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.

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.

Risk of congenital malformations associated with first-trimester exposure to antipsychotics: A propensity score-weighted population-based cohort study.

BACKGROUND: There is growing concern regarding teratogenic effect of antipsychotics. Previous research assessing association between antipsychotics and congenital malformations (CMs) yielded mixed results and were all derived from Western countries. We aimed to examine risk of major and organ/system-specific CMs associated with prenatal antipsychotic exposure in Hong Kong. METHODS: This population-based study identified women aged 15-50 years who delivered their first/singleton child between 2003-2018 from public healthcare service database. Propensity score (PS)-weighted logistic-regression analyses were performed to examine risk of CMs following first-trimester exposure to antipsychotic classes (second- and first-generation antipsychotic; SGA and FGA) and six most frequently-prescribed individual antipsychotics. RESULTS: Of 465,069 women, 419 and 420 redeemed ≥1 prescription of SGA and FGA during first-trimester, respectively. Prevalence of any CMs was 4.9% (95%CI:4.9-5.0%) in unexposed-infants, 9.1% (6.7-12.3%) in SGA-exposed infants, and 6.2% (4.3-9.0%) in FGA-exposed infants. SGA exposure (adjusted-odds-ratio: 2.11 [95%CI:1.19-3.86]) was associated with increased risk of CMs. This finding was consistent with sensitivity analyses addressing exposure misclassification and confounding by treatment indication, but not with PS-matched sensitivity analysis. Elevated risk of CMs was observed in infants exposed to high-dose olanzapine (7.50 [1.65-36.13]) and high-dose quetiapine (15.03 [4.86-56.72]), but with wide-CIs. Organ/system-specific malformations were not associated with SGA, FGA or individual antipsychotics. CONCLUSION: We observed a small increased risk of major malformations associated with SGA, but was not consistently affirmed in sensitivity analyses, precluding firm conclusions. Research with large sample size clarifying comparative safety of individual antipsychotics on specific malformations is warranted.

What makes an optimal delivery for PrEP against HIV: A qualitative study in MSM.

BACKGROUND: Pre-exposure prophylaxis (PrEP) is an effective means of HIV prevention for men who have sex with men (MSM), a key population whose engagement is crucial for achieving effective public health outcomes. An optimal service model would be important in planning the implementation of PrEP in places where such service has not been established. METHODS: A qualitative study was conducted to delineate the attributes of an optimal PrEP service model for MSM in Hong Kong, a city where no formal PrEP programs existed. Twenty purposively sampled MSM who were enrollees of two pilot PrEP projects participated in the semi-structured interviews promoting story-telling. The coded data were thematically analyzed following Grounded Theory approach, focusing on uncovering a typology of the essential attributes of an optimal PrEP service model, and the reasons for such preferences. RESULTS: Participating MSM were all ethnic Chinese and aged 26 to 52 years. All had received PrEP from pilot projects in conjunction with periodic screening of sexually transmitted infections (STI), HIV antibody, and plasma creatinine. Four major themes emerged as regards the attributes of a preferred PrEP service: (i) comprehensiveness of HIV/STI and safety monitoring; (ii) convenient unitary service; (iii) stigma-free PrEP access and protecting confidentiality; and (iv) affordable price. Whereas regular provision of PrEP was acceptable to MSM, unaffordability and related stigma were the anticipated challenges for potential service providers. CONCLUSIONS: The qualitative assessment of MSM's preference for PrEP service delivery has yielded important information on the many facets of a desirable service model.

The effects of widespread methadone treatment on the molecular epidemiology of hepatitis C virus infection among injection drug users in Hong Kong.

The distribution of HCV genotypes among injection drug users in Hong Kong was assessed in context of methadone treatment availability. Three time periods were defined by the year of initiating injection-on or before 1980, 1981-1994, and 1995-2006-with methadone becoming widely available since the second period. Of the 273 HCV RNA-positive cases, the most prevalent subtype was HCV 6a (52.4%), followed by HCV 1b (38.5%). The new variants of HCV subtypes 6e and 6h were detected. Both subtypes 1b and 6a were prevalent among older injectors, while subtype 3a was more common in young injectors and those initiating injection recently during the third time period. Age (P < 0.05) and recent injection frequency (P < 0.01) were independently associated with HCV 6a infection. Subtype 1b was predominant in the first period, whereas 6a was more common in the second and third. Subtype 1b sequences appeared to have originated at two positions on the phylogenetic tree, while 6a showed a more disperse distribution suggestive of multiple introductions. Phylogenetic analysis on the NS5B region did not reveal specific clustering of any subtype/genotype. Overall, there was no suggestion of outbreaks of HCV. The extensive use of methadone may have protected Hong Kong from the emergence of HCV clusters among injection drug users.

Institutional risk factors for norovirus outbreaks in Hong Kong elderly homes: a retrospective cohort study.

BACKGROUND: Most of the institutional outbreaks of norovirus in Hong Kong occur in elderly homes, the proportion being 69% in 2006. Residents in elderly homes are a special population seriously affected by norovirus infections, it is necessary to investigate the risk factors of the norovirus outbreaks in Hong Kong elderly homes at the facility level. METHODS: A cohort of 748 elderly homes was followed up from January 2005 to December 2007; each elderly home was treated as one observation unit and the outcome event was the norovirus outbreak. Cox regression models were fitted to estimate the rate ratio (RR) and 95% confidence interval (CI) for the potential risk factors. RESULTS: A total of 276 norovirus outbreaks were confirmed during the study period; the outbreak rate was 12.2 (95% CI: 9.9-14.6) per 100 home-years; elderly homes with a larger capacity (RR = 1.4, 95% CI: 1.3-1.5 (per 30-resident increment)), a higher staff-to-resident ratio (RR = 1.2, 95% CI: 1.1-1.3 (per 1/30 increment) and better wheelchair accessibility (RR = 2.0, 95% CI: 1.3-3.2) were found to have an elevated norovirus outbreak rate in Hong Kong elderly homes; Elderly homes with partitions between beds had a lower rate of norovirus outbreaks (RR = 0.6, 95% CI: 0.4-0.8). CONCLUSIONS: Elderly home capacity, staff-to-resident ratio and wheelchair accessibility were risk factors for norovirus outbreaks in Hong Kong elderly homes. Partitions between beds were a protective factor of norovirus outbreaks. These results should be considered in the infection control in Hong Kong elderly homes.

Profiling advanced disease in an Asian clinical human immunodeficiency virus cohort: comparison of two definitions for acquired immunodeficiency syndrome.

OBJECTIVE: To compare advanced human immunodeficiency virus disease defined immunologically and clinically by evaluating the characteristics of human immunodeficiency virus patients in Hong Kong. DESIGN: Retrospective observational study. SETTING: A human immunodeficiency virus cohort database established at a university and the major human immunodeficiency virus specialist services in Hong Kong. PATIENTS: Patients diagnosed with acquired immunodeficiency syndrome at the study centres between 1985 and 2006 were included. MAIN OUTCOME MEASURES: Comparison of advanced human immunodeficiency virus disease defined (a) clinically as World Health Organization stage IV, and (b) immunologically as a CD4 count lower than 350/microL. RESULTS: Between 1985 and 2006, a total of 1317 patients, a majority of whom Chinese, were evaluated. Of these, 914 (69%) and 335 (25%) fulfilled the criteria for immunologically and clinically defined advanced disease, respectively. The mean age of the study population was 38 years and male-to-female ratio 4:1. There were two peaks in the frequency distribution of CD4 counts, one at a low count of less than 100/microL and the other between 200 and 400/microL. All except four with clinically defined advanced disease had CD4 counts lower than 350/microL on presentation. Of those with immunologically defined advanced disease, men having sex with men accounted for a lower proportion in the clinically advanced category, and Pneumocystis pneumonia was the commonest advanced disease at presentation. CONCLUSIONS: Both clinical and immunological definitions provide a consistent means for assessing advanced disease, the implications of which are different. Such profiling has been made possible through the operation of a standardised cohort database, which is useful in (1) enhancing human immunodeficiency virus epidemiology studies, and (2) evaluating the performance of public health services.

Failure of pre-exposure prophylaxis with daily tenofovir/emtricitabine and the scenario of delayed HIV seroconversion.

Failure of pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate and emtricitabine may occur despite perfect adherence, although this is uncommon. Failure results in breakthrough HIV infection. Delayed seroconversion associated with antiretroviral use may complicate the picture, causing uncertainties in interpreting adherence patterns for establishing the true cause of PrEP failure.

High prevalence of HCV in a cohort of injectors on methadone substitution treatment.

BACKGROUND: In Hong Kong, methadone treatment is widely accessible. Injecting drug users (IDU) have a relatively low risk behavioural profile and low HIV prevalence (0.3%). The corresponding Hepatitis C (HCV) level, however, is unclear. OBJECTIVES: To determine the HCV prevalence in IDU in Hong Kong and to identify any associated factors. STUDY DESIGN: A community-based HCV prevalence study of IDU was conducted in methadone clinics. Demographics and drug use pattern were collected through a questionnaire survey and blood samples were obtained for HCV serological tests. RESULTS: Data of 567 IDU were analyzed. Most were male (84%) and ethnic Chinese (98%). The median age was 49 years and median injection duration 17 years. Two-thirds (62%) admitted ever sharing injecting equipments. Most (76%) reported having injection drug use in the preceding 3 months, and 44% abused midazolam/triazolam in addition to heroin. Prevalence of HCV antibodies was 85% (95% confidence interval 82.5-88.3%). Injection duration, recent injection, ever sharing injecting equipments and concomitant use of other drugs were independent factors associated with HCV infection. CONCLUSIONS: HCV prevalence is high in IDU despite a low HIV prevalence and widely available substitution treatment, which has probably slowed but not prevented the HCV epidemic in IDU in Hong Kong.

Low compliance of men having sex with men with self-deferral from blood donation in a Chinese population.

BACKGROUND: The prevalence of human immunodeficiency virus (HIV) in men having sex with men (MSM) is generally higher than that in the average adult male population. In Hong Kong a permanent deferral mechanism is in place to minimise viral transmission during the window period. As regards donor deferral, the attitudes and behaviours of MSM in the community are crucial to ensuring blood safety. MATERIALS AND METHODS: A web-based questionnaire was constructed in the Chinese language. Through online advertisement and the assistance of outreach workers, sexually active MSM were recruited to participate in the survey. The questionnaire was composed of items on: (i) demographics, (ii) history and frequency of blood donations, (iii) profile of sexual practice, and (iv) views on time-limited vs permanent deferral. RESULTS: Over a 6-week period in 2012, 250 MSM, three-quarters of whom were aged between 16 and 30 years old, were recruited. Almost half (47.6%) gave a history of blood donation. The majority (75.6%) were repeat donors, one-third of whom gave blood every 3-6 months. Compared to non-donors, a higher proportion of blood donors had had anal sex and multiple partners in the preceding year, while their condom usage rate was similar. Current donors were inclined to agree with time-limited deferral. With the latter's implementation, the number of donors would increase, but the compliance rate might vary widely. DISCUSSION: Blood donation is common among MSM in Hong Kong. The risk of HIV transmission depends largely on their compliance with the deferral mechanism applied, irrespectively of whether it is permanent or time-limited.

Comparison of the characteristics of elderly influenza patients in two consecutive seasons.

The seasonality of influenza infections can be affected by virus subtypes, climate, and social networking in populations. While these factors are well known, their relative influences in specific age groups have not been fully investigated. During 2010-2011, patients aged 65 years and above with influenza virus infections were recruited from a regional hospital in Hong Kong. They were either residents of homes for the elderly (n=60) or living with their family (n=75). Two seasons were distinguished, the summer season of 2010 dominated by H3N2 and the winter season of 2011 dominated by H1N1. The patients' clinical presentations and patterns of inter-personal connectivity were assessed. Overall, more elderly people living with their family were diagnosed with H1N1 compared to those in the homes for the elderly, and the former had visited a more diverse range of places 1 week prior to diagnosis. A higher proportion of patients living with family presented with lower respiratory tract symptoms, but these patients were less likely to have pre-existing chronic diseases. The results suggest that elderly patients infected during an influenza season could vary by virus subtype, which in turn is dependent on exposure locations and the pattern of social connectivity.