Tuberculosis among healthcare workers, United States, 1995-2007

The American Association of Tissue Banks tissue donor screening for Mycobacterium tuberculosis-Recommended criteria and literature review

After two multistate outbreaks of allograft tissue-transmitted tuberculosis (TB) due to viable bone, evidence-based donor screening criteria were developed to decrease the risk of transmission to recipients. Exclusionary criteria, commentary, and references supporting the criteria are provided, based on literature search and expert opinion. Both exposure and reactivation risk factors were considered, either for absolute exclusion or for exclusion in combination with multiple risk factors. A criteria subset was devised for tissues containing viable cells. Risk factors for consideration included exposure (e.g., geographic birth and residence, travel, homelessness, incarceration, healthcare, and workplace) and reactivation (e.g., kidney disease, liver disease, history of transplantation, immunosuppressive medications, and age). Additional donor considerations include the possibility of sepsis and chronic illness. Donor screening criteria represent minimal criteria for exclusion and do not completely exclude all possible donor TB risks. Additional measures to reduce transmission risk, such as donor and product testing, are discussed but not included in the recommendations. Careful donor evaluation is critical to tissue safety.

Tuberculosis infection status and risk factors among health workers: an updated systematic review

Tuberculosis (TB) infection is a common occupational risk for health workers (HWs) and poses a threat to the patients under their care and to other HWs. Hence, the development of a prevention strategy is crucial. We conducted a study to understand the status and risk factors of TB infection among HWs. The existing literature was searched for all published reports from 1 August 2010 to 31 December 2018, related to TB among HWs according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The inclusion criteria were: (1) study participants working in a health care facility; (2) TB cases diagnosed by medical professionals; (3) original research articles; and (4) English reports in a peer-reviewed journal. We finally included 61 studies from 642 articles searched initially. The TB infection rate in HWs was higher than that of the general population. Based on 39 studies, the prevalence of TB in HWs (tuberculin skin test positive) was 29.94%. In contrast, the global burden of latent TB infection was 23.0% (95% uncertainty interval: 20.4%–26.4%) in 2014. The risk factors of TB among HWs were aging, long duration of employment, nursing professionals, lack of Bacillus Calmette-Guerin vaccination, and low body mass index. HWs have an increased risk for TB infection, which can cause secondary infections in patients or other HWs. An effective prevention strategy must be developed to enable early diagnosis and prompt treatment.

Identifying factors affecting latent tuberculosis treatment acceptance among healthcare workers: a retrospective analysis in a tertiary care centre

OBJECTIVE

Official guidelines recommend tuberculosis (TB) screening programmes for all healthcare workers (HCWs), along with offering treatment when latent TB infection (LTBI) is diagnosed. However, adherence to treatment among HCWs is lower compared with non-HCWs. The aim of the present study was to examine the rate of LTBI treatment acceptance among HCWs and to characterise the factors associated with non-acceptance.

DESIGN AND SETTING

This was a retrospective cohort study. All HCWs diagnosed with LTBI, who had tuberculin skin test (TST) conversion during their work, between 2000 and 2015, in a single tertiary academic medical centre, and who consented to answer a questionnaire, were enrolled.

RESULTS

Overall, 147 of 219 (67%) with TST conversion agreed to participate. Acceptance rate for LTBI treatment was only 16%. The overall completion rate among those who accepted treatment was 87%. HCWs' recall of discussing the importance of LTBI treatment with their caregiver had the strongest association with LTBI treatment acceptance: 23 of 52 HCWs (44%) who recalled this discussion accepted treatment (adjusted OR=10.2, 95% CI: 2.2 to 47.6, p=0.003). Knowing the risk of developing TB was associated with 3.7 increased odds to accept treatment (95% CI: 1.2 to 11.8, p=0.02).

CONCLUSIONS

LTBI acceptance rate was very low among our HCWs. Focusing on educating HCWs is potentially the key step towards an increased rate of LTBI treatment acceptance.

Tuberculosis Screening, Testing, and Treatment of US Health Care Personnel: ACOEM and NTCA Joint Task Force on Implementation of the 2019 MMWR Recommendations

: On May 17, 2019, the US Centers for Disease Control and Prevention and National Tuberculosis Controllers Association issued new Recommendations for Tuberculosis Screening, Testing, and Treatment of Health Care Personnel, United States, 2019, updating the health care personnel-related sections of the Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Settings, 2005. This companion document offers the collective effort and experience of occupational health, infectious disease, and public health experts from major academic and public health institutions across the United States and expands on each section of the 2019 recommendations to provide clarifications, explanations, and considerations that go beyond the 2019 recommendations to answer questions that may arise and to offer strategies for implementation.

Update in Outpatient General Internal Medicine: Practice-Changing Evidence Published in 2019

Clinicians are challenged to stay informed of new and changing medical literature. To facilitate knowledge updates and synthesis of practice-changing information, a group of 6 internists reviewed the titles and abstracts in the 7 outpatient general internal medicine journals with the highest impact factors and relevance to outpatient internal medicine physicians: New England Journal of Medicine (NEJM), Lancet, Annals of Internal Medicine, Journal of the American Medical Association (JAMA), JAMA Internal Medicine, British Medical Journal (BMJ), and Public Library of Science (PLoS) Medicine. The following collections of article synopses and databases were also reviewed: American College of Physicians Journal Club, NEJM Journal Watch, BMJ Evidence-Based Medicine, McMaster/DynaMed Evidence Alerts, and Cochrane Reviews. A modified Delphi method was used to gain consensus based on clinical relevance to outpatient internal medicine, potential impact on practice, and strength of evidence. Article qualities and importance were debated until consensus was reached. Clusters of articles pertaining to the same topic were considered together. In total, 7 practice-changing articles were included.

Cost-Effectiveness of Annual Screening for Tuberculosis among Italian Healthcare Workers: A Retrospective Study

Background. In the past few years, healthcare workers (HCWs) have been considered at higher risk for tuberculosis (TB) infection than the general population. On the other hand, recent studies have reported a low conversion rate among these workers. Recently, the Center for Disease Control (CDC) updated its recommendations, suggesting that an annual screening should not be performed in the absence of a documented exposure but only in workers with high-risk duties or with job tasks in settings at high risk of tuberculosis contagion (e.g., departments of infectious or pulmonary diseases). In fact, some studies showed that annual tuberculosis screening for all the HCWs was not cost-effective in countries with a low incidence of TB. In this study, we evaluated the conversion rate and the cost-effectiveness of two different tuberculosis screening strategies in a large population of Italian HCWs. Methods. In our retrospective study, we reviewed data coming from a tuberculosis screening conducted on 1451 HCWs in a teaching hospital of Rome. All workers were evaluated annually by means of the Quantiferon test (QFT) for a five-year period. Then, the conversion rate was calculated. Results. We found a cumulative conversion rate of 0.6%. Considering the cost of the QFT test (48.26 euros per person), the screening of the HCWs resulted in a high financial burden (38,902.90 euros per seroconversion). Only one seroconversion would have been missed by applying the CDC updated recommendations, with a relevant drop of the costs: 6756.40 euros per seroconversion, with a global save of 296,075.10 euros. Conclusion: The risk of TB conversion among our study population was extremely low and it was related to the risk classification of the setting. Giving these results, the annual tuberculosis screening appeared to not be cost effective. We conclude that a targeted screening would be a better alternative in HCWs with a higher risk of TB exposure.

The Occupational Burden of Nonmalignant Respiratory Diseases. An Official American Thoracic Society and European Respiratory Society Statement

Rationale: Workplace inhalational hazards remain common worldwide, even though they are ameliorable. Previous American Thoracic Society documents have assessed the contribution of workplace exposures to asthma and chronic obstructive pulmonary disease on a population level, but not to other chronic respiratory diseases. The goal of this document is to report an in-depth literature review and data synthesis of the occupational contribution to the burden of the major nonmalignant respiratory diseases, including airway diseases; interstitial fibrosis; hypersensitivity pneumonitis; other noninfectious granulomatous lung diseases, including sarcoidosis; and selected respiratory infections. Methods: Relevant literature was identified for each respiratory condition. The occupational population attributable fraction (PAF) was estimated for those conditions for which there were sufficient population-based studies to allow pooled estimates. For the other conditions, the occupational burden of disease was estimated on the basis of attribution in case series, incidence rate ratios, or attributable fraction within an exposed group. Results: Workplace exposures contribute substantially to the burden of multiple chronic respiratory diseases, including asthma (PAF, 16%); chronic obstructive pulmonary disease (PAF, 14%); chronic bronchitis (PAF, 13%); idiopathic pulmonary fibrosis (PAF, 26%); hypersensitivity pneumonitis (occupational burden, 19%); other granulomatous diseases, including sarcoidosis (occupational burden, 30%); pulmonary alveolar proteinosis (occupational burden, 29%); tuberculosis (occupational burden, 2.3% in silica-exposed workers and 1% in healthcare workers); and community-acquired pneumonia in working-age adults (PAF, 10%). Conclusions: Workplace exposures contribute to the burden of disease across a range of nonmalignant lung conditions in adults (in addition to the 100% burden for the classic occupational pneumoconioses). This burden has important clinical, research, and policy implications. There is a pressing need to improve clinical recognition and public health awareness of the contribution of occupational factors across a range of nonmalignant respiratory diseases.

Epidemiology of Tuberculosis in the United States

Although considerable progress has been made in reducing US tuberculosis incidence, the goal of eliminating the disease from the United States remains elusive. A continued focus on preventing new tuberculosis infections while also identifying and treating persons with existing tuberculosis infection is needed. Continued vigilance to ensure ongoing control of tuberculosis transmission remains key.

Tuberculosis among healthcare personnel, United States, 2010-2016

We describe characteristics of US healthcare personnel (HCP) diagnosed with tuberculosis (TB). Among 64,770 adults with TB during 2010-2016, 2,460 (4%) were HCP. HCP with TB were more likely to be born outside of the United States, and less likely to have TB attributed to recent transmission, than non-HCP.

A screening strategy for latent tuberculosis in healthcare workers: Cost-effectiveness and budget impact of universal versus targeted screening

OBJECTIVE

To evaluate the clinical, cost-efficiency, and budgetary implications of universal versus targeted latent tuberculosis infection (LTBI) screening strategies among healthcare workers (HCWs) in an intermediate tuberculosis (TB)-burden country.

DESIGN

Pragmatic cost-effectiveness and budget impact analysis using decision-analytic modeling.

SETTING

A tertiary-care hospital in Singapore.

METHODS

We compared 7 potentially implementable LTBI screening programs including universal and targeted strategies with different screening frequencies. Feasible targeting methods included stratification by country of origin (a proxy for risk of prior TB exposure) and by high-risk occupation. The clinical and financial consequences of each strategy were estimated relative to "no screening" (current practice) and compared to locally appropriate cost-effectiveness thresholds. All analyses were conducted from the hospital's perspective over a 3-year time horizon, based on the typical hospital planning period. Parameter uncertainties were accounted for using sensitivity analyses.

RESULTS

In our model, relative to current practice, screening new international hires and triennial screening of existing high-risk workers is most cost-effective (US$58 per quality adjusted life year [QALY]) and decreases active TB cases from 19 to 14. Screening all new hires combined with triennial universal screening, with or without annual high-risk screening or annual universal screening, reduced active TB to a range of 19 to 6 cases, but these strategies are less cost-effective and require substantially higher expenditures.

CONCLUSIONS

Targeted LTBI screening for HCWs can be highly cost-effective for hospitals in settings similar to Singapore. More inclusive screening strategies (including regular universal screening) can yield better outcomes but are less efficient and may even be unaffordable.

Improvement in tuberculosis infection control practice via technical support in two regions of Ethiopia

BACKGROUND

Globally recommended measures for comprehensive tuberculosis (TB) infection control (IC) are inadequately practiced in most health care facilities in Ethiopia. The aim of this study was to assess the extent of implementation of TB IC measures before and after introducing a comprehensive technical support package in two regions of Ethiopia.

METHODS

We used a quasi-experimental design, whereby a baseline assessment of TB IC practices in 719 health care facilities was conducted between August and October 2013. Based on the assessment findings, we supported implementation of a comprehensive package of interventions. Monitoring was done on a quarterly basis, and one-year follow-up data were collected on September 30, 2014. We used the Student's t-test and chi-squared tests, respectively, to examine differences before and after the interventions and to test for inter-regional and inter-facility associations.

RESULTS

At baseline, most of the health facilities (69%) were reported to have separate TB clinics. In 55.2% of the facilities, it was also reported that window opening was practiced. Nevertheless, triaging was practiced in only 19.3% of the facilities. Availability of an IC committee and IC plan was observed in 29.11 and 4.65% of facilities, respectively. Health care workers were nearly three times as likely to develop active TB as the general population. After 12 months of implementation, availability of a separate TB room, TB IC committee, triage, and TB IC plan had increased, respectively, by 18, 32, 44, and 51% (p < 0.001).

CONCLUSIONS

After 1 year of intervention, the TB IC practices of the health facilities have significantly improved. However, availability of separate TB rooms and existence of TB IC committees remain suboptimal. The burden of TB among health care workers is higher than in the general population. TB IC measures must be strengthened to reduce TB transmission among health workers.

False-Positive Tuberculin Skin Test Results Among Low-Risk Healthcare Workers Following Implementation of Fifty-Dose Vials of Purified Protein Derivative

Following large declines in tuberculosis transmission the United States, large-scale screening programs targeting low-risk healthcare workers are increasingly a source of false-positive results. We report a large cluster of presumed false-positive tuberculin skin test results in healthcare workers following a change to 50-dose vials of Tubersol tuberculin.Infect Control Hosp Epidemiol 2018;39:750-752.

The Prevalence and Risk Factors of Latent Tuberculosis Infection among Health Care Workers Working in a Tertiary Hospital in South Korea

Background

The risk of tuberculosis (TB) infection among health care workers (HCWs) is higher than as noted among workers in the general population. The prevalence and risk factors of TB infection among HCWs were assessed in a tertiary hospital in South Korea, resulting in a conclusion of an intermediate TB burden within the country.

Methods

This cross-sectional study enrolled HCWs who underwent a QuantiFERON-TB Gold In-Tube (QFT-GIT) test to detect the presence of a latent TB infection (LTBI), in patients admitted to a tertiary hospital in South Korea in 2017. The departments of the hospital were divided into TB-related and TB-unrelated departments, which were based on the risk of exposure to TB patients. In this sense, the risk factors for LTBI, including current working in the TB-related departments, were analyzed.

Results

In this case, a total of 499 HCWs (54 doctors, 365 nurses and 80 paramedical personnel) were enrolled in this study. The median age of the subjects was 31 years (range, 20–67 years), 428 (85.8%) were female, and 208 (41.7%) were working in the TB-related departments. The prevalence of LTBI was 15.8% based on the QFT-GIT. Additionally, the prevalence of experience of exposure to pre-treatment TB patents was higher among HCWs working in the TB-related departments, than among HCWs working in the TB-unrelated departments (78.8% vs. 61.9%, p<0.001). However, there was no significant difference in the prevalence of LTBI between the two groups (17.3% vs. 14.8%, p=0.458). On a review of the multivariate analysis, only the factor of age was independently associated with an increased risk of LTBI (p=0.006).

Conclusion

Broadly speaking, the factor of age was associated with an increased risk of LTBI among the HCWs in South Korea. However, those workers current working in the TB-related departments was not associated with an increased risk of LTBI.

A "Stone in the Pond" Approach to Contact Tracing: Responding to a Large-Scale, Nosocomial Tuberculosis Exposure in a Moderate TB-Burden Setting

A "stone in the pond" strategy is a practical approach to investigating large-scale nosocomial tuberculosis (TB) exposures. Here, we describe such a risk-stratified approach to contact tracing after a TB exposure that occurred over 5 months in a pediatric inpatient ward in a country with a moderate TB burden. Infect Control Hosp Epidemiol 2017;38:1509-1511.

Tuberculosis in Enclosed Populations

Transmission of tuberculosis (TB) is most effective in close contact indoor environments in various congregate settings including health care facilities, homeless shelters, correctional facilities, long-term care facilities, as well as community settings such as homes, schools, workplaces, and various modes of transportation. Outbreaks are fueled by numerous factors including the HIV epidemic, ease of global travel, unstable socio-economic and/or political situations, and lapses in response to potentially infectious patients. Organized approaches to TB control include an appropriate index of suspicion, identification and isolation of contagious patients in appropriate facilities, use of environmental controls, and personal protective equipment in accordance to national and international published guidelines. These all require tailoring to the various settings where TB is encountered using a determination of risk. Concerted efforts at the local, regional, national, and international levels at identifying patients with active disease, enforcing completion of treatment, and testing and fully treating patients with latent TB infection are paramount in reducing TB burden and continued transmission.

Revisiting annual screening for latent tuberculosis infection in healthcare workers: a cost-effectiveness analysis

BACKGROUND

In North America, tuberculosis incidence is now very low and risk to healthcare workers has fallen. Indeed, recent cohort data question routine annual tuberculosis screening in this context. We compared the cost-effectiveness of three potential strategies for ongoing screening of North American healthcare workers at risk of exposure. The analysis did not evaluate the cost-effectiveness of screening at hiring, and considered only workers with negative baseline tests.

METHODS

A decision analysis model simulated a hypothetical cohort of 1000 workers following negative baseline tests, considering duties, tuberculosis exposure, testing and treatment. Two tests were modelled, the tuberculin skin test (TST) and QuantiFERON®-TB-Gold In-Tube (QFT). Three screening strategies were compared: (1) annual screening, where workers were tested yearly; (2) targeted screening, where workers with high-risk duties (e.g. respiratory therapy) were tested yearly and other workers only after recognised exposure; and (3) post exposure-only screening, where all workers were tested only after recognised exposure. Workers with high-risk duties had 1% annual risk of infection, while workers with standard patient care duties had 0.3%. In an alternate higher-risk scenario, the corresponding annual risks of infection were 3% and 1%, respectively. We projected costs, morbidity, quality-adjusted survival and mortality over 20 years after hiring. The analysis used the healthcare system perspective and a 3% annual discount rate.

RESULTS

Over 20 years, annual screening with TST yielded an expected 2.68 active tuberculosis cases/1000 workers, versus 2.83 for targeted screening and 3.03 for post-exposure screening only. In all cases, annual screening was associated with poorer quality-adjusted survival, i.e. lost quality-adjusted life years, compared to targeted or post-exposure screening only. The annual TST screening strategy yielded an incremental cost estimate of $1,717,539 per additional case prevented versus targeted TST screening, which in turn cost an incremental $426,678 per additional case prevented versus post-exposure TST screening only. With the alternate "higher-risk" scenario, the annual TST strategy cost an estimated $426,678 per additional case prevented versus the targeted TST strategy, which cost an estimated $52,552 per additional case prevented versus post-exposure TST screening only. In all cases, QFT was more expensive than TST, with no or limited added benefit. Sensitivity analysis suggested that, even with limited exposure recognition, annual screening was poorly cost-effective.

CONCLUSIONS

For most North American healthcare workers, annual tuberculosis screening appears poorly cost-effective. Reconsideration of screening practices is warranted.

Serial testing for latent tuberculosis using QuantiFERON-TB Gold In-Tube: A Markov model

Healthcare workers (HCWs) in low-incidence settings are often serially tested for latent TB infection (LTBI) with the QuantiFERON-TB Gold In-Tube (QFT) assay, which exhibits frequent conversions and reversions. The clinical impact of such variability on serial testing remains unknown. We used a microsimulation Markov model that accounts for major sources of variability to project diagnostic outcomes in a simulated North American HCW cohort. Serial testing using a single QFT with the recommended conversion cutoff (IFN-g > 0.35 IU/mL) resulted in 24.6% (95% uncertainty range, UR: 23.8–25.5) of the entire population testing false-positive over ten years. Raising the cutoff to >1.0 IU/mL or confirming initial positive results with a (presumed independent) second test reduced this false-positive percentage to 2.3% (95%UR: 2.0–2.6%) or 4.1% (95%UR: 3.7–4.5%), but also reduced the proportion of true incident infections detected within the first year of infection from 76.5% (95%UR: 66.3–84.6%) to 54.8% (95%UR: 44.6–64.5%) or 61.5% (95%UR: 51.6–70.9%), respectively. Serial QFT testing of HCWs in North America may result in tremendous over-diagnosis and over-treatment of LTBI, with nearly thirty false-positives for every true infection diagnosed. Using higher cutoffs for conversion or confirmatory tests (for initial positives) can mitigate these effects, but will also diagnose fewer true infections.

Latent Tuberculosis in Health Care Workers Exposed to Active Tuberculosis in a Tertiary Care Hospital in Oman

OBJECTIVES

Data on the prevalence of tuberculosis (TB) in healthcare workers (HCW) in Oman and the Arabian Gulf is scarce. The aim of this study was to estimate the prevalence of latent tuberculosis (LTB) among HCW exposed to active TB in one of the tertiary care hospitals in Muscat.

METHODS

Exposed HCW were screened for LTB from January to June 2012 using skin tuberculin and serum interferon tests. Candidates were followed-up for a total of nine months. Descriptive statistics were used to summarize the data.

RESULTS

A total of 371 exposed HCW were involved in the study. The incidence of LTB in exposed HCW was 33.2% (n = 123). Almost 54% (66/123) of the HCW started treatment and only 42.4% (28/66) completed the full nine-month treatment course.

CONCLUSIONS

The high prevalence of LTBI in exposed HCW merits further evaluation of the screening and treatment programs in the country. Future countrywide studies are warranted to provide more precise statistics on the prevalence and management of this public health issue.

Risk factors for nosocomial tuberculosis transmission among health care workers

We conducted hospital-based contact investigations of 55 serial sputum smear-positive tuberculosis (TB) patients and 771 health care workers (HCWs) from 2006-2013. HCWs who made contact with TB patients in the absence of appropriate airborne precautions were evaluated using interferon gamma release assays to identify TB infection. Twenty-nine HCWs (3.8%) were newly diagnosed with TB infection. The 10 TB patients responsible for transmission had a duration of contact of >7 days by multivariate analysis.

An epidemiologic investigation of occupational transmission of Mycobacterium tuberculosis infection to dental health care personnel: infection prevention and control implications

BACKGROUND

The authors describe an investigation of a dental hygienist who developed active pulmonary tuberculosis (TB), worked for several months while infectious and likely transmitted Mycobacterium tuberculosis in a dental setting in Washington state.

METHODS

Clark County Public Health (CCPH) conducted an epidemiologic investigation of 20 potentially exposed close contacts and 734 direct-care dental patients in 2010.

RESULTS

Of 20 close contacts, one family member and two coworkers, all of whom were from countries in which TB is endemic, had latent TB infection (LTBI). One U.S.-born coworker experienced a tuberculin skin test (TST) conversion from 0 to 8 millimeters. Of the 305 of 731 (41.7 percent) potentially exposed patients who received a single TST, 23 (7.5 percent) had a positive TST result of at least 5 mm. Among the subset of 157 patients tested by CCPH staff, 16 (10.2 percent) had a positive TST result. The dental office did not have infection prevention and control policies related to TB identification, prevention or education.

CONCLUSIONS

The coworker's TST conversion indicated a recent infection, likely owed to occupational transmission. The proportion of dental patients with positive TST results was greater than the 1999-2000 National Health and Nutrition Examination Survey prevalence estimate in the general population, and it may reflect transmission from the hygienist with active TB or a prevalence of LTBI in the community. Practical Implications All dental practices should implement administrative procedures for TB identification and control as described in this article, even if none of their patients are known to have TB.

Cost Effectiveness of Preventive Treatment for Tuberculosis in Special High-Risk Populations

OBJECTIVE

In view of the goal of eliminating tuberculosis (TB) by 2050, economic evaluations of interventions against the development of TB are increasingly requested. Little research has been published on the incremental cost effectiveness of preventative therapy (PT) in groups at high risk for progression from latent TB infection (LTBI) with Mycobacterium TB (MTB) to active disease. A systematic review of studies with a primary focus on model-driving inputs and methodological differences was conducted.

METHODS

A search of MEDLINE, the Cochrane Library and EMBASE to July 2014 was undertaken, and reference lists of eligible articles and relevant reviews were examined.

RESULTS

A total of 876 citations were retrieved, with a total of 24 studies being eligible for inclusion, addressing six high-risk groups other than contact persons. Results varied considerably between studies and countries, and also over time. Although the selected studies generally demonstrated cost effectiveness for PT in HIV-infected subjects and healthcare workers (HCWs), the outcome of these analyses can be questioned in light of recent epidemiologic data. For immigrants from high TB-burden countries, patients with end-stage renal disease, and the immunosuppressed, now defined as further vulnerable groups, no consistent recommendation can be taken from the literature with respect to cost effectiveness of screening and treating LTBI. When the concept of a fixed willingness-to-pay (WTP) threshold as a prerequisite for final categorization was used, the sums ranged between 'no specification' and US$100,000 per quality-adjusted life-year.

CONCLUSIONS

To date, incremental cost-effectiveness analyses on PT in groups at high risk for TB progression, other than contacts, are surprisingly scarce. The variation found between studies likely reflects variations in the major epidemiologic factors, particularly in the estimates on the accuracy of the tuberculin skin test (TST) and interferon-gamma release assays (IGRA) as screening methods used before considering PT. Further research, including explicit evaluation of local epidemiological conditions, test accuracy, and methodology of WTP thresholds, is needed.

Detection of latent tuberculosis infection among laboratory personnel at a University Hospital in Eastern Saudi Arabia using an interferon gamma release assay

BACKGROUND/AIMS

A few recent reports have demonstrated an elevated prevalence of latent tuberculosis infection (LTBI) among laboratory personnel. We sought to evaluate the prevalence of LTBI among laboratory personnel using the QuantiFERON-TB Gold In-Tube (QFT-GIT) assay and to assess the risk factors associated with positive test results.

METHODS

The study population included laboratory personnel who were working in the routine diagnostic laboratories of different departments of a university hospital. Subjects were interviewed using a standardized questionnaire that assessed information related to risk factors for LTBI and underwent the QFT-GIT assay.

RESULTS

Positive QFT-GIT tests results were detected in 19.4% (26/134) of the laboratory personnel. The following factors were significantly associated with positive QFT-GIT results: age≥30 years [odds ratio (OR): 4.741, 95% CI: 1.41-17.50, P=0.004]; duration of employment in the healthcare profession >10 years (P<0.0001); and non-Saudi nationality (OR: 21.67, 95% CI: 6.69-73.94, P<0.0001).

CONCLUSION

These data highlight the need for effective institutional TB infection control plans. Additionally, our data reinforce the necessities of pre-employment and regular LTBI screening of laboratory personnel and the importance of offering preventive therapies to positive subjects to prevent the progression to active disease.