Young MSM changed temporal HIV-1 epidemic pattern in Heilongjiang Province, China

Abstract

Background: Human immunodeficiency virus type 1 (HIV-1) epidemic in China is featured by geographical diversity of epidemic patterns. Understanding the characteristics of regional HIV-1 epidemic allows carrying out targeted prevention and controlling measures. This seven-year cross-sectional study was conducted in Heilongjiang, one province of Northeast China, where newly diagnosed infection is fast increasing yearly, but temporal HIV-1 epidemic trend is largely unknown.

Methods: Information of 1,006 newly diagnosed HIV-1-infected participants were collected before antiretroviral therapy during 2010-2016 in Heilongjiang province. HIV-1 genotype was identified based on the viral gag and env gene sequences. Recent infection was determined by Limiting-Antigen Avidity assays. Comparison analyses on the median ages, CD4 counts, proportions of stratified age groups and CD4 count groups, and rates of recent HIV-1 infection among different population and sampling times were performed to understand temporal HIV-1 epidemic features.

Results: Homosexual contact among men who have sex with men (MSM) was the main transmission route and CRF01_AE was the most dominant HIV-1 genotype. During 2010-2016, the HIV-1 epidemic showed three new changes: the median age continued to decline, the cases with a CD4 count more than 500 cells/μl (CD4hi cases) disproportionally expanded, and the recent HIV-1 infection rate steadily increased. MSM cases determined the temporal trend of HIV-1 epidemic here. Increase of young MSM cases (aged <30 years) made the main contribution to the younger age trend of MSM cases. These young MSM exhibited a higher median CD4 count, a higher proportion of CD4hi cases, and a higher rate of recent HIV-1 infection than cases aged 30 years and more. MSM infected by CRF01_AE virus mostly affected HIV-1 epidemic patterns among MSM population.

Conclusion: Young MSM have become a new hotspot and vulnerable group for HIV-1 transmission in Heilongjiang Province, Northeast China. The rapid increase in the number of young MSM cases, mainly those with CRF01_AE infection, changed temporal HIV-1 epidemic pattern here. Measures for prevention and control of HIV-1 infection among this population are urgently needed in the future.

Keywords: CRF01_AE; HIV-1 epidemic; immune status; recent infection; young men who have sex with men.

Figure 1

Comparison analyses on ages and CD4 cell counts in three sampling times. (A–C) The age in all participants, men who have sex with men (MSM) and heterosexuals. (D–F) The CD4 cell count in all participants, MSM and heterosexuals. Data were shown as median with interquartile range. Comparison across groups was done by Kruskal–Wallis test.

Figure 2

Comparison analyses between age groups and HIV-1 infection status groups of men who have sex with men (MSM). (A) The CD4 cell count in cases aged <30 years and those aged ≥30 years. (B) The normalized optical density (ODn) value of plasma samples from cases aged <30 years and cases aged ≥30 years in Limiting-Antigen Avidity assays. (C) The ages of MSM with recent and long-term HIV-1 infections. (D) The CD4 cell count of MSM with recent and long-term HIV-1 infections. (E,F) Correlation analyses between age and CD4 cell count and ODn value. Data in (A–D) were shown as median with interquartile range, and the comparison across groups was done by Kruskal–Wallis test. The correlation analyses in (E,F) were done by nonparametric Spearman correlation test.

Figure 3

Comparison analyses among men who have sex with men (MSM) infected by different HIV-1 genotypes. (A) The age of MSM infected by different genotypes. (B) The age of CRF01_AE-infected MSM in three sampling times. (C) The CD4 cell count of MSM infected by CRF01_AE, subtype B, and 07&08&C viruses. (D) The CD4 cell count of cases aged <30 years and aged ≥30 years with different HIV-1 genotype infection. (E) The normalized optical density (ODn) value of plasma samples from MSM infected by different genotypes in Limiting-Antigen Avidity assays. (F) The ODn value of plasma samples from MSM aged <30 years and aged ≥30 years with different HIV-1 genotype infection. Data in (A–D) were shown as median with interquartile range, and the comparison across groups was done by Kruskal–Wallis test. 07&08&C, virus that had a genotype of CRF07_BC, CRF08_BC or subtype C.