Decreased HIV transmission after a policy of providing free access to highly active antiretroviral therapy in Taiwan

Background. Taiwan established a nationwide surveillance system for human immunodeficiency virus (HIV) infection in 1989 and adopted a policy to provide all HIV-infected citizens with free access to highly active antiretroviral therapy ( HAART) beginning in April 1997. This provided an opportunity to determine the effect of the widespread use of HAART on the evolution of the HIV epidemic. Methods. We analyzed national HIV surveillance data. The HIV transmission rate was estimated by use of an exponential model of HIV epidemic evolution, with statistical projection over the interval between infection and detection to fit the surveillance data. Results. By the end of 2002, the cumulative number of HIV-infected citizens in Taiwan had reached 4390 (0.019% of the total population). After free access to HAART was established, the estimated HIV transmission rate decreased by 53% (0.391 vs. 0.184 new cases/prevalent case-year [95% confidence interval, 31%-65%]). There was no statistically significant change in the incidence of syphilis, in the general population or among HIV-positive patients, during the same period. Conclusion. Providing free HAART to all HIV-infected citizens was associated with a 53% decrease in the HIV transmission rate and contributed to the control of the HIV epidemic in Taiwan.