Multiple clades of SARS-CoV-2 were introduced to Thailand during the first quarter of 2020.

In early January 2020, Thailand became the first country where a coronavirus disease 2019 (COVID-19) patient was identified outside China. In this study, 23 whole genomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from patients who were hospitalized from January to March 2020 were analyzed, along with their travel histories. Six lineages were identified including A, A.6, B, B.1, B.1.8, and B.58, among which lineage A.6 was dominant. Seven patients were from China who traveled to Thailand in January and early February. Five of them were infected with the B lineage virus, and the other two cases were infected with different lineages including A and A.6. These findings present clear evidence of the early introduction of diverse SARS-CoV-2 clades in Thailand.

Evaluating the efficiency of specimen pooling for PCR-based detection of COVID-19.

In the age of a pandemic, such as the ongoing one caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the world faces a limited supply of tests, personal protective equipment, and factories and supply chains are struggling to meet the growing demands. This study aimed to evaluate the efficacy of specimen pooling for testing of SARS-CoV-2 virus, to determine whether costs and resource savings could be achieved without impacting the sensitivity of the testing. Ten previously tested nasopharyngeal and throat swab specimens by real-time polymerase chain reaction (PCR), were pooled for testing, containing either one or two known positive specimens of varying viral concentrations. Specimen pooling did not affect the sensitivity of detecting SARS-CoV-2 when the PCR cycle threshold (Ct) of original specimen was lower than 35. In specimens with low viral load (Ct > 35), 2 of 15 pools (13.3%) were false negative. Pooling specimens to test for Coronavirus Disease 2019 infection in low prevalence (≤1%) areas or in low risk populations can dramatically decrease the resource burden on laboratory operations by up to 80%. This paves the way for large-scale population screening, allowing for assured policy decisions by governmental bodies to ease lockdown restrictions in areas with a low incidence of infection, or with lower-risk populations.

Imported case of Middle East respiratory syndrome coronavirus (MERS-CoV) infection from Oman to Thailand, June 2015.

Thailand reported the first Middle East respiratory syndrome (MERS) case on 18 June 2015 (day 4) in an Omani patient with heart condition who was diagnosed with pneumonia on hospital admission on 15 June 2015 (day 1). Two false negative RT-PCR on upper respiratory tract samples on days 2 and 3 led to a 48-hour diagnosis delay and a decision to transfer the patient out of the negative pressure unit (NPU). Subsequent examination of sputum later on day 3 confirmed MERS coronavirus (MERS-CoV) infection. The patient was immediately moved back into the NPU and then transferred to Bamrasnaradura Infectious Disease Institute. Over 170 contacts were traced; 48 were quarantined and 122 self-monitored for symptoms. High-risk close contacts exhibiting no symptoms, and whose laboratory testing on the 12th day after exposure was negative, were released on the 14th day. The Omani Ministry of Health (MOH) was immediately notified using the International Health Regulation (IHR) mechanism. Outbreak investigation was conducted in Oman, and was both published on the World Health Organization (WHO) intranet and shared with Thailand's IHR focal point. The key to successful infection control, with no secondary transmission, were the collaborative efforts among hospitals, laboratories and MOHs of both countries.

Elimination of Mother-to-Child Transmission of HIV - Thailand.

Thailand experienced a generalized human immunodeficiency virus (HIV) epidemic during the 1990s. HIV prevalence among pregnant women was 2.0% and the mother-to-child transmission (MTCT) rate was >20% (1-3). In June 2016, Thailand became the first country in Asia to validate the elimination of MTCT by meeting World Health Organization (WHO) targets. Because Thailand's experience implementing a successful prevention of MTCT program might be instructive for other countries, Thailand's prevention of MTCT interventions, outcomes, factors that contributed to success, and challenges that remain were reviewed. Thailand's national prevention of MTCT program has evolved with prevention science from national implementation of short course zidovudine (AZT) in 2000 to lifelong highly active antiretroviral therapy regardless of CD4 count (WHO option B+) in 2014 (1). By 2015, HIV prevalence among pregnant women had decreased to 0.6% and the MTCT rate to 1.9% (the elimination of MTCT target is <2% for nonbreastfeeding populations) (4). A strong public health infrastructure, committed political leadership, government funding, engagement of multiple partners, and a robust monitoring system allowed Thailand to achieve this important public health milestone.

Tuberculosis treatment with mobile-phone medication reminders in northern Thailand.

Thailand's implementation of the Directly Observed Treatment, Short course (DOTS) strategy to increase tuberculosis (TB) control program efficacy has not achieved the World Health Organization (WHO) TB key targets. We defined two TB control models in the study. Patients in Model 1 were treated with a conventional DOTS strategy and in Model 2, patients were treated the same as Model method 1 but were given a phone call reminder to take their medication. Multi-drug resistant tuberculosis (MDR-TB) and non-MDR-TB patients were randomized into either Model 1 or 2. Treatment outcomes were given as cure rates, completion rates, failure rates or success rates at 18 months in the MDR-TB group and 6 months in the non-MDR-TB group. The sputum conversion rate at 1 month were evaluated for both groups. In the MDR-TB group, the sputum conversion rate was 20% (95% CI 8-45) in Model 1 and 90% (95% CI 73-98) in Model 2 (p < 0.001). In the non-MDR-TB group, the sputum conversion rate was 52% (95% CI 36-70) in Model 1 and 37% (95% CI 22-56) in Model 2 although the difference was not significant (p = 0.221). The Model 2 success rates were significantly higher (73.7%, 96.7%) in both the MDR-TB and non-MDR-TB groups (p < 0.001, p = 0.047). The MDR-TB rate in northern Thailand decreased from 4.1% during April-September 2008 to 1.8% during April-September 2009. Further study of the association between implementation of Model 2 and MDR-TB incidence reduction needs to be carried out.

The Impact of Preparedness in Defying COVID-19 Pandemic Expectations in the Lower Mekong Region: A Case Study.

Dire COVID-19 expectations in the Lower Mekong Region (LMR) can be understood as Cambodia, the Lao PDR, Myanmar, Thailand, and Vietnam have stared down a succession of emerging infectious disease (EID) threats from neighboring China. Predictions that the LMR would be overwhelmed by a coming COVID-19 tsunami were felt well before the spread of the COVID-19 pandemic had been declared. And yet, the LMR, excepting Myanmar, has proved surprisingly resilient in keeping COVID-19 contained to mostly sporadic cases. Cumulative case rates (per one million population) for the LMR, including or excluding Myanmar, from January 1 to October 31 2020, are 1,184 and 237, respectively. More telling are the cumulative rates of COVID-19-attributable deaths for the same period of time, 28 per million with and six without Myanmar. Graphics demonstrate a flattening of pandemic curves in the LMR, minus Myanmar, after managing temporally and spatially isolated spikes in case counts, with negligible follow-on community spread. The comparable success of the LMR in averting pandemic disaster can likely be attributed to years of preparedness investments, triggered by avian influenza A (H5N1). Capacity building initiatives applied to COVID-19 containment included virological (influenza-driven) surveillance, laboratory diagnostics, field epidemiology training, and vaccine preparation. The notable achievement of the LMR in averting COVID-19 disaster through to October 31, 2020 can likely be credited to these preparedness measures.

Identification of a Novel Pathogen Using Family-Wide PCR: Initial Confirmation of COVID-19 in Thailand.

In resource-limited countries, early detection of novel pathogens is often challenging, due to financial and technical constraints. This study reports the efficacy of family-wide polymerase chain reaction (PCR) in screening, detecting, and identifying initial cases of the novel SARS-CoV-2 in Thailand. Respiratory secretions were collected from suspected individuals traveling from Wuhan, China to Thailand at the beginning of January 2020. Family-wide PCR assays yielded positive results for coronavirus in one traveler within 12 h on January 8, 2020. Nucleotide sequences (290 bp) showed 100% similarity to SARS-CoV-2. The whole genome sequence was further characterized by Next Generation Sequencing (NGS) for confirmation. Combining family-wide PCR, as a rapid screening tool, with NGS, for full genome characterization, could facilitate early detection and confirmation of a novel pathogen and enable early containment of a disease outbreak.

Reduction in mother-to-child transmission of HIV in Thailand, 2001-2003: Results from population-based surveillance in six provinces.

BACKGROUND: In 2000, Thailand implemented a national program to prevent mother-to-child HIV transmission (PMTCT). OBJECTIVE: To describe the effectiveness of the prevention of mother-to-child HIV transmission program in Thailand. DESIGN AND METHODS: A register of HIV-exposed children at birth was created with follow-up of infection status. The register included children born to HIV-infected women between 1 January 2001 and 31 December 2003 at 84 public health hospitals in six provinces of Thailand. The main outcome measure was HIV infection in children. RESULTS: A total of 2200 children born to HIV-infected mothers were registered. Of these mother-infant pairs, 2105 (95.7%) received some antiretroviral prophylaxis, including 1358 (61.7%) who received the complete short-course zidovudine regimen during pregnancy and labor for the mother and after birth for the infant, with or without other antiretrovirals. HIV infection outcome was determined for 1667 (75.8%) children, of whom 158 [9.5%, 95% confidence interval (CI), 8.1-11.0%] were infected. Transmission risk was 6.8% (95% CI 5.2-8.9%) among 761 mother-infant pairs that received the complete zidovudine regimen alone, and 3.9% (95% CI, 2.2-6.6%) among 361 mother-infant pairs that received the complete zidovudine regimen combined with other antiretrovirals, usually nevirapine. The overall transmission risk from this cohort, including all antiretroviral prophylaxis combinations, is estimated to be 10.2%. CONCLUSIONS: The Thai national PMTCT program is effective in reducing mother-to-child transmission risk from the historical risk of 18.9-24.2%. The addition of nevirapine to short-course zidovudine beginning in 2004 may further improve program effectiveness in Thailand.

Prevalence of nosocomial infection in Thailand 2006.

OBJECTIVE: To study the prevalence of nosocomial infection (NI). MATERIAL AND METHOD: A point prevalence study was done in 20 hospitals across the country in August 2006. RESULTS: The present study was done in 20 hospitals: three university, five regional, five provincial, and seven other hospitals. 9,865 patients were included Male and female patients were almost equal in number with an average age of 42.7 years. The NI proportion was 6.5%, 7.0% in male and 5.9% in female patients. The prevalence rate of NI was highest in university and other hospitals (7.6%), followed by provincial (6.0%), and regional hospital (4.9%). There were two hospitals, one regional and one other hospital with NI prevalence rates over 10%. All three university hospitals had NI exceeding 7%. The infection rate was highest in ICU (22.6%), followed by surgical (6.8%), medical and orthopedic (6.7% each) departments. The commonest site of NI was lower respiratory tract (36.1%) followed by urinary tract (25.5%). Causative organisms were identified in 70.8% of all sites of infection and over 63% were by bacteria. Gram-negative bacteria were responsible for 70.2% and gram-positive bacteria for 19.9% of all pathogens. Pseudomonas aeruginosa, Klebsiella spp., Acinetobacter baumannii, MRSA, and enterococci were the leading bacterial isolates. At the time of the present study, 47.0% of patients were receiving antimicrobials. Cephalosporins, penicillins, and aminoglycosides were most commonly used CONCLUSION: The prevalence rate of NI in Thailand in 2006 was 6.5%, similar to previous studies. Changes in NI rates in certain hospitals, even though subtle, need additional studies to improve the efficacy of NI control.

Circulation of HIV-1 Multiple Complexity Recombinant Forms Among Female Sex Workers Recently Infected with HIV-1 in Thailand.

The circulating subtype distribution of HIV-1 has not been well characterized in female sex worker (FSW) populations in Thailand. To understand the mechanisms and interrelationships of epidemics involving FSWs in Thailand, we performed a large molecular epidemiological study of FSWs aged 25 years with recently acquired HIV-1 infections. The samples were collected in 2005, 2007, 2009, and 2011 in 38 provinces, representing every region of Thailand. After gag (p24), pol (pro-RT), and env (C2/V3) were sequenced, comprehensive genome analysis was performed. Genetic subtypes were determined in 159 plasma samples. The percentage of circulating recombinant forms (CRFs) CRF01_AE (90.6%) predominated, while subtype B (1.3%), other CRFs (1.9%), and unique recombinant forms (URFs) (6.2%) were identified as minor populations. Interestingly, the unique recombinant nature of these HIV-1 strains was verified in 10 specimens, indicating the presence of new forms of HIV-1 intersubtypes G/A, C/B, AE/B/C, and AE/B with different recombination breakpoints. Subtype B has contributed to these new generations of unique CRF01/B recombinants, especially in the pol (RT) gene, in which the template switching of the RT genomes occurred during reverse transcription. These results imply that the several unique recombinant viruses circulating in Thailand were probably generated in the population or introduced from neighboring countries. Our study helps clarify the patterns of viral transmission and define transmission pathways in Thailand.

Prevention of mother-to-child transmission and voluntary counseling and testing programme data: what is their utility for HIV surveillance?

OBJECTIVE: Antenatal clinic (ANC)-based surveillance through unlinked anonymous testing (UAT) for HIV without informed consent provides solid long-term trend data in resource-constrained countries with generalized epidemics. The rapid expansion of the prevention of mother-to-child transmission (PMTCT) and voluntary counseling and testing (VCT) programmes prompts the question regarding their utility for HIV surveillance and their potential to replace UAT-based ANC surveillance. METHODS: Four presentations on the use of PMTCT or VCT data for HIV surveillance were presented at a recent international conference. The main findings are presented in this paper, and the operational and epidemiological aspects of using PMTCT or VCT data for surveillance are considered. RESULTS: VCT data in Uganda confirm the falling trend in HIV prevalence observed in ANC surveillance. Thailand, a country with nationwide PMTCT coverage and a very high acceptance of HIV testing, has replaced UAT data in favor of PMTCT data for surveillance. Studies from Botswana and Kenya showed that PMTCT-based HIV prevalences was similar, but the quality and availability of the PMTCT data varied. CONCLUSION: The strength of UAT lies in the absence of selection bias and the availability of individual data. Conversely, the quantity of VCT and PMTCT programme testing data often exceed those in UAT, but may be subject to bias due to self-selection or test refusal. When using VCT or PMTCT data for surveillance, investigators must consider these caveats, as well as their varying data quality, accessibility, and availability of individual records.

Detection of Zika Virus Infection in Thailand, 2012-2014.

Zika virus (ZIKV) is an emerging mosquito-borne pathogen with reported cases in Africa, Asia, and large outbreaks in the Pacific. No autochthonous ZIKV infections have been confirmed in Thailand. However, there have been several cases reported in travelers returning from Thailand. Here we report seven cases of acute ZIKV infection in Thai residents across the country confirmed by molecular or serological testing including sequence data. These endemic cases, combined with previous reports in travelers, provide evidence that ZIKV is widespread throughout Thailand.

A survey of sexual risk behavior for HIV infection in Nakhonsawan, Thailand, 2001.

OBJECTIVE: To determine the prevalence of sexual risk behaviors for HIV in the general population aged 15-44 years in Nakhonsawan province, Thailand. DESIGN: Cross-sectional survey. METHODS: A two-stage cluster sampling technique was used to select 630 participants aged 15-44 years from the general population. Tape-recorders with earphones provided questions to the respondents, who used self-administered answer sheets to record their responses. RESULTS: Most participants were rural, married and educated at the primary school level. The mean age was 31.5 years. Seventy-eight percent of all participants had ever had sexual intercourse. The prevalence of premarital sex among married participants was 41%. In the previous year, 20% of the participants had had sex with commercial or non-regular partners. Sex with non-regular partners occurred more frequently than sex with commercial partners. Sixty-one percent had used condoms the last time they had sex with a commercial partner and 46% had used condoms the last time they had sex with non-regular partners. Consistent condom use with non-regular partners was lower than with commercial partners. Voluntary HIV testing during the previous year was reported by 24% of the participants who had had sex with commercial or non-regular partners. CONCLUSIONS: The results suggest that Nakhonsawan needs to strengthen implementation of the 100% condom programme, address condom use with non-commercial partners, promote awareness of personal risk rather than identification of risk groups and increase voluntary HIV testing among people who engage in risky behaviors.

Trends in HIV Prevalence, Estimated HIV Incidence, and Risk Behavior Among Men Who Have Sex With Men in Bangkok, Thailand, 2003­2007.

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 age­age at start of anal intercourse]) 3 100). 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.