Prevalence and Trends of HIV, Syphilis, and HCV in Migrant and Resident Men Who Have Sex with Men in Shandong, China: Results from a Serial Cross-Sectional Study

Condom use and drug consumption in migrants: a systematic review

OBJECTIVE

To identify condom use and drug consumption in migrants, as well as the association between these variables.

METHOD

A systematic search was carried out for articles published in Spanish and English (2017-2022), in PubMed, EBSCO, WEB of SCIENCE, Elsevier, Scielo, Redalyc, with eligible studies reporting on condom use and drug consumption, and their association.

RESULTS

The search strategy found 147 articles with the combination of terms and other sources. After excluding articles by title, abstract, and finding that they had the study variables, eight articles were included for qualitative analysis and only three met the criteria for quantitative analysis.

CONCLUSION

Drug consumption favors inconsistent condom use, increasing the risk of acquiring an STI, and can lead to other mental health issues derived from the use of these substances.

[High seroprevalence of syphilis and genital herpes in migrants in transit in Chiapas, MexicoAlta soroprevalência de sífilis e herpes genital em migrantes em trânsito por Chiapas, México]

Objectives

To determine the prevalence of antibodies against Treponema pallidum and herpes simplex virus type 2 (HSV-2), and to identify the factors associated with these infections among migrants in transit in Chiapas, Mexico.

Methods

Cross-sectional study conducted during 2021-2022, in three migrant shelters in Chiapas, Mexico. Participants answered a questionnaire and provided a blood sample to detect antibodies against Treponema pallidum and HSV-2. The study calculated seroprevalence and assessed associated factors using Chi-square (χ²) tests and odds ratios.

Results

A total of 462 migrants participated, with an average age of 31.2 years; 56.9% were women, and 41.1% came from Honduras. The seroprevalence of HSV-2 was 29.9%; for syphilis it was 4.5%, and it was higher in men (8.0%) than in women (1.9%). Among pregnant women, 15.4% had antibodies against syphilis. Notable variables associated with syphilis include being male, having a history of genital lesions, having same-sex partners, and seropositivity to HSV-2. Regarding HSV-2, factors associated with infection included being female, age, schooling, sleeping in the street, a history of HIV testing, early sexual debut, number of sexual partners, and syphilis.

Conclusions

A high prevalence of syphilis and HSV-2 was found among the migrant population evaluated. Syphilis is confirmed as a re-emerging infection, even in women. Migrants have vulnerabilities associated with sexual behavior, so prevention, diagnosis, and treatment measures should be focused on this population group.

Predicting the risk of HIV infection among internal migrant MSM in China: An optimal model based on three variable selection methods

Introduction

Internal migrant Men who have sex with men (IMMSM), which has the dual identity of MSM and floating population, should be more concerned among the vulnerable groups for HIV in society. Establishing appropriate prediction models to assess the risk of HIV infection among IMMSM is of great significance to against HIV infection and transmission.

Methods

HIV and syphilis infection were detected using rapid test kits, and other 30 variables were collected among IMMSM through questionnaire. Taking HIV infection status as the dependent variable, three methods were used to screen predictors and three prediction models were developed respectively. The Hosmer-Lemeshow test was performed to verify the fit of the models, and the net classification improvement and integrated discrimination improvement were used to compare these models to determine the optimal model. Based on the optimal model, a prediction nomogram was developed as an instrument to assess the risk of HIV infection among IMMSM. To quantify the predictive ability of the nomogram, the C-index measurement was performed, and internal validation was performed using bootstrap method. The receiver operating characteristic (ROC) curve, calibration plot and dynamic component analysis (DCA) were respectively performed to assess the efficacy, accuracy and clinical utility of the prediction nomogram.

Results

In this study, 12.52% IMMSMs were tested HIV-positive and 8.0% IMMSMs were tested syphilis-positive. Model A, model B, and model C fitted well, and model B was the optimal model. A nomogram was developed based on the model B. The C-index of the nomogram was 0.757 (95% CI: 0.701-0.812), and the C-index of internal verification was 0.705.

Conclusions

The model established by stepwise selection methods incorporating 11 risk factors (age, education, marriage, monthly income, verbal violence, syphilis, score of CUSS, score of RSES, score of ULS, score of ES and score of DS) was the optimal model that achieved the best predictive power. The risk nomogram based on the optimal model had relatively good efficacy, accuracy and clinical utility in identifying internal migrant MSM at high-risk for HIV infection, which is helpful for developing targeted intervention for them.

Systematic Review of Hepatitis C Virus Prevalence in the WHO Western Pacific Region

BACKGROUND

This review aimed to identify hepatitis C virus (HCV) prevalence estimates among the general population and six key populations (people who inject drugs, men who have sex with men, sex workers, prisoners/detainees, Indigenous people, and migrants) in the World Health Organization Western Pacific Region (WHO WPR).

METHODS

Original research articles published between 2016 and 2020 were identified from bibliographic databases. Publications were retrieved, replicas removed, and abstracts screened. Retained full texts were assessed and excluded if inclusion criteria were not met. Methodological quality was assessed using the Johanna Briggs Institute critical appraisal checklist for prevalence data. Data on HCV exposure and active infection were extracted and aggregated and forest plots generated for each population by country.

RESULTS

There were no HCV prevalence estimates in any population for more than half of WPR countries and territories. Among the 76 estimates, 97% presented prevalence of exposure and 33% prevalence of active infection. General population viraemic prevalence was 1% or less, except in Mongolia. Results confirm the endemic nature of HCV among people who inject drugs, with estimates of exposure ranging from 30% in Cambodia to 76% in Hong Kong.

CONCLUSIONS

Countries require detailed knowledge of HCV prevalence in diverse populations to evaluate the impact of efforts to support WHO HCV elimination goals. Results provide baseline estimates from which to monitor and evaluate progress and by which to benchmark future elimination efforts.

HIV incidence and risk factors among transgender women and cisgender men who have sex with men in two cities of China: a prospective cohort study

Background

HIV epidemic among men who have sex with men (MSM) remains a major public health concern in China. Despite a growing body of research on transgender women worldwide, little is known about Chinese transgender women within MSM. We sought to estimate HIV incidence and distinguish risk factors of HIV acquisition among them from that among cisgener (non-transgender) MSM (cis-MSM).

Methods

We conducted an open cohort study among Chinese MSM, including those who were identified as transgender in Shanghai and Tianjin. Participants were initially recruited by local community-based organizations from January to June, 2016, and were followed up approximately every 6 months until June 2018. At each visit, a structured questionnaire was used to gather information on demographics, sexual risk behaviors, and HIV status. HIV incidence was calculated as the number of seroconversions divided by total number of person-years of follow-up among HIV-negatives at baseline. Risk factors of HIV acquisition were assessed by univariate and multivariate Cox regression models with time-dependent variables.

Results

A total of 1056 participants contributed 1260.53 person-years (PYs) of follow-up, 33 HIV seroconversions occurred during the follow-up period, yielding an estimated HIV incidence of 2.62 (95% CI 1.80–3.68) per 100 PYs. HIV incidence among transgender women was 4.42 per 100 PYs, which was significantly higher than that of 1.35 per 100 PYs among cis-MSM, demonstrating a threefold higher odds of HIV infection than cis-MSM. For transgender women, those lived locally ≤ 2 years (adjusted hazard ratio [aHR] = 1.76, 95% CI 1.13–2.76) and unprotected anal sex last time (aHR = 4.22, 95% CI 1.82–9.79) were more likely to acquire HIV. For cis-MSM, factors associated with HIV acquisition were frequency of anal sex ≥ 3 times in past one month (aHR = 4.19, 95% CI 1.06–16.47) and unprotected anal sex last time (aHR = 5.33, 95% CI 1.52–18.73).

Conclusions

Compared to cis-MSM, transgender women were at higher risk of HIV acquisition, highlighting an urgent need of tailored prevention. Future HIV program should consider to include them to ensure that this population in China are not left behind.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-022-00947-3.

Trends of HIV/Syphilis/HSV-2 seropositive rate and factors associated with HSV-2 infection in men who have sex with men in Shenzhen, China: A retrospective study

Objectives

To analyze the trends of HIV/syphilis/HSV-2 seropositive rate and explore the related factors with HSV-2 infection to provide the basis for adjusting STD intervention strategies and formulating prevention and control measures among MSM in Shenzhen.

Methods

Time-location sampling was conducted among MSM in Shenzhen in 2012, 2014, 2016, and 2018. Data on demographics, sexual behaviors and the laboratory test results of HIV, syphilis, HSV-2 were collected. The χ² trend test was used to analyze the trends of HIV/syphilis/HSV-2 seropositive rate. The binary logistic regression model was used to explore the factors associated with HSV-2 infection.

Results

The seropositive rate of HIV fell significantly from 15.9% in 2012 to 8.7% in 2018 (P_trend = 0.003), syphilis seropositive rate was significantly decreased from 20.4% in 2012 to 14.8% in 2018 (P_trend = 0.025), HSV-2 seropositive rate had no significant change (16.7% in 2012 to 14.0% in 2018; P_trend = 0.617). In principal component logistic regression analysis showed that FAC1_1 (X₁ = Ever had sex with female, X₂ = Gender of first sexual partner, X₃ = Marital status, X₄ = Age group), FAC2_1 (X₅ = Education, X₆ = Monthly income (RMB), X₇ = Frequency of condom use in anal sex with men in the past 6 months), and FAC4_1 (X₉ = History of STDs) were significantly associated with HSV-2 infection.

Conclusions

The seropositive rates of HIV and syphilis have dropped significantly but are still high. HSV-2 seropositive rate had no significant change and maintained a high level. It is necessary to continue strengthening HIV and syphilis interventions among MSM in Shenzhen. HSV-2 detection and intervention are urgently required for MSM, which might be another effective biological strategy further to control the HIV epidemic among MSM in Shenzhen.

Evolving HIV Epidemiology in Mainland China: 2009-2018

PURPOSE OF REVIEW

This review is intended to provide an overview of the evolution of HIV epidemiology over the past decade in China.

RECENT FINDINGS

We provided a succinct overall view of the epidemic, followed by surveillance data, profiles of key populations, HIV molecular epidemiology, and drug resistance, as well as survival in the age of antiretroviral therapy usage. For each topical issue, we first reviewed the latest empirical evidence, followed by a brief summary assessment. We briefly addressed the challenges and opportunities of the next generation of HIV control and prevention efforts in China. Notably, macro-social factors need to be integrated into the next generation of clinical and/or behavioral HIV research to inform disease progression and management, as well as control and prevention.

High HIV Incidence Among Men Who Have Sex With Men in 8 Chinese Cities: Results From a Trial

Background

In China, while the overall HIV prevalence has been decreasing within key populations, the epidemic among men who have sex with men (MSM) is still on the rise. This study aims to assess the HIV incidence rate and identify driving forces of HIV seroconversion among MSM in a closed cohort.

Methods

This study is a secondary analysis of a large trial of HIV testing promotion among Chinese MSM in 2016–2017. Sexual behaviors, HIV testing activities, and HIV serostatus were measured at baseline and follow-up every 3 months. HIV seroconversion in this study was defined as a self-reported HIV-positive test result. Participants who reported testing for HIV at least twice during different follow-up periods were included. Subgroup analysis and Cox regression were used to examine the correlates with HIV seroconversion.

Results

Overall, 347 participants were included in this study, with a mean age of 25.3 ± 6.1, and 71.2% were migrants. The sociodemographic characteristics of the included participants were similar to the rest of the participants in the trial (n = 1034); 7.2% (25/347) of participants seroconverted during the study period, resulting in an incidence rate of 15.56/100 person-years. In subgroup analysis, the HIV incidence rate was higher among migrants than nonmigrants (incidence rate ratio, 1.26; 95% confidence interval [CI], 0.47–3.87). In the time-dependent Cox regression model, bisexual MSM had a higher risk of contracting HIV than gay men (adjusted hazard ratio, 2.19; 95% CI, 1.02–4.72).

Conclusions

Our findings suggest a high HIV incidence rate among Chinese MSM. Further expansion of pre-exposure prophylaxis and other effective HIV prevention interventions are urgently needed.

Gender Identity and Sexual Orientation in Chinese Men Who Have Sex with Men: A Latent Class Analysis

Men who have sex with men (MSM) are a diverse population yet are often treated as a monolithic risk group. In China, MSM have long been characterized as a "bridge population" of closeted men who are married to (or will marry) women due to sociocultural expectations. Latent class models can inform a more nuanced yet empirical characterization of this population. In total, 1424 eligible respondents recruited online provided self-reported behavioral data. Nine items related to constructs including sexual behaviors, sexual orientation, and gender identity informed the latent class model. Logistic regression was used to measure associations between latent class membership and HIV-related sexual and health-seeking behaviors. Model fit indicated a population structure made up of four classes that we characterized as "Gender nonconforming" (4.3%), "Closeted-unmarried" (29.9%), "Closeted-married" (24.6%), and "Out" (41.2%). Members of the "gender nonconforming" class were more likely to report HIV-related risk behaviors, and "Closeted-unmarried" class members were less likely to report health-seeking behaviors, both relative to "Out" members. The largest latent class was made up of members of the "Out" class, an enlightening revision of a population traditionally viewed as largely closeted men. Two types of "closeted" classes emerged, distinguished by divergent tendencies regarding marriage and health seeking. Findings suggest that current understandings of Chinese MSM are simplistic (regarding closeted behaviors) and too narrow (in its definition of MSM as cisgender men). A more nuanced understanding of MSM subgroups and their heterogeneous risk behaviors will be critical for provision of more meaningful prevention services.

Injection and Heterosexual Risk Behaviors for HIV Infection Among Non-gay Identifying Men Who Have Sex with Men and Women

Non-gay identifying men who have sex with men and women (MSMW) are an important subgroup of men who have sex with men (MSM) and have been underrepresented in studies of MSM that only use gay venues to draw their samples. We assessed heterosexual and drug use risks of MSMW who use drugs in a sample of male entrants to the Mount Sinai Beth Israel drug treatment programs from 2005 to 2018. Blood samples were collected and tested for HIV and HSV-2 infections. Among HIV seronegative participants, MSMW had significantly greater odds of sharing used needles with others, and reporting unprotected sex with female casual partners and female commercial sex partners, compared to their counterparts who reported sex with women exclusively (MSWE). Although not recruited from gay venues, MSMW had a significantly higher HIV prevalence than MSWE (23% vs. 10%, p < 0.001). Interventions that are specifically tailored to HIV prevention among MSMW are needed to ameliorate the prevalence of HIV risks and infection.

Molecular epidemiology of acute HCV infection in HIV-positive patients from Hong Kong, Taipei, Tokyo

BACKGROUND

Acute hepatitis C virus (HCV) infections have been increasingly reported among human immunodeficiency virus (HIV)-positive men who have sex with men (MSM) in the Asia-Pacific region. It remains unknown whether international network of HCV transmission has occurred in this region.

METHODS

HIV-positive patients with acute HCV infection, defined as HCV seroconversion within a year or documented acute hepatitis with seroconversion, diagnosed in Hong Kong, Taipei and Tokyo during 2010-2016 were included in this molecular epidemiology study. The NS5B region of the HCV genome (365 bp) was amplified using nested polymerase chain reaction and sequenced.

RESULTS

Of 234 HIV-positive patients with acute HCV infection, all were male with 94% being MSM. At the diagnosis of acute HCV infection, 73.5% had concurrent sexually transmitted diseases and 88.0% were receiving combination antiretroviral therapy. The most prevalent HCV genotype was 3a, 2a and 1b in Hong Kong, Taipei and Tokyo respectively. Nine independent clusters belonging to five genotypes (1b, 2a, 2c, 3a and 6a) were identified, each of which occurred in one city without overlapping except for one 3a sequence from Taipei that was closely related genetically to the Hong Kong cluster.

CONCLUSIONS

No international network of HCV transmission was identified among HIV-positive patients in the three Asia-Pacific cities. The transmission dynamics of sexually acquired HCV differed by city, but the risk of intercity clustering should not be ignored.

Assessing consistent condom use among migrant men who have sex with men in Shanghai, China: validation of an information-motivation-behavioural skills model

BACKGROUND

In China, high prevalence of risky sexual behaviours and inequity in health services lead to situations in which migrant men who have sex with men face higher risk of contracting the human immunodeficiency virus. Consistent condom use is a primary means of preventing HIV infection during anal sex among MSM. This study aimed to apply the information-motivation-behavioural skills model to examine the predictors of consistent condom use among migrant MSM in Shanghai, and tested the associations between model constructs.

METHODS

A cross-sectional study was conducted among 412 migrant MSM in Shanghai. Data on HIV-related information, motivation, behavioural skills, and behaviours were collected via structured questionnaires. A structural equation model was used to assess the IMB model.

RESULTS

Of the 412 participants, 4.4% reported HIV-positive status, and prevalence of consistent condom use in the previous 6 months was 44.9%. A restricted IMB model provided an acceptable fit to the data. Behavioural skills were found to directly predict consistent condom use (β = 0.629, P < 0.01). Neither information nor motivation could directly predict consistent condom use (P > 0.05), but motivation predicted it indirectly and was mediated by behavioural skills.

CONCLUSION

The prevalence of consistent condom use was found to be relatively low among migrant MSM in Shanghai. The restricted IMB model was found to be a good predictor of consistent condom use among them. The results of this study indicate that intervention strategies for safer sexual behaviour should not only include information dissemination, but also emphasize motivation and behavioural skills among this population.

Crowdsourcing to expand HIV testing among men who have sex with men in China: A closed cohort stepped wedge cluster randomized controlled trial

BACKGROUND

HIV testing rates are suboptimal among at-risk men. Crowdsourcing may be a useful tool for designing innovative, community-based HIV testing strategies to increase HIV testing. The purpose of this study was to use a stepped wedge cluster randomized controlled trial (RCT) to evaluate the effect of a crowdsourced HIV intervention on HIV testing uptake among men who have sex with men (MSM) in eight Chinese cities.

METHODS AND FINDINGS

An HIV testing intervention was developed through a national image contest, a regional strategy designathon, and local message contests. The final intervention included a multimedia HIV testing campaign, an online HIV testing service, and local testing promotion campaigns tailored for MSM. This intervention was evaluated using a closed cohort stepped wedge cluster RCT in eight Chinese cities (Guangzhou, Shenzhen, Zhuhai, and Jiangmen in Guangdong province; Jinan, Qingdao, Yantai, and Jining in Shandong province) from August 2016 to August 2017. MSM were recruited through Blued, a social networking mobile application for MSM, from July 29 to August 21 of 2016. The primary outcome was self-reported HIV testing in the past 3 months. Secondary outcomes included HIV self-testing, facility-based HIV testing, condom use, and syphilis testing. Generalized linear mixed models (GLMMs) were used to analyze primary and secondary outcomes. We enrolled a total of 1,381 MSM. Most were ≤30 years old (82%), unmarried (86%), and had a college degree or higher (65%). The proportion of individuals receiving an HIV test during the intervention periods within a city was 8.9% (95% confidence interval [CI] 2.2-15.5) greater than during the control periods. In addition, the intention-to-treat analysis showed a higher probability of receiving an HIV test during the intervention periods as compared to the control periods (estimated risk ratio [RR] = 1.43, 95% CI 1.19-1.73). The intervention also increased HIV self-testing (RR = 1.89, 95% CI 1.50-2.38). There was no effect on facility-based HIV testing (RR = 1.00, 95% CI 0.79-1.26), condom use (RR = 1.00, 95% CI 0.86-1.17), or syphilis testing (RR = 0.92, 95% CI 0.70-1.21). A total of 48.6% (593/1,219) of participants reported that they received HIV self-testing. Among men who received two HIV tests, 32 individuals seroconverted during the 1-year study period. Study limitations include the use of self-reported HIV testing data among a subset of men and non-completion of the final survey by 23% of participants. Our study population was a young online group in urban China and the relevance of our findings to other populations will require further investigation.

CONCLUSIONS

In this setting, crowdsourcing was effective for developing and strengthening community-based HIV testing services for MSM. Crowdsourced interventions may be an important tool for the scale-up of HIV testing services among MSM in low- and middle-income countries (LMIC).

TRIAL REGISTRATION

ClinicalTrials.gov NCT02796963.

An Update on the Global Epidemiology of Syphilis

PURPOSE OF REVIEW

Syphilis continues to cause morbidity and mortality worldwide. While syphilis infection is easily identifiable and treatable, rates of syphilis infection continue to increase among select populations in high-income countries and remain at endemic levels in low- and middle-income counties.

RECENT FINDINGS

World Health Organization recommended strategies have led to the dual elimination of mother-to-child transmission of syphilis and HIV in several countries, however outbreaks among select populations need to be adequately addressed.

SUMMARY

Continued vigilance and investment is needed to address syphilis worldwide. The epidemiology of syphilis differs in high-income and low- and middle-income counties.

Transplantation or rurality? Migration and HIV risk among Chinese men who have sex with men in the urban areas

INTRODUCTION

Migration of men who have sex with men (MSM) from rural to urban areas is common across low- and middle-income countries and is widely believed to contribute to elevated HIV risk among migrant MSM in urban areas. Little consensus exists on whether their risk is due to their transplantation or their being from resource-constrained rural areas. This study seeks to clarify the relationship between migration and HIV risks by comparing differences in HIV-related risky sexual behaviours and healthcare utilization across competing conceptualizations of migratory statuses.

METHODS

In July 2016, MSM ≥16 years old currently residing in one of eight urban cities in China were recruited for an online cross-sectional survey, which collected information on socio-demographics, sexual behaviours, HIV care-seeking behaviours, and healthcare utilization. Based on a question about residency status, each participant was classified as an urban local resident, urban transplant, or rural transplant. Multivariable multinomial logistic regression was used to examine the associations between risky behaviours and healthcare utilization among these three groups.

RESULTS

Among 2007 MSM, the proportion of local, urban transplant and rural transplant were 32% (648/2007), 24% (478/2007), and 44% (881/2007), respectively. Compared with urban local resident MSM, urban transplant MSM were more likely to have ever tested for HIV (adjusted odds ratio (aOR) = 1.39, 95% confidence interval (CI): 1.08 to 1.80). Compared with urban transplant MSM, rural transplant MSM were less likely to have utilized any governmental sexual health services in the past three months (aOR = 0.75, 95% CI: 0.60 to 0.93), ever tested for HIV (aOR = 0.77, 95% CI: 0.61 to 0.96), ever initiated antiretroviral therapy (ART) (aOR = 0.16, 95% CI: 0.05 to 0.52), and ever purchased sex (aOR = 0.57, 95% CI: 0.38 to 0.85). No other significant differences were found in sexual behaviours among three groups.

CONCLUSIONS

The widely used local/migrant categorization obscures important differences in HIV risk present between urban/rural subgroups among them. Previous studies of HIV risks in Chinese "migrant" may have failed to consider the role of structural factors such as discrimination or barriers to healthcare when interpreting their findings of higher HIV prevalence in this population. Low ART uptake among rural transplant MSM in this study is particularly concerning and underscore the need for HIV-related interventions tailored for this group.

A randomised controlled trial to evaluate the impact of sexual health clinic based automated text message reminders on testing of HIV and other sexually transmitted infections in men who have sex with men in China: protocol for the T2T Study

INTRODUCTION

The frequency of screening for HIV and other sexually transmitted infections (STIs) among men who have sex with men (MSM) is still low in China.

METHODS AND ANALYSIS

A sexual health clinic based randomised controlled trial will be conducted in Guangzhou, Wuxi and Shenzhen, China, enrolling 600 MSM. Eligibility will be judged by the pre-programed iPad based questionnaire: (1) age ≥18 years and (2) have had two or more male anal sex partners, or condomless anal sex with a casual male sex partner, or an STI history, in the past 6 months, and (3) provides a valid mobile phone number. Eligible men will be randomly allocated 1:1 to the intervention arm (with monthly text messages reminding them to test for HIV/STIs) or to the control arm (with no reminders). Men in both arms will complete a questionnaire onsite at enrolment and after 12 months, and another questionnaire online at 6 months. Men in both arms will be tested for HIV, syphilis, anal gonorrhoea/chlamydia and penile gonorrhoea/chlamydia at enrolment and at 12 months. The primary outcome is the rate and frequency of HIV testing within the 12 months after enrolment. The secondary outcome is the rate of unprotected anal intercourse. An assessment of the cost effectiveness of this intervention is also planned.

ETHICS AND DISSEMINATION

The study has been approved by the ethical review committees of the University of New South Wales, Australia (HC16803), the Guangdong Provincial Centre for Skin Disease and STI Control (GDDHLS-20160926) and the Wuxi Centre for Disease Control and Prevention (WXCDC2016009), China. Study findings will be submitted to academic journals and disseminated to local health authorities.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry at: http://www.chictr.org.cn/showprojen.aspx?proj=15752 and WHO International Clinical Trials Registry Platform at: http://apps.who.int/trialsearch/Trial2.aspx?TrialID=ChiCTR-IOR-16009304.