Clinical characteristics and drug susceptibility profiles of Mycobacterium abscessus complex infection at a medical school in Thailand.

OBJECTIVES: This study investigated the differences in epidemiological and clinical data, and antimicrobial susceptibilities among different subspecies of Mycobacterium abscessus complex (MABSC) clinical isolates at a medical school in Thailand. METHODS: A total of 143 MABSC clinical isolates recovered from 74 patients were genotypically analyzed for erm(41), rrl, and rrs mutations, and antimicrobial susceptibilities were determined using a broth microdilution method. Patient characteristics and clinical outcomes were reviewed from the medical records. RESULTS: Seventy-four patients were infected with 28/74 (37.8%) M. abscessus subspecies abscessus (MAB), 43/74 (58.1%) M. abscessus subsp. massiliense (MMA), and 3/74 (4.1%) M. abscessus subsp. bolletii (MBO). The clinical findings and outcomes were generally indistinguishable between the three subspecies. All three subspecies of MABSC clinical isolates exhibited high resistance rates to ciprofloxacin, doxycycline, moxifloxacin, TMP/SMX, and tobramycin. MAB had the highest resistance rates to clarithromycin (27.8%, 20/72) and amikacin (6.9%, 5/72) compared to MBO and MMA, with p < 0.001 and p = 0.004, respectively. In addition, the rough morphotype was significantly associated with resistance to amikacin (8.9%, 5/56), clarithromycin (26.8%, 15/56), and imipenem (76.8%, 43/56) (p < 0.001), whereas the smooth morphotype was resistant to linezolid (57.1%, 48/84) (p = 0.002). In addition, T28 of erm(41), rrl (A2058C/G and A2059C/G), and rrs (A1408G) mutations were detected in 87.4% (125/143), 16.1% (23/143), and 9.1% (13/143) of MABSC isolates, respectively. CONCLUSIONS: Three MABSC subspecies caused a variety of infections in patients with different underlying comorbidities. The drug susceptibility patterns of the recent circulating MABSC strains in Thailand were different among the three MABSC subspecies and two morphotypes.

Short-term immune response after inactivated SARS-CoV-2 (CoronaVac®, Sinovac) and ChAdOx1 nCoV-19 (Vaxzevria®, Oxford-AstraZeneca) vaccinations in health care workers.

BACKGROUND: Inactivated SARS-CoV-2 (CoronaVac®, Sinovac, or SV) and ChAdOx1 nCoV-19 (Vaxzevria®, Oxford-Astra Zeneca, or AZ) vaccines have been administered to the health care workers (HCWs). OBJECTIVE: To determine the short-term immune response after the SV and AZ vaccinations in HCWs. METHODS: In this prospective cohort study, HCWs who completed a 2-dose regimen of the SV or AZ were included. Immune response was evaluated by surrogate viral neutralization test (sVNT) and anti-SARS-CoV-2 total antibody. Blood samples were analyzed at 4 and 12 weeks after the complete vaccination. The primary outcome was the seroconversion rate at 4-weeks after complete immunization. RESULTS: Overall, 185 HCWs with a median (IQR) age of 40.5 (30.3-55.8) years (94 HCWs in the SV group and 91 in the AZ group) were included. At 4 weeks after completing the SV vaccination, 60.6% (95%CI: 50.0-70.6%) had seroconversion evaluated by sVNT (≥ 68% inhibition), comparable to the patients recovered from mild COVID-19 infection (69.0%), with a rapid reduction to 12.2% (95%CI: 6.3-20.8) at 12 weeks. In contrast, 85.7% (95%CI: 76.8-92.2%) HCWs who completed two doses of the AZ for 4 weeks had seroconversion, comparable to the COVID-19 pneumonia patients (92.5%), with a reduction to 39.2% (95%CI: 28.4-50.9%) at 12 weeks. When using the anti-SARS-CoV-2 total antibody level (≥ 132 U/ml) criteria, only 71.3% HCWs in the SV group had seroconversion, compared to 100% in the AZ group at 4 weeks. CONCLUSIONS: A rapid decline of short-term immune response in the HCWs after the SV vaccination indicates the need for a vaccine booster, particularly during the ongoing spreading of the SARS-CoV-2 variants of concern.

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.

Prevalence of latent tuberculosis infection and feasibility of TB preventive therapy among Thai prisoners: a cross-sectional study.

BACKGROUND: Prisons are considered as major reservoirs for tuberculosis. Preventive therapy for latent TB infection (LTBI) is an adjunctive strategy to control TB. However, LTBI data in Thai prisoners is limited. This study assessed the prevalence of LTBI and feasibility of isoniazid preventive therapy (IPT). METHODS: A cross-sectional study was conducted among prisoners in Klong Prem Central Prison, Bangkok. Participants were screened for active TB by questionnaire and chest X-ray. LTBI was evaluated by Tuberculin skin test (TST) and QuantiFERON-TB Gold Plus (QFTP) among subgroup. Participants with positive TST or QFTP were considered to have LTBI. Participants with LTBI were offered IPT. RESULTS: From August 2018-November 2019, 1002 participants were analyzed. All participants were male with a median age of 38 (IQR 32-50) years. LTBI identified by either TST/QFTP was present in 466 (46.5%) participants. TST was positive in 359 (36%) participants. In the subgroup of 294 participants who had both TST and QFTP results, 181/294 (61.6%) tested positive by QFTP. Agreement between TST and QFTP was 55.1% (Kappa = 0.17). The risk factors associated with LTBI were previous incarceration (aOR 1.53, 95%CI, 1.16-2.01, p = 0.002), history of prior active TB (aOR 3.02, 95%CI, 1.74-5.24, p < 0.001) and duration of incarceration ≥10 years (aOR 1.86, 95%CI, 1.24-2.79, p = 0.003). Majority of LTBI participants (82%) agreed to take IPT. Three hundred and 56 (93%) participants completed treatment whereas 27 (7%) participants discontinued IPT due to the side effects of INH. CONCLUSION: This is the first study to evaluate the prevalence of LTBI and feasibility of IPT among Thai prisoners. LTBI prevalence in male prisoners in Thailand is high. LTBI screening and treatment should be implemented together with other preventive components.

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.

Evaluation of Anyplex™ II MTB/MDR kit's performance to rapidly detect isoniazid and rifampicin resistant Mycobacterium tuberculosis from various clinical specimens.

To determine the accuracy of multiplex real-time PCR (Anyplex™ II MTB/MDR kit) in detecting Isoniazid (INH)- and Rifampin (RIF)-resistant Mycobacterium tuberculosis strains from various clinical specimens. The performance of Anyplex™ II MTB/MDR kit in detecting INH- and RIF-resistant M. tuberculosis compared to the conventional drug susceptibility tests by Mycobacterial Growth Indicator Tube (MGIT). A total of 430 clinical samples had positive results for M. tuberculosis from both Anyplex™ II MTB/MDR kit assay and mycobacterial cultures by MGIT method. When compared to MGITs, the sensitivity and specificity of Anyplex™ II MTB/MDR kit in detecting INH-resistant TB were 85.71% and 99.75%, respectively. For the detection of MDR-TB, the sensitivity and specificity of the test were 82.35% and 99.76%, respectively. The positive predictive values and negative predictive values to detect INH-resistant TB were 96.77% and 98.75%, respectively. Anyplex™ II MTB/MDR kit can be used to rapidly detect isoniazid and rifampicin resistances. It has a high sensitivity, specificity and PPV in detecting INH-resistant TB and MDR-TB. This test can be used as an alternative test to Xpert MTB/RIF because it can rapidly detect both INH-resistant TB and RIF-resistant TB.

Real-Life Clinical Practice of Using the Xpert MTB/RIF Assay in Thailand.

BACKGROUND: Delayed diagnosis of tuberculosis (TB) and drug-resistant TB are major challenges of TB control in Thailand. This study assessed the practicality of the Xpert MTB/RIF assay in a real-life setting with high prevalence of human immunodeficiency virus (HIV) infection and pulmonary tuberculosis (PTB). METHODS: This prospective study was conducted at 3 large tertiary care hospitals. Patients who had suspected PTB were enrolled into the study. Expectorated sputum samples were sent for staining, mycobacterial culture, and Xpert MTB/RIF. RESULTS: Four hundred ninety-four patients were enrolled. From 355 cases with final diagnosis of PTB, 263 (71.8%) had definite diagnosis and 92 cases had probable diagnosis. Among TB culture-positive cases, Xpert MTB/RIF had 100% and 81% sensitivity in sputum smear-positive and smear-negative groups, respectively. The specificity was 95.7%. The sensitivity and positive predictive value of Xpert MTB/RIF in culture-negative but clinically diagnosed PTB was 37.8% and 83.8%, respectively. Centrifugation was required in 59% cases with scanty sputum. Five cases were false-positive by Xpert MTB/RIF in patients with nontuberculous mycobacteria, old PTB scar, and immune reconstitution syndrome. Discordant rifampicin susceptibility results of Xpert MTB/RIF and mycobacteria growth indicator tube (MGIT) were confirmed by using rpoB gene sequencing, which raised the sensitivity of Xpert MTB/RIF in detecting rifampicin resistance to 93.8%. CONCLUSIONS: Xpert MTB/RIF is an effective tool in diagnosing PTB but will be more cost-effective for sputum-negative patients and in settings with high prevalence of rifampicin resistance. Early diagnosis of TB results in early treatment and implementation of strategies to limit spreading of TB. Sputum centrifugation may increase the yield of Xpert MTB/RIF.

Molecular epidemiology of tuberculosis in foreign-born persons living in San Francisco.

RATIONALE: In San Francisco, 70% of the tuberculosis cases occur among foreign-born persons, mainly from China, the Philippines, and Mexico. We postulate that there are differences in the characteristics and risk factors for tuberculosis among these populations. OBJECTIVES: To determine the clinical, epidemiological and microbiological characteristics of tuberculosis caused by recent infection and rapid evolution in the major groups of foreign-born and the U.S.-born populations. METHODS: We analyzed data from a 20-year prospective community-based study of the molecular epidemiology of tuberculosis in San Francisco. We included all culture-positive tuberculosis cases in the City during the study period. MEASUREMENTS AND MAIN RESULTS: We calculated and compared incidence rates, clinical and microbiological characteristics, and risk factors for being a secondary case between the various foreign-born and U.S.-born tuberculosis populations. Between 1991 and 2010, there were 4,058 new cases of tuberculosis, of which 1,226 (30%) were U.S.-born and 2,832 (70%) were foreign-born. A total of 3,278 (81%) were culture positive, of which 2,419 (74%) had complete data for analysis. The incidence rate, including the incidence rate of tuberculosis due to recent infection and rapid evolution, decreased significantly in the U.S.-born and the major foreign-born populations. The clinical and microbiological characteristics and the risk factors for tuberculosis due to recent infection differed among the groups. CONCLUSIONS: There are differences in the characteristics and the risk factors for tuberculosis due to recent transmission among the major foreign-born and U.S.-born populations in San Francisco. These differences should be considered for the design of targeted tuberculosis control interventions.

Prevalence, risk factors and treatment outcomes of fluoroquinolones-associated tendinopathy in tuberculosis patients at university hospital, Thailand.

Background: Tuberculosis (TB) is an epidemic disease in Thailand. Fluoroquinolones are used to treat TB and have a lengthy treatment course. Therefore, many patients may have adverse effects from these medications. Tendinopathy has been reported as a significant adverse effect of fluoroquinolones. Although the mechanism of tendinopathy from fluoroquinolones is not fully understood, it can progress to a more serious consequence such as a ruptured tendon which can result in morbidity if not treated effectively. Methods: This study was a single-centered, retrospective descriptive study conducted in patients at a tertiary-level university hospital in Thailand. TB patients who received fluoroquinolones for the treatment of TB from January 2017 to December 2019 were enrolled. This study assessed the prevalence, clinical characteristics, treatment, treatment outcomes for fluoroquinolones-associated tendinopathy, and treatment outcomes of TB. Results: During the study period, 184 participants that were diagnosed with TB and used fluoroquinolones were enrolled in the study. 34 (18.5%) participants developed tendinopathy. The risk factors that were associated with fluoroquinolones-associated tendinopathy were younger age (<60 years) (Odd ratio (OR) 3.61; 95% CI 1.16-11.23), female (OR 3.54; 95% CI 1.58-7.90), and prolonged usage of levofloxacin (>180 days) (OR 2.61; 95%CI 1.12-6.08). All participants who developed tendinopathy received conservative treatment; the dose of fluoroquinolones was reduced in 9 (26.4%) participants, fluoroquinolones were discontinued in 7 (20.6%) participants and the rest of the participants (n = 18; 52.9%) had conservative treatment. After conservative treatment, 25 (73.5%) participants recovered from tendinopathy. For the TB treatment, 27 (79.4%) participants in the tendinopathy group completed TB treatment and none of them experienced treatment failure. On the other hand, 89 (59.3%) participants in the no tendinopathy group had completed their TB treatment and 3 (2%) of them experienced treatment failure. Conclusions: The prevalence of fluoroquinolones-associated tendinopathy was not uncommon, and the risk of fluoroquinolones-associated tendinopathy was high in young and female patients. Levofloxacin use was related to an elevated risk of developing tendinopathy, which was dose- and duration-dependent. Conservative treatment, reducing the dose or discontinuation of fluoroquinolones successfully improved the symptoms of tendinopathy. Fluoroquinolones-associated tendinopathy did not affect the treatment of TB.

Prevalence of depression and anxiety in pulmonary tuberculosis patients and its association with unsuccessful treatment outcome: A prospective cohort study.

BACKGROUND: Pulmonary tuberculosis (TB) remains a major public health problem in Thailand. TB causes chronic disease which may cause physical disability, mental and socioeconomic problems in TB patients. Mental disorders may occur after TB infection or co-exist with the disease. This study assessed the prevalence of depression and anxiety among pulmonary TB patients and its association with treatment outcome. METHODS: This is a single-center prospective study. Pulmonary TB patients who were treated at a tertiary hospital, in both outpatient and in-patient settings, were enrolled into the study. Demographic data and Thai Hospital Anxiety and Depression Scale (HADS) score at baseline and at least 2 months after diagnosis were collected to evaluate the probability of depression and anxiety. Logistic regression model was used to analyze the data. Association between suspicious mental disorder and treatment outcome were evaluated at the end of each participant's treatment. RESULTS: One hundred and three participants were enrolled into the study on March 2018 to October 2019. The prevalence of probable depression and anxiety (Thai HADS score ≥11 from both test) were 7.8% and 6.8%, respectively. Unsuccessful treatment outcome rate was 10.7% (11/103). From the multivariate analysis, people previously treated/relapsed (aOR (95%CI): 7.04 (1.19-41.85), p = 0.03) and probable depression/anxiety with Thai HADS score ≥11 (10.12 (1.54-66.45), p = 0.02) were associated with unsuccessful treatment outcome. CONCLUSIONS: In this study, Thai HADS score could identify probable depression and anxiety among pulmonary TB patients, and its association with unfavorable treatment outcome. Clinicians should keep in mind that pulmonary TB can affect the mental status of the patients and therefore, should evaluate them and provide appropriate treatment.

First case series and literature review of coronavirus disease 2019 (COVID-19) associated pulmonary tuberculosis in Southeast Asia: Challenges and opportunities.

BACKGROUND: Subclinical tuberculosis (TB) is accidentally detected by radiologic and microbiologic findings. Transmission by those with subclinical TB could delay prevention effort. However, our study demonstrated positive aspect of COVID-19 outbreak as it could allow subclinical TB to be detected faster through a chest X-Ray (CXR). METHODS: This cross-sectional cohort study aimed to report demographics, comorbidities, and outcomes related to early detection of TB among COVID-19 patients, and to elaborate the association between SARS-CoV-2 and pulmonary TB. Data of patients with SARS-CoV-2 co-infection with Mycobacterium tuberculosis (MTB) diagnosed between March 2020 - March 2022 was collected. RESULTS: Out of 12,275 COVID-19 patients, 26 were definitively diagnosed with MTB infection (mean age 48.16 ± 20.17 years). All cases that had suspicious CXR that were not typical for COVID-19, were tested for MTB. On average, pulmonary TB was diagnosed after admission 5(3-10) days, the treatment initiation period was 3(1-5) days from the TB diagnosis. CONCLUSIONS: This suggests an early detection of tuberculosis among COVID-19 patients by quicker screening CXR and sputum comparing to previous symptom guided screening. Thereby reducing the chance of TB transmission demonstrated during COVID-19 pandemic. So, clinicians should be aware of pulmonary tuberculosis in COVID-19 patients with atypical radiologic findings.

Long-term immunogenicity in previously vaccinated healthcare workers with inactivated virus vaccine after SARS-CoV-2 infection or booster vaccination.

Immunity against SARS-CoV-2 infection in vaccinated individuals varies based on the vaccine type, duration after vaccination or infection, and SARS-CoV-2 variant type. We conducted a prospective observational study to evaluate the immunogenicity of a booster vaccination with AZD1222 after two doses of CoronaVac (booster group) compared to individuals who had SARS-CoV-2 infection after receiving two doses of CoronaVac (infection group). We used a surrogate virus neutralization test (sVNT) to evaluate immunity against wild-type and Omicron variant (BA.1) at 3 and 6 months after infection or booster dose. Of the 89 participants, 41 were in the infection group, and 48 were in the booster group. At 3 months post-infection or booster vaccination, the median (IQR) sVNT against wild-type was 97.87 % (97.57-97.93 %) and 97.65 % (95.38-98.00 %), p = 0.66, respectively, while the sVNT against Omicron was 18.8 % (0-47.10 %) and 24.46 (11.69-35.47 %), p = 0.72 respectively. At 6 months, the median (IQR) sVNT against wild-type was 97.68 % (95.86-97.92 %) in the infection group, higher than 94.7 % (95.38-98.00 %) in the booster group (p = 0.03). Results showed no significant difference in immunity against wild-type and Omicron at 3 months between the two groups. However, the infection group exhibited better immunity than the booster group at 6 months.

High Transmission Rates of Early Omicron Subvariant BA.2 in Bangkok, Thailand.

The emergence of Omicron as the fifth variant of concern within the SARS-CoV-2 pandemic in late 2021, characterized by its rapid transmission and distinct spike gene mutations, underscored the pressing need for cost-effective and efficient methods to detect viral variants, especially given their evolving nature. This study sought to address this need by assessing the effectiveness of two SARS-CoV-2 variant classification platforms based on RT-PCR and mass spectrometry. The primary aim was to differentiate between Delta, Omicron BA.1, and Omicron BA.2 variants using 618 COVID-19-positive samples collected from Bangkok patients between November 2011 and March 2022. The analysis revealed that both BA.1 and BA.2 variants exhibited significantly higher transmission rates, up to 2-3 times, when compared to the Delta variant. This research presents a cost-efficient approach to virus surveillance, enabling a quantitative evaluation of variant-specific public health implications, crucial for informing and adapting public health strategies.

Clinical characteristics and treatment outcomes among patients with tuberculosis in Bangkok and Nonthaburi, Thailand.

Tuberculosis (TB) is a public health problem in many large cities. We retrospectively studied the clinical characteristics and treatment outcomes of patients with active TB at 6 hospitals in Bangkok and Nonthaburi, Thailand during 2008-2009. Eight hundred thirteen patients were included in the study. The mean age of subjects +/- SD was 41 +/- 14 years and mean body weight +/- SD was 53 +/- 11 kilograms. The three leading co-morbid conditions were HIV infection (40%), diabetes (6%) and chronic liver disease (2%). Two-thirds of subjects had isolated pulmonary TB. Isoniazid, rifampicin and multi-drug resistance were seen in 13, 7 and 5%, respectively. After 1 year, 52% were cured or completed treatment, 19% transferred out, 12% defaulted, 9% were still on-going TB treatment, 7% had died and 1% had failed treatment. Survival rates at 2, 6 and 12 months were 93, 85 and 81% among HIV seropositive subjects; 96, 94 and 92% among HIV seronegative subjects and 98, 97 and 97% among subjects with unknown HIV status (p < 0.001). On multivariate analysis, death was associated with: TB/HIV co-infection (HR 2.8; 95% CI 1.6-5.0), low body weight (HR 1.6; 95% CI 1.2-2.3), being elderly (HR 1.4; 95% CI 1.1-1.8) and having extrapulmonary/disseminated TB (HR 2.2; 95% CI 1.1-4.2). HIV infection and diabetes were the most common co-morbidities among TB subjects in our study. The percent of patients with unfavorable outcomes was relatively high, particularly among HIV co-infected and elderly subjects. Further effort needs to be made to improve these unfavorable TB outcomes in Nonthaburi and Bangkok, Thailand.

Intravenous to oral transition of antibiotics for gram-negative bloodstream infection at a University hospital in Thailand: Clinical outcomes and predictors of treatment failure.

BACKGROUND: Limited studies evaluate the outcome of intravenous antibiotics to oral transition in Gram-negative bloodstream infection (GN-BSI), particularly GN-BSI originating outside the urinary tract. This study aimed to evaluate treatment success in patients with GN-BSI treated with either intravenous therapy or intravenous to oral transition and to identify factors associated with treatment failure in those undergoing intravenous to oral transition. METHODS: A retrospective cohort study was conducted at King Chulalongkorn Memorial Hospital, Thailand. Patients were included if they were ≥18 years of age, hospitalized in general medical wards with GN-BSI between August 1, 2015, to July 31, 2020, received intravenous antibiotic agents and had a functioning gastrointestinal tract. RESULTS: Of 955 patients, 545 (57.1%) were in the intravenous to oral transition group. The urinary tract was the most common source of infection (38.8%). Ciprofloxacin was the most prescribed oral antibiotic (53%). Treatment success occurred in 94.3% in the intravenous antibiotic to oral transition group. There was no significant difference in treatment success between the two groups (P = 0.790) with a concordant result after using propensity score matching (P = 0.223). Independent predictors of treatment failure in the intravenous to oral transition group included metastatic solid cancer (aOR = 4.355), HIV infection with CD4 < 200 cells/mm3 (aOR = 8.452), qSOFA score ≥ 2 (aOR = 2.545), multidrug-resistant infection (aOR = 2.849), and respiratory tract infection (aOR = 8.447). Hospital length of stay in the intravenous to oral transition group was shorter than in the intravenous group (P < 0.001). CONCLUSIONS: Intravenous to oral transition may be a practical approach in GN-BSI. Patients with Gram-negative bacteremia who have HIV infection with CD4 < 200 cells/mm3, multidrug-resistant infections, and respiratory tract sources of infection may not be ideal candidates for this approach. Future research is needed from a randomized controlled trial.

Prevalence of latent tuberculosis infection among pre-clinical and clinical medical students using QuantiFERON-TB gold plus and tuberculin skin test at a teaching hospital in Thailand: A cross-sectional study.

BACKGROUND: Healthcare workers are considered to be at a higher risk of acquiring tuberculosis (TB) infection than the general population. Clinical medical students are part of the healthcare team and clinical practice are done during their clinical rotation. They could be exposed to similar occupational risks as the healthcare workers. Most students who become infected have latent tuberculosis infection (LTBI) and may not exhibit any clinical symptoms. Some students with LTBI can progress to TB disease during clinical rotations in the hospitals. Therefore, screening for LTBI in this population represents hospital aspect of public health strategy and infection control in medical school in high TB burden countries. OBJECTIVE: We aimed to determine the prevalence of LTBI among fourth-year medical students and sixth-year medical students by using QuantiFERON-TB Gold Plus (QFT-Plus) and Tuberculin Skin Test (TST). METHODS: A cross-sectional study of fourth-year medical students (n = 73) and sixth-year medical students (n = 85) was conducted at the School of Medicine, Chulalongkorn University, Bangkok, Thailand. The medical students (n = 158) who met the eligibility criteria were recruited into the study. LTBI was detected by using QFT-Plus and some of the participants had a tuberculin skin test (TST). The TST was interpreted after 48-72 h. The participants who tested positive by QFT-Plus were considered to have LTBI. Demographic information and data on occupational TB exposure were collected via a questionnaire. A multivariate logistic regression was used to test for associations between independent variables and results of the QFT-Plus. RESULTS: A total of 158 participants were included in this study. The overall prevalence of LTBI was 6.3% (n = 10) as determined by QFT-Plus. The LTBI prevalence was higher in the sixth-year medical students (9.4%) compared to the fourth-year medical students (2.7%). Higher risk of LTBI was associated with sixth-year medical students (odds ratio, 3.69 [95%CI, 0.75-17.96]), but this was not significant. Moreover, history of occupational TB exposure without PPE yielded an odds ratio of 2.98 [95%CI, 0.68-13.12] but it was not statistically significant due to the small sample size. One hundred thirty-nine (88%) participants were BCG vaccinated as per the national vaccination requirements. No abnormal chest X-rays were found for any of the positive participants. Of the 158 participants, 41 (25.9%) of them had TST. Of the 41 participants, 6 (14.6%) tested positive at a cut-off of ≥ 10 mm for TST, which was concordant with QFT-Plus results. The agreement between the two tests was 0.57 using kappa coefficients. CONCLUSION: The screening of TB infection in new healthcare workers (HCWs), especially medical students, is essential to reduce future nosocomial TB incidences in the hospitals. This study showed that there was a high prevalence of LTBI among sixth-year medical students compared to fourth-year medical students. Our results suggest that tendency of higher LTBI prevalence might be associated with advanced clinical years, thus tailored public health education strategy and infection control in tertiary care hospitals for new healthcare workers in TB endemic countries may prevent nosocomial TB disease from developing in the future. Therefore, active surveillance should be done for all new HCWs, and TB preventive therapy should be administered to recent converters.

Tuberculosis at a university hospital, Thailand: A surprising incidence of TB among a new generation of highly exposed health care workers who may be asymptomatic.

OBJECTIVES: There are a few reports of TB disease among healthcare workers (HCWs) in Thailand. The authors assessed the demographic data and incidence of overall TB disease including specific profession among HCWs in order to reduce the incidence rate. METHODS: This was a descriptive, cross-sectional study of 195 HCWs at King Chulalongkorn Memorial Hospital (KCMH), Bangkok, Thailand, who had TB disease from 2003-2020. RESULTS: The average incidence of TB disease in HCWs at KCMH was 164 per 100,000 HCWs with 95% confidential interval [CI], 107 to 220; (94.4% had pulmonary TB). Most of the HCWs were from a young age group (43.08% were 20-29 years old) and the duration of work was short (58.82% had worked at KCMH for less than 5 years). Radiological technicians had the highest incidence of TB, followed by supportive teams, scientists, and physicians (429, 241, 205, and 193 per 100,000 HCWs according to their profession, respectively). Seventy five percent of TB disease was found in physicians who worked at KCMH within 2 years. TB incidence was highest among residents (688 per 100,000 residents) in a subgroup of physicians. CONCLUSIONS: The incidence of TB disease in HCWs was close to the general population of Thailand (153 per 100,000 population with 95% CI, 116 to 195). A higher incidence was observed in the profession that had contact with TB patients and their specimens. A high proportion of asymptomatic HCWs also had TB disease and TB incidence was found in a new generation of HCWs who have worked for less than 5 years. More rigorous epidemiology investigations are needed to establish a definitive relation to subsequently developing TB after working in a hospital. The authors suggest active surveillance in all new incoming HCWs and TB preventive therapy should also be provided to recent converters.

The Validity and Reliability of the Chula COVID-19 Psychosocial Home Isolation Evaluation Tool (CCPHIET).

BACKGROUND: The growing number of cases presenting with COVID-19 during the pandemic has led to a significant shortage of hospital beds. Many patients may not require hospitalization and can be clinically observed in home settings. We have identified a set of psychosocial factors that correlate with unsuccessful home isolation (HI), which in turn might negatively affect the transmission control in the community. Therefore, we developed the Chula COVID-19 Psychosocial Home Isolation Evaluation Tool (CCPHIET), a new screening tool for assessing the psychosocial suitability for HI. This study examines the CCPHIET's validity and reliability. METHODS: This cross-sectional descriptive study included COVID-19 patients who were deemed to be medically safe for 14-days of HI. The CCPHIET is comprised of eight clinical domains pertinent to HI behavioral compliance and risk for non-adherence. We explored its statistical validity and reliability and discussed the potential utility of this tool. RESULTS: A total of 65 COVID-19 patients participated in this study. Most patients (58.5%) were deemed to be appropriate candidates for HI according to the CCPHIET. The results of this study demonstrate that the CCPHIET has an acceptable content validity (IOC index > 0.5), moderate internal consistency (Cronbach's alpha = 0.611) and substantial to excellent inter-rater reliability (Intraclass correlation coefficient = 0.944, Cohen's kappa= 0.627). CONCLUSIONS: CCPHIET is an easy-to-use tool for assessing the psychosocial suitability of patients advised for at-home isolation with mild and asymptomatic COVID-19. Its implementation can assist clinicians in identifying and redirecting resources to patients at the highest risk for breaking quarantine and save on unnecessary, costly absolute institutional quarantine for those deemed to be psychosocially fit for full adherence.

Incidence of active tuberculosis among people living with HIV receiving long-term antiretroviral therapy in high TB/HIV burden settings in Thailand: implication for tuberculosis preventive therapy.

INTRODUCTION: Among high tuberculosis (TB) and HIV burden countries in Asia, tuberculosis preventive therapy (TPT) in people living with HIV (PLWH) has been underutilized despite its proven benefits independent of antiretroviral therapy (ART). Therefore, we determined the incidence of active TB and mortality among 9179 adult PLWH who attended and received ART from 15 tertiary care hospitals across Thailand. METHODS: A retrospective study was conducted in 2018 using follow-up data from 1999 to 2018. The primary endpoint was incident TB disease after ART initiation. Factors associated with TB incidence were analysed using competing risk regression. The Kaplan-Meier method was used to estimate mortality after ART initiation. RESULTS: During a median of 5.1 years of ART (IQR 2.2-9.5 years), 442 (4.8%) PLWH developed TB (TB/HIV), giving an overall incidence of 750 (95% CI 683-823) per 100,000 persons-year of follow up (PYFU). In multivariate analysis, lower CD4 at ART initiation (≤100 cells/mm3 , adjusted sub-distribution hazard ratio [aSHR]: 2.08, 95% CI, 1.47-2.92; 101-200 cells/mm3 , aSHR: 2.21, 95% CI, 1.54-3.16; 201-350 cells/mm3 , aSHR: 1.59, 95% CI, 1.11-2.28 vs. >350 cells/mm3 ), male sex (aSHR: 1.40, 95% CI, 1.11-1.78), lower body weight (<50 kg, aSHR: 1.52, 95% CI, 1.17-1.95) and prior TB event (aSHR: 3.50, 95% CI, 2.72-4.52) were associated with TB incidence. PLWH with HIV RNA ≥50 copies/ml had 5-9 times higher risk of active TB disease higher than those with HIV RNA <50 copies/ml at the same CD4 level. The risk for developing TB was remarkably high during the initial period of ART (175,511 per 100,000 PYFU at<3 months) and was comparable to the general population after 10 years of ART (151 per 100,000 PYFU). TB/HIV had higher mortality (10% vs. 5%) and poorer HIV treatment outcomes: HIV RNA <50 copies/ml (63.8% vs. 82.8%), CD4 cells count (317 vs. 508 cells/mm3 ) at the most recent visit. CONCLUSIONS: In this high TB burden country, TB incidence was remarkably high during the first few years after ART initiation and thereafter decreased significantly. Rapid ART initiation and appropriate TPT can be potential key interventions to tackle the TB epidemic and reduce mortality among PLWH in TB/HIV high burden settings.

Pulmonary Nocardiosis with Superior Vena Cava Syndrome in a HIV-Infected Patient: a Rare Case Report in the World.

Pulmonary nocardiosis is a common disease in human immunodeficiency virus (HIV)infected patients. In most cases, the disease progresses slowly. Here, we have presented a case of pulmonary nocardiosis that rapidly progressed. A 35-year-old woman with acquired immune deficiency syndrome and superior vena cava (SVC) syndrome, who was previously lost to follow-up, presented to our hospital chronic non-productive cough. Her CD4 count was 33 cells/µL (4%). Chest X-ray revealed opacity in the right upper lobe of the lung, and the results of sputum acid-fast staining were negative. Anti-tuberculosis agents were prescribed. Two weeks later, superficial vein dilatation was noted on her chest wall and the chest X-ray revealed worse findings. Chest CT showed a heterogeneous mass measuring 9.6 × 9.8 × 8.3 cm in the right lung. Further, necrotic mediastinal nodes nearly obliterated the SVC. Gram-positive beaded branching filamentous organisms were identified in the sputum by modified acid-fast staining. Hence, she was diagnosed with pulmonary nocardiosis. Culture results confirmed the presence of Nocardia beijingensis with SVC syndrome. She responded to treatment. After 2 weeks of parenteral administration, we switched her to oral trimethoprim/sulfamethoxazole, which was later followed by antiretroviral agents.