Wipa Reechaipichitkul

Can workplaces be predictors for recent onset latent tuberculosis in health care workers

ObjectiveTo study the association of workplaces and recent onset latent tuberculosis (LTB) in health care workers (HCW).MethodsA case-control study was conducted at Srinagarind Hospital, Khon Kaen University, Thailand. We recruited HCW who had results of tuberculin test within 2 consecutive years from 2001–2008 and also had fixed workplaces (working hours more than 40 hours/week). Cases were subjects with tuberculin conversion, while controls were subjects with negative results of tuberculin test in two consecutive years. Tuberculin conversion was defined if a subject had a negative baseline tuberculin test and a positive tuberculin test in the next consecutive years. Baseline characteristics, workplaces (office, in-patient unit, out-patient unit, intensive care, operating room, and laboratory unit), tuberculosis related variables, and prevention strategies were studied. Multiple logistic regression analysis was used to identify predictors for tuberculin conversion.ResultsThere were 624 subjects who met the criteria and 163 subjects had tuberculin conversion (26.1%; case group). The median age and male/female ratio of both groups were 39 years old and about 1:4. The cases group had higher percentage of subjects who worked at in- and out-patient department (30.7 vs 20.2 and 17.2 vs 12.2, respectively), had history of tuberculosis exposure in the past year (32.1 vs 16.1), and had history of prevention by any method and by surgical mask (49.4 vs 37.0 and 54.3 vs 38.3, respectively). Workings at in- and out-patient unit and history of tuberculosis exposure in the past year were significant predictors for tuberculin conversion (adjusted odds ratio and [95% confidence interval] of 1.99 [1.25–3.17], 1.91 [1.10–3.17], and 2.26 [1.47–4.96], respectively).SummaryWorkplaces in health care facilities do increase risks of LTB in HCW, particularly in in- and out-patient unit. Policy development regarding tuberculosis infection control programs focused on workplace prevention in health care facilities in Thailand is needed.

Evaluation of the QuantiFERON?-TB Gold In-Tube assay and tuberculin skin test for the diagnosis of Mycobacterium tuberculosis infection in northeastern Thailand.

BACKGROUND The diagnosis of latent Mycobacterium tuberculosis infection (LTBI) is currently based on the immunological response of T-cells to M. tuberculosis (MTB) antigens. However, the QuantiFERON®-TB Gold In-Tube assay (QFT) has not yet been evaluated in the Thai adult population. OBJECTIVE To evaluate the diagnostic performance and determine predictors of discordant results between the QFT and tuberculin skin test (TST). METHODS Active tuberculosis (ATB) patients (n=54), close contacts (CCs) living in the same household as a TB patient (n=100) and healthy controls (HCs) (n=60) were interviewed and underwent the QFT and TST at Srinagarind Hospital in Thailand. Various cut-off values for the QFT (0.25-0.35 IU/mL) and TST (5-15 mm) were applied. RESULTS The maximum agreement rate between the tests was 71.5% (κ=0.41) with cut-offs of 0.35 IU/mL and 10 mm or 0.25 IU/mL and 10 mm. Based on standard cut-off values (0.35 IU/mL and 10 mm) and using ATB patients and HCs as positive and negative controls, the TST was more sensitive than the QFT (87.0% vs. 66.7%, respectively), whereas the QFT was more specific than the TST (83.3% vs. 70.0%, respectively). Being underweight (OR 3.86, 95%CI 1.3-11.48) or overweight (OR 5.9, 95%CI 1.24-28.16) was significantly associated with TST+/QFT- results. Diabetes (OR 32.56, 95%CI 1.73-613.49) and poor or fair nutrition (OR 7.4, 95%CI 1.23-44.57) were significantly associated with TST-/QFT+ results. CONCLUSION The TST should be used as a screening test based on its higher sensitivity, whereas the QFT should be used as a confirmatory test because of its higher specificity.

Epidemiology of and risk factors for extrapulmonary nontuberculous mycobacterial infections in Northeast Thailand

Background Nontuberculous mycobacterial (NTM) infection is increasing worldwide. Current epidemiological data and knowledge of risk factors for this disease are limited. We investigated the trends in and risk of NTM infection in Northeast Thailand during 2012–2016. Methods Patient demographics, infection site(s), and underlying disease or conditions from 530 suspected cases of NTM infections were retrieved from medical records, reviewed and analyzed. A diagnosis of true NTM infection was accepted in 150 cases. Risk factor analyses were done for extrapulmonary NTM infections compared to pulmonary NTM infections and for Mycobacterium abscessus compared to members of the Mycobacterium avium complex (MAC). Trend analysis among NTM species causing NTM infections was performed. Results The most common species of NTMs causing extrapulmonary (n = 114) and pulmonary (n = 36) NTM infections in Northeast Thailand were M. abscessus (25.4% of extrapulmonary infected cases and 27.8% of pulmonary cases) followed by MAC (14.9% of extrapulmonary and 13.9% of pulmonary cases). Presence of anti-IFN-γ autoantibodies was the major risk factor for extrapulmonary (odds ratio (OR) = 20.75, 95%CI [2.70–159.24]) compared to pulmonary NTM infection. M. abscessus infection was less likely (OR = 0.17; 95%CI [0.04–0.80]) to be found in patients with HIV infection than was MAC infection. The prevalence of NTM infection, especially M. abscessus, in Northeast Thailand has recently increased. Extrapulmonary NTM and complicated NTM infections have increased in concordance with the recent trend of increasing frequency of anti-IFN-γ autoantibodies in the population. Conclusions M. abscessus was the commonest NTM pathogen followed by MAC. The prevalence of NTM infections and anti-IFN-γ are showing an upward trend. Autoimmune disease due to anti-IFN-γ is the major risk factor for extrapulmonary NTM infection in Northeast Thailand.

Age is associated with latent tuberculosis in nurses

Abstract Objective To evaluate risk factors for developing latent tuberculosis (LTB) in Thai nurses. Methods A comparison study was conducted at Srinagarind Hospital, Khon Kaen, Thailand. Clinical factors were compared between persons with tuberculin conversion and those without tuberculin conversion identified by tuberculin skin test. Results There were 173 eligible persons with the LTB (34.7%). There were five workplaces where participants worked regularly including the general ward, surgical ward, pediatric ward, medical ward and critical care ward. In a multivariate model, two factors were significantly associated with LTB including age and history of tuberculosis in colleagues. The adjusted odds ratio (95% confidence interval) of both variables were 1.056 (1.004–1.104) and 0.202 (0.044–0.941). Conclusions Older age is associated with latent tuberculosis in nurses. LTB should be screened routinely and treated if diagnosed for nurses.