Asymptomatic and pre-symptomatic cases of COVID-19 contribution to spreading the epidemic and need for targeted control strategies / 中华流行病学杂志

The asymptomatic carrier state of COVID-19 has become a topic of concern for preventing a possible epidemic rebound. This review describes and defines the COVID-19 asymptomatic carrier state and outlines methods for identifying counting and reporting these cases. The author elaborates that the asymptomatic carrier state can be further divided into asymptomatic infection and pre-symptomatic infection after extended follow-up based on the nature of disease progression. The author presents the limited available data about infectiousness of asymptomatic and pre-symptomatic cases and their possible contributions to the overall epidemic of COVID-19 observed so far in China. Challenges of a possible second epidemic wave of COVID-19 caused by asymptomatic and pre-symptomatic cases are discussed and suggestions for control strategies and scientific research are provided.

Follow-up of community injecting drug user cohort, 2014-2017 / 中华流行病学杂志

Objective@#To explore the methods of establishing and maintaining community injecting drug user (IDU) cohort.@*Methods@#From June 2014 to June 2017, a community survey was conducted on basis of local needle and syringe exchange site to recruit 200 HIV sero-negative IDU for a prospective cohort study in Longyang district of Baoshan city, Yunan province. Follow-up was carried out every six month to investigate high risk drug use behavior and sexual behavior, and blood samples were collected from them for the tests of HIV and HCV serum antibodies. The cohort would be opened every 12 months to replenish the cohort to 200 subjects.@*Results@#The follow up was conducted for 3 years in 229 IDUs. Cohort follow-up rate was 93.0% (213/229) for 6 months, 92.1% (211/229) for 12 months, 91.7% (200/218) for 18 months, 87.2% (190/218) for 24 months, 86.0% (172/200) for 30 months and 86.0% (172/200) for 36 months.@*Conclusion@#The community IDU cohort has a high follow-up rate.

Control of HIV/AIDS can be achieved with multi-strategies / 《全球健康杂志（英文）》

Over past three decades,many prevention strategies have been proven effective in reducing human immunodeficiency virus (HIV) transmission.However,none of these strategies alone are effective to stop the spread of HIV.This review discusses a few key prevention strategies,including testing,harm reduction,prevention,prophylaxis,and modern communication strategies.We argue that although there are great challenges remaining to stop HIV transmission via sexual contact and injecting drug use routes,the combination of these effective strategies,control HIV epidemic can be achieved.

Characteristics of HIV sexually transmission and challenges for controlling the epidemic in China / 中华流行病学杂志

Sexual transmission became the major mode of HIV infection in this country and accounted for 95% of the newly diagnosed cases, 67% and 28% of heterosexual and male homosexual infections, respectively, in 2016. Heterosexual transmission was mostly reported in South-west while male homosexual transmission in North-east and major metropolitan areas. Elderly and young students became the two special groups of people with increased reported HIV cases in the past years, with major modes of transmission as both heterosexual and homosexual. HIV testing and treatment of all HIV infections have been national control strategies and implemented and have significantly reduced HIV sexual transmission among sero-discordant couples. However, about one-third HIV infections remained undiagnosed. HIV infection through sexual transmission will remain a challenge in the years to come.

Changes of proportion regarding consistent condom use and syphilis infection among low-fee female sex workers aged 35 and above / 中华流行病学杂志

Objective: To investigate the changes of proportion on both consistent condom use and syphilis infection among low-fee female sex workers aged 35 and above (LFSW), in order to provide evidence for targeted intervention strategies. Methods: A total of six cities-Liuzhou city and Pingnan couty of Guigang city of Guangxi Zhuang Autonomous Region, Jinghong city of Xishuangbanna Dai autonomous prefecture and Dali city of Dali Bai autonomous prefecture of Yunnan province, Zhangjiajie city and Jianghua Yao autonomous county of Yongzhou city Hunan province were involved in this study, with 60 eligible participants needed in each city, estimated through a pre-study. The first cross-sectional survey was completed from October 2012 to January 2013. Face-to-face questionnaire interview was carried out to collect information on socio-demography, work-related information and condom use situation. Blood was collected for syphilis testing. The second cross-sectional survey was carried out from June to September, 2015 under the same procedure. Results: A total of 371 and 403 eligible participants were included in the first and second survey, respectively. When comparing the two surveys, we noticed that the average age showed a slight change, from 42.4 years to 43.8 years old (t=3.537, P<0.001) and the average price for every commercial sex exchange increased from 36.8 RMB to 49.5 RMB (t=11.961, P<0.001). In the first survey, 46.9% (174/371) of the participants had more than two years of experience working as LFSW, compared to 61.3% (247/403) in the second survey (χ(2)=16.125, P<0.001). Also, 46.9% (174/371) of the participants consistently used condoms with clients in the past month in the first survey versus 64.3% (259/403) (χ(2)=23.641, P<0.001) in the second one. Rates of syphilis infection were found from 15.9% (59/371) in the first survey reduced to 7.2% (29/403) in the second survey (χ(2)=14.533, P<0.001). Conclusion: Compared with the first survey, the proportion of consistent condoms use showed an increase. Although the proportion of syphilis infection decreased in the second survey, the scope did not meet the criteria on syphilis, set by the government. Targeted intervention strategies on condom promotion and syphilis control should be implemented consistently in this population.

Application of Bernoulli Process Model fitting the effect of intervention measures on sexual transmission among HIV sero-discordant couples / 中华流行病学杂志

Objectives: To undersand the outcomes of major intervention measures on sexual transmission among HIV sero-discordant couples. Methods: Bernoulli Process Model was applied to model the major influencing factors of HIV transmission among HIV sero-discordant couples. The major influencing factors appeared as consistent condom use, antiretroviral therapy, frequency of sexual behavior. These parameters were from the HIV sero-discordant couples in 30 counties in 4 provinces (Guangxi Zhuang Autonomous Region, Yunnan Province, Xinjiang Uygur Autonomous Region and Henan provinces) from January 1, 2011 to December 31, 2012. According to the main factors, modeling-intervention strategies and measures on reduction HIV transmission among serodiscordant couples were formed. Results: Data from the present proportion of consistent condom use (85%) modeling and the coverage of antiretroviral treatment (60%) showed that, the proportion of cumulative seroconversion among the spouses was 1.76%. Results from the sensitivity analysis on modeling the consistent condom use and the antiretroviral treatment showed that, when the coverage of antiretroviral treatment was as 90% and the proportion of consistent condom use increased from 50% to 90%, with 80.7% of the risk of spouse seroconversion could be reduced. Or, when the proportion of consistent condom use was as 90% and the coverage of antiretroviral treatment increased from 50% to 90%, with 64.5% of the risk of spouse seroconversion could be reduced. Conclusions: With measures as consistent condom use plus provision of timely antiretroviral therapy to HIV positive index spouses, the risk of sexual transmission among sero-discordant couples could be greatly reduced.

Acceptability of HIV testing using oral quick self-testing kit in men who have sex with men / 中华流行病学杂志

Objective: To evaluate the acceptability of oral quick HIV self-testing in men who have sex with men (MSM). Methods: From April 2013 to April 2014, MSM in Beijing and Nanning of China were recruited for an observational study including baseline survey and follow-up, including questionnaire survey, oral HIV self-testing and clinic-based HIV confirmation testing. The sensitivity and specificity of oral quick self-testing were evaluated through comparing the results of oral quick testing with blood testing. The acceptability and associated factors were evaluated by logistic model. Results: A total of 510 MSM were recruited at baseline survey and 279 accepted follow-up. The sensitivity of the oral self-test was 86.00% (43/50) and specificity was 98.23% (445/453) at baseline survey. At baseline survey, 78.63% (401/510) of the MSM showed willingness to use oral quick HIV self-testing. The associated factors included unprotected anal intercourse with a regular male partner in the past 6 months (aOR=0.30, 95%CI: 0.10-1.00) and preference of oral quick HIV self-testing (aOR=7.32, 95%CI: 1.61- 33.31). At baseline survey, 34.51% (176/510) of the MSM reported that oral quick HIV self-testing was the preferred testing method rather than blood testing, which was associated with their birth places-urban area. Conclusion: The acceptability of oral quick HIV self- testing in MSM in the two cities was high.

Estimation of HIV diagnosis rate with CD4+ T-lymphocyte level and infected-time model in Dehong Prefecture, Yunnan Province / 中华预防医学杂志

Objective@#To estimate the total number of people infected with HIV and to calculate the diagnosis rate of HIV in Dehong Prefecture, Yunnan Province.@*Methods@#Through the comprehensive AIDS prevention and treatment information system, we collected and analyzed the relevant information of the new diagnosis report of HIV in Dehong Prefecture, Yunnan Province in 2006-2015, mainly including age, sex, infected transmission, CD4+ T-lymphocyte counts, diagnostic time and so on. The content of the study was to establish a model method for estimating the diagnosis rate of HIV in Dehong. First, used the first CD4+ T-lymphocyte count after HIV diagnosis to estimate the date of infection. Then based on the estimated time from HIV infection to diagnosis we can estimate the diagnosis delay distribution which in turn can be used to account for individuals infected but not yet diagnosed and thus estimated the total number of HIV infections (diagnosed and undiagnosed). Finally, the number of new infections in each year was added to estimate the total number of infected people, and the number of people who had been diagnosed was divided by the total number of infected persons to obtain the proportion of HIV diagnosis rate.@*Results@#There were 8 215 reported cases in Dehong from 2006 to 2015, of which 1 297 cases were reported in 2007 (15. 8%) and 361 cases (4.4%) in 2015. The diagnosis rate of newly infected persons were 88% in 2005 and before. And from 2006 to 2015, the diagnosis rate of newly infected persons were 75%, 71%, 68%, 66%, 61%, 58%, 53%, 45%, 40% and 33%, respectively. The total number of newly infected persons in 2005 and before was 11 197 cases. The annual new infected number from 2006 to 2015 was 653, 671, 723, 640, 509, 468, 369, 375, 285 and 224 cases. The total number of people infected with HIV in Dehong was 16 114 cases, and the diagnosis rate was 87.7%.@*Conclusion@#The diagnosis rate of HIV in Dehong was at a high level. Since 2008, the annual number of new infections in Dehong has been declining.

Risk of HIV infection and its factors among men who have sex with men: a geosocial networking application-based survey in Beijing of China, 2017 / 中华预防医学杂志

Objective@#To assess risk of HIV infection and its risk factors among men who have sex with men (MSM) in Beijing, China.@*Methods@#We conducted a cross-sectional online survey in October, 2017. Inclusion criteria of participants were: aged 18 year or more; resided in Beijing; conducted homosexual activities in past six months; self-reported HIV status as negative or unclear. Demographic information, HIV test history, social media use, and high-risk sexual behaviors were collected by a self-reporting questionnaire, and a HIV risk assessment tool was used to assess HIV risk of MSM, 5 388 particpants were finally enrolled in the study. Logistic regression model was used to analyze factors associated with risk of HIV infection.@*Results@#Of the total 5 388 participants, most were 18-29 years old (64.35%), and the proportion of medium and high HIV risk score was 40.36%. The odds of medium and high HIV risk score among MSM who logged onto the app 1-20 times per week and>20 times per week were higher comparing with those who logged onto the app<1 time per week (OR=1.22, 95%CI: 1.02-1.46; OR=1.69, 95%CI: 1.38-2.06, respectively); MSM who completed college or higher education had lower probability of medium and high HIV infection risk, comparing with those who only had high school education level (OR=1.25, 95%CI:1.09-1.43) or junior or below education level (OR: 1.27, 95%CI: 1.05-1.53); MSM who did not conduct HIV test in past year had lower risk of medium and high HIV infection risk comparing with MSM who conducted HIV test in past year (OR=0.87, 95%CI: 0.77-0.99), and those who reported their HIV infection status unclear had higher probability of medium and high HIV infection risk than MSM who reported their HIV infection status negative (OR: 1.63, 95%CI: 1.44-1.86).@*Conclusion@#The proportion of MSM who were in medium and high HIV infection risk score was high in Beijing. Lower level of education, high frequency of social media use, conducted HIV test in past year, and unclear of their own HIV infection status were associated with medium and high level of HIV infection risk.

Qualitative study on unprotected sexual behaviors among male students who have sex with men in Beijing / 中华预防医学杂志

Objective@#To investigate the related factors of unprotected sexual behaviors among male students who have sex with men in Beijing.@*Methods@#Male students who have sex with men were recruited from May 2018 to July 2018 at two voluntary counseling and testing (VCT) clinics in Beijing by convenient sampling method. Information being collected during in-depth personal interviews with a semi-structured outline included ways to seek sexual partners, sexual partners characteristics, attitude of condom use, incidence and causes of unprotected sexual behaviors, rush poppers and alcohol use. The text information was summarized and analyzed by Nvivo 11.0 software.@*Results@#A total of 35 male students who have sex with men were recruited and interviewed, the median of age was 22 years old (P25-P75: 21-24 years old). We found that incomprehensive knowledge of condom use, low risk perception of non-anal sexual behaviors, rush poppers and alcohol use were risk factors of unprotected sexual behaviors on individual level. Besides, sex with regular sex partners, partners who were much older or not from campus, and insertive partners are more likely to be unprotected. Furthermore, refusal of condom use by sexual partners and low self-efficacy of decision-making on condom use were the main reasons for unprotected sexual behaviors among male student who have sex with men.@*Conclusion@#Lack of condom use knowledge, low risk perception of non-anal sexual behaviors and insufficient ability to refuse non-condom requirements for regular sex partners, partners who were much older or not from campus, and insertive partners are related factors of unprotected sexual behaviors among male students who have sex with men.