Analysis of HIV transmission characteristics and intervention effects in Guangxi based on molecular networks

This study evaluates changes in HIV transmission and the effectiveness of interventions after two rounds of the Guangxi AIDS Conquering Project (GACP) in Guangxi, China.

Samples and epidemiological data from newly diagnosed people with HIV (PWH) between 2014 and 2020 were analyzed. Molecular networks were constructed using nested PCR amplification and sequencing of the pol region, and multivariable logistic regression identified factors associated with clustering and high-degree nodes.

A total of 4227 valid sequences (73.12% inclusion rate) were analyzed. Demographic changes included an increasing proportion of individuals aged at least 50 years (49.66%), with lower education (50.51%), peasants (76.82%), and heterosexual transmission (90.29%). The overall clustering rate was 86.89%, with higher clustering among individuals aged at least 50 years (92.57%), those with primary school or below (89.09%), peasants (88.11%), and CRF08_BC infections (91.48%). Annual declines in cluster growth rate and clustering rates were observed, particularly among individuals aged less than 30 years, college graduates, MSM, and people who inject drugs (PWID). Key transmission hotspots were identified in Lingshan, particularly among older, less-educated individuals, and peasants. Factors associated with clustering included being male (aOR: 1.27), aged at least 50 years (aOR: 3.84), and infected with CRF08_BC (aOR: 2.12). From 2017 to 2020, the risk of clustering and high-degree nodes was lower compared to 2014-2016, suggesting the effectiveness of interventions.

Interventions in Guangxi effectively reduced HIV transmission among younger, high-degree populations. However, older, less-educated individuals remain at high risk, necessitating targeted strategies to address their specific needs and achieve better HIV control.