Mason Lau

SARS transmission, risk factors, and prevention in Hong Kong.

We analyzed information obtained from 1,192 patients with probable severe acute respiratory syndrome (SARS) reported in Hong Kong. Among them, 26.6% were hospital workers, 16.1% were household members of SARS patients and had probable secondary infections, 14.3% were Amoy Garden residents, 4.9% were inpatients, and 20.1% were contacts of SARS patients who were not family members. The remaining 347 case-patients (29.1%) did not have “known” sources of infection. Excluding those <16 years of age, 330 patients with cases from “undefined” sources were used in a 1:2 matched case-control study. Multivariate analysis of this case-control study showed that having visited mainland China, hospitals, or the Amoy Gardens were risk factors (odds ratio [OR] 1.95 to 7.63). In addition, frequent mask use in public venues, frequent hand washing, and disinfecting the living quarters were significant protective factors (OR 0.36 to 0.58). In Hong Kong, therefore, community-acquired infection did not make up most transmissions, and public health measures have contributed substantially to the control of the SARS epidemic.

A randomized controlled study to evaluate the efficacy of an Internet-based intervention in reducing HIV risk behaviors among men who have sex with men in Hong Kong.

Abstract A randomized controlled study evaluated an Internet-based HIV behavioral intervention for men who have sex with men (MSM). Hong Kong Chinese men aged ≥18 having engaged in oral or anal MSM behaviors in the last six months were randomly allocated into the intervention (n=140) and the control groups (n=140). Participants were interviewed anonymously at the baseline and after six months. Interventions included periodic HIV information dissemination, monitoring of risk behaviors and interactive feedback, online peer counseling and provision of a hotline. The control group only received some educational materials. Efficacy of the intervention was not supported as no statistically significant between-group differences in background characteristics, HIV risk behaviors and perceptions were observed both at the baseline and after the 6-month period. Effectiveness of online interventions should not be taken for granted and evidence-based approach is warranted.

Knowledge about cataract, glaucoma, and age related macular degeneration in the Hong Kong Chinese population

Aims: Patients’ knowledge and participation in their care are important in prevention of blindness from common eye diseases such as cataract, glaucoma, and age related macular degeneration (AMD). The aim of this study was to measure knowledge of these conditions in the Hong Kong Chinese population. Methods: Subjects aged 40 and above in the Shatin district of Hong Kong were randomly selected as part of a larger study of causes of adult visual loss. The subjects received eye examinations in which the primary cause of visual disability was recorded. The respondents were asked by trained interviewers in a standardised fashion about their knowledge of cataract, glaucoma, and AMD. Their answers were rated for accuracy by a senior ophthalmologist. Results: Out of the 2538 eyes examined, 7.0% had visual acuity less than 6/18. Fully 69.6% of the visual disability for those aged 60 or above was caused by cataract, AMD, or glaucoma. Awareness of cataract in particular was high, in that over 90% of respondents had heard of it. However, only 22.9% of them could describe cataract symptoms correctly, and these percentages were even lower in glaucoma (10.2%) and AMD (<1%). Over 40% of subjects did not know that surgery was an appropriate treatment for cataract. Conclusion: This sample of the Hong Kong Chinese population had limited knowledge of common eye diseases. Educational programmes to enhance public awareness may be needed to improve the effectiveness of health promotion and thus prevent unnecessary blindness.

HIV related behaviours and attitudes among Chinese men who have sex with men in Hong Kong: a population based study

Objective: This study was conducted in order to determine the prevalence of men having sex with men (MSM) and their HIV related behaviours and attitudes among Chinese men in Hong Kong. Methods: A large scale, random, population based, anonymous telephone survey of 14 963 men between the ages of 18–60 was conducted. The overall response rate was approximately 57%. Results: Of the respondents, 4.6% had ever engaged in MSM activity. In the 6 months preceding the survey, 2.0% had engaged in MSM behaviours (active MSM) and 0.5% reported having engaged in anal sex MSM behaviours. Among anal sex MSM, consistent condom use was 42.9% with male non-commercial sex partners and even lower with male commercial sex partners (35.7%). Approximately 11% of anal sex MSM and 4.1% of the non-anal sex MSM had contracted an STD in the last 6 months. The prevalence of HIV testing was only 20.6% among anal sex MSM and 11.9% among non-anal sex MSM. Conclusions: Active MSM in Hong Kong are at high risk of HIV infection. The belief of low vulnerability to HIV is prevalent among active MSM in Hong Kong with only 2.0% believing that their chances of HIV infection as being “very likely.”

Probable Secondary Infections in Households of SARS Patients in Hong Kong

Although severe acute respiratory syndrome (SARS) is highly infectious in clinical settings, SARS has not been well examined in household settings. The household and household member attack rates were calculated for 1,214 SARS case-patients and their household members, stratified by two phases of the epidemic. A case-control analysis identified risk factors for secondary infection. Secondary infection occurred in 14.9% (22.1% versus 11% in earlier and later phases) of all households and 8% (11.7% versus 5.9% in the earlier and later phases) of all household members. Healthcare workers’ households were less likely to be affected. Risk factors from the multivariate analysis included at-home duration before hospitalization, hospital visitation to the SARS patient (and mask use during the visit), and frequency of close contact. SARS transmission at the household level was not negligible in Hong Kong. Transmission rates may be greatly reduced with precautionary measures taken by household members of SARS patients.

Prevalence and risk behaviors of Hong Kong males who seek cross-border same-sex partners in mainland China.

Background: Little is known about cross-border sex-networking behaviors among men who have sex with men (MSM) Goal: The goal of this study was to determine the prevalence of cross-border sex-networking in mainland China among MSM in Hong Kong and the associated risk behaviors Study: A telephone survey was conducted. A total of 15,230 Hong Kong Chinese men aged 18 to 60 participated in the study. Results: Of the 283 MSM engaged in some MSM behaviors in the last 6 months, 15.2% had engaged in sexual activity with a man in mainland China in the 6 months before the survey. These “cross-border MSM” were more likely than others to have practiced risk behaviors such as having patronized male commercial sex workers, having contracted a sexually transmitted disease (STD), having had ≥3 MSM partners, and having higher prevalence of HIV testing in the last 6 months (adjusted odds ratio, 3.32–43.83). Conclusions: There is an urgent need for a regional approach to HIV/STD prevention for MSM in southern China.

Changes in the prevalence of HIV-related behaviors and perceptions among 1832 injecting drug users in Sichuan, China.

Objective: To evaluate overall effectiveness of human immunodeficiency virus-related prevention programs among injecting drug users in Sichuan, China. Design: Behavioral surveillance data were analyzed. Results: The coverage rates for various service types increased from 2002–2004. The prevalence of using other’s used syringes in the last month decreased from between 24.7% and 54.1% in the baseline years (2002 or 2003) to between 11% and 18.9% in 2004 [odds ratio (OR) = 0.1, 95% confidence interval (CI): 0.06–0.2 to OR = 0.6, 95% CI: 0.4–0.9, P <0.05]. Improvements were observed in prevalence of giving used syringes to others for drug injection in the last month (OR = 0.1, 95% CI: 0.06–0.1 to OR = 0.7, 95% CI: 0.5–0.9 in 3 counties, P <0.05) etc. Increase in prevalence of condom use with commercial sex partners or nonregular partners were observed in 3 counties (2004 vs. baseline year: OR = 0.2, 95% CI: 0.1–0.5 to OR = 0.4, 95% CI: 0.2–0.9, P <0.05) but not for prevalence of condom use with regular sex partners. Conclusion: The results supported the claim that harm reduction programs targeting injecting drug users have been effective.

Acceptability of HPV Vaccines and Associations with Perceptions Related to HPV and HPV Vaccines Among Men Who Have Sex with Men in Hong Kong

HPV vaccines are available to men but there are few studies investigating the acceptability of HPV vaccines among men who have sex with men (MSM), a high risk group. We assessed the intention to take up HPV vaccines among MSM in Hong Kong and the associated factors related to cognitions on HPV and HPV vaccines, basing on the Health Belief Model (n = 542). The acceptability of HPV vaccines was 20% (unconditional on efficacies and price), 29.2% (conditional on efficacies and market price), 51.7% (conditional on efficacies and discounted price) and 79.1% (conditional on efficacies and free price). Adjusting for background variables, composite scores of perceived susceptibility, perceived severity, perceived barriers and cue to actions were significantly associated with acceptability of HPV vaccines conditional on specific efficacies and the market price. Acceptability of HPV vaccines was highly price sensitive. Future studies need to use conditional measures. Implementation and translational researches are warranted.

Attitudes towards and perceptions of visual loss and its causes among Hong Kong Chinese adults

Background: As part of a study of visual function among Hong Kong Chinese adults, their attitudes and perceptions related to visual loss were examined. These included fear of visual loss, negative functional impacts of visual loss, the relationship between ageing and visual loss and help‐seeking behaviours related to visual loss. Demographic factors associated with these variables were also studied.

A pilot clustered randomized control trial evaluating the efficacy of a network-based HIV peer-education intervention targeting men who have sex with men in Hong Kong, China

HIV is a serious health threat among men who have sex with men (MSM). A 2-month pilot network-based peer intervention was conducted among Chinese MSM in Hong Kong. Eight MSM peer educators were randomized into the Intervention or the Control Groups and recruited 36 and 33 peers to join the program, respectively. The educators of the Intervention Group delivered standardized and theory-based preventive messages to their peers via daily social interactions. The Control Group received education materials. Baseline between-group differences were non-significant. At post-intervention, intervened participants were more likely than controlled participants to intend to use condoms consistently during anal sex with men in the next 6 months [94.4% versus 60.6%; Relative Risk (RR): 1.56 (95% Confidence Interval (CI): 1.17, 2.08)] and to perceive behavioral control over taking up voluntary HIV testing and counseling [97.2% versus 72.7%; RR: 1.34 (95% CI: 1.08, 1.66)]. Large scale randomized trials are warranted.