[HIV epidemic among pregnant women in China, 2016: trend and spatial analysis]

Objective: To describe the spatial distribution characteristics of the HIV prevalence among pregnant women in mainland China in 2016, providing scientific evidence for the prevention of mother-to-child transmission of HIV. Methods: Data on pregnant women and those living with HIV in 2016 for all counties in mainland China is from the National Maternal & Child Health Statistics dataset. To obtain robust estimates, 2 964 counties were merged into 344 cities. Spatial autocorrelation analysis and trend analysis were performed based on the city-level dataset to detailedly describe the characteristics of the spatial distribution. Results: A total of 14 879 082 pregnant women were included in the analysis, among whom 5 051 were diagnosed to be infected with HIV, giving an overall prevalence of 34.0 per 100 000 pregnant women. The prevalence was higher in the south than in the north, and decreased from the west (93.5/100 000) to the east(8.6/100 000 ), more specifically, the prevalence in the West region was 11 times as high as that in the East region(χ(trend)(2)=68.61, P<0.01). Stratified analysis by provinces showed that there were 6 provinces whose prevalence was >50.0 per 100 000, and they (Yunnan, Xinjiang, Sichuan, Guangxi, Guizhou and Chongqing) were all located in the West Region; pregnant women in these provinces accounted for 21% of all pregnant women, but the HIV cases accounted for 76% of all cases diagnosed in mainland China. Stratified analysis by cities showed that there were 30 cities whose prevalence was >100.0 per 100 000, and 28 of these cities were also located in the western provinces above. Furthermore, the global Moran's I (0.5, P<0.01) indeed indicated a strong clustered distribution across mainland China; 2 hot spots were observed in the Midwest of Xinjiang, and Yunnan and its bordering areas (Sichuan, Guizhou, Guangxi and Chongqing), while 1 cold spot in the central and east China. The HIV prevalence in the hot spots (183.6/100 000) was 23 times as much as that in the cold spot (8.1/100 000). Conclusion: The overall HIV prevalence for pregnant women who lived in mainland China in 2016 (34.0/100 000) ranked at low-level worldwide, but varied markedly across the whole country with 2 high-prevalence-clustered areas: the Midwest of Xinjiang Uygur Autonomous Region, and Yunnan province along with its bordering areas, indicating comprehensive intervention strategies especially targeted to the areas with high HIV prevalence should be developed.