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

[This corrects the article DOI: 10.1371/journal.pone.0172561.].

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.

Population-based sexual behavior surveys in China: Liuzhou compared with other prefectural cities.

Sexual behaviors in China are rapidly changing; simultaneously, sexually transmitted infections (STI)/HIV prevalence is increasing in the general population. To investigate these major shifts, we examined sexual behaviors and self-reported STI in one prefectural city in southern China, Liuzhou, and compared it to other prefectural cities throughout China. We used adults age 18-39 from two sets of population-based surveys that paralleled each other in both content and method. The first set was the Liuzhou survey conducted in 2008 (n = 398). The second set consisted of two national surveys collected in 2006 and 2010 (n = 2,186). Liuzhou respondents reported more active social and sexual behaviors than their national counterparts, including more socializing, dancing, drinking excessively, sexual activity among never married men and women, purchasing commercial sex among men, one-night stands among men, multiple sexual partnerships and self-reported STI among both men and women. Women in Liuzhou reported greater sexual risk behavior than their national counterparts, although overall they reported less than their male counterparts; they were also more likely to have had an abortion than women in other prefectural cities. Our findings provide a comprehensive overview of the sexual context of Liuzhou among the general population, which may help explain the greater STI/HIV prevalence in Liuzhou.

Sexual infidelity in China: prevalence and gender-specific correlates.

The nature of extra-relational sex in societies with rapidly changing sexual mores and widespread commercial sex remains under-explored. The 2006 Sexuality Survey of China provides a national probability survey with data on 3,567 people 18-49 years old who were in a marital (89%) or dating/cohabiting (11%) relationship. In attitudes, extramarital sex was completely unacceptable to 74% of women and 60% of men and either somewhat or completely unacceptable to 95% of women and men. Most (77%) women wanted severe punishment of men's short-term commercial sex and women's jealousy was equally elevated by their primary partner's episodes of commercial and non-commercial sex. Nevertheless, the prevalence of infidelity during the last 12 months was 4.5% (women's non-commercial sex), 11.0% (men's non-commercial), and 5.5% (men's commercial), with each percent matching or exceeding the median for other countries. In multivariate equations for non-commercial infidelity, men's infidelity was significantly more responsive to sexual dissatisfaction with his primary partner while women's was more responsive to deficits in love. In commercial sex, men were uninfluenced by primary partner deficits in love, sexual satisfaction or oral sex-pursuing, it would seem, simply a greater variety of sexual partners. In a "trading up" pattern, women partnered with low income men had elevated infidelity. The minority of women reporting early masturbation and premarital sex were just as likely as men with these backgrounds to have elevated infidelity. The Chinese patterns provide ample material for deliberations on gender similarities and differences in extra-relational sex.

Clients of female sex workers: a population-based survey of China.

The control of HIV and other sexually transmitted infections (STI) is a challenge in China, with female sex workers (FSW) and male clients suspected as bridge groups. This study used a 2006 national probability survey of 2,707 adult men. Among men 15-49 years old, the prevalence of FSW contacts last year was 4.2% (95% CI, 3.3-5.2) overall, with 7.2% (CI, 5.9-8.7) in urban and 1.8% (CI, 1.0-3.3) in rural areas. In urban areas, the men most at risk for FSW were high income, often traveled, engaged in business entertaining, ages 25-39, and had early sex histories. When compared to men with only wife or stable sex partner, those most likely to report STI last year also reported FSW sex of any type (aOR,13.10; CI, 5.87-29.42). Additionally, when compared to men reporting consistent condom use with FSW, men with inconsistent condom use had elevated STI (aOR, 3.71; CI, 1.18-11.66). Additional efforts are needed for high income men in urban areas, and on consistent condom use with FSW.

Partner violence and sexual jealousy in China: a population-based survey.

Using data from a nationally representative survey in China, this article examines the prevalence and risk factors for partner violence with a special focus on the important role of sexual jealousy. Among women aged 20 to 49, 7.2% reported that they were hit by their partners in the past year. Comparison shows that the Chinese prevalence is modestly below the overall median for other societies. Net of other factors, jealousy exacerbates hitting for both men and women in a reactive pattern, with the jealous partner getting hit. This suggests a rethinking of the role of sexual jealousy in spousal violence in some social settings.

Masturbation in urban China.

This study examined the prevalence and sources of masturbatory practice in a nationally representative sample from China completed in the year 2000, with analysis of sources focused on 2,828 urban respondents aged 20-59. In this subpopulation, 13% (95% CI, 10-18) of women and 35% (CI, 26-44) of men reported any masturbation in the preceding year. Prevalence for people in their 20s was higher, and closer to US and European levels, especially for men. Particularly for women, masturbation not only compensated for absent partners but also complemented the high sexual interests of a subset of participants. For both women and men, practicing masturbation appeared to be a two-step process. In the first step, events such as sexual contact in childhood, early puberty, and early sex were related to sexualization and the "gateway event" of adolescent masturbation. In the second step, other factors, such as liberal sexual values and sexual knowledge, further increased the current probability of masturbation. Overall, the results suggest that masturbation is readily adopted even at more modest levels of economic and social development, that masturbation is often more than simply compensatory behavior for regular partnered sex, that masturbatory patterns are heavily influenced by early sexualization, and that a complex model is needed to comprehend masturbatory practice, particularly for women.

A population-based study of childhood sexual contact in China: prevalence and long-term consequences.

OBJECTIVES: This study provides national estimates of the prevalence of childhood sexual contact and its association with sexual well-being and psychological distress among adults in China. METHOD: A national stratified probability sample of 1,519 women and 1,475 men aged 20-64 years in urban China completed a computer-administered survey in 1999-2000. The data from this survey on both adult-to-child and peer-to-peer sexual contact before age 14 were subjected to descriptive and multivariate analyses that were adjusted for both sampling weights and sampling design. RESULTS: The overall prevalence of reported childhood sexual contact was 4.2%, with prevalence higher among men (5.1%) than among women (3.3%) and higher among those aged 20-29 years (8.3%). Childhood sexual contact was associated with multiplex consequences, including hyper-sexuality (high levels of masturbation, thoughts about sex, varieties of sexual practices, partner turnover), adult sexual victimization (unwanted sex, unwanted sexual acts, sexual harassment), sexual difficulties (genitor-urinary symptoms, sexually transmitted infections, sexual dysfunctions), and psychological distress. Psychological distress was largely mediated by adult sexual victimization, sexual difficulties, and hyper-sexuality. CONCLUSIONS: Despite the relatively modest prevalence of childhood sexual contact among Chinese adults, the association with multiplex adult outcomes suggests that much as in the West early sexual contact is a significant issue. PRACTICE IMPLICATIONS: The findings underscore the importance of public education about childhood sexual contact and abuse in China. The findings suggest a need for public health campaigns that tackle the stigma associated with being abused and encourage victims to report abusive behavior to proper sources. The findings are also consistent with new efforts to alleviate the negative long-term impact of childhood sexual abuse.

Genitourinary symptoms in urban China: a population-based study.

Analysis of the first population-based sexual health survey in China found a prevalence of self-reported genitourinary (GU) symptoms among 2999 urban respondents for men and women as follows: burning (12.5% and 15.7%), discharge (2.6% and 20.1%), ulcer (1.3% and 3.6%) and warts (1.2% and 2.0%). Risk factors among men were unprotected commercial sex, short-term and other secondary partners, and living elsewhere than a coastal area or a major city. Among women, risk factors were her main partner's having other concurrent partners or socializing often, and her absence of condom use with her main partner, prior forced sex, low education and living elsewhere than a coastal area or a major city. These findings were consistent with many GU symptoms being concentrated in paths that led from commercial sex workers or short-term partners to husband/steady partner to wife/steady partner. The results also reveal factors other than sexual behaviour as predictors for GU symptoms.

Sexual dysfunctions in urban china: a population-based national survey of men and women.

INTRODUCTION: While sexual dysfunctions are closely related to overall well-being, epidemiological data based on population-based surveys remain scant. AIM: To investigate the prevalence and correlates for sexual dysfunctions in urban China. METHODS: Of the 4,157 urbanites sampled nationally, 3,159 participants completed the interview, giving a response rate of 76%. The focus was on 78% of these participants (2,478 adults aged 20-64) who were sexually active within a stable sexual relationship, typically with the spouse. MAIN OUTCOME MEASURE: Prevalence and correlates for sexual dysfunctions. RESULTS: Fully 35% of women and 21% of men had at least one persistent sexual dysfunction. Prevalence by age was similar to the results from Western developed countries. With sharp differences for men and women, the correlates for distress in China were multiple, with aging and physical issues accounting for only a portion of the total set of mental health, stress, relationship, and values and knowledge issues related to reports of sexual dysfunctions. CONCLUSIONS: Both the prevalence and correlates for sexual dysfunctions in urban China were similar to those in other societies. Mental distress, age, and poor communication (producing the report that "my partner does not understand my sexual needs") were the correlates shared by both men and women. Other correlates were more distinct by gender. The multiplicity of correlates for men and women suggests a need for a holistic approach to sexual dysfunctions.

Unwanted sexual activity among married women in urban China.

This paper examines the prevalence, precursors, and consequences of unwanted marital sex activities in a national sample of 1,127 married urban Chinese women aged 20-64. During the lifetime of their current marriage, 32% reported ever experiencing unwanted spousal intercourse, with about one-fifth reporting that this unwanted intercourse ever involved force. Reports for the past year were 21% unwanted intercourse, 22% unwanted sex act(s), and 72% sex only to please the husband. The major risk factors for these activities were poor relationship quality (hitting, lack of daily intimacy and foreplay, and husband insensitivity to wife's sexual needs); a woman's negative attitudes towards sex, and weak bargaining position (low income share, husband's family of superior economic status, and no additional adults in home). In addition, unwanted activity was more common when women reported sexual dysfunctions (dryness, pain, low arousal, inorgasmia), were more educated, and had more permissive sex attitudes. Net of feedback effects, unwanted sexual activity diminished women's psychological well-being.

Sexual practices and sexual satisfaction: a population based study of Chinese urban adults.

This study examined sexual satisfaction and its social and behavioral correlates among urbanites aged 20-64 in China, using data from a nationally representative sample of 1,194 women and 1,217 men with a spouse or other long-term sexual partner with whom they had sex during the last year. The results from structural equation models suggest a multiplex set of determinants of sexual satisfaction, including relationship characteristics, sexual knowledge and personal values, physical vitality, and environmental impediments. A large proportion of the effect of these background characteristics was mediated by frequent orgasms, varied sexual practices, and perceived partner affection. In particular, much of the effect of knowledge and beliefs was mediated through variety in sexual practices. While many of the observed patterns were shared among women and men, much of the effect of relationship characteristics was mediated through perceived partner affection for women. Men, in contrast, paid greater attention to his partner's physical attractiveness and to her extramarital sex. A sexual transition is well underway in urban China, even if more rapidly for men than for women. While knowledge and values are arguably more important in this transitional period, many antecedents of sexual well-being drawn from the literature on sexual behavior in developed Western countries are also applicable to urban China.

Sexual harassment of women in urban China.

Using data from the Chinese Health and Family Life survey, this study analyzed the prevalence of and risk factors for sexual harassment in China in the year 2000. It was the first study to use a general population sample to examine all types of harassment in an Asian country. The dataset was a stratified probability sample with 3,821 participants, and was nationally representative (apart from Hong Kong and Tibet) of China's adult population aged 20-64. In total, 12.5% of all women and 15.1% of urban women reported some form of harassment in the past year. Among urban women age 20-45, most cross-sex harassment was not from supervisors or superiors (1.4%) but from coworkers and other peers (7.0%), strangers (4.6%), dates and boyfriends (3.6%), and others (2.6%). Multivariate analysis of risk factors for cross-sex harassment suggested that, despite its predominance in the Western literature on sexual harassment, the power differentials approach, focusing on male-female power differentials in patriarchal societies, was of modest utility. The results were more consistent with a more comprehensive routine activities approach borrowed from criminology, which emphasizes situational opportunity, perceived benefit to the harasser, and reduced costs for the harasser. The most striking result from the data represents the area receiving the least attention in the West, namely, the perpetrator's perception of "benefit," deriving from the victim's inadvertent "signaling."

A population-based study of body image concerns among urban Chinese adults.

Using a nationally representative Chinese urban sample of 930 women and 893 men aged 20-45 who were married or had a steady sexual partner, this study examines the prevalence, risk factors and sequelae of body image concerns. Women's weight loss desires begin at modest BMI levels and are more pronounced among youth, among people of urban origin, and among the educated. Women also have stronger body image concerns if they are single, living in coastal areas, taller or larger than their partner, or if their relationship with their partner is poor. Moreover, women who perceive themselves as unattractive and who want to lose weight report more psychological distress. These findings suggest that China has joined the worldwide diffusion of the thin ideal, with negative consequences for women.

Intimate partner violence in China: national prevalence, risk factors and associated health problems.

CONTEXT: Intimate partner violence has been studied in many developed and developing countries. China remains one of the few large societies for which the prevalence and correlates of intimate partner violence are unknown. METHODS: Data from a nationally representative sample of women and men aged 20-64 with a spouse or other steady partner provide estimates of intimate partner violence in China. Binomial and multinomial logistic regression analyses adjusted for sample design examine risk factors and negative outcomes associated with partner violence. RESULTS: Altogether, 34% of women and 18% of men had ever been hit during their current relationship; the prevalence of hitting resulting in bleeding, bruises, swelling, or severe pain and injuries was 12% for women and 5% for men. Significant risk factors for partner violence included sexual jealousy, patriarchal beliefs, low female contribution to household income, low male socioeconomic status, alcohol consumption and residence in regions other than the South and Southeast. Severe hitting was a significant risk factor for self-reported adverse general and sexual health outcomes, including sexual dysfunction, sexual dissatisfaction and unwanted sex. CONCLUSIONS: As in other societies, intimate partner violence in China is common and is correlated with adverse general and sexual health outcomes.

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

CONTEXT: Sexually transmitted diseases are increasing rapidly in China. Surveillance data imperfectly indicate current prevalence and risk factors. OBJECTIVES: To estimate the prevalence of genital chlamydial and gonococcal infections and to describe patterns of infection by subgroup and behavioral patterns. DESIGN, SETTING, AND PARTICIPANTS: A national stratified probability sample of 3426 Chinese individuals (1738 women and 1688 men) aged 20 to 64 years, who were interviewed between August 1999 and August 2000, completed a computer-administered survey, and provided a urine specimen (69% total participation rate). MAIN OUTCOME MEASURE: Positive test result for chlamydial or gonococcal infections. RESULTS: The overall prevalence per 100 population of chlamydial infection was 2.6 (95% confidence interval [CI], 1.6-4.1) for women and 2.1 (95% CI, 1.3-3.3) for men. For gonococcal infection, the overall prevalence per 100 population was 0.08 (95% CI, 0.02-0.4) for women and 0.02 (95% CI, 0.005-0.1) for men. Risk factors for chlamydial infection among men aged 20 to 44 years were unprotected sex with a commercial sex worker (odds ratio [OR], 8.24; 95% CI, 3.51-19.35), less education (OR, 7.20; 95% CI, 2.31-22.37), and recent sex with their spouse or other steady partner (OR, 7.73; 95% CI, 2.70-22.10). Among women aged 20 to 44 years, risk factors for chlamydial infection were having less education (OR, 2.82; 95% CI, 1.01-7.91) and living in a city (OR, 3.46; 95% CI, 1.67-7.18) or along the southern coast (OR, 2.16; 95% CI, 1.29-3.63) and having a spouse or other steady sexual partner who earned a high income (OR, 2.85; 95% CI, 1.11-7.29), who socialized often (OR, 2.79; 95% CI, 1.08-7.19), or who traveled less than 1 week per year (OR, 5.40; 95% CI, 1.44-20.3). CONCLUSIONS: The prevalence of chlamydial infection in China is substantial. The patterns of infection suggest potential avenues for intervention.