The origin, dissemination, and molecular networks of HIV-1 CRF65_cpx strain in Hainan Island, China

Area of Science:

• Molecular epidemiology of HIV-1 strains
• Viral phylodynamics and transmission networks
• Public health and infectious disease control

Background:

• The HIV-1 CRF65_cpx strain harbors drug-resistant mutations, posing a risk for virologic failure.
• CRF65_cpx is the fourth most prevalent HIV-1 strain on Hainan Island, China.
• The origin and molecular epidemiology of CRF65_cpx on Hainan Island are not well understood.

Purpose of the Study:

• To investigate the spatial origins and dissemination patterns of HIV-1 CRF65_cpx on Hainan Island.
• To understand the transmission dynamics and molecular epidemiology of this specific HIV-1 strain.
• To identify potential hotspots and key populations for targeted HIV intervention strategies.

Main Methods:

• Phylogenetic analysis of 58 HIV-1 CRF65_cpx pol sequences collected between 2018-2021.
• Bayesian coalescent-based approach to infer evolutionary history and introduction.
• HIV-TRACE tool for constructing transmission networks and analyzing viral migration patterns.

Main Results:

• The CRF65_cpx strain on Hainan Island originated in Beijing and was introduced around 2013, primarily among men who have sex with men (MSM).
• Haikou was identified as the central epidemic hub, with subsequent spread to other locations on Hainan Island.
• Transmission networks revealed viral migration from older to younger age groups and from MSM to heterosexual individuals.

Conclusions:

• Haikou is a significant hotspot for HIV-1 CRF65_cpx transmission on Hainan Island.
• Middle-aged MSM represent a key population for HIV-1 CRF65_cpx transmission.
• Targeted public health interventions in identified hotspots and key populations are crucial for controlling the HIV epidemic.