A survey of latent tuberculosis infection among laboratory healthcare workers in New York City.

OBJECTIVE: To determine the prevalence of positive tuberculin skin tests (TSTs), incidence of TST conversion, risk factors for positive TSTs, and history of active TB among HCWs in microbiology laboratories in New York City. DESIGN: Two-year survey from May 1999 to June 2001. SETTING: Nineteen microbiology laboratories. RESULTS: During the first year, interviews were conducted with 345 laboratory HCWs (mean, 18 HCWs per site; range, 2 to 51) to assess the prevalence of positive TSTs, but 3 (1%) could not recall their result and were excluded from further analyses. The mean age of the remaining 342 HCWs was 48 years; 68% (n = 233) were female, 54% (n = 183) received bacille Calmette-Guerin (BCG) vaccination, and 71% (n = 244) were foreign born. The prevalence of a positive TST was 57% (n = 196), but only 20% (n = 39) of the HCWs received isoniazid. The incidence of TST conversion in the second year of the study was 1% (1 of 108). Multivariate analysis identified age (odds ratio [OR] per year, 1.05; 95% confidence interval [CI95], 1.02-1.08), foreign birth (OR, 3.80; CI95, 1.98-7.28), BCG immunization (OR, 4.89; CI95, 2.72-8.80), and employment in a mycobacteriology laboratory (OR, 2.14; CI95, 1.25-3.68) as risk factors for a positive TST. Only one HCW had been treated for active TB. CONCLUSIONS: The prevalence of positive TSTs was high among laboratory HCWs, but the TST conversion rate was low. Higher rates of treatment for latent TB infection are desirable.     

Completion of screening for latent tuberculosis infection among immigrants

The objective of our study was to evaluate the sociodemographic factors associated with completion of screening for latent tuberculosis infection (LTBI) among undocumented immigrants in Brescia, Italy. Screening for LTBI was offered to 649 immigrants; 213 (33%) immigrants completed the first step of screening; only 44% (55/124) of individuals with a positive tuberculin skin test result started treatment for LTBI. The univariate analysis showed that being unmarried, of Senegalese nationality and being interviewed by a health-care worker with the same native language as the immigrant were significantly associated with completion of screening for LTBI. In the multiple logistic regression, being interviewed in the native language of the health-care worker (OR 2.5, 95% CI 1.3-4.8, P = 0.004) and being of Senegalese origin (OR 2.3, 95% CI 1.4-3.6, P = 0.0005) were independently associated with adherence to LTBI screening. Our results suggest that knowledge of the sociodemographic characteristics of immigrants, and the participation of health-care workers of the same cultural origin as the immigrant during the visits, can be an important tool to improve completion of screening for LTBI.     

Ethical evaluation of immigration screening policy for latent tuberculosis infection

Objective : In Australia and New Zealand, immigration screening policy relating to tuberculosis is targeted towards identifying potential new arrivals with active infectious pulmonary disease. Recently, extensions of immigration policies to include latent tuberculosis infections have been proposed, which raise a new spectrum of ethical issues. Methods : Existing Australian and New Zealand immigration policy was reviewed. A principle‐based analytic framework was adopted for consideration of the ethical implications of proposed public health policy. Potential extensions of current policy in relation to latent tuberculosis infection are evaluated using this approach. Results : Current immigration policies related to tuberculosis focus on identification of immigrants with active infection. A principle‐based analytic framework allows evaluation of potential extensions of public health policy to incorporate screening and treatment for latent tuberculosis. Conclusions : Our paper explores the dynamic ethical tensions related to burdens and benefits of immigration screening for latent tuberculosis, and suggests that such policies could be justified under certain circumstances, including non‐arbitrary screening and post‐arrival management. The results of testing should not influence immigration outcome, but be used to mandate medical review and consideration of voluntary preventative treatment. Implications : Immigration strategies targeting latent tuberculosis could be ethically justified within appropriate guidelines. Proposed changes to policy should be evaluated on ethical grounds prior to introduction.     

Using computerized clinical decision support for latent tuberculosis infection screening

BACKGROUND: The Centers for Disease Control and Prevention (CDC) has published guidelines recommending screening high-risk groups for latent tuberculosis infection (LTBI). The goal of this study was to determine the impact of computerized clinical decision support and guided web-based documentation on screening rates for LTBI. DESIGN: Nonrandomized, prospective, intervention study. SETTING AND PARTICIPANTS: Participants were 8463 patients seen at two primary care, outpatient, public community health center clinics in late 2002 and early 2003. INTERVENTION: The CDC's LTBI guidelines were encoded into a computerized clinical decision support system that provided an alert recommending further assessment of LTBI risk if certain guideline criteria were met (birth in a high-risk TB country and aged <40). A guided web-based documentation tool was provided to facilitate appropriate adherence to the LTBI screening guideline and to promote accurate documentation and evaluation. Baseline data were collected for 15 weeks and study-phase data were collected for 12 weeks. MAIN OUTCOME MEASURES: Appropriate LTBI screening according to CDC guidelines based on chart review. RESULTS: Among 4135 patients registering during the post-intervention phase, 73% had at least one CDC-defined risk factor, and 610 met the alert criteria (birth in a high-risk TB country and aged <40 years) for potential screening for LTBI. Adherence with the LTBI screening guideline improved significantly from 8.9% at baseline to 25.2% during the study phase (183% increase, p < 0.001). CONCLUSIONS: This study demonstrated that computerized, clinical decision support using alerts and guided web-based documentation increased screening of high-risk patients for LTBI. This type of technology could lead to an improvement in LTBI screening in the United States and also holds promise for improved care for other preventive and chronic conditions.     

staffTRAK-TB: software for surveillance of tuberculosis infection in healthcare workers.

The Centers for Disease Control and Prevention (CDC) recommends periodic tuberculin skin testing of healthcare workers with potential exposure to Mycobacterium tuberculosis. However, many healthcare facilities have neither a system to identify workers due for their skin test nor a means of analyzing aggregate data. To illustrate some of the complexities involved in tuberculin skin test (TST) tracking and analysis, and how these might be addressed, this report describes a software package called staffTRAK-TB, developed by the CDC to facilitate surveillance of tuberculosis infection in healthcare workers. staffTRAK-TB records data for each healthcare worker, including demographic information, occupation, work location, multiple TST results, and results of evaluations to determine if clinically active tuberculosis is present. Programmed reports include lists of workers due and overdue for skin tests, and skin test conversion rates by occupation or worksite. Standardization of types of occupations and locations allows data from multiple facilities to be aggregated and compared. Data transfer to the CDC can be performed via floppy diskettes. staffTRAK-TB illustrates important issues in software structure, standardization of occupation and work-location information, relevant data items, and reports and analyses that would be useful in practice. Developing software that adequately addresses the epidemiological issues is complex, and the lessons learned may serve as a model for hospital epidemiologists, infection control personnel, occupational health personnel, and computer programmers considering software development in this area or trying to optimize their facility's TST surveillance.     

Occupational tuberculosis in healthcare workers in sub-Saharan Africa: A systematic review

ABSTRACT

This article investigates the incidence, prevalence and factors associated with occupational tuberculosis (TB) in healthcare workers (HCWs) in sub-Saharan Africa (SSA). Studies were extracted from MEDLINE, PsycINFO, CINAHL, Cochrane Library, and SCOPUS databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement from inception to the 2^nd of June 2017. Twenty-one studies met the inclusion criteria. The median prevalence of latent TB infection in HCWS was 62% (IQR 22%) and the median incidence of TB disease was 3871/100,000 (IQR 9314/100,000). The risk factors associated with LTBI or active TB disease were workplace, history of contact with TB patients, and longer duration of employment. The findings of this review demonstrate that the risk of acquiring TB among HCWs in SSA is high. This may impact on the recruitment, longevity and retention of HCWs.     

Early therapy for latent tuberculosis infection

The risk of developing active tuberculosis is highest within the first 2 years of infection. Therefore, an intervention that targets persons with recent infection, such as identifying contacts of active cases, could be particularly effective as an epidemic control measure. A mathematical model of a tuberculosis epidemic is formulated and used to evaluate the strategy of targeting therapy to persons with recently acquired latent tuberculosis infection. The model is used to quantify the effectiveness of therapy for early latent tuberculosis infection in reducing the prevalence of active tuberculosis. The model is also used to demonstrate how effective therapy for early latent tuberculosis infection has to be to eliminate tuberculosis, when used in conjunction with therapy for active tuberculosis. Analysis of the model suggests that programs such as contact investigations, which identify and treat persons recently infected with Mycobacterium tuberculosis, may have a substantial effect on controlling tuberculosis epidemics.     

Risk of tuberculosis in correctional healthcare workers

OBJECTIVE: The objective of this study was to determine the prevalence, incidence, and risk factors for occupational infection with tuberculosis among healthcare workers employed in correctional facilities. METHODS: The authors conducted a self-administered survey, clinical interview, and tuberculin skin testing. RESULTS: The overall tuberculin skin test point prevalence rate was 17.7%, the reactivity rate was 2.2%, and the annual incidence was 1.3%. At the multivariate level, after controlling for bacille Calmette-Guérin vaccination, only origin of birth remained significantly associated with prevalence of tuberculosis infection. CONCLUSIONS: Although the prevalence of tuberculin reactivity was high in this population, the risk factors were predominantly demographic rather than occupational. Nevertheless, continued vigilance to control occupational exposure to this and other respiratory pathogens is warranted, given the potential for future outbreaks of tuberculosis, as well as other known and emerging airborne pathogens.     

The effectiveness of using interferon-gamma release assays in screening immigration employees for latent tuberculosis infection

We assessed the prevalence of latent tuberculosis infection in immigration employees and compared two of the screening methods. Using a cross-sectional study design, we administered questionnaires regarding demographics, work, medical history, and tuberculosis risk factors to employees at two immigration facilities. Participants underwent tuberculin skin test (TST) placement and blood collection for the QuantiFERON-TB Gold in-Tube (QFT-GIT) assay. Fifty-four employees underwent QFT-GIT and TST placement. All QFT-GIT results were negative, and three employees tested TST positive. Twenty-three (49%) of 47 employees requiring two-step TST testing underwent second TST placement. Return rates for first and second TST reading were 76% and 74%, respectively. The QFT-GIT completion rate was higher than that for TST (100% vs. 39%, P < 0.001). Agreement between TST and QFT-GIT was 94%. Immigration employees had low return rates for their TST reading and second TST placement. Performing the one-visit QFT-GIT has administrative and logistical advantages in this occupational group.     

Compliance with national recommendations for tuberculosis screening and immunization of healthcare workers in a children's hospital.

Physicians and clinical employees at a children's hospital were surveyed to compare their tuberculosis (TB) screening and immunization statuses. Failure to offer screening and immunization services to non-employee physicians was associated with lower rates of reported immunity to several vaccine-preventable diseases and with markedly lower rates of TB screening.     

Screening for tuberculosis infection using whole-blood interferon-gamma and Mantoux testing among Japanese healthcare workers.

OBJECTIVE: To examine the hypothesis that results of the QuantiFERON-TB Gold assay (QFT-G), a whole-blood test for detection of tuberculosis infection, are more significantly related to known risk factors for tuberculosis infection in healthcare workers (HCWs) who have received bacille Calmette-Guerin vaccine than are results of the Mantoux tuberculin skin test (TST). DESIGN: All HCWs (approximately 510) from a 370-bed general hospital in Tokyo where patients with and patients without tuberculosis are treated were invited to participate in the study. All study participants completed a questionnaire about their Mycobacterium tuberculosis infection risk factors as HCWs at the general hospital. They were then tested for LTBI by means of the QFT-G, followed by the TST. Statistical analyses were performed to compare results of each test with M. tuberculosis infection risk factors (age, length of employment in the healthcare industry, history of working with tuberculosis-positive patients in a tuberculosis ward or in the outpatient department of the hospital's tuberculosis clinic for more than 1 year, chest radiograph evidence of healed tuberculosis, history of performing bronchoscope procedures, and job classification), and for TST-positive HCWs, to compare the QFT-G result with the TST induration diameter. RESULTS: A total of 332 HCWs (95% of whom had been vaccinated with BCG) participated in the study, and 33 had positive QFT-G results, suggesting a prevalence of LTBI of 9.9%. Of 304 HCWs who underwent TST, 283 (93.1%) had an induration diameter of 10 mm or more. Multiple logistic regression analysis revealed that positive QFT-G results were significantly associated with age and with a history of working in a tuberculosis ward or an outpatient department of a tuberculosis clinic. TST results were not correlated with any of the tuberculosis infection risk factors we evaluated. CONCLUSIONS: Positive QFT-G results were closely associated with the presence of risk factors for LTBI in a hospital setting, suggesting that the QFT-G can detect LTBI in a population composed predominantly of BCG vaccinees. Because most HCWs worldwide have been vaccinated with BCG, the QFT-G offers a significant improvement over the TST in tuberculosis screening programs and minimizes unwarranted use of tuberculosis prophylaxis.     

潜伏性结核感染筛查在炎症性肠病患者药物治疗前的应用价值

目的探索潜伏性结核感染(LTBI)筛查在炎症性肠病(IBD)患者药物治疗前的应用价值。方法回顾性分析2015年9月-2017年9月于医院接受治疗的118例IBD患者临床资料,按照患者是否进行LTBI筛查将患者分为LTBI筛查组(n=66)和非LTBI筛查组(n=52)。统计LTBI筛查率、LTBI筛查方案、活动性结核发生率。结果 118例IBD患者英夫利西治疗前LTBI筛查患者66例,筛查率为55.93%,其中克罗恩患者LTBI筛查率70.79%显著高于溃疡性结肠炎患者LTBI筛查率10.34%(P<0.05)。LTBI筛查组中19例行胸部影像学、结核菌素试验(PPD)、T细胞酶联免疫斑点试验(T-STOP.TB)三者联合检查;25例行T-STOP.TB联合胸部影像学检查; LTBI筛查组中共检出9例LTBI患者,检出率为13.64%。LTBI筛查组不同时间段活动性结核发生率为1.52%,显著低于非LTBI筛查组11.54%(P<0.05)。结论 IBD患者行英夫利西治疗前LTBI筛查率仍然较低,克罗恩患者LTBI筛查重视程度高于溃疡性结肠炎患者,LTBI筛查方案选择较为多样,但检出率较低,LTBI筛查有助于降低活动性结核发生率,适合临床推广。     

我国学生结核分枝杆菌潜伏感染和预防治疗现状

目的了解上海市浦东新区大中专院校肺结核患者学生密切接触者结核潜隐感染(LTBI)的情况及影响因素。方法2017年1月1日—12月31日采用结核分枝杆菌特异性细胞免疫反应检测(酶联免疫法)(QFT)对479例肺结核患者学生密切接触者的LTBI情况进行检测,同时收集性别、年龄、户籍、接触时间等信息并进行单因素和多因素分析。结果479例学生密切接触者的平均年龄为(20.8±1.4)岁,QFT试验结果阳性47例。同寝室室友以及同楼层寝室且同班级的密切接触学生QFT阳性率(30.0%和12.5%)显著高于一般接触者(7.3%)。多因素分析结果显示,男生密切接触者发生LTBI的风险高于女生(OR=3.72,95%CI：1.06~12.99);累计接触时间≥80 h的学生密切接触者发生LTBI的风险高于累计接触时间＜40 h者(OR=3.33,95%CI：1.12~9.86)。结论LTBI与接触程度和接触时间显著相关,其中同寝室室友以及同楼层寝室且同班级的密切接触学生是LTBI的高风险人群,应当在现有学校结核病防控的基础上增加对密切接触者的早期LTBI筛查,并尽早向LTBI者提供预防性治疗等。     

Incentives vs outreach workers for latent tuberculosis treatment in drug users

BACKGROUND: Drug users are at increased risk for latent tuberculosis infection (LTBI) and also at increased risk for noncompletion of medication regimens for treatment of LTBI or tuberculosis disease. Directly observed therapy (DOT) provided by outreach workers, the use of incentives, or both have been suggested as a means to increase adherence. OBJECTIVE: To compare the independent and combined effects of monetary incentives and outreach worker provision of DOT for LTBI treatment in a sample of active drug users. METHODS: The research design was a randomized controlled trial in a community outreach program setting. Participants consisted of a volunteer sample of 163 active injection drug and crack cocaine users placed on twice weekly DOT. Condition 1 of the interventions consisted of provision of DOT by an outreach worker at a location chosen by the participant (active outreach) and a $5 per visit incentive. Condition 2 was comprised of active outreach with no monetary incentive, and Condition 3, provision of DOT at the study community site and a $5 per visit incentive. The main outcome measures were percentage of medication taken as prescribed and completion of medication regimen. RESULTS: The percentage of prescribed medication taken was higher for those who received incentives, either with (71%) or without (68%) active outreach, compared to those who received active outreach alone (13%). Only 4% of participants assigned to Condition 2 completed treatment, compared to 53% of Condition 1 participants, and 60% of Condition 3 participants. CONCLUSIONS: Monetary incentives were clearly superior to active outreach. Active outreach in combination with monetary incentives did not increase adherence over incentives alone.     

Results of audiometry screening in adolescent workers

Results of screening audiometry of male youths aged 16 to 25 (n = 3969) in occupations from metallurgy, machine-building industry and traffic are demonstrated. Part of persons they have hearing loss between 5 to 10 percent increases from 2.8% of pupils before starting vocational training to 4.5% or 7.1% of apprentices and 9.7% of skilled workers. The incidence of persons with respective without middle ear inflammation in anamnesis only differ in stages about 20 percent hearing loss. It shows sensitivity of screening audiometry nevertheless there are possibilities of mistakes. Adolescents already may show measurable hearing loss in connection with professional and nonprofessional expositions as well as individual dispositions.     

Incidence of pertussis infection in healthcare workers.

OBJECTIVE: To determine the incidence of pertussis infection in two groups of healthcare workers. DESIGN: Retrospective cohort study. SETTING: 660-bed, urban, tertiary-care university hospital. PARTICIPANTS: 106 resident physicians and 39 emergency department employees. INTERVENTIONS: Antibodies to pertussis toxin and filamentous hemagglutinin were determined in fresh serum specimens and in stored sera collected 1 to 3 years previously. A 50% rise in both the pertussis toxin and filamentous hemagglutinin from the initial to the follow-up specimen was considered diagnostic of a pertussis infection. RESULTS: Two of 106 residents had serological evidence of a pertussis infection during 151.3 subject-observation years, for an annual incidence rate of 1.3% (95% confidence interval [CI95], 0%-3.5%). Three of 39 emergency department employees had serological evidence of a pertussis infection during 81.2 subject-observation years, for an annual incidence of 3.6% (CI95, 0%-9.6%). Of these 5 subjects, 2 had symptomatic disease. CONCLUSION: We found both symptomatic and asymptomatic pertussis infections in two cohorts of healthcare workers. Although the incidence rates were somewhat lower than found in other studies, they nonetheless were higher than for almost all other diseases for which we vaccinate healthcare workers. Our results would support the use of acellular pertussis vaccine in healthcare workers.     

Prevalence of latent tuberculosis infection in German radiologists

Healthcare workers have an increased risk of tuberculosis infection compared with the general population. There have been few attempts to quantify the prevalence of latent tuberculosis infection amongst German healthcare workers, due to inadequacy of the current tuberculin skin test (TST). Therefore, it was our aim to investigate the prevalence of latent tuberculosis in this cohort using a tuberculosis-specific ELISpot (T-SPOT.TB) test and to compare the performance of this test to that of the TST. Ninety-five healthy participants working in departments of radiology were examined by ELISpot, lymphocyte transformation test and TST. For cellular in-vitro tests, tuberculosis-specific peptides and purified protein derivate (PPD) were used as antigens. These tests were combined with a questionnaire on prior tuberculosis exposure. Out of 95 healthcare workers, only one (1%) was defined as positive by T-SPOT.TB, 92 (97%) by PPD-ELISpot, 78 (82%) by PPD-lymphocyte transformation test and 32 (34%) by TST. Multivariate analysis showed that the TST was significantly affected (P<0.0001 and P=0.001, respectively) by foreign birth and prior skin testing. The T-SPOT.TB test results were independent of foreign birth, prior skin testing and prior vaccination against tuberculosis. In contrast to the TST, T-SPOT.TB appears to be an accurate and useful tool to track tuberculosis infection in this at-risk group. With only one of 95 participants having acquired latent tuberculosis, these preliminary results argue for a low incidence of latent tuberculosis in German radiologists.     

Immigrant screening for latent tuberculosis in Norway: a cost-effectiveness analysis

The incidence of tuberculosis (TB) disease has increased in Norway since the mid-1990s. Immigrants are screened, and some are treated, for latent TB infection (LTBI) to prevent TB disease (reactivation). In this study, we estimated the costs of both treating and screening for LTBI and TB disease, which has not been done previously in Norway. We developed a model to indicate the cost-effectiveness of four different screening algorithms for LTBI using avoided TB disease cases as the health outcome. Further, we calculated the expected value of perfect information (EVPI), and indicated areas of LTBI screening that could be changed to improve cost-effectiveness. The costs of treating LTBI and TB disease were estimated to be €1938 and €15,489 per case, respectively. The model evaluates four algorithms, and suggests three cost-effective algorithms depending on the cost-effectiveness threshold. Screening all immigrants with interferon-gamma release assays (IGRA) requires the highest threshold (€28,400), followed by the algorithms “IGRA on immigrants with risk factors” and “no LTBI screening.” EVPI is approximately €5 per screened immigrant. The costs for a cohort of 20,000 immigrants followed through 10 years range from €12.2 million for the algorithm “screening and treatment for TB disease but no LTBI screening,” to €14 million for “screening all immigrants for both TB disease and LTBI with IGRA.” The results suggest that the cost of TB disease screening and treatment is the largest contributor to total costs, while LTBI screening and treatment costs are relatively small. Increasing the proportion of IGRA-positive immigrants who are treated decreases the costs per avoided case substantially.