 2007, to 48 000 in 2009. Data quality improvements have increased the precision of China's HIV estimates.
Conclusion: Repeated estimates have improved understanding of the HIV/AIDS epidemic in China. HIV estimates are a valuable tool for guiding national AIDS policies evaluating HIV prevention and control programmes.