Temporal trend of drug-resistant tuberculosis among Thai children during 2006-2021.

Background: The prevalence of drug-resistant tuberculosis (DR-TB) in adults has stabilized in the past decade. Our study aimed to describe the prevalence of DR-TB in Thai children between 2006 and 2021. Materials and methods: Children younger than 15 years old who had culture-confirmed Mycobacterium tuberculosis complex (MTB), positive PCR-MTB, or positive Xpert MTB/RIF were included in this cohort. Drug susceptibility testing (DST) was performed using phenotypic and/or genotypic methods. The prevalence of DR-TB was compared using the chi-square test. Results: Among 163 confirmed TB cases (44% as pulmonary TB, 27% as extrapulmonary TB, and 29% with both), the median age (IQR) was 12.2 (7.3-14.2) years. DST was performed in 139 cases (85%), revealing prevalences of all DR-TB, isoniazid-resistant TB (Hr-TB), and rifampicin monoresistant/multidrug-resistant TB (Rr/MDR-TB) of 21.6% (95% CI 14.7-28.4), 10.8% (95% CI 5.6-16.0%), and 2.9% (95% CI 0.1-5.7%), respectively. The DR-TB rates did not differ significantly between 2006-2013, 2014-2018, and 2019-2021 (p > 0.05). Two pre-extensively DR-TB (pre-XDR) cases with fluoroquinolone resistance were detected after 2014. Conclusion: The prevalence of DR-TB in Thai children was stable. However, one-tenth of DR-TB cases confirmed with DST were Hr-TB, which required adjustment of the treatment regimen. The pre-XDR cases should be closely monitored.

Predictors and outcomes of peritoneal dialysis-related infections due to filamentous molds (MycoPDICS).

INTRODUCTION: We sought to evaluate the predictors and outcomes of mold peritonitis in patients with peritoneal dialysis (PD). METHODS: This cohort study included PD patients from the MycoPDICS database who had fungal peritonitis between July 2015-June 2020. Patient outcomes were analyzed by Kaplan Meier curves and the Log-rank test. Multivariable Cox proportional hazards model regression was used to estimating associations between fungal types and patients' outcomes. RESULTS: The study included 304 fungal peritonitis episodes (yeasts n = 129, hyaline molds n = 122, non-hyaline molds n = 44, and mixed fungi n = 9) in 303 patients. Fungal infections were common during the wet season (p <0.001). Mold peritonitis was significantly more frequent in patients with higher hemoglobin levels, presentations with catheter problems, and positive galactomannan (a fungal cell wall component) tests. Patient survival rates were lowest for non-hyaline mold peritonitis. A higher hazard of death was significantly associated with leaving the catheter in-situ (adjusted hazard ratio [HR] = 6.15, 95%confidence interval [CI]: 2.86-13.23) or delaying catheter removal after the diagnosis of fungal peritonitis (HR = 1.56, 95%CI: 1.00-2.44), as well as not receiving antifungal treatment (HR = 2.23, 95%CI: 1.25-4.01) or receiving it for less than 2 weeks (HR = 2.13, 95%CI: 1.33-3.43). Each additional day of antifungal therapy beyond the minimum 14-day duration was associated with a 2% lower risk of death (HR = 0.98, 95%CI: 0.95-0.999). CONCLUSION: Non-hyaline-mold peritonitis had worse survival. Longer duration and higher daily dosage of antifungal treatment were associated with better survival. Deviations from the 2016 ISPD Peritonitis Guideline recommendations concerning treatment duration and catheter removal timing were independently associated with higher mortality.

Genetically Confirmed Edwardsiella tarda Peritonitis was Associated with Improper Caregiver's Hand Hygiene during Peritoneal Dialysis Bag Exchange.

Edwardsiella tarda is a Gram-negative bacillus and is responsible for waterborne disease. This is the first case report of peritoneal dialysis (PD)-associated peritonitis caused by genetically confirmed E. tarda, which was transmitted from the caregiver's hand during PD bag exchange. Aside from that, the caregiver was a fishmonger and a gastrointestinal carrier of the pathogen. Prior to the onset of peritonitis, the caregiver reported that she did not wash her hands every time when performing the PD bag exchange. Although extraintestinal edwardsiellosis usually poses a poor outcome, PD-associated peritonitis with this species is paradoxical if diagnosed early, and treatment is promptly provided, as presented here. This case emphasizes the importance of hand hygiene in preventing environment-bound infection in patients on PD and demonstrates the unusual route of infection, contamination during PD bag exchange.

Notch 2 receptor expression and reduced cytotoxicity in MAIT cells of active pulmonary TB patients.

BACKGROUND: Knowledge of the prevalence of common sensitizing allergens may aid in overall management of allergic disease in a specified area. OBJECTIVE: The aim of this study was to identify and analyse the prevalence of common inhaled and food sensitizing allergens in Beijing. METHODS: This was a retrospective study, analysing demographic data and serum sIgE antibody test results from 59057 outpatients who presented to Beijing TongRen Hospital, from January 2013 to December 2019. RESULTS: 28879 patients (48.9%) showed positive sIgE test results; with significantly more males aged under 16 years sensitized to at least one allergen than females, and most patients (53.62%) were sensitized to multiple allergens. The first inhaled sensitizing allergens was Artemisia grass (11910 (41.24%)); and the first food allergens was crab (3547 (12.28%)). For Artemisia sensitized patients, sIgE levels were mostly at level 5. The number of patients with ragweed allergy is increasing year by year. The detection rates for sIgE to Artemisia, common ragweed, and Humulus grass allergens were significantly higher in August and September. R package ggplot2 analysis, demonstrated strong correlations between tree allergens and common ragweed and Humulus grass allergens (phi coefficients = 0.50 and 0.46, respectively; both P < 0.01). CONCLUSIONS: The prevalence of sensitization to different allergens in Beijing showed Artemisia grass was the most commonly inhaled sensitizing allergen, and the number of patients with ragweed grass allergy was increasing by year.

Association of Local Unit Sampling and Microbiology Laboratory Culture Practices With the Ability to Identify Causative Pathogens in Peritoneal Dialysis-Associated Peritonitis in Thailand.

INTRODUCTION: This describes variations in facility peritoneal dialysis (PD) effluent (PDE) culture techniques and local microbiology laboratory practices, competencies, and quality assurance associated with peritonitis, with a specific emphasis on factors associated with culture-negative peritonitis (CNP). METHODS: Peritonitis data were prospectively collected from 22 Thai PD centers between May 2016 and October 2017 as part of the Peritoneal Dialysis Outcomes and Practice Patterns Study. The first cloudy PD bags from PD participants with suspected peritonitis were sent to local and central laboratories for comparison of pathogen identification. The associations between these characteristics and CNP were evaluated. RESULTS: CNP was significantly more frequent in local laboratories (38%) compared with paired PDE samples sent to the central laboratory (12%, P < 0.05). Marked variations were observed in PD center practices, particularly with respect to specimen collection and processing, which often deviated from International Society for Peritoneal Dialysis Guideline recommendations, and laboratory capacities, capabilities, and certification. Lower rates of CNP were associated with PD nurse specimen collection, centrifugation of PDE, immediate transfer of samples to the laboratory, larger hospital size, larger PD unit size, availability of an on-site nephrologist, higher laboratory capacity, and laboratory ability to perform aerobic cultures, undertake standard operating procedures in antimicrobial susceptibilities, and obtain local accreditation. CONCLUSION: There were large variations in PD center and laboratory capacities, capabilities, and practices, which in turn were associated with the likelihood of culturing and correctly identifying organisms responsible for causing PD-associated peritonitis. Deviations in practice from International Society for Peritoneal Dialysis guideline recommendations were associated with higher CNP rates.

The culture from peritoneal dialysis catheter enhances yield of microorganism identification in peritoneal dialysis-related peritonitis.

An additional yield of culture from the removed peritoneal dialysis (PD) catheter in diagnosis of pathogen causing refractory peritonitis was assessed in 118 eligible patients from 7 PD centers. Peritoneal dialysis fluid (PDF) culture identified organisms in 86 (72.9%) patients, while the catheter culture identified organisms in 55 (46.6%) patients. PD catheter culture could additionally identify organisms in 19 patients whose PDF culture were negative, increasing the positive culture rate to 89%, in other word 16.1% reducing the culture-negative rate. PD catheter culture provided additional yield, especially in fungal and enterococcal infections.

Nontuberculous mycobacterial disease in patients with HIV in Southeast Asia.

RATIONALE: Although nontuberculous mycobacteria (NTM) are widely documented as a cause of illness among HIV-infected people in the developed world, studies describing the prevalence of NTM disease among HIV-infected people in most resource-limited settings are rare. OBJECTIVES: To evaluate the prevalence of mycobacterial disease in HIV-infected patients in Southeast Asia. METHODS: We enrolled people with HIV from three countries in Southeast Asia and collected pulmonary and extrapulmonary specimens to evaluate the prevalence of mycobacterial disease. We adapted American Thoracic Society/Infectious Disease Society of America guidelines to classify patients into NTM pulmonary disease, NTM pulmonary disease suspects, NTM disseminated disease, and no NTM categories. MEASUREMENTS AND MAIN RESULTS: In Cambodia, where solid media alone was used, NTM was rare. Of 1,060 patients enrolled in Thailand and Vietnam, where liquid culture was performed, 124 (12%) had tuberculosis and 218 (21%) had NTM. Of 218 patients with NTM, 66 (30%) were classified as NTM pulmonary disease suspects, 9 (4%) with NTM pulmonary disease, and 10 (5%) with NTM disseminated disease. The prevalence of NTM disease was 2% (19 of 1,060). Of 51 patients receiving antiretroviral therapy (ART), none had NTM disease compared with 19 (2%) of 1,009 not receiving ART. CONCLUSIONS: Although people with HIV frequently have sputum cultures positive for NTM, few meet a strict case definition for NTM disease. Consistent with previous studies, ART was associated with lower odds of having NTM disease. Further studies of NTM in HIV-infected individuals in tuberculosis-endemic countries are needed to develop and validate case definitions.

Molecular characterization of extended spectrum beta-lactamase among clinical isolates Escherichia coli and Klebsiella pneumoniae.

BACKGROUND: Resistance to beta-lactams has been increasing in the treatment of infections caused by Escherichia coli and Klebsiella pneumoniae. The production of extended-spectrum beta-lactamases (ESBLs), that hydrolyze extended-spectrum cephalosporins, is the major cause of beta-lactam resistance. OBJECTIVE: To determine the prevalence and characterize of ESBLs produced by E. coli and K. pneumoniae from clinical specimens. MATERIAL AND METHOD: ESBLs were determined by disk diffusion test, double disk synergy test, and E-test ESBLs. All ESBLs producing isolates were investigated for the presence of bla(TEM) bla(SHV), bla(CTX-M) and bla(VEB) genes by polymerase chain reaction (PCR). Nucleotide sequencing of bla(TEM) and bla(SHV) were performed E. coli and K. pneumoniae were isolated from clinical specimens of patients in King Chulalongkorn Memorial Hospital between February and May 2002. Of the 270 isolates, 212 were E. coli and 58 were K. pneumoniae. RESULTS: ESBL roduction was detected in 17% (36/212) of E. coli and 34.5% (20/58) of K. pneumoniae isolates. Of the 20 K. pneumoniae isolates, the beta-lactamase genes were bla(SHV) (18/20, 90%), bla(TEM) (10/20, 50%), bla(VEB-like) (6/20, 30%) and bla(CTX-M-like) (3/20, 15%). Thirty-six E. coli isolates carried bla(TEM) bla(CTX-M-like) and bla(VEB-like) genes in 72.2% (26/36), 52.8% (19/36) and 16.7% (6/36), respectively Bla(SHV) was not detected in ESBL-producing E. coli, whereas it predominated in K. pneumoniae. Of the 56 ESBL producing isolates, 30 (53.6%) coharboured at least two different bla genes. All TEM identified were TEM-1B, which is not an ESBL. CTX-M ESBLs were the most common in E. coli. CONCLUSION: The double disk diffusion test should be added routinely in the antibiotic susceptibility test for the Enterobacteriaceae. It is simple to perform, easy to interpret, and economical. The presence of bla(CTX-M) and bla(VEB) in ESBL-producing E. coli and K. pneumoniae indicates the high prevalence of these genes in Thailand.

Bloodstream infections among HIV-infected outpatients, Southeast Asia.

Bloodstream infections (BSIs) are a major cause of illness in HIV-infected persons. To evaluate prevalence of and risk factors for BSIs in 2,009 HIV-infected outpatients in Cambodia, Thailand, and Vietnam, we performed a single Myco/F Lytic blood culture. Fifty-eight (2.9%) had a clinically significant BSI (i.e., a blood culture positive for an organism known to be a pathogen). Mycobacterium tuberculosis accounted for 31 (54%) of all BSIs, followed by fungi (13 [22%]) and bacteria (9 [16%]). Of patients for whom data were recorded about antiretroviral therapy, 0 of 119 who had received antiretroviral therapy for ≥14 days had a BSI, compared with 3% of 1,801 patients who had not. In multivariate analysis, factors consistently associated with BSI were fever, low CD4+ T-lymphocyte count, abnormalities on chest radiograph, and signs or symptoms of abdominal illness. For HIV-infected outpatients with these risk factors, clinicians should place their highest priority on diagnosing tuberculosis.

Yield of acid-fast smear and mycobacterial culture for tuberculosis diagnosis in people with human immunodeficiency virus.

RATIONALE: The World Health Organization recently revised its recommendations for tuberculosis (TB) diagnosis in people with HIV. Most studies cited to support these policies involved HIV-uninfected patients and only evaluated sputum specimens. OBJECTIVES: To evaluate the performance of acid-fast bacilli smear and mycobacterial culture on sputum and nonsputum specimens for TB diagnosis in a cross-sectional survey of HIV-infected patients. METHODS: In Thailand and Vietnam, we enrolled people with HIV regardless of signs or symptoms. Enrolled patients provided three sputum, one urine, one stool, one blood, and, for patients with palpable peripheral adenopathy, one lymph node aspirate specimen for acid-fast bacilli microscopy and mycobacterial culture on solid and broth-based media. We classified any patient with at least one specimen culture positive for Mycobacterium tuberculosis as having TB. MEASUREMENTS AND MAIN RESULTS: Of 1,060 patients enrolled, 147 (14%) had TB. Of 126 with pulmonary TB, the incremental yield of performing a third sputum smear over two smears was 2% (95% confidence interval, 0-6), 90 (71%) patients were detected on broth-based culture of the first sputum specimen, and an additional 21 (17%) and 12 (10%) patients were diagnosed with the second and third specimens cultured. Of 82 lymph nodes cultured, 34 (42%) grew M. tuberculosis. In patients with two negative sputum smears, broth-based culture of three sputum specimens had the highest yield of any testing strategy. CONCLUSIONS: In people with HIV living in settings where mycobacterial culture is not routinely available to all patients, a third sputum smear adds little to the diagnosis of TB. Broth-based culture of three sputum specimens diagnoses most TB cases, and lymph node aspiration provides the highest incremental yield of any nonpulmonary specimen test for TB.

Amplification of P1 gene by polymerase chain reaction for detection of Mycoplasma pneumoniae.

Mycoplasma pneumoniae is a causative agent of human respiratory tract infection of which the clinical features are not significantly different from those of infections caused by other respiratory pathogens. The diagnosis is based principally on laboratory tests. Since conventional methods such as culture and serological tests are time-consuming, insensitive, and non-specific, polymerase chain reaction (PCR) was employed for laboratory diagnostics. This study was aimed to develop PCR method to detect M. pneumoniae by designing primers to amplify fragment of the P1 adhesin gene. Two protocols, PCR-probe hybridization and nested PCR, were carried out. False-positive result due to amplicon carry over was prevented by using dUTP instead of dTTP and the addition of enzyme uracil DNA glycosylase (UDG). For nested PCR, UDG was added only in the first round reaction mixture. The sensitivity of PCR was 10 fg of M, pneumoniae DNA as detected by agarose gel electrophoresis and increased to be 1 fg as detected by either probe hybridization or nested PCR. The specificity of PCR was tested with DNAs from Mycoplasma spp, a variety of different bacterial genera and human leukocyte. All gave negative results. Considering of the speed, sensitivity, specificity and the prevention of amplicon carryover, the developed PCR-based protocols were suitable and reliable for the detection of M. pneumoniae in routine laboratory.