Population-based study of chlamydial infection in China: a hidden epidemic

Differences in socio-demographics status, risk behaviours, healthcare uptake and HIV/ sexually transmitted infections (STIs) between brothel-based and street-based female sex workers in Yunnan, China

BACKGROUND

Heterosexual contact is the primary mode of HIV transmission in China and commercial sex is thought to play a crucial role in China's epidemic. Female sex workers (FSWs) in China tend to be either brothel-based (BSWs) or street-based (SSWs), but few studies have investigated the differences between these important segments of this difficult-to-reach, high-risk population. Our aim was to explore the differences between SSWs and BSWs in terms of socio-demographic characteristics, sexual and risky practices, HIV/STI-related knowledge, health services, HIV/STI prevalence and other aspects.

METHODS

A cross-sectional survey was conducted in Yunnan Province of China in partnership with a local FSW-friendly non-governmental organization. Face-to-face interviews using a structured questionnaire were conducted to collect data on socio-demographic characteristics, sex work history, sexual behaviours, HIV/STI-related knowledge, HIV testing history, and healthcare services uptake. Blood samples were taken for HIV and syphilis testing, and urine samples for gonorrhea and chlamydia testing. Descriptive statistics were used to evaluate differences between SSWs and BSWs.

RESULTS

A total of 185 BSWs and 129 SSWs were included in the study. SSWs were older and less educated, had more dependents and more clients, lower condom use and accessed fewer healthcare services. Moreover, 37.2% of SSWs and 24.9% of BSWs were found to have HIV/STI infection. Unfortunately, the awareness related to STIs was relatively low in both groups, especially SSWs.

CONCLUSIONS

Our study provides evidence that confirms the disproportionately high vulnerability of SSWs to HIV and other STIs, underscoring the urgent need for the Chinese health and public health sectors to prioritize outreach to SSWs. Awareness and educational programs, condom distribution, testing and health check-ups should be included in a comprehensive strategy for HIV/STI prevention in this high-risk population.

The serodiagnositic value of Chlamydia trachomatis antigens in antibody detection using luciferase immunosorbent assay

Introduction

Among the different antigens used in the detection of anti-Chlamydia trachomatis antibodies, significant differences in sensitivity and specificity have been observed. Further evaluation of C. trachomatis antigens in antibody detection is urgently needed for the development and application of C. trachomatis serologic assays.

Methods

Chlamydia trachomatis antigens Pgp3, TmeA, InaC, and HSP60 were selected and used in luciferase immunosorbent assay (LISA). The detection results obtained from well-defined C. trachomatis positive and negative samples were compared with the commercial C. trachomatis ELISA (Mikrogen) for performance evaluation.

Results

Pgp3, TmeA, InaC, and HSP60-based LISA showed sensitivity of 92.8, 88.8, 90.4, and 94.4%, and specificity of 99.2, 99.2, 99.2, and 92%, respectively. ROC analysis indicated that Pgp3-based LISA showed similar performance to Mikrogen ELISA (AUC 0.986 vs. 0.993, p = 0.207). Furthermore, four C. trachomatis antigens achieved strong diagnostic efficiency, i.e., positive likelihood ratios [+LR] ≥ 10 in C. trachomatis-infected women and negative likelihood ratios [-LR] ≤ 0.1 in C. trachomatis negative low exposure risk children, but only Pgp3 and TmeA showed strong diagnostic value in general adults. In addition, Pgp3, TmeA, and InaC, but not HSP60, achieved high performance, i.e., both positive predictive value (PPV) and negative predictive value (NPV) ≥ 90.9%, and showed no significant cross-reactivity with anti-Chlamydiapneumoniae.

Conclusion

Three C. trachomatis species-specific antigens Pgp3, TmeA, and InaC show superior performance in the detection of anti-C. trachomatis antibody, indicating the potential to be used in developing C. trachomatis serologic tests.

Evaluating the effect of the plan of national syphilis control in controlling the syphilis epidemic in Jiangsu, China 2010-2020

Background

Starting in 2010, the Chinese government initiated a 10-year syphilis control plan, called the national syphilis control plan (NSCP), to address the emerging threat of syphilis. We aimed to evaluate the effect of the NSCP plan on syphilis control in Jiangsu, China.

Methods

The temporal trends of syphilis incidence, prevalence and rate of condom use were estimated by Joinpoint regression with average annual percent change (APC) and average annual percentage (APPC). A Chi-square test was conducted to analyze the outcomes in different subgroups. ArcGIS was used to analyze the spatiotemporal distribution of syphilis incidence.

Results

Geographically, early and congenital syphilis incidence decreased significantly in all areas of the province during the period of NSCP. Early syphilis incidence decreased from 21.1 to 8.8 (APC: -7.5, 95%CI: -8.6, -6.5, p < 0.001) per 100,000 people, and congenital syphilis decreased from 63.6 to 4.1 (APC: -14.8, 95%CI: -20.8, -8.4, p < 0.01) per 100,000 newborns from 2010 to 2020. Also, syphilis prevalence reduced from 13.4 to 3.8% (APC: -8.7, 95%CI: -12.1, -5.0, p = 0.001) among men who have sex with men, from 5.3 to 1.7% (APC: -7.9, 95%CI: -11.7, -3.8, p = 0.002) among female sex workers and remained under 1.0% with slight variations among pregnant women (APC: 0.3, 95%CI: -4.3, 5.1, p = 0.877) from 2010 to 2020. 0.2% (2,436) of pregnant women who received free syphilis testing during pregnancy were diagnosed with current syphilis infection, and 97.0% (2,555) of newborns in the province were delivered to women diagnosed with syphilis. 91.8% (2,346) of live babies and about 90% of diagnosed patients received complete standard syphilis diagnosis and treatment services.

Conclusion

Trends of early syphilis incidence and syphilis prevalence show a considerable decreasing trend among almost all the key populations after implementing NSCP. Congenital syphilis has significantly decreased as well and hence, the NSCP program should be sustained and strengthened to control the syphilis epidemic in China further.

Genomic epidemiology of Neisseria gonorrhoeae in Shenzhen, China, during 2019-2020: increased spread of ceftriaxone-resistant isolates brings insights for strengthening public health responses

The antimicrobial resistance (AMR) in gonorrhea poses global threat of increasing public health concern. In response to this concern, molecular surveillance has been widely utilized to detail the changes in the evolution and distribution of Neisseria gonorrhoeae during AMR transmission. In this study, we performed a comprehensive molecular surveillance of 664 N. gonorrhoeae isolates collected in Shenzhen, one of the cities with the largest mobile population in China, 2019-2020. In 2020, ceftriaxone showed an unprecedented high resistance rate of 24.87%, and 67.83% of the ceftriaxone-resistant (Cro-R) isolates harbored a nonmosaic penA allele. The Cro-R isolates with nonmosaic penA alleles showed a tremendous increasing trend from 0.00% in 2014 to 20.45% in 2020, which proves the need for monitoring nonmosaic penA-related resistance. Importantly, genotyping indicated that multilocus sequence typing ST11231 (35.71%) had a notable rate of ceftriaxone resistance, which might become the focus of future surveillance. Whole-genome sequencing analysis showed that the internationally spreading FC428 clones have circulated in Shenzhen region with typical ceftriaxone resistance (MIC ≥ 0.5 mg/L) maintained. Our surveillance combined with genomic analysis provides current information to update gonorrhea management guidelines and emphasizes that continuous AMR surveillance for N. gonorrhoeae is essential. IMPORTANCE We conducted a comprehensive molecular epidemiology analysis for antimicrobial-resistant Neisseria gonorrhoeae in Shenzhen during 2019-2020, which provided important data for personalized treatment and adjustment of monitoring strategy. Briefly, the proportion of ceftriaxone-resistant (Cro-R) isolates reached a stunning prevalence rate of 24.87% in 2020. A typical increment of Cro-R isolates with nonmosaic penA alleles proves the necessity of monitoring nonmosaic AMR mechanism and involving it into developing molecular detection methods. Whole-genome sequencing analysis showed that the international spreading FC428 clone has been circulating in Shenzhen with typical ceftriaxone resistance (MIC ≥ 0.5 mg/L) maintained. In summary, we conducted a comprehensive epidemiology study, providing significant data for therapy management. Our results not only improve the understanding of the distribution and transmission of AMR in N. gonorrhoeae but also provide effective AMR data for improving surveillance strategies in China.

Orgasm and Faking Orgasm: Heterosexual Interactions in China

This article examines the prevalence and correlates of orgasm and faking orgasm in the last year among a representative sample of Chinese men and women. Existing research on orgasm in China has largely been confined to medical research. To our knowledge, no published studies have examined faking orgasm in a Chinese context. These data come from the Chinese Health and Family Life Survey (CHFLS) conducted in 1999 and 2000. We used multivariable logistic regression to identify independent correlates of orgasm and faking orgasm among 1496 women and 1497 men, ages 20-64. In accounting for orgasm and faking orgasm in China, we found evidence that men and women are trying to manage social expectations and to act in accordance with gender expectations, consistent with research in other countries. Results provide insight into how specific sexual practices (e.g., oral sex) and interactional pressures (e.g., insecurity) are correlated with orgasm and faking orgasm. Findings pave the way for future research on the presence of gender inequality as evidenced through lower orgasm rates among women and higher rates of faking orgasm. These findings have implications for how we conceptualize and study gendered and interactional components of sex, which are often overlooked in research and programmatic efforts in China.

Preconception syphilis seroprevalence and association with duration of marriage and age among married individuals in Guangdong Province, China: A population-based cross-sectional study

BACKGROUND

Duration of marriage (DoM) and age are important characteristics of married individuals, who are the critical population for eliminating mother-to-child transmission (MTCT) of syphilis. A deep understanding of the preconception syphilis seroprevalence (PSS) and its distribution among this population may be able to help to eliminate MTCT. However, few population-based epidemiological studies have been focused on this group, and the association of DoM and age with PSS remains unclear.

METHODOLOGY/PRINCIPAL FINDINGS

This study used data from 4,826,214 married individuals aged 21-49 years who participated in the National Free Preconception Health Examination Project in Guangdong Province, China, between 2014 and 2019. Syphilis was screened using the rapid plasma reagin (RPR) test. The seroprevalence time series, seroprevalence map, and hot spot analysis (HSA) were employed to visualize the spatiotemporal distribution. The restricted cubic spline (RCS) based on multivariate logistic regression was used to model the association of DoM and age with PSS. The interactions on the additive scale of DoM and age were also assessed. The PSS was 266.61 per 100,000 persons (95% CI: 262.03-271.24) and the burden was higher in economically underdeveloped area within the province. A strong J-shaped non-linearity association was observed between age and PSS. Specifically, the risk of seropositivity was relatively flat until 27 years of age among men and increased rapidly afterwards, with an adjusted odds ratio (aOR) of 1.13 (95% CI: 1.12-1.13) per unit. Among women, the risk of seropositivity was relatively flat until 25 years of age and increased rapidly afterwards with an aOR of 1.08 (95% CI: 1.08-1.09) per unit. DoM was negatively associated with PSS among married individuals. Moreover, the combined effects of age and DoM appeared to be synergistic.

CONCLUSIONS/SIGNIFICANCE

Our findings suggest that attention should be paid to preventing syphilis in underdeveloped areas and that syphilis screening in newly married individuals who are in their late 20s or older should be recommended. Additionally, early syphilis prevention strategies should be implemented among young people as early as possible.

Sero-prevalence of 19 infectious pathogens and associated factors among middle-aged and elderly Chinese adults: a cross-sectional study

OBJECTIVES

To systematically assess the sero-prevalence and associated factors of major infectious pathogens in China, where there are high incidence rates of certain infection-related cancers.

DESIGN

Cross-sectional study.

SETTING

10 (5 urban, 5 rural) geographically diverse areas in China.

PARTICIPANTS

A subcohort of 2000 participants from the China Kadoorie Biobank.

PRIMARY MEASURES

Sero-prevalence of 19 pathogens using a custom-designed multiplex serology panel and associated factors.

RESULTS

Of the 19 pathogens investigated, the mean number of sero-positive pathogens was 9.4 (SD 1.7), with 24.4% of participants being sero-positive for >10 pathogens. For individual pathogens, the sero-prevalence varied, being for example, 0.05% for HIV, 6.4% for human papillomavirus (HPV)-16, 53.5% for Helicobacter pylori (H. pylori) and 99.8% for Epstein-Barr virus . The sero-prevalence of human herpesviruses (HHV)-6, HHV-7 and HPV-16 was higher in women than men. Several pathogens showed a decreasing trend in sero-prevalence by birth cohort, including hepatitis B virus (HBV) (51.6% vs 38.7% in those born <1940 vs >1970), HPV-16 (11.4% vs 5.4%), HHV-2 (15.1% vs 8.1%), Chlamydia trachomatis (65.6% vs 28.8%) and Toxoplasma gondii (22.0% vs 9.0%). Across the 10 study areas, sero-prevalence varied twofold to fourfold for HBV (22.5% to 60.7%), HPV-16 (3.4% to 10.9%), H. pylori (16.2% to 71.1%) and C. trachomatis (32.5% to 66.5%). Participants with chronic liver diseases had >7-fold higher sero-positivity for HBV (OR=7.51; 95% CI 2.55 to 22.13).

CONCLUSIONS

Among Chinese adults, previous and current infections with certain pathogens were common and varied by area, sex and birth cohort. These infections may contribute to the burden of certain cancers and other non-communicable chronic diseases.

High chlamydia infection and its associated factors among patients seeking clinic-based STI services in Southern China: A preliminary cross-sectional study

OBJECTIVE

Chlamydia trachomatis (CT) infection is one of the most common sexually transmitted infections (STIs) worldwide. This study aimed to provide prevalence and associated factors data among patients seeking clinic-based STI services for estimating the disease burden of CT.

STUDY DESIGN AND METHOD

A cross-sectional survey was conducted among patients attending clinics for STI services. Patients' social-demographic and behavioral information was collected and CT infection was determined by nucleic acid amplification test (NAAT) with self-collected urine specimens. Associated factors were identified using logistic regression.

RESULTS

Among the 8,324 participants, the overall prevalence was 9.0% with 10.7% for males and 8.3% for females respectively. Multivariate analysis showed that aged < 24 [adjusted odds ratio (aOR) = 1.27, 95% confidence interval (CI) = 1.01-1.59], being unmarried (aOR = 1.64, 95%CI = 1.35-2.00), having junior high school or below education level (aOR = 1.47, 95%CI = 1.13-1.91), having no access to health insurance (aOR = 1.27, 95%CI = 1.07-1.51), and being positive for Neisseria gonorrhoeae (NG, aOR = 4.49, 95%CI = 3.25-6.21) were significantly associated with CT infection.

CONCLUSION

We found that CT infection is prevalent among patients seeking clinic-based STI services in Southern China. Targeted interventions could be implemented for patients with a higher risk of CT infection including those aged < 24, being unmarried, having junior high school or below education level, having no access to health insurance, and being positive for NG. In addition, routine CT screening could be considered a public health strategy by the government.

Prevalence and spatial heterogeneity of Trichomonas vaginalis infection among the female population and association with climate in Guangxi Zhuang autonomous region, Southern China

BACKGROUND

Two cervical cancer screening (CCS) projects have been ongoing for years in Guangxi Zhuang autonomous region (Guangxi), and some Trichomonas vaginalis infection (TVI) cases have been found as an opportunistic finding. This study aimed to identify the high-risk population and expound the spatial epidemiological features of TVI in Guangxi.

METHODS

This study was based on CCS from 2012 to 2019. Adjusted odds ratio (AOR), and spatial analyses were used to identify the high-risk subgroups, as well as to depict the spatial epidemiological feature and its relationship with meteorological factors.

RESULTS

The infection rate of TVI was 0.38% in 873,880 samples. Significant association with a high risk of TVI was found in the following: females aged 40-49 years (aOR=4.464; 95% CI, 3.359-5.932; p<0.001), aged 50-59 years (aOR=3.169; 95% CI, 2.370-4.237; p<0.001), from urban (aOR=1.577; 95% CI, 1.471-1.691; p<0.001), from minority areas (aOR=1.183; 95% CI, 1.060-1.320; p=0.003), areas with GPD <41,500 CNY (aOR=1.191; 95% CI, 1.106-1.282; p<0.001), and inland areas (aOR=1.520; 95% CI, 1.339-1.726; p<0.001). Counties with higher infection rate were concentrated in northwest Guangxi's mountainous area (Z-score=3.9656, p<0.001), in the upper reaches of the Hongshui River and Yu River, and with a significant spatial autocorrelation (Moran's I=0.581, p=0.002). Spatial error model showed significantly negative regressions among temperature (B=-0.295, p=0.002), annual temperature range (B=-0.295, p=0.002), and TVI spatial distribution.

CONCLUSION

The spatial clustering and disparity of TVI in northwest Guangxi warrant further study, and meteorological conditions may play an important role in TVI in northwest Guangxi.

Seroepidemiology of Chlamydia trachomatis Infection in the General Population of Northern China: The Jidong Community Cohort Study

A longitudinal serological study to investigate the seropositive frequency, incidence, and antibody dynamics of Chlamydia trachomatis infection in the general population of China is urgently needed in order to optimize the strategies for surveillance and precise prevention of C. trachomatis infection. This longitudinal study enrolled 744 subjects aged 18-65 years from Jidong Community of Northern China from 2014 to 2018. Seropositive frequency, incidence, and reinfection of C. trachomatis were determined by detecting antibody against C. trachomatis Pgp3 using "in-house" luciferase immunosorbent assay (LISA). The dynamic of anti-Pgp3 antibody was analyzed using the Generalized Estimating Equation (GEE) model. The overall Pgp3 seropositive frequency among the 18-65-year-old population was 28.1% (95% CI 24.9-31.5), and significantly increased from 12.0% in those aged 18-29 years to 48.6% in the 60-65 years old. The seropositive frequency was slightly higher in women than in men (31.3% vs. 25.4%) without statistical significance. The C. trachomatis incidence and reinfection rate were 11 and 14 per 1,000 person-years, respectively, and showed no significant difference with respect to age, gender, ethnicity, marital status, and education levels. Furthermore, anti-Pgp3 antibody remained detectable in 93.3% (195/209) of the seropositive subjects during the 5 years of follow-up. The overall decay rate for anti-Pgp3 antibody for CT-infected persons was -0.123 Log2 RLU/year, which was dramatically slower than in CT new infection (-3.34 Log2 RLU/year) or reinfection (-1.1 Log2 RLU/year). In conclusion, at least one quarter of the people aged 18-65 years have been infected with C. trachomatis over their lifetime while all age groups are susceptible to C. trachomatis infection in the community of Northern China. Therefore, comprehensive prevention strategies are urgently needed.

Effects of an Internet-Based and Teacher-Facilitated Sexuality Education Package: A Cluster-Randomized Trial

BACKGROUND

This study aimed to evaluate the effects of an internet-based and teacher-facilitated sexuality education package on the sexual knowledge and attitudes of Chinese adolescents.

METHODS

Six middle schools where no sexuality education had been performed with a total of 501 adolescent students (245 males and 256 females) were included in the trial. In total, 14 classes were randomly assigned to the intervention (internet-based sexuality education package) or the control group (classes were conducted as per normal). Students' sexual knowledge and attitudes were assessed at the baseline, at the end of the intervention, and 12 months after the intervention. Generalized linear models were employed to assess the effects of the intervention.

RESULTS

Positive effects of the intervention were observed on sexual knowledge (β = 4.65, 95% CI: 4.12-5.17) and attitudes (β = 1.25, 95% CI: 1.00-1.50) at the end of the intervention. After 12 months, the effects sustained but the magnitude declined for sexual knowledge (β = 2.39, 95% CI: 1.85-2.93) and attitudes (β = 0.49, 95% CI: 0.23-0.75). There were no significant differences between male and female students.

CONCLUSIONS

Although further modifications are required, the sexuality education package can increase the accessibility of comprehensive sexuality education to adolescents in rural areas in China.

Spatiotemporal analysis of 11 years of Chlamydia trachomatis data from southern China

BACKGROUND

Urogenital Chlamydia trachomatis is the most prevalent bacterial sexually transmitted infection (STI) globally. Reviews suggest high and persistently endemic STI epidemics in low and middle income countries. However population-based prevalence estimates in these settings are less common, underscoring the need for analyses of available data to characterize patterns of disease burden. We identified spatio-temporal clusters and key behavioral, social, or environmental factors contribution to transmission in order to inform the prioritization and targeting of evidence based interventions.

METHODS

Using 11 years of data (2006-2016) from the chlamydia case report system of Guangdong, China, we identified county level spatio-temporal hot and cold spots using the Getis-Ord Gi* statistic and discrete Poisson models in SaTScan 9.6. We also estimated associations between observed distribution patterns and area-level demographic, social, and economic factors using quasi-Poisson regression models that controlled for annual counts of certified laboratories to account for fluctuations in location-specific detection capacity.

FINDINGS

Cluster analysis indicates an expanding chlamydia epidemic in Guangdong, with cases clustered in regions of greatest economic activity. Greater male-to-female sex ratio (RR, 3.63; 95% CI, 1.41-9.45) and greater urbanicity (RR, 2.44; 95% CI, 1.98-2.99) were predictive of higher chlamydia case occurrence.

INTERPRETATION

We found that chlamydia case occurrence in Guangdong province has been accelerating over the past 11 years and that its expansion is tied to indicators of social and economic development. These estimates not only identify high prevalence regions to target but also areas where data gaps potentially remain. The salience of sex ratios and urbanicity may best be understood through the lens of China's modern history of labor migration which has reshaped the gender dynamics and health access landscape of urban China. Future chlamydia control efforts will require a population-based approach focused on reengaging sexually active adults of diverse economic and migratory backgrounds.

FUNDING

This was an unfunded study using routinely collected public health data.

Prevalence of Chlamydia trachomatis Among Pregnant Women, Gynecology Clinic Attendees, and Subfertile Women in Guangdong, China: A Cross-sectional Survey

Background

Chlamydia trachomatis (CT) is a major cause of infertility and adverse birth outcomes, but its epidemiology among childbearing-age women remains unclear in China. This study investigated the prevalence of CT and associated factors among Chinese women aged 16–44 years who were either (1) pregnant, (2) attending gynecology clinics, or (3) subfertile.

Methods

We conducted a cross-sectional survey and recruited participants from obstetrics, gynecology, and infertility clinics in Guangdong between March and December 2019. We collected information on individuals’ sociodemographic characteristics, previous medical conditions, and sexual behaviors. First-pass urine and cervical swabs were tested using nucleic acid amplification testing. We calculated the prevalence in each population and subgroup by age, education, and age at first sex. Multivariable binomial regression models were used to identify factors associated with CT.

Results

We recruited 881 pregnant women, 595 gynecology clinic attendees, and 254 subfertile women. The prevalence of CT was 6.7% (95% CI, 5.2%–8.5%), 8.2% (95% CI, 6.2%–10.7%), and 5.9% (95% CI, 3.5%–9.3%) for the above 3 populations, respectively. The subgroup-specific prevalence was highest among those who first had sex before age 25 years and older pregnant women (>35 years). The proportion of asymptomatic CT was 84.8%, 40.0%, and 60.0% among pregnant women, gynecology clinic attendees, and subfertile women, respectively. Age at first sex (<25 years), multipara, and ever having more than 1 partner increased the risk of CT.

Conclusions

Childbearing-age women in China have a high prevalence of CT. As most women with CT were asymptomatic, more optimal prevention strategies are urgently needed in China.

De-Sexualizing Partner Notification: A Qualitative Study on Chinese Young Adults with Chlamydia

Background: Chlamydia is common amongst the sexually active population in Hong Kong. As most cases are asymptomatic, partner notification may be helpful in controlling chlamydia. This study examined attitudes towards partner notification for chlamydia among Hong Kong Chinese youths in order to inform a culturally appropriate, patient-empowering sexual health service. Methods: Sixteen individuals (aged 20 to 31) who received a confirmed diagnosis of chlamydia within the previous twelve months of data collection were recruited from two community-based organizations between June and December 2017. Semi-structured individual interviews were conducted by a health psychologist. Results: Nine participants notified a total of eleven current and ex-partners. Seven participants did not notify their sexual partner(s). Our findings revealed how participants struggled with the discrediting sexual aspect of their infection, and how de-sexualizing the infection and selected disclosure facilitated partner notification and social acceptance. Perceived stigma regarding chlamydia however did not dissipate with their disclosure. Participants did not perceive lasting impact of chlamydia on their well-being as they thought they have much control over whether and how to disclose to their (future) partners. All participants agreed there was a pressing need to raise public awareness on this silent but highly prevalent sexually transmitted infection. Conclusions: Our findings illustrate the complex struggle behind communicating about chlamydia to one’s sexual partner and how strategizing the disclosure process served to circumvent embarrassment and foster testing of sexual partners.

Nomadic Tibetan women's reproductive health: findings from cross-sectional surveys with a hard-to-reach population

Background

Western China has undergone substantial sociodemographic change, yet little is known about the health status of ethnic minority populations living in these areas.

Methods

We report findings from two cross-sectional surveys conducted with female Tibetan nomads living in rural areas of Western China/Eastern Tibet. We present results of descriptive analyses of data collected from reproductive-aged females who attended community health fairs in 2014 (n = 193) and 2016 (n = 298).

Results

On average, sexual debut preceded marriage among study participants, with fertility near replacement levels (2.7 and 2.1 in 2014 and 2016, respectively). Contraceptive use was common, and dominated by use of IUDs and female sterilization. Although over three-quarters (76%) of 2016 survey participants reported ever having at least one sexually transmitted infection (STI) symptom, there was low awareness of STIs (59%) and action to prevent STIs (21%). Younger women (< 40) were more likely to report having had had an STI symptom, as compared to older women (84% versus 71%; p < 0.05).

Conclusions

We demonstrate feasibility of collecting data with this hard-to-reach population. Reporting of STI symptoms warrants further investigation to identify and address health conditions in this population of Tibetan nomadic women, especially amidst broader social and contextual changes that may affect the Tibetan population.

Western China has undergone substantial sociodemographic change, yet little is known about the health status of ethnic minority populations living in these areas. We report findings from two cross-sectional surveys conducted with female Tibetan nomads living in rural areas of Western China/Eastern Tibet. We present results of descriptive analyses of data collected from reproductive-aged females who attended community health fairs in 2014 (n = 193) and 2016 (n = 298). On average, sexual debut preceded marriage among study participants, with fertility near replacement levels (2.7 and 2.1 in 2014 and 2016, respectively). Contraceptive use was common, and dominated by use of IUDs and female sterilization. Although over three-quarters (76%) of 2016 survey participants reported ever having at least one sexually transmitted infection (STI) symptom, there was low awareness of STIs (59%) and action to prevent STIs (21%). Younger women (less than 40 years old) were more likely to report having had had an STI symptom, as compared to women over 40 years old (84% versus 71%; p < 0.05). We demonstrate feasibility of collecting data with this hard-to-reach population. Reporting of STI symptoms warrants further investigation to identify and address health conditions in this population of Tibetan nomadic women, especially amidst broader social and contextual changes that may affect the Tibetan population.

Prevalence and Patterns of Extramarital Sex among Chinese Men and Women: 2000-2015

Despite growing concern about the "sexual revolution" in China in the past decades, empirical evidence regarding the national trends in prevalence and patterns of extramarital sex (EMS) remains sparse. This study aimed to fill this gap, using data from a population-based, repeated cross-sectional survey administered at four time points during the period 2000-2015. EMS was assessed by asking whether a person in marriage had engaged in sexual activity with someone else during the relationship with his/her current partner. Our findings showed that among married adults aged 20-59, the occurrence rate of EMS nearly tripled over the period 2000-2015, increasing from 12.9% to 33.4% for men, and from 4.7% to 11.4% for women. Moreover, in the early years of this century, EMS was negatively associated with older age (50-59 years), lower educational level (elementary and below) and rural residence for men, and negatively associated with older age and positively associated with higher educational level (college and above) for women. All these differences, however, disappeared in more recent years. Overall, this study indicates a marked increase in EMS, a widening gender gap in EMS, and for each gender, a convergence of EMS across various sociodemographic groups.

Coinfection of High-Risk Human Papillomavirus and Lower Genital Tract Pathogens in the Development of High-Grade Cervical Lesions

Purpose

This study investigated the infection status and relationship between other common lower genital tract infectious pathogens and high-risk human papillomavirus (HR-HPV) in the high-grade cervical lesions.

Methods

Overall, 882 patients were enrolled in this retrospective study, of which 339 patients (≥HSIL group) were confirmed with high-grade squamous intraepithelial lesions (HSIL) or cervical squamous cell carcinoma (SCC), while 543 patients (≤LSIL group) were diagnosed with low-grade squamous intraepithelial lesions (LSIL) or normal cervical pathology diagnosis. Cervical swab specimens were tested for HPV, pathogenic bacteria (PB), U. urealyticum (UU), M. hominis (MH), and C. trachomatis (CT) in both groups.

Results

The infection rates of HR-HPV, PB, UU (at high density), and CT were higher in the ≥HSIL group than in the ≤LSIL group (P < 0.001); however, higher infection rates with MH were not observed (P > 0.05). PB, UU, and CT were associated with HR-HPV infection (P < 0.001). The PB and UU infection rates in the ≥HSIL group were significantly different from those in the ≤LSIL group, regardless of whether there was an HR-HPV infection at the same time (P < 0.05). However, this was not the case for the CT (P > 0.05). Furthermore, 259 pathogenic bacterial strains were detected in 882 cases. The difference in the distribution of pathogenic bacterial flora in the different grades of cervical lesions had no statistical significance, which was prioritized over Escherichia coli (P > 0.05).

Conclusion

PB, UU, and CT infection is associated with susceptibility to HR-HPV, HR-HPV coinfection with these pathogens might increase the risk of high-grade cervical lesions, and PB and UU might be independent risk factors for cervical lesions.

Prevalence of co-infections with other sexually transmitted infections in patients newly diagnosed with anogenital warts in Guangzhou, China

Prevalence of co-infecting sexually transmitted infections (STIs) among patients newly diagnosed with anogenital warts is under-reported. Our objective is to determine the prevalence of six common STIs, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), genital herpes (herpes simplex virus type 2 [HSV-2]), HIV, and syphilis for patients visiting a sexual health clinic in Guangzhou, China. Demographics, sexual health, and medical histories were collected at patient intake. Patients diagnosed with anogenital warts (N = 200) were invited to participate. We collected urine samples, and urethral, cervical, and rectal swabs to test for CT, NG, and MG, and blood samples for serological detection of HSV-2, syphilis, and HIV. Overall 49 (24.5%) had a co-infection (22.2% of men and 27.7% of women). All six STIs were observed among men: CT (6.8%), NG (3.4%), MG (5.1%), HIV (4.3%), HSV-2 (4.3%), and syphilis (1.7%). Women had fewer STIs, but at higher rates: CT (13.3%), MG (6.0%), and HSV-2 (8.4%). Individual men had up to two co-infections, while women had no more than one co-infection. Chlamydia was the most common STI. Patients aged 18-25 years (35.4%) had the highest prevalence. Although opportunistic screening is often applied for high-risk groups, expansion to patients with anogenital warts in all health-care settings would improve detection of problematic asymptomatic co-infections, thereby increasing China's capacity to contribute toward global surveillance systems.

Prevalence of genital Chlamydia trachomatis infection in the general population: a meta-analysis

Background

Estimating prevalence of Chlamydia trachomatis (CT) worldwide is necessary in designing control programs and allocating health resources. We performed a meta-analysis to calculate the prevalence of CT in the general population.

Methods

The Pubmed and Embase databases were searched for eligible population-based studies from its inception through June 5, 2019. Q test and I² statistic were used to calculate the heterogeneity between studies. Random effects models were used to pool the prevalence of CT. Meta regression was performed to explore the possible sources of heterogeneity. Publication bias was evaluated using a funnel plot and “trim and fill” method.

Results

Twenty nine studies that reported prevalence of CT infection from 24 countries were identified, including a total population of 89,886 persons. The pooled prevalence of CT among the general population was 2.9% (95% CI, 2.4–3.5%), and females had a higher CT prevalence (3.1, 95% CI, 2.5–3.8%) than males (2.6, 95% CI, 2.0–3.2%) (χ² = 10.38, P <  0.01). Prevalence of CT was highest in region of America (4.5, 95% CI, 3.1–5.9%), especially in Latin America (6.7, 95% CI, 5.0–8.4%), followed by females in region of Africa (3.8, 95% CI, 0.7–6.9%), while South-East Asia had a lowest CT prevalence 0.8% (95% CI, 0.3–1.3%).

Conclusions

This study provided the updated prevalence of CT among general population worldwide. General population from Latin America, especially females, and women in Africa should be given priority by WHO when design and delivery CT control programs.

Prevalence, concordance and reproductive sequelae after Chlamydia trachomatis infection in Mexican infertile couples

There are few concordance studies on the Chlamydia trachomatis (infection among infertile couples. The objective of this research was to know the prevalence, concordance and reproductive sequelae that couples may develop when both partners show a C. trachomatis infection. A cross-sectional study among 688 infertile couples using the C. trachomatis detection by real-time PCR was performed. The infertility causes were obtained from their medical records. The prevalence of infection was 8.68%. The percentage of concordance was 22.4% (13 couples). A presence of tubal occlusion was only associated with infected-discordant women [RR = 3.46, 95% CI (1.54-7.74), p < .003]. Seminal values were not associated with discordant men. The concordant couples showed association with the infection and tubal occlusion [RR = 3.19, 95% CI (1.09-9.34), p < .05], and oligozoospermia [RR = 12.17, 95% CI (4.29-34.54), p < .001], hypospermia [RR = 14.13, 95% CI (4.78-41.84), p < .001]. An alteration in semen quality was shown particularly in men whose sexual partners show a tubal pathology. This could occur due to a C. trachomatis infection in the testis, which underlines the need to carry out effective and efficient strategies to identify and treat all sexual partners exposed to C. trachomatis.

Prevalence of and factors associated with behavioral intention to take up home-based HIV self-testing among male clients of female sex workers in China - an application of the Theory of Planned Behavior

ABSTRACTHIV self-testing (HIVST) is a useful means to increase coverage of HIV testing but under-utilized by male clients of female sex workers (MCFSW) in China. This study investigated the prevalence of and factors associated with behavioral intention to take up HIVST in the next year among MCFSW in Hong Kong, China. We recruited Chinse-speaking adult men who had patronized at least one female sex worker in the past six months. A total of 303 MCFSW completed a self-administered questionnaire. Univariate and multivariable ordinal logistic regression models were fit. Only 23.8% of participants indicated that they probably/definitely would take up HIVST in the next year. The multivariable ordinal logistic regression model showed that positive attitudes towards HIVST (adjusted odds ratios (aOR): 1.24, 95%CI: 1.13, 1.37), perceived HIVST uptake is completely under one's control (perceived behavioral control) (aOR: 1.44, 95%CI: 1.08, 1.92), and perceived higher risk of HIV infection (aOR: 1.32, 95%CI: 1.01, 1.76) were associated with higher intention to take up HIVST in the next year. The prevalence of behavioral intention to use HIVST was low among MCFSW in Hong Kong. Perceptions based on the Theory of Planned Behavior and perceived risk of HIV infection were associated with behavioral intention to use HIVST.

Cross-sectional study of asymptomatic Neisseria gonorrhoeae and Chlamydia trachomatis infections in sexually transmitted disease related clinics in Shenzhen, China

The aims of this study were to investigate the prevalence and proportion of laboratory-confirmed urethral Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections that were asymptomatic among individuals presenting to clinics in Shenzhen and the risk factors related to asymptomatic CT infection. In a cross-sectional study, eligible individuals were invited to participate in the questionnaire, and urine specimens were collected to identify CT and NG infections using a nucleic acid amplification test (NAAT). Considering the differences in the presentation of symptoms between men and women, this study was stratified by gender. Corresponding outcomes were analyzed by Chi-square test and multivariate logistic regression. A total of 2,871 participants were asymptomatic and included in our analyses: 1120 (39.0%) men and 1751 (61.0%) women. The prevalence of asymptomatic NG and CT infections was 0.9% and 6.2% in men, and 0.4% and 7.9% in women, respectively. The proportion of asymptomatic urethral CT among men with urethral CT was 28.3%; for women, it was 34.2%. For asymptomatic men with CT, 3 independent risk factors were identified: (1) men under the age of 30 (aOR, 1.83; 95% CI, 1.11-3.03); (2) being employed in the commercial service work (2.82; 1.36-5.84); and (3) being recruited through the urological department (2.12; 1.19-3.79). For asymptomatic women with urethral CT, age less than 30 years was a risk factor. In conclusion, a substantial prevalence of asymptomatic CT infections was found among men and women presenting to clinics in Shenzhen. The significant correlation between asymptomatic CT infection and these risk factors could help identify high-risk populations and guide screening.

Chlamydia trachomatis and Human Papillomavirus Infection in Women From Southern Hunan Province in China: A Large Observational Study

Chlamydia trachomatis and human papillomavirus (HPV) are the most common pathogens of sexually transmitted infections (STIs), which can increase the risk of cervical cancer and infertility. The purpose of this study was to evaluate the prevalence, genotype and risk factors of C. trachomatis and/or HPV infection in women attending the annual physical examination, assistant reproductive treatment and visiting the gynecology clinics from Southern Hunan province in China. Cervical-swab samples were collected from 5006 participants. We found that the overall prevalence of C. trachomatis, HPV infection and C. trachomatis/HPV coinfection was 4.7% (236/5006), 15.5% (778/5006) and 1.2% (59/5006), while the prevalence of asymptomatic infection of that was 3.8% (38/1006), 10.8% (109/1006) and 0.6% (6/1006), respectively. Furthermore, 25.0% (59/236) of C. trachomatis infection and 7.6% (59/778) of HPV infection were attributable to C. trachomatis and HPV coinfection. C. trachomatis and HPV infection were more often observed in young women of less than 25 years (10.4% and 21.3%, respectively) and in the outpatients from gynecology clinics (5.2% and 18.0%, respectively). Of note, a higher prevalence of C. trachomatis infection was observed in HPV-positive women (7.6%) than HPV- negative ones (4.2%), and vice versa. The top three C. trachomatis genotypes were E (1.4%), F (1.1%) and J (0.8%), and the counterparts of HPV genotypes were HPV52 (4.2%), HPV16 (2.3%) and HPV58 (2.2%), respectively. Among the 151 outpatients with colposcopy data, HPV infection was associated with severe cervical lesions with OR of 15.86 (95% CI 3.14–80.0, P < 0.001) while C. trachomatis infection was more likely associated with a low grade colposcopy impression (OR = 3.25, 95% CI: 1.22–8.65, P = 0.018). Our data highlight the high prevalence of asymptomatic C. trachomatis and HPV infection, particularly among women of <25 years. The two pathogens may serve as mutual risk factors to increase the risk of infections and cervical lesions. Widespread implementation of HPV and C. trachomatis screening programs, especially for young women, would be an effective strategy to relieve the burden of sexually transmitted infections.

Out of the Closet, Into the Clinic: Opportunities for Expanding Men Who Have Sex With Men-Competent Services in China

BACKGROUND

Despite the high human immunodeficiency virus (HIV) burden among men who have sex with men (MSM), there is little research on health services provided to MSM in China and other low- and middle-income countries. Discrimination and inadequate services may discourage MSM from seeking health care services. This study examined essential services provided to MSM and health care discrimination among MSM in China.

METHODS

A nationwide cross-sectional online survey was conducted among MSM who saw a physician in the last 24 months in China. The survey included items on sociodemographic information, HIV testing, experiences from the last physician encounter, and history of perceived health care discrimination. We defined MSM-competent physicians as physicians who asked their patient about having sex with other men, asked about anal sex, and either asked about or recommended HIV testing at the most recent visit.

RESULTS

Among the 503 participants, 35.0% (176/503) saw an MSM-competent physician. In multivariate analyses, respondents who saw an MSM-competent physician were more likely to be younger (adjusted odds ratio [AOR], 0.87; 95% confidence interval [CI], 0.81-0.94), have a primary care physician (AOR, 3.24; 95% CI, 1.85-5.67), and be living with HIV (AOR, 2.01; 95% CI, 1.13-3.56). 61.2% (308/503) of MSM had ever experienced health care discrimination.

CONCLUSIONS

Our data suggest that there is variability in the extent to which physicians are meeting the needs of MSM in China. There is an urgent need to evaluate and expand MSM-competent services in China.

Prevalence, risk factors, and medical costs of Chlamydia trachomatis infections in Shandong Province, China: a population-based, cross-sectional study

Background

A population-based study of Chlamydia trachomatis (CT) infections is essential in designing a specific control program; however, no large investigation of CT infections among the general population in mainland China has been conducted since 2000. We aimed to determine the prevalence, risk factors, and associated medical costs of CT among residents, 18–49 years of age, in Shandong, China.

Methods

From May to August 2016, a multistage probability sampling survey involving 8074 individuals was distributed. Data were collected via face-to-face interviews, followed by self-administered questionnaire surveys. First-void urines were collected and tested for CT and Neisseria gonorrhoeae (NG) using nucleic acid amplification.

Results

The weighted prevalence of CT infection was 2.3% (95% confidence interval [CI], 1.5–3.2) in females and 2.7% (1.6–3.8) in males. Women, 30–34 years of age, had the highest prevalence of CT infections (3.5%, 2.6–4.4), while the highest prevalence of CT infections in males was in those 18–24 years of age (4.3%, 0.0–8.8). Neisseria gonorrhoeae infection had a prevalence of 0.1% (0.0–0.3) in women and 0.03% (0.0–0.1) in men. Risk factors for CT infections among females included being unmarried, divorced, or widowed (odds ratio [OR], 95% CI 3.57, 1.54–8.24) and having two or more lifetime sex partners (3.72, 1.14–12.16). Among males, first intercourse before 20 years of age (1.83, 1.10–3.02) and having two or more lifetime sex partners (1.85, 1.14–3.02) were associated with CT infections. The estimated lifetime cost of CT infections in patients 18–49 years of age in Shandong was 273 million (range, 172–374 million) China Renminbi in 2016.

Conclusions

This study demonstrated a high burden of CT infections among females < 35 years of age and males < 25 years of age in Shandong. Thus, a CT infection control program should focus on this population, as well as others with identified risk factors.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3432-y) contains supplementary material, which is available to authorized users.

Prevalence of Sexually Transmitted Infections among Married Women in Rural Nepal

Introduction

We have previously determined the prevalence of human papillomavirus (HPV) infection among women in rural Nepal. In the current study, we also wanted to examine the prevalence of and risk factors for other sexually transmitted infections (STIs) in the same population.

Methods

Population-based study of nonpregnant women ≥ 15 years who were married or had a history of marriage in the past, residing in five rural villages in Nepal. Data on sociodemographic characteristics, reproductive history, and genitourinary symptoms were collected, and a gynecological examination was conducted. Cervical samples were analyzed by real-time PCR for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis and HPV, and a serum sample was analyzed for syphilis, hepatitis B virus (HBV) and HIV infection by serology.

Results

Of 2416 eligible women, 62% participated. Trichomoniasis, Chlamydia trachomatis infection, HPV and HBV infection, and syphilis were detected in 5.4%, 0.8%, 14.3%, 0.3%, and 0.2% of the women. None had gonorrhea or HIV infection. Of those with genitourinary symptoms, 6.3% had a curable STI. Vaginal discharge classified as abnormal by gynecological examination, but not self-reported discharge, was significantly associated with laboratory diagnosis of a curable STI. Risk factors for trichomoniasis were reproductive age and high cast/ethnicity. Due to low prevalence, risk factors for other STIs could not be disclosed.

Conclusion

We observed high prevalence of HPV infection followed by trichomoniasis, while other STIs were rare among women in rural Nepal. There was no association between genitourinary symptoms and laboratory-confirmed STIs.

Spatiotemporal distribution and determinants of gonorrhea infections in mainland China: a panel data analysis

OBJECTIVES

Gonorrhea remains a major public health concern worldwide. This study aims to explore the spatiotemporal distribution and sociodemographic determinants of gonorrhea rates during 2004-2014 in mainland China.

STUDY DESIGN

Space-time scan statistics and spatial panel regression model.

METHODS

The gonorrhea infection data and sociodemographic data during 2004-2014 at the provincial level in mainland China were extracted from the China Public Health Science Data Center and China Statistical Yearbooks, respectively. The space-time scan statistics were used to identify the high-risk clusters of gonorrhea, and the spatial panel regression model was adopted to examine the sociodemographic determinants.

RESULTS

One most likely and five secondary high-risk clusters of gonorrhea rates were identified, which were mainly located in southern and eastern China. The regions with higher GDP per capita, larger floating population, less access to healthcare, higher male-female ratio, and higher divorce rate were more likely to become high-risk areas of gonorrhea.

CONCLUSIONS

Gonorrhea rates were distributed unevenly through space and time and affected by various sociodemographic variables. The space-time scan statistics and spatial panel regression are viable tools for identifying clusters and examining determinants of gonorrhea rates. The findings provide valuable implications for developing targeted prevention and control programs in public health practice.

Trend and Factors Associated with Condom Use Among Male Clients of Female Sex Workers in Hong Kong: Findings of 13 Serial Behavioural Surveillance Surveys

This study investigated the trend and associated factors of condom use among male clients of female sex workers (CFSW) in Hong Kong. A total of 25,443 males of the general population were screened to identify 2,330 CFSW via 13 rounds of population-based serial cross-sectional telephone surveys during 1998 through 2015. Over time, there were no significant changes in condom use with various types of female sex partners (p ranged 0. 219-0.837) and prevalence of self-reported STI (p = 0.975) in the past 6 months. Decrease in the prevalence of non-regular sex partners (p < 0.001) and increase in perceived efficacy of condom use for HIV prevention (p = 0.028) were observed. Perceived efficacy of condom use for HIV prevention and self-reported STI experience were significantly associated with condom use with various types of female sex partners in the past 6 months. No evident improvement for condom use was found. Tailored intervention programs are warranted.

Population-based study of chlamydial and gonococcal infections among women in Shenzhen, China: Implications for programme planning

This study was aimed to estimate the prevalences of chlamydia (CT) and gonococcal (NG) infections and explore risk factors associated with the CT infection among women in Shenzhen, China. We collected socio-demographic and clinical data from women (aged 20–60) and determined positivity of CT or NG by nucleic acid amplification test (NAAT) with self-collected urine specimens. We estimated prevalence of CT and NG and determined risk factors associated with CT infection. Among 9,207 participants, 4.12% (95% confidence interval [CI], 3.71%-4.53%) tested positive for CT and 0.17% (95% CIs, 0.09%-0.25%) for NG. Factors significantly associated with CT infection included being an ethnic minority (ethnicity other than Han China) (Adjusted odds ratio [AOR], 1.9; 95% CI, 1.2–3.0), using methods other than condom for contraception (AOR, 1.5; 95% CI, 1.2–1.8), having a history of adverse pregnancy outcomes (AOR, 1.4; 95% CI, 1.1–1.8), and experiencing reproductive tract symptoms in the past three months (AOR, 1.3; 95% CI, 1.0–1.7). we found that CT infection is prevalent among women in Shenzhen, China and associated with both demographic and behavioral factors. A comprehensive CT screening, surveillance and treatment programme targeting this population is warranted.

Molecular Evidence of Chlamydia trachomatis Infection and Its Relation to Miscarriage

Background

Chlamydia trachomatis (CT) infection is the most common sexually transmitted disease in the world that can persist and also ascend in the genital tract. This intracellular and silent infection is related to some adverse pregnancy outcomes, such as miscarriage. The aims of this study were to explore the best CT screening tests using blood and vaginal samples and to investigate the correlation between CT infection and the incidence of miscarriage.

Materials and Methods

This case-control study was done in October 2013 through June 2014, using purposive sampling from 157 female participants with or without a history of miscarriage. The samples were taken after each participant had signed a letter of consent and had completed a questionnaire. To achieve the objectives of this study, polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) tests were performed on vaginal swabs and blood samples, respectively.

Results

PCR results showed a significantly higher CT infection rate in the miscarriage group compared to the control group (11.3 vs. 0%, P=0.007). Anti-CT IgG and IgA antibodies were found in 4.2 and 2.1% of cases in the miscarriage group, and in 1.7 and 6.7% of cases in the control group, respectively (P>0.05). Despite lower humoral responses in this study, positive samples were detected only by one of the following techniques; PCR, ELISA IgA and ELISA IgG. It also should be noted that PCR worked best in terms of detection.

Conclusion

Based on the obtained data, there is a strong association between molecular evidence of CT infection and miscarriage. A higher rate of CT detection in molecular tests compared to serological assays suggests that PCR could be used as the first-choice assay for detection of C. trachomatis. However, the importance of serological tests in detecting potential past CT infection or upper genital infection not amenable to sampling is undeniable.

Susceptibility of Neisseria gonorrhoeae to azithromycin and ceftriaxone in China: A retrospective study of national surveillance data from 2013 to 2016

BACKGROUND

Gonorrhea remains one of the most common sexually transmitted diseases worldwide. Successful treatment has been hampered by emerging resistance to each of the antibiotics recommended as first-line therapies. We retrospectively analyzed the susceptibility of gonorrhea to azithromycin and ceftriaxone using data from the China Gonococcal Resistance Surveillance Programme (China-GRSP) in order to provide evidence for updating the treatment recommendations in China.

METHODS AND FINDINGS

In this study, we included 3,849 isolates collected from patients with a confirmed positive Neisseria gonorrhoeae (N. gonorrhoeae) culture at clinic visits during the period of 1 January 2013 through 31 December 2016 in 7 provinces. Antimicrobial susceptibility testing of gonorrhea isolates using agar dilution was conducted to determine minimum inhibitory concentration (MIC). Resistance to azithromycin (RTA) was defined as MIC ≥ 1.0 mg/l, and decreased susceptibility to ceftriaxone (DSC) was defined as MIC ≥ 0.125 mg/l. The prevalence of isolates with RTA was 18.6% (710/3,827; 95% CI 17.4%-19.8%). The percentage of patients with DSC fluctuated between 9.7% and 12.2% over this period. The overall prevalence of isolates with both RTA and DSC was 2.3% (87/3,827; 95% CI 1.9%-2.8%) and it increased from 1.9% in 2013 to 3.3% in 2016 (chi-squared test for trend, P = 0.03). Study limitations include the retrospective study design and potential biases in the sample, which may overrepresent men with symptomatic infection, coastal residents, and people reporting as heterosexual.

CONCLUSIONS

To our knowledge, this is the first national study on susceptibility of N. gonorrhoeae to azithromycin and ceftriaxone in China. Our findings indicate high rates of RTA and DSC from 2013 to 2016. Although dual therapy with azithromycin and ceftriaxone has been recommended by WHO and many countries to treat gonorrhea, reevaluation of this therapy is needed prior to its introduction in China.

Presence of Chlamydia trachomatis and Mycoplasma spp., but not Neisseria gonorrhoeae and Treponema pallidum, in women undergoing an infertility evaluation: high prevalence of tetracycline resistance gene tet(M)

Chlamydia trachomatis, Mycoplasma spp., Neisseria gonorrhoeae and Treponema pallidum are sexually transmitted pathogens that threaten reproductive health worldwide. In this study, vaginal swabs obtained from women (n = 133) that attended an infertility clinic in China were tested with qPCRs for C. trachomatis, Mycoplasma spp., N. gonorrhoeae, T. pallidum and tetracycline resistance genes. While none of vaginal swabs were positive for N. gonorrhoeae and T. pallidum, 18.8% (25/133) of the swabs were positive for Chlamydia spp. and 17.3% of the swabs (23/133) were positive for Mycoplasma species. All swabs tested were positive for tetracycline resistance gene tet(M) which is the most effective antibiotic for bacterial sexually transmitted infections. The qPCRs determined that the gene copy number per swab for tet(M) was 7.6 times as high as that of C. trachomatis 23S rRNA, and 14.7 times of Mycoplasma spp. 16S rRNA. In China, most hospitals do not detect C. trachomatis and Mycoplasma spp. in women with sexually transmitted infections and fertility problems. This study strongly suggests that C. trachomatis and Mycoplasma spp. should be routinely tested in women with sexually transmitted infections and infertility in China, and that antimicrobial resistance of these organisms should be monitored. Further studies are warranted to determine the prevalences in different regions and associated risk factors.

Opportunities and barriers to STI testing in community health centres in China: a nationwide survey

BACKGROUND

China has strengthened its primary care workforce and implemented a wide network of community health centres (CHCs). However, STI testing and management are not currently included in the 'Essential Package of Primary Health Care in China'. Legislation change to encourage STI service delivery would be important, but it is also critical to determine if there are also provider-related opportunities and barriers for implementing effective STI programmes through CHCs if future legislation were to change.

METHODS

A national representative survey was conducted between September and December 2015 in a stratified random sample of 180 CHCs based in 20 cities in China. Primary care practitioners (PCPs) provided information on current experiences of STI testing as well as the barriers and facilitators for STI testing in CHCs. Multivariate logistic regression was conducted to determine factors associated with PCPs performing STI testing.

RESULTS

3580 out of 4146 (86%) invited PCPs from 158 CHCs completed the survey. The majority (85%, 95% CI 84% to 87%) of doctors stated that STI testing was an important part of healthcare. However, less than a third (29%, 95% CI 27% to 31%) would perform an STI test if the patients asked. Barriers for performing STI testing included lack of training, concerns about reimbursement, concerns about damage to clinics' reputations and the stigma against key populations. Respondents who reported that they would perform an STI test were likely to be younger, received a bachelor degree or higher, received specific training in STIs, believed that STI test was an important part of healthcare or had resources to perform STI testing.

CONCLUSIONS

There is potential for improving STI management in China through upskilling the primary care workforce in CHCs. Specific training in STIs is needed, and other structural, logistical and attitudinal barriers are needed to be addressed.

Sexually transmitted infections: challenges ahead

WHO estimated that nearly 1 million people become infected every day with any of four curable sexually transmitted infections (STIs): chlamydia, gonorrhoea, syphilis, and trichomoniasis. Despite their high global incidence, STIs remain a neglected area of research. In this Commission, we have prioritised five areas that represent particular challenges in STI treatment and control. Chlamydia remains the most commonly diagnosed bacterial STI in high-income countries despite widespread testing recommendations, sensitive and specific non-invasive testing techniques, and cheap effective therapy. We discuss the challenges for chlamydia control and evidence to support a shift from the current focus on infection-based screening to improved management of diagnosed cases and of chlamydial morbidity, such as pelvic inflammatory disease. The emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae is globally recognised. We review current and potential future control and treatment strategies, with a focus on novel antimicrobials. Bacterial vaginosis is the most common vaginal disorder in women, but current treatments are associated with frequent recurrence. Recurrence after treatment might relate to evidence that suggests sexual transmission is integral to the pathogenesis of bacterial vaginosis, which has substantial implications for the development of effective management approaches. STIs disproportionately affect low-income and middle-income countries. We review strategies for case management, focusing on point-of-care tests that hold considerable potential for improving STI control. Lastly, STIs in men who have sex with men have increased since the late 1990s. We discuss the contribution of new biomedical HIV prevention strategies and risk compensation. Overall, this Commission aims to enhance the understanding of some of the key challenges facing the field of STIs, and outlines new approaches to improve the clinical management of STIs and public health.

Is there a relationship between geographic distance and uptake of HIV testing services? A representative population-based study of Chinese adults in Guangzhou, China

Achieving high coverage of HIV testing services is critical in many health systems, especially where HIV testing services remain centralized and inconvenient for many. As a result, planning the optimal spatial distribution of HIV testing sites is increasingly important. We aimed to assess the relationship between geographic distance and uptake of HIV testing services among the general population in Guangzhou, China. Utilizing spatial epidemiological methods and stratified household random sampling, we studied 666 adults aged 18-59. Computer-assisted interviews assessed self-reported HIV testing history. Spatial scan statistic assessed the clustering of participants who have ever been tested for HIV, and two-level logistic regression models assessed the association between uptake of HIV testing and the mean driving distance from the participant's residence to all HIV testing sites in the research sites. The percentage of participants who have ever been tested for HIV was 25.2% (168/666, 95%CI: 21.9%, 28.5%), and the majority (82.7%) of participants tested for HIV in Centres for Disease Control and Prevention, public hospitals or STIs clinics. None reported using self-testing. Spatial clustering analyses found a hotspot included 48 participants who have ever been tested for HIV and 25.8 expected cases (Rate Ratio = 1.86, P = 0.002). Adjusted two-level logistic regression found an inverse relationship between geographic distance (kilometers) and ever being tested for HIV (aOR = 0.90, 95%CI: 0.84, 0.96). Married or cohabiting participants (aOR = 2.14, 95%CI: 1.09, 4.20) and those with greater social support (aOR = 1.04, 95%CI: 1.01, 1.07) were more likely to be tested for HIV. Our findings underscore the importance of considering the geographical distribution of HIV testing sites to increase testing. In addition, expanding HIV testing coverage by introducing non-facility based HIV testing services and self-testing might be useful to achieve the goal that 90% of people living with HIV knowing their HIV status by the year 2020.

Prevalence and risk factors of chlamydia infection in Hong Kong: A population-based geospatial household survey and testing

BACKGROUND

Chlamydia causes infertility and increases risk of HIV infection, and population-based studies provide essential information for effective infection control and prevention. This study examined Chlamydia trachomatis prevalence and risk factors among a representative sample of 18-49-year-old residents in Hong Kong.

METHODS

Census boundary map of 412 constituency areas was used as primary sampling units to construct the sampling frame and, residential buildings and units were randomly selected using geospatial modelling. A questionnaire on sexual practice and health was conducted, and polymerase chain reaction was used to test the urine for genital chlamydial infection. Invitation letters were sent to the selected households and a team of interviewers were sent to recruit one subject per household. Prevalence data was weighted according to the 2011 census and risk factors identified through logistic regression.

RESULTS

Among 881 participants (response rate of 24.5%), the overall Chlamydia trachomatis prevalence was low at 1.4% (95%CI 0.8-2.5%) but sexually active young (18-26 years) women had relatively high prevalence (5.8%, 95%CI 1.7-18.2%) in Hong Kong. A unique U-shape disease burden was observed with peaks in younger and older (40-49 years) women. Amongst the sexually active women, the risk factors of Chlamydia trachomatis infection were: younger age (aOR = 25.4, 95% CI 2.81-230); living alone (aOR = 8.99, 95% CI 1.46-55.40); and, among all the sexually active participants, males (including the male partners of the female participants) who had travelled out of Hong Kong in the previous 12 months had higher risks of infection (aOR = 5.35; 95% CI 1.25-22.8). A core-peripheral geographical distribution of Chlamydia trachomatis prevalence was also observed.

CONCLUSION

Young and older sexually active women in Hong Kong have high prevalence of chlamydia. Routine screening for sexually active women and young men should be considered. Further research on testing feasibility and linkage-to-care are urgently needed to control the infection.

Comparative study in infertile couples with and without Chlamydia trachomatis genital infection

BACKGROUND

Chlamydia, caused by the bacterium Chlamydia trachomatis(C. trachomatis), is the most common sexually transmitted disease. The incidence is not clear due to the asymptomatic nature of early stage of infections. The incidence of Chlamydia has not been fully investigated in the Chinese Han population. Since chronic infection with can C. trachomatis can lead to infertility in males and females, it is important to determine the impact of infection on clinical outcomes. The aim of this study is to explore the epidemiology of C. trachomatis in subfertile couples and to determine whether infections will adversely affect clinical outcomes after assisted reproduction technique (ART) treatment.

METHODS

Subfertile patients (n = 30760) were screened in the research for C. trachomatis in our center from January 2010 to December 2014. C. trachomatis-specific DNA was detected by Taq-man PCR from semen or swabs from the urethral, endocervix or vaginal. The control group consisted of 1140 subfertile patients without C. trachomatis infection. The prevalence and characteristics of C. trachomatis were identified for subfertile couples and clinical outcomes were collected and analyzed. A retrospective study was performed.

RESULTS

Nine hundred and seventy patients were diagnosed with C. trachomatis infection, and the overall prevalence was 3.15% in the most recent five years, with a yearly increasing. The incidence was a higher in the second half of the year (3.40%) compared to the first half (2.69%). The age group with the highest-risk of infection with C. trachomatis was between 26 to 35 years old, and in about one third of the couples, both partners were infected. The basic parameters and clinical outcomes were not statistically significant between different the groups (P > 0.05), even though some minor data were different (P < 0.05).

CONCLUSIONS

C. trachomatis is a common infection in subfertile people and it is essential to test for this organism in ART couples' screening. This study identified no adverse on clinical outcomes after successful treatment of C. trachomatis infection, regardless of gender, age and number of C. trachomatis copies.

Depression and HIV Risk Behaviors among Female Sex Workers in Guangdong, China: A Multicenter Cross-Sectional Study

Background. Our study aimed to assess the burden of depression and evaluate factors associated with depression and status of HIV risk behaviors among female sex workers (FSWs) in Guangdong, China. Method. We recruited FSWs from massage parlors, saunas, restaurants, hotels, hair salons, and streets in Guangdong, China, in 2014. Information on demographic characteristics, HIV testing history, and sexual behaviors was collected using a questionnaire. A blood sample was collected to test for HIV, syphilis, and HCV. A participant was defined as being depressed if she obtained 6 points or above using the 12-item General Health Questionnaire. Results. Among the 653 participants, 41.7% were 21–30 years old and 43.6% married. Overall, 52.4% were found to be depressed. FSWs who had correct syphilis related knowledge [aOR = 1.45; 95% CI: 1.04–2.03] and had primary sex partner (1.63, 1.14–2.33) were more likely to be depressed. FSWs who did not use a condom during their last sex with the primary sex partner were less likely to be depressed (0.47, 0.31–0.71). Conclusion. Our study observed high level of depression and HIV risk behaviors among Chinese FSWs. Future interventions should integrate mental health services in comprehensive interventions to prevent depression among Chinese FSWs.

Improved Fecundity in Northern China: A Secular Trend from 1980 to 2003

Objective

This study aimed to assess the trend of human fecundity over time in China.

Methods

This retrospective study was conducted in Tongliao, China. Couples who were married during the time period between January 1, 1981 and December 31, 2003 were considered eligible for this study. A total of 27,413 individuals provided valid information via house-to-house interviews. The 12-month cumulative pregnancy rate (CPR) and annual percentage change were used as the outcome measurements.

Results

There was a significant increase in the CPR over the five successive time groups. A break point in 1988 divided the entire study period into two distinct segments: 1981–1988, during which the CPR increased from 72.2% to 84.2%, and 1988–2003, during which the CPR increased from 84.2% to 87.2%.

Conclusions

The findings were unlikely to be the result of biases, and could not be explained by increased medical treatment for infertility and changes in the prevalence of sexually transmitted diseases. Dramatic societal and behavioral changes due to the unique family planning policy and economic reform policies in China might have been the plausible reason for the results.

Chlamydiaphage φCPG1 Capsid Protein Vp1 Inhibits Chlamydia trachomatis Growth via the Mitogen-Activated Protein Kinase Pathway

Chlamydia trachomatis is the most common cause of curable bacterial sexually transmitted infections worldwide. Although the pathogen is well established, the pathogenic mechanisms remain unclear. Given the current challenges of antibiotic resistance and blocked processes of vaccine development, the use of a specific chlamydiaphage may be a new treatment solution. φCPG1 is a lytic phage specific for Chlamydia caviae, and shows over 90% nucleotide sequence identity with other chlamydiaphages. Vp1 is the major capsid protein of φCPG1. Purified Vp1 was previously confirmed to inhibit Chlamydia trachomatis growth. We here report the first attempt at exploring the relationship between Vp1-treated C. trachomatis and the protein and gene levels of the mitogen-activated/extracellular regulated protein kinase (MAPK/ERK) pathway by Western blotting and real-time PCR, respectively. Moreover, we evaluated the levels of pro-inflammatory cytokines interleukin (IL)-8 and IL-1 by enzyme-linked immunosorbent assay after Vp1 treatment. After 48 h of incubation, the p-ERK level of the Vp1-treated group decreased compared with that of the Chlamydia infection group. Accordingly, ERK1 and ERK2 mRNA expression levels of the Vp1-treated group also decreased compared with the Chlamydia infection group. IL-8 and IL-1 levels were also decreased after Vp1 treatment compared with the untreated group. Our results demonstrate that the inhibition effect of the chlamydiaphage φCPG1 capsid protein Vp1 on C. trachomatis is associated with the MAPK pathway, and inhibits production of the pro-inflammatory cytokines IL-8 and IL-1. The bacteriophages may provide insight into a new signaling transduction mechanism to influence their hosts, in addition to bacteriolysis.

Spatial distribution and cluster analysis of risky sexual behaviours and STDs reported by Chinese adults in Guangzhou, China: a representative population-based study

OBJECTIVES

To assess associations between residences location, risky sexual behaviours and sexually transmitted diseases (STDs) among adults living in Guangzhou, China.

METHODS

Data were obtained from 751 Chinese adults aged 18-59 years in Guangzhou, China, using stratified random sampling by using spatial epidemiological methods. Face-to-face household interviews were conducted to collect self-report data on risky sexual behaviours and diagnosed STDs. Kulldorff's spatial scan statistic was implemented to identify and detect spatial distribution and clusters of risky sexual behaviours and STDs. The presence and location of statistically significant clusters were mapped in the study areas using ArcGIS software.

RESULTS

The prevalence of self-reported risky sexual behaviours was between 5.1% and 50.0%. The self-reported lifetime prevalence of diagnosed STDs was 7.06%. Anal intercourse clustered in an area located along the border within the rural-urban continuum (p=0.001). High rate clusters for alcohol or other drugs using before sex (p=0.008) and migrants who lived in Guangzhou <1 year (p=0.007) overlapped this cluster. Excess cases for unprotected sex (p=0.031) overlapped the cluster for college students (p<0.001). Five of nine (55.6%) students who had sexual experience during the last 12 months located in the cluster of unprotected sex.

CONCLUSIONS

Short-term migrants and college students reported greater risky sexual behaviours. Programmes to increase safer sex within these communities to reduce the risk of STDs are warranted in Guangzhou. Spatial analysis identified geographical clusters of risky sexual behaviours, which is critical for optimising surveillance and targeting control measures for these locations in the future.

Sustained high prevalence of viral hepatitis and sexually transmissible infections among female sex workers in China: a systematic review and meta-analysis

Background

The 1980’s economic boom has been associated with a rapid expansion of China’s sex industry over the past three decades. Consequently, the spread of sexually transmitted infections (STIs) and hepatitis infections among female sex workers (FSW) has become an important public health issue in China. This study identifies prevalence and risks of hepatitis and STIs in Chinese FSWs.

Method

Four electronic databases were searched for Chinese and English language peer-reviewed studies conducted between 01/2000-12/2011 that reported prevalence of hepatitis and STIs (excluding HIV) among Chinese FSW. Following the PRISMA guidelines, meta-analysis was used to estimate pooled prevalence and 95 % confidence intervals for each infection.

Result

Three hundred and thirty nine articles (34 in English and 305 in Chinese) investigating 603,647 FSWs in 29 Chinese provinces were included in this review. Over the period 2000–2011, the seroprevalence of active hepatitis B and hepatitis C among FSW were 10.7 % (7.3–15.5 %) and 1.0 % (0.7–1.3 %), respectively. The most prevalent STI was human papillomavirus (HPV, 27.0 % [10.1–55.1 %]), followed by herpes simplex virus-2 (HSV-2, 15.8 % [11.7–20.9 %]), chlamydia (13.7 % [12.1–15.4 %]), gonorrhoea (6.1 % [5.3–7.0 %]), syphilis (5.2 % [4.8–5.7 %]), genital warts (3.3 % [2.5–4.2 %]) and Trichomonas vaginitis (2.1 % [1.5–24.2 %]). Disease burden of both hepatitis and STI among FSW were concentrated in South Central and Southwest China. In particular, chlamydia and syphilis demonstrated a significant declining trend during the studied period (P < 0.05). Compared with the general Chinese population, FSW had significantly higher prevalence of all STIs except Trichomonas vaginitis. Further, compared to the general FSW population, HIV-positive FSW had significantly higher prevalence of syphilis, chlamydia, HSV-2 and Trichomonas vaginitis.

Conclusion

Prevalence of hepatitis and STIs remained high and mostly stable among Chinese FSW over the period of 2000–2011. Targeted STI and hepatitis surveillance and interventions should be strengthened among Chinese FSWs, especially those who are HIV-positive.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1322-0) contains supplementary material, which is available to authorized users.

Community-based sexually transmitted infection screening and increased detection of pharyngeal and urogenital Chlamydia trachomatis and Neisseria gonorrhoeae infections in female sex workers in Hong Kong

Chlamydia and gonorrhea remain the most commonly sexually transmitted infections detected in female sex worker. Although the prevalence of urogenital Chlamydia trachomatis is increasing, pharyngeal gonococcal infection is likely to be overlooked in Hong Kong.

Background

Female sex workers (FSWs) are vulnerable to sexually transmitted infections (STIs) and are one of the key populations being infected most by Chlamydia trachomatis and Neisseria gonorrhoeae infections. In Hong Kong, limited data on the burden of chlamydial and gonococcal infections exist because regular screenings are not offered. This study aimed to investigate the prevalence of C. trachomatis and N. gonorrhoeae in FSWs and to assess predictors associated with unprotected fellatio.

Methods

A cross-sectional study was conduct on 340 FSWs attending a community organization for HIV/STI screening, and a questionnaire addressing sociodemographic and behavioral characteristics was administered to all FSWs.

Results

The prevalence of syphilis infection was 2.1%, and none was tested positive for HIV. The positivity for pharyngeal C. trachomatis and N. gonorrhoeae was 3.2% and 4.4%, respectively, whereas that for urogenital chlamydial and gonococcal infection was 10.6% and 0.9%, respectively. Of 313 FSWs offering fellatio, having unprotected fellatio with clients was significantly associated with the perceived low risk of contracting STI via fellatio (adjusted odds ratio [OR], 1.88), working in clubs (adjusted OR, 11.14), working on streets (adjusted OR, 3.28), recently started working in the sex industry for 1 year or less (adjusted OR, 3.05), and reporting group sex in the previous year (adjusted OR, 11.03).

Conclusions

The prevalence of HIV and syphilis infection remains low. This study reveals a relatively high prevalence of N. gonorrhoeae detected mostly in the pharynx. Offering pharyngeal screening for STI would facilitate early diagnosis and treatment of gonococcal infection in FSWs in Hong Kong.

Sexual Mixing in Shanghai: Are Heterosexual Contact Patterns Compatible With an HIV/AIDS Epidemic?

China's HIV prevalence is low, mainly concentrated among female sex workers (FSWs), their clients, men who have sex with men, and the stable partners of members of these high-risk groups. We evaluate the contribution to the spread of HIV of China's regime of heterosexual relations, of the structure of heterosexual networks, and of the attributes of key population groups with simulations driven by data from a cross-sectional survey of egocentric sexual networks of the general population of Shanghai and from a concurrent respondent-driven sample of FSWs. We find that the heterosexual network generated by our empirically calibrated simulations has low levels of partner change, strong constraints on partner selection by age and education, and a very small connected core, mainly comprising FSWs and their clients and characterized by a fragile transmission structure. This network has a small HIV epidemic potential but is compatible with the transmission of bacterial sexually transmitted infections (STIs), such as syphilis, which are less susceptible to structural breaks in transmission of infection. Our results suggest that policies that force commercial sex underground could have an adverse effect on the spread of HIV and other STIs.

Risk behaviours among female sex workers in China: a systematic review and data synthesis

BACKGROUND

Commercial sex is one of the major modes of HIV transmission in China. Understanding HIV risk behaviours in female sex workers (FSW) is of great importance for prevention. This study aims to assess the magnitude and temporal changes of risk behaviours in Chinese FSW.

METHOD

Five electronic databases were searched to identify peer-reviewed English and Chinese language articles published between January 2000 and December 2012 that reported risk behaviours among FSW in China, including condom use, HIV testing, and drug use. Linear regression and Spearman's rank correlation were used to examine temporal trends in these risk factors. The study followed PRISMA guidelines for meta-analyses and was registered in the PROSPERO database for systematic reviews.

RESULTS

A total of 583 articles (44 English, 539 Chinese) investigating 594,583 Chinese FSW were included in this review. At last sex, condom use was highest with commercial partners (clients), increasing from 53.7% in 2000 to 84.9% in 2011. During this same time period, condom use increased with regular partners from 15.2% to 40.4% and with unspecified partners from 38.6% to 82.5%. Increasing trends were also found in the proportion of sampled FSW who reported testing for HIV in the past 12 months (from 3.2% in 2000 to 48.0% in 2011), while drug use behaviours decreased significantly from 10.9% to 2.6%.

CONCLUSION

During the first decade of 2000, Chinese FSWs' self-reported risk behaviours have decreased significantly while HIV testing has increased. Further outreach and intervention efforts are needed to encourage condom use with regular partners, continue promotion of HIV testing, and provide resources for the most vulnerable FSW, particularly low tier FSW, who may have limited access to sexual health and prevention programs.

Female streetwalkers' perspectives on migration and HIV/STI risks in a changing economic and social environment: a qualitative study in Shanghai, China

China's 30-year economic boom has created a unique social and economic market for commercial sex, as well as for a workforce of migrant women from rural China. This qualitative study explores the impact of the rapidly changing social and economic environment on migration patterns, knowledge of sexually transmitted infections (STIs), STI risk behaviours and health beliefs among female streetwalkers in Shanghai. Qualitative data were collected in 2010 through semi-structured in-depth interviews with 16 streetwalkers to characterise their migration passages, sexual health and behaviours, and peer networks. Many streetwalkers reported histories of childhood impoverishment, of family or partner violence or trauma, of migration consistent with the timeline and routes of economic development and of a scarcity in health, social or economic support. Their knowledge of the prevention and treatment of HIV and STIs was limited. They had little bargaining power on condom use and the majority resorted to vaginal douching and self-management with antibiotics as preventative measures. The study identifies streetwalkers' perspectives on the changing environment, their options and actions and, finally, HIV/STI risks that were unique to this hidden population.

Asexuality: what it is and why it matters

In this review article, human asexuality, a relatively understudied phenomenon, is discussed. Specifically, definitions and conceptualizations of asexuality (e.g., is it a unique category of sexual orientation?), biological and historical contexts, identity issues, discrimination against asexual people relative to other minorities, origins, and variations, including gender differences, are reviewed. Whether asexuality should be construed as a disorder is also discussed. The study of asexuality allows for a better understanding of an underrecognized sexual minority but also affords a unique opportunity to examine and better understand human sexuality.