Prevalence and Factors Associated With HIV Self-testing Uptake Among Men Who Have Sex With Men in Ningbo, China: A Cross-sectional Study

HIV testing and early linkage to care are critical for reducing the risk of HIV transmission. HIV self-testing (HIVST) is an useful tool for increasing HIV testing frequency.This study aimed to investigate HIVST rates among men who have sex with men (MSM), the characteristics of MSM who had HIVST, and factors associated with HIVST uptake among MSM in Ningbo, China. A cross-sectional study was conducted from April to October 2019 in Ningbo,China. Participants were aged at least 18 years and having had sexual contact with men in the past year. Proportions were used for categorical variables. Adjusted Odds Ratio (AOR) and 95% Condence Interval (CI) for characteristics associated with HIVST uptake was processed by multiple logistic regression models.


Introduction
Globally, there were an estimated 37.9 million people are living with HIV (PLWH), with about 1.7 million people newly infected with HIV at the end of 2018 1 . Men who have sex with men(MSM) has become the high-risk group of HIV acquisition. 2,3 . MSM accounted for an estimated 17% of new HIV infections globally, including more than half of new HIV infections in western and central Europe and North America 4 , and MSM was about 28 times more likely to be living with HIV than it was among all adult men in 2018 5 .
To end the AIDS epidemic by 2030, the "90-90-90" goal set up by UNAIDS in 2014 (90% of people with HIV infection diagnosed, 90% of people diagnosed on treatment, and 90% of people on treatment achieving virological suppression) 6 . However, it seems unlikely that many regions and countries would reach the 2020 target, especially the rst 90% 7 . In China, an estimated less than 70% of PLWH were aware of their HIV-positive status by the end of 2018 8 . HIV testing and early linkage to care are critical for reducing the risk of viral transmission from infected persons However, key population groups including MSM were unwilling to seek voluntary HIV counseling and testing (VCT) in the hospital or Centers for Disease Control and Prevention (CDC) due to stigma and discrimination [9][10][11] .
HIV self-testing (HIVST), testers take their blood sample to perform HIV rapid tests and interpret the result at the time and location of their choosing, has recommended being offered as an additional HIV testing approach by WHO in 2016 12 . Several studies showed that HIVST had generally high sensitivity and speci city and was an acceptable and feasible testing approach due to the convenience, privacy, and ease of use [13][14][15] . These characteristics make it a potentially useful tool for increasing testing frequency and easy to reach rst time and repeat testers for HIV 16,17 .
Given the need to improve HIV testing rates and target the rst of the United Nation's 90-90-90 HIV testing and treatment goals, the purpose of this study was to investigate HIVST uptake rates among MSM, the characteristics and factors associated with HIVST uptake among MSM in Ningbo, China.

Study design and participants
We conducted a cross-sectional survey from April 1 to October 30, 2019, in Ningbo. Ningbo is an eastern coastal city of China, nearby Shanghai, with an area of 9365 km 2 and a population of approximately 8.54 million people. Convenience sampling of participants was recruited through a mixed recruitment method of a venue-based method (3 parks, 2 bars, and 8 community events), web-based methods (internet invitations on gay websites and gay apps), and VCT clinic-based method. The survey was anonymous, with no identifying information obtained, and was self-administered. The criteria for recruiting were (1) being male, (2) aged at least18 years, (3) having resided in Ningbo for at least 6 months,(4) having had sexual contact with men in the past year. Questionnaire All data were collected through self-administered questionnaires by trained project workers. The following variables were included: (1) demographic information including age, marital status, education level, duration of local residence, monthly income, and sexual orientation; (2) gay apps use including duration and frequency of apps use; (3) Sexual behaviors including role and frequency in sexual intercourse, multiple male sex partners, unprotected sex with men and syphilis infection in the past 6 months; (4) HIV testing including reasons for test, frequency of test, time since latest test and site of the latest test.

Statistical analysis
Characteristics of all participants were described by categorical variables presented as absolute values and percentages. The demographic information, gay apps use, sexual behaviors and HIV testing compared between HIVST users and Non-HIVST users were examined by chi-square tests. Univariate and multivariate logistic regression models were performed to examine risk factors associated with HIVST. The statistically signi cant was de ned as P < 0.05. All statistical analyses were performed in SPSS (version 21.0, IBM, Armonk, NY, USA).

Ethical Considerations
This study protocol was reviewed and approved by the Institutional Review Board of the Ningbo CDC.
Informed consent was asked to sign for all eligible participants when the survey was starting. Participants could receive a gift for prizes of up to 7 USD upon the completion of the survey. Table 1 demonstrates the characteristics of the 699 MSM in Ningbo. The mean age was 31.9 (SD 8.8

Participant Characteristics
)years. Most participants (81.1%) were less than 30 years, 63.4% were single, 70.4% had a high school education or above, 77.7% had lived in Ningbo for at least two years, 62.9% had an income above 5000 China Yuan (CNY) per month, and 74.8% self-identi ed as gay.

Factor Associated With Hivst Uptake
As show in Table 2, multivariate logistic regression analyses found that HIVST were associated with older age (  Univariate and multivariate regression analyses were used to generate odds ratios (ORs) and 95% con dence intervals (CIs).

Discussion
Globally, HIV testing had become an important strategy to end the HIV epidemic 18,19 . HIVST is reliable, safe, and accurate, which can help increase serostatus awareness and ultimately linkage-to-care or prevention services among HIV high-risk populations 20,21 . The proportion of HIV testing among MSM in the lifetimes and the past year in our analysis was higher than in other studies, but there is a certain distance to reach the rst 90% targets by 2020 7,19 . The study revealed that 38.2% of MSM had used HIVST before in Ningbo, which was lower than the rates reported in studies from other areas 22,23 . Our study's contribution to investigate factors associated with HIVST and help the government develop targeted strategies to improve HIV testing among MSM in China.
Our study showed that those MSM who were younger or high education levels were more likely to have had HIVST. It is possible that younger MSM had more worries about positive test results 11 . Worldwide, about 32% of new HIV infections among adults aged 15 years and older have occurred in youth ages 15 to 24 years in 2018 4 . Therefore, HIVST education should be included as a part of comprehensive sexual and reproductive health education for school-age children and teenagers 21 . Moreover, a larger proportion of HIVST Users had a higher income in our study. It is possible that commercial HIVST kits can be easily bought by online shopping platform in China. But to avoid possible cost barriers, free HIVST kits might be provided to low-income high-risk populations to achieve the increased testing frequency 17 .
Gay apps were very popular among MSM in China 24 . HIV prevention through gay apps was widely applied toward reducing high-risk behaviors and promoting HIV testing 25,26 . Our results showed that HIVST Users had a higher frequency of gay apps use than Non-HIVST users in the prior 6 months. Informed consent was asked to sign for all eligible participants when the survey was starting. Participants could receive a gift for prizes of up to 7 USD upon the completion of the survey.

Availability of data and materials
The datasets used and/or analyzed during this study is not publicly available, but may be available from the corresponding author upon reasonable request, and with permission from Ningbo Municipal Center for Disease Control and Prevention. Author Contributions HH and HS designed the study, HH and HD coordinated the study, HS and HJ collected the data, HH did the primary data analysis, HH and HS contributed to part of the analysis. HH, HS, and YS drafted the paper. All authors contributed to results interpretation interpreted the data, revised the article, and approved the nal version and manuscript revision. YS had access to all the data and was responsible for the nal decision to submit the manuscript for publication.