An alternative colorimetric RT-LAMP assay for the rapid detection of SARS-CoV-2: development and validation in Thailand.

Introduction: COVID-19, an emerging infectious disease caused by SARS-CoV-2, continues to be a global public health threat. The development of a colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) can extend the availability of simple, reliable molecular tests for the rapid detection of COVID-19.

Methodology: The RT-LAMP assay was developed using a new primer set targeting a portion of SARS-CoV-2 orf8.

Prevalence, Risk Factors, and Result Features in the Detection of Latent Tuberculosis Infection in Thai Healthcare Workers Using QuantiFERON-TB Gold Plus.

Introduction Latent tuberculosis infection (LTBI) is an enormous reservoir for tuberculosis (TB), and healthcare workers (HCWs) are at high risk for TB infection. QuantiFERON-TB Gold Plus (QFT-Plus) is an alternative to the tuberculin skin test for LTBI detection, but data on its application and LTBI detected by QFT-Plus in high TB burden countries are limited. This study aimed to determine the prevalence of LTBI and its risk factors, and to investigate the QFT-Plus results in Thai HCWs.

The first insight into Mycobacterium tuberculosis complex isolates in the lower northern region in Thailand.

Background: Tuberculosis (TB) remains an important infectious disease and different genotypes have been reported. This study aimed to investigate the genetic diversity and molecular epidemiology of TB in the lower northern region of Thailand, where genotyping data are limited.

Methods: A total of 159 Mycobacterium tuberculosis complex (MTBC) isolates from this region were genotyped by spoligotyping and the major spoligotypes were further subdivided by the mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) method.

Clinical Performance of the Reverse Transcription-Loop-Mediated Isothermal Amplification Assay for the Diagnosis of COVID-19 in a Thai Community Hospital at the Thailand-Myanmar Border.

Introduction: Coronavirus disease 2019 (COVID-19) continues to be a global health threat and is a public health issue in Thailand and other countries. The extensive cross-border between Thailand and Myanmar is considered to be at a potentially high risk for COVID-19 distribution in this region. In this instance, simple and cost-effective tests for rapid and early detection of COVID-19 would be useful for effective patient management and control of the disease.

QuantiFERON-TB Gold Plus and QuantiFERON-TB Gold In-tube assays for detecting latent tuberculosis infection in Thai healthcare workers.

Detecting latent tuberculosis infection (LTBI) is important, especially in high-risk populations including healthcare workers (HCWs). QuantiFERON-TB Gold Plus (QFT-Plus) is a new version of the interferon-gamma release assays (IGRAs) to replace the QuantiFERON-TB Gold In-tube (QFT-GIT). However, data on the use of QFT-Plus for LTBI detection in high TB-burden countries are limited.

Evaluation of an in-house loop-mediated isothermal amplification for Mycobacterium tuberculosis detection in a remote reference laboratory, Thailand.

Loop-mediated isothermal amplification (LAMP) is a simple and efficient nucleic acid amplification method for the rapid diagnosis of infectious diseases. This study assessed the performance of an in-house LAMP for tuberculosis (TB) diagnosis at a remote reference laboratory in the endemic setting of Thailand. As part of the routine service, 1,882 sputum samples were processed for mycobacterial culture in Lowenstein-Jensen and MGIT media.

Molecular Characterization of Mutations in Isoniazid- and Rifampicin-Resistant Mycobacterium tuberculosis Isolated in Thailand.

The control of drug-resistant tuberculosis (TB) is a major challenge. The frequency and mutation characteristics indicate the efficiency of molecular tests for the rapid detection of TB drug resistance. This study examined the existence of katG and inhA mutations for isoniazid (INH) resistance and rpoB mutations for rifampicin (RFP) resistance.

Putative extensive and pre-extensive drug resistant-tuberculosis associated with unusual genotypes on the Thailand-Myanmar border.

Extensive drug-resistant tuberculosis (XDR-TB) is highly life threatening and its diagnosis is usually difficult and time-consuming. Here we present the first two cases of XDR and pre-XDR-TB diagnosed in 2018 on the Thailand-Myanmar border, more specifically in Tak province. Rapid detection of XDR-TB was performed by loop-mediated isothermal amplification (LAMP), Xpert MTB/RIF, and line probe assays.

Drug-resistant Mycobacterium tuberculosis and its genotypes isolated from an outbreak in western Thailand.

Background: Multidrug-resistant TB (MDR-TB) outbreaks have occurred in the Thamaka district, Kanchanaburi province in Thailand.

Methods: Seventy-two isolates, which included 7% mono-, 30.6% MDR and extensively drug-resistant TB (XDR-TB), were genotyped by spoligotyping, mycobacterial interspersed repetitive unit-variable-number tandem repeat (MIRU-VNTR) and single nucleotide polymorphism genotyping, and their drug resistance was analysed.

The performance of an in-house loop-mediated isothermal amplification for the rapid detection of Mycobacterium tuberculosis in sputum samples in comparison with Xpert MTB/RIF, microscopy and culture.

Simple, low-cost and effective diagnostic tests for tuberculosis (TB) are needed especially in TB-high burden settings. The present study evaluated the performance of an in-house loop-mediated isothermal amplification (LAMP) for diagnosing TB by comparing it to Xpert MTB/RIF, microscopy and culture. In Thailand, a total of 204 excess sputum samples volume after the processing of cultures were used for Mycobacterium tuberculosis (MTB) detection by Xpert MTB/RIF and LAMP.

Comparison of Loop-Mediated Isothermal Amplification, Microscopy, Culture, and PCR for Diagnosis of Pulmonary Tuberculosis.

The diagnosis of tuberculosis (TB) in endemic countries is challenging due to high caseloads and limited resources. A simple and cost-effective diagnostic test for the rapid detection of Mycobacterium tuberculosis (M. tuberculosis) in clinical specimens is crucially needed.

T-SPOT®.TB test and clinical risk scoring for diagnosis of latent tuberculosis infection among Thai healthcare workers.

Background: Screening for latent tuberculosis infection (LTBI) is important to identify healthcare workers (HCWs) benefiting from preventive therapy. Interferon-gamma release assays (IGRAs) are sensitive and specific tests for LTBI diagnosis. However, in settings where IGRAs are not available, clinical risk assessment may be used as an alternative to diagnose LTBI.

Loop-Mediated Isothermal Amplification for Rapid Identification of Mycobacterium tuberculosis in Comparison with Immunochromatographic SD Bioline MPT64 Rapid in a High Burden Setting.

Loop-mediated isothermal amplification (LAMP) was assessed for rapid identification of Mycobacterium tuberculosis complex (MTC) in comparison with an immunochromatographic test (ICT) using SD Bioline Ag MPT64 Rapid. One hundred and fifty-one MGIT cultures positive for acid-fast bacilli were tested for MTC. DNA was extracted from a small portion of culture samples by heat lysis and subjected to LAMP analysis.

Tuberculin Skin Test and QuantiFERON(®)-TB Gold In-Tube Test for Diagnosing Latent Tuberculosis Infection among Thai Healthcare Workers.

A cross-sectional study was conducted on the performance of the tuberculin skin test (TST) and QuantiFERON(®)-TB Gold In-Tube test (QFT-IT) for detecting latent tuberculosis infection among Thai healthcare workers (HCWs). Each HCW underwent both the TST and QFT-IT during the annual health screening. Among the 260 HCWs enrolled, the median age was 30 years (range 19-60 years), 92% were women, 64% were nurses and nurse assistants, 78% were Bacillus Calmette Guérin vaccinated, and 37% had previously taken the TST.

Applicability of in-house loop-mediated isothermal amplification for rapid identification of Mycobacterium tuberculosis complex grown on solid media.

A simple, rapid, and low-cost identification method is required in tuberculosis high-burden countries. We report the applicability of in-house loop-mediated isothermal amplification (LAMP) targeting 16S ribosomal RNA for the rapid identification of Mycobacterium tuberculosis complex grown on Lowenstein-Jensen media. Eighty acid-fast staining-positive clinical isolates were selected and used to evaluate the LAMP assay in comparison with polymerase chain reaction and conventional culture-based tests.

Rapid identification of Mycobacterium tuberculosis in BACTEC MGIT960 cultures by in-house loop-medicated isothermal amplification.

Definitive diagnosis of tuberculosis (TB) by conventional culture, followed by bacterial identification based on biochemical tests is time-consuming and tedious. Simple loop-mediated isothermal amplification (LAMP) specific for Mycobacterium tuberculosis complex, targeting the M. tuberculosis 16S ribosomal RNA gene, termed TB-LAMP, was evaluated as an alternative for rapid culture confirmation.

SNP genotypes of Mycobacterium leprae isolates in Thailand and their combination with rpoT and TTC genotyping for analysis of leprosy distribution and transmission.

Based on the discovery of three single nucleotide polymorphisms (SNPs) in Mycobacterium leprae, it has been previously reported that there are four major SNP types associated with different geographic regions around the world. Another typing system for global differentiation of M. leprae is the analysis of the variable number of short tandem repeats within the rpoT gene.