Temporal trends in the prevalence of HIV and other transfusion-transmissible infections among blood donors in northern Thailand, 1990 through 2001

BACKGROUND: Thailand's epidemic of HIV infection, which began in 1988, has primarily involved heterosexual transmission of the virus. This study describes changes in prevalence of HIV and other infectious diseases among blood donors in northern Thailand from 1990 through 2001. STUDY DESIGN AND METHODS: Serologic screening results and demographic data were analyzed from 276,066 donors screened at two blood collection facilities in Chiang Mai, Thailand, from 1990 through 2001. RESULTS: The HIV prevalence peaked in 1991 to 1993 at 4.04 percent and then declined to 0.38 percent in 2001. The overall prevalence of HIV infection was 2.16 percent; HIV prevalence was higher among male (2.24%) than among female (0.64%) donors, in first-time donors, and in replacement volunteer donors. The majority of the donors were men and first-time donors throughout this study. The prevalence of antibodies to syphilis decreased significantly in both men and women. However, the prevalence of antibodies to HCV and HBsAg were stable. CONCLUSIONS: The declining HIV prevalence from 1990 through 2001 among blood donors in two large blood banks in northern Thailand indicates significant progress toward recruitment of a safer donor population in a developing country despite a major HIV and AIDS epidemic involving the general population.