ABSTRACT
<p><b>BACKGROUND</b>Heterosexual sex has become the dominant transmission route in China. Recently studies reported high heterogeneity in heterosexual transmission risk in resource-limited countries. The aim of this study was to summarize the risk of HIV transmission among Chinese serodiscordant couples.</p><p><b>METHODS</b>A systematic review and meta-analysis of observational studies of heterosexual HIV transmission among serodiscordant couples in China was conducted. Two reviewers conducted a literature search using the China National Knowledge Infrastructure (CNKI), Chinese Medical Current Contents (CMCC), and Medline databases. Pooled transmission estimates per 100 person-years (PY) were calculated using a random-effects model. Meta-regression analysis and subgroup analysis stratified by study design, transmission direction and period of antiretroviral therapy (ART) availability were conducted to assess the factors associated with transmission.</p><p><b>RESULTS</b>Eleven eligible studies were identified reporting on 11 984 couples and 405 HIV transmission events. HIV transmission risk from HIV-positive individuals to heterosexual partners was 1.68 (95%CI 0.74 - 2.62) per 100 PY. Study design did not reach statistical significance in meta-regression analysis. The pooled female-to-male transmission estimate was 1.11 (95%CI 0.09 - 2.14) per 100 PY and male-to-female transmission estimate was 1.43 (95%CI 0.19 - 2.68) per 100 PY. The pooled estimate for those before the availability of the Chinese National Free Antiretroviral Therapy Program (2.13 (95%CI 0.00 - 4.63) per 100 PY) was higher than that for those after the implementation of this program (1.44 (95%CI 0.62 - 2.26) per 100 PY).</p><p><b>CONCLUSIONS</b>Transmission estimates in China were lower than other developing countries, but higher than developed countries. Research that better defines HIV secondary transmission rates and the associated behavioral, treatment adherence, and health-related risk factors among heterosexual serodiscordant couples in China is needed.</p>