BACKGROUND: A recent infection testing algorithm (RITA) incorporating case surveillance (CS) with the rapid test for recent HIV infection (RTRI) was integrated into HIV testing services in Thailand as a small-scale pilot project in October 2020. OBJECTIVE: We aimed to describe the lessons learned and initial outcomes obtained after the establishment of the nationwide recent HIV infection surveillance project from April through August 2022. METHODS: We conducted desk reviews, developed a surveillance protocol and manual, selected sites, trained staff, implemented surveillance, and analyzed outcomes. Remnant blood specimens of consenting newly diagnosed individuals were tested using the Asanté HIV-1 Rapid Recency Assay. The duration of HIV infection was classified as RTRI-recent or RTRI-long-term. Individuals testing RTRI-recent with CD4 counts <200 cells/mm3 or those having opportunistic infections were classified as RITA-CS-long-term. Individuals testing RTRI-recent with CD4 counts >200 cells/mm3, no opportunistic infections, and not on antiretroviral treatment were classified as RITA-CS-recent. RESULTS: Two hundred and one hospitals in 14 high-burden HIV provinces participated in the surveillance. Of these, 69 reported ≥1 HIV diagnosis during the surveillance period. Of 1053 newly diagnosed cases, 64 (6.1%) were classified as RITA-CS-recent. On multivariate analysis, self-reporting as transgender women (adjusted odds ratio [AOR] 7.41, 95% CI 1.59-34.53) and men who have sex with men (AOR 2.59, 95% CI 1.02-6.56) compared to heterosexual men, and students compared to office workers or employers (AOR 3.76, 95% CI 1.25-11.35) were associated with RITA-CS-recent infection. The proper selection of surveillance sites, utilizing existing surveillance tools and systems, and conducting frequent follow-up and supervision visits were the most commonly cited lessons learned to inform the next surveillance phase. CONCLUSIONS: Recent HIV infection surveillance can provide an understanding of current epidemiologic trends to inform HIV prevention interventions to interrupt ongoing or recent HIV transmission. The key success factors of the HIV recent infection surveillance in Thailand include a thorough review of the existing HIV testing service delivery system, a streamlined workflow, strong laboratory and health services, and regular communication between sites and the Provincial Health Offices.

BACKGROUND: Respondent-driven sampling (RDS) is the current standard for sampling key populations at risk for HIV infections but is usually limited to local implementation in single towns or cities. Web-based sampling eliminates this spatial constraint but often relies on self-selected convenience samples. We piloted a web-based RDS survey with biomarker collection among men who have sex with men (MSM) in Thailand. OBJECTIVE: This study aimed to evaluate and demonstrate the feasibility of implementing a web-based RDS survey as a routine surveillance system in Thailand. The goal was to enhance surveillance efforts targeting hard-to-reach populations in the country. METHODS: We developed a website to fully function like a conventional RDS survey office, including coupon verification, eligibility screening, consenting, interviewing (self-administered), peer recruitment training, coupon issuance, compensation, and recruitment tracking. All functions were automated; data managers monitored recruitment, data collection, and payment and could be contacted by recruits as needed. Eligible participants were male, older than 15 years, resided in Thailand, and had anal sex with a man in the past 6 months. Recruits who resided in Bangkok were additionally invited to physically attend a participating health clinic of their choice for an HIV-related blood draw. Data were weighted to account for the complex sampling design. RESULTS: The survey was implemented from February to June 2022; seeds (21 at start, 14 added later) were identified mostly through targeted web-based banner ads; coupon uptake was 45.1%. Of 2578 candidate recruits screened for eligibility, 2151 (83.4%) were eligible and 2142 (83.1%) enrolled. Almost all (2067/2578, 80.2%) completed the questionnaire; however, 318 survey records were removed from analysis as fraudulent enrollments. The final sample size was 1749, the maximum number of waves achieved was 191, and sampling covered all 6 geographic regions and 75 of 77 (97.4%) provinces; convergence was reached for several salient variables. The mean age was 20.5 (SD 4.0) years, and most (69.8%) had never tested for HIV before, with fear of stigma as the biggest reason (97.1%) for not having tested. Most (76.9%) had visited gay-focused physical venues several times a week. A condom was used in 97.6% of the last sex acts, 11.0% had purchased sex from other men (past 12 mo), 4.5% had sold sex to men (past 12 mo), and 95.3% had 3+ male sex partners (last 3 mo). No participant in Bangkok presented for a blood draw. CONCLUSIONS: We successfully conducted a web-based RDS survey among MSM in Thailand, covering nearly the entire country, although, as in physical RDS surveys, sampling was dominated by younger MSM. The survey also failed to collect biomarkers in Bangkok. Public health interventions should aim at increasing testing and addressing (the perception of) stigma.

BACKGROUND: Thailand's HIV epidemic is heavily concentrated among men who have sex with men (MSM), and surveillance efforts are mostly based on case surveillance and local biobehavioral surveys. OBJECTIVE: We piloted Kai Noi, a web-based respondent-driven sampling (RDS) survey among MSM. METHODS: We developed an application coded in PHP that facilitated all procedures and events typically used in an RDS office for use on the web, including e-coupon validation, eligibility screening, consent, interview, peer recruitment, e-coupon issuance, and compensation. All procedures were automated and e-coupon ID numbers were randomly generated. Participants' phone numbers were the principal means to detect and prevent duplicate enrollment. Sampling took place across Thailand; residents of Bangkok were also invited to attend 1 of 10 clinics for an HIV-related blood draw with additional compensation. RESULTS: Sampling took place from February to June 2022; seeds (21 at the start, 14 added later) were identified through banner ads, micromessaging, and in online chat rooms. Sampling reached all 6 regions and almost all provinces. Fraudulent (duplicate) enrollment using "borrowed" phone numbers was identified and led to the detection and invalidation of 318 survey records. A further 106 participants did not pass an attention filter question (asking recruits to select a specific categorical response) and were excluded from data analysis, leading to a final data set of 1643 valid participants. Only one record showed signs of straightlining (identical adjacent responses). None of the Bangkok respondents presented for a blood draw. CONCLUSIONS: We successfully developed an application to implement web-based RDS among MSM across Thailand. Measures to minimize, detect, and eliminate fraudulent survey enrollment are imperative in web-based surveys offering compensation. Efforts to improve biomarker uptake are needed to fully tap the potential of web-based sampling and data collection.

BACKGROUND: Songkhla has one of the most serious provincial HIV epidemics among people who inject drugs (PWID). However, there remains a lack of systematic data on drug use patterns, HIV risk behaviors and access to interventions. To address the gap, we conducted an integrated bio-behavioral survey in 2010. METHODS: Respondent-driven sampling (RDS) was used to recruit PWID who reported injecting in the last six months. Participants were interviewed and tested for HIV and sexually transmitted infections (STIs). RDS Analysis Tool (RDSAT) was used to generate adjusted proportion estimates. RESULTS: Of 202 participants, almost all were men, 90% injected heroin, followed by methamphetamine (22%). One-third (37%) injected multiple drugs. HIV prevalence was high (22%). Seven percent reported needle sharing at last injection and 27% reported using a condom at last sex. Nearly half (42%) were currently on methadone treatment. Few participants received new needles (10%) and condoms (11%) from drop-in centers and/or peer outreach workers. CONCLUSION: This RDS survey informs the understanding of the HIV epidemic and the programmatic response among PWID in Songkhla. It was effective at recruiting PWID who were currently out-of-treatment. Given the increasing trend of poly-drug injecting use documented, a comprehensive and integrated combination intervention approach for HIV services is recommended.

BACKGROUND: Thailand's long-standing HIV sero-sentinel surveillance system for people who inject drugs (PWID) is confined to those in methadone-based drug treatment clinics and representative data are scarce, especially outside of Bangkok. METHODS: We conducted probability-based respondent-driven sampling (RDS) surveys in Bangkok (n=738) and Chiang Mai (n=309) to increase understanding of local HIV epidemics and to better inform the planning of evidence-based interventions. RESULTS: PWID had different epidemiological profiles in these two cities. Overall HIV prevalence was higher in Bangkok (23.6% vs. 10.9%, p<0.001) but PWID in Bangkok are older and appear to have long-standing HIV infections. In Chiang Mai, HIV infections appear to be more recently acquired and PWID were younger and had higher levels of recent injecting and sexual risk behaviors with lower levels of intervention exposure. Methamphetamine was the predominant drug injected in both sites and polydrug use was common although levels and patterns of the specific drugs injected varied significantly between the sites. In multivariate analysis, recent midazolam injection was significantly associated with HIV infection in Chiang Mai (adjusted odds ratio=8.1; 95% confidence interval: 1.2-54.5) whereas in Bangkok HIV status was not associated with recent risk behaviors as infections had likely been acquired in the past. CONCLUSION: PWID epidemics in Thailand are heterogeneous and driven by local factors. There is a need to customize intervention strategies for PWID in different settings and to integrate population-based survey methods such as RDS into routine surveillance to monitor the national response.

The pattern of sex work in Thailand has shifted substantially over the last two decades from direct commercial establishments to indirect venues and non-venue-based settings. This respondent-driven sampling survey was conducted in Bangkok in 2007 among female sex workers (FSW) in non-venue-based settings to pilot a new approach to surveillance among this hidden population. Fifteen initial participants recruited 707 consenting participants who completed a behavioural questionnaire, and provided oral fluid for HIV testing, and urine for sexually transmitted infection (STI) testing. Overall HIV prevalence was 20.2% (95% confidence interval [CI] 16.3-24.7). Three-quarters of women were street-based (75.8%, 95% CI 69.9-81.1) who had an especially high HIV prevalence (22.7%, 95% CI 18.2-28.4); about 10 times higher than that found in routine sentinel surveillance among venue-based FSW (2.5%). STI prevalence (Chlamydia trachomatis and Neisseria gonorrhoeae) was 8.7% (95% CI 6.4-10.8) and 1.0% (95% CI 0.2-1.9), respectively. Lower price per sex act and a current STI infection were independently associated with HIV infection (P < 0.05). High HIV prevalence found among FSW participating in the survey, particularly non-venue-based FSW, identifies need for further prevention efforts. In addition, it identifies a higher-risk segment of FSW not reached through routine sentinel surveillance but accessible through this survey method.

The aim of this study is to estimate HIV prevalence and assess sexual behaviors in a high-risk and difficult-to-reach population of clients of female sex workers (FSWs). A modified variation of respondent-driven sampling was conducted among FSWs in Bangkok, where FSWs recruited 3 FSW peers, 1 client, and 1 nonpaying partner. After informed consent was obtained, participants completed a questionnaire, were HIV-tested, and were asked to return for results. Analyses were weighted to control for the design of the survey. Among 540 FSWs, 188 (35%) recruited 1 client, and 88 (16%) recruited 1 nonpaying partner. Clients' median age was 38 years. HIV prevalence was 20% and was associated with younger age at first sexual experience [relative risk (RR) = 3.10, 95% confidence interval (CI) 1.16-8.24] and condom use during last sexual encounter with regular partner (RR = 3.97, 95% CI 1.09-14.61). Median age of nonpaying partners was 34 years, and HIV prevalence was 15.1%. There were 56 discordant FSW-client pairs and 14 discordant FSW-nonpaying partner pairs. Condom use was relatively high among discordant FSW-client pairs (90.1%) compared to discordant FSW-nonpaying partner pairs (18.7%). Results suggest that sexual partners of FSWs have a high HIV prevalence and can be a bridge for HIV transmission to other populations. Findings also highlight the importance of initiating surveillance and targeted programs for FSW partners, and demonstrate a recruitment method for hard-to-reach populations.

BACKGROUND: Men who have sex with men (MSM) continue to be at high risk for HIV infection. Here we evaluate trends in HIV prevalence, estimated HIV incidence, and risk behavior among MSM in Bangkok, Thailand. METHODS: Between 2003 and 2007, 3 biennial cross-sectional HIV prevalence assessments were conducted among MSM in Bangkok, Thailand, using venue-day-time sampling. Oral fluid was tested for HIV infection; demographic and behavioral data were self-collected using hand-held computers. Estimates of annual HIV incidence in young MSM were derived as follows: (number of HIV infections/sum of [current age-age at start of anal intercourse]) x 100). Logistic and Poisson regression was used to evaluate trends in HIV prevalence, estimated HIV incidence, and risk behavior. FINDINGS: The overall HIV prevalence increased from 17.3% in 2003 to 28.3% in 2005 to 30.8% in 2007 (P < 0.001 for trend). The estimated HIV incidence among young MSM increased from 4.1% in 2003 to 6.4% in 2005, to 7.7% in 2007 (P < 0.02 for trend). The increase in HIV prevalence from 2005 to 2007 was not statistically significant. The proportion of men reporting anal sex and casual or steady male sex partners in the past 3 months significantly decreased, whereas the proportion reporting drug use and drug use during sex significantly increased. No increase was observed in the proportion of men reporting consistent condom use. INTERPRETATION: Our data suggest that after a strong increase from 2003 to 2005, the HIV prevalence among MSM in Bangkok may have begun to stabilize. Given the continuing high levels of risk behavior and the estimated high HIV incidence in young MSM, additional HIV preventive interventions are necessary.