Incidence of tuberculosis infection among healthcare workers: risk factors and 20-year evolution

Interventions for increasing the uptake of immunisations in healthcare workers: A systematic review

OBJECTIVE

This systemic review aimed to evaluate the effectiveness of interventions for increasing the uptake of immunisation in healthcare workers (HCWs) compared to no or alternative interventions.

METHODS

A systematic review was undertaken (until March 2022) using a search strategy established a priori to capture studies that examined the effect of interventions on vaccination levels in HCWs. We included randomised controlled trials (RCT), cluster RCTs, controlled before-after (CBA) studies and interrupted time-series (ITS) studies. We described studies descriptively and synthesized results with a fixed-effect or random-effects model meta-analysis, where appropriate. The risk of bias was assessed for each study; the quality evidence per comparison was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

We identified three RCTs, six cluster RCTs and four ITS studies. There was a diverse range of interventions; many included an educational component. Based on the evidence examined the following may be effective strategies in increasing the proportion of HCWs vaccinated: policy interventions, targeted and multicomponent strategies, tailored programs directed at management, physician delivered education with a vaccine 'champion' and individual decision analysis. Limited eligible studies restricted synthesis and interpretation of findings. No studies evaluated the effectiveness of legislation. Nor did we find studies evaluating the effectiveness of incentives on their own or studies focusing solely on improving access to vaccination. We judged all the studies as either unclear or high risk of bias.

CONCLUSION

Few robust studies that evaluate interventions to increase vaccination in HCWs are available. A limitation of this systematic review is that interventions are diverse, poorly reported and few were sufficiently alike to combine in an evaluation. More research on the effects of interventions to increase vaccination in HCWs is required, this should address a variety of vaccines and not just influenza vaccination.

Occupational Health and Safety Statistics as an Indicator of Worker Physical Health in South African Industry

Operations in general industry, including manufacturing, expose employees to a myriad of occupational health hazards. To prevent exposure, occupational health and safety regulations were enacted, with both employers and workers instituting various risk reduction measures. The analysis of available occupational disease and injury statistics (indicators of worker physical health) can be used to infer the effectiveness of risk reduction measures and regulations in preventing exposure. Thus, using the READ approach, analyses of occupational disease and injury statistics from South African industry, derived from annual reports of the Compensation Fund, were conducted. The publicly available database of occupational disease and injury statistics from the South African general industry is unstructured, and the data are inconsistently reported. This data scarcity, symptomatic of an absence of a functional occupational disease surveillance system, complicates judgement making regarding the effectiveness of implemented risk reduction measures, enacted occupational health and safety regulations and the status of worker physical health from exposure to workplace hazards. The statistics, where available, indicate that workers continue to be exposed to occupational health impacts within general industry, notwithstanding risk reduction measures and enacted regulations. In particular, worker physical health continues to be impacted by occupational injuries and noise-induced hearing loss. This is suggestive of shortcomings and inefficiencies in industry-implemented preventive measures and the regulatory state. A robust national occupational disease surveillance system is a regulatory tool that should detect and direct policy responses to identified occupational health hazards.

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.

Validity and Reliability of Self-Assessment Tool for Risk Prioritization Following Exposure to Tuberculosis in a Hospital Setting

The Modified Self-Assessment (MSA) and Present Self-Assessment (PSA) forms are questionnaires used to prioritize the risk of infection of health workers exposed to tuberculosis (TB) in Srinagarind Hospital in Thailand. As MSA was developed from PSA, the validity and reliability of MSA need to be assessed. The research aim is to examine the content validity of MSA and to assess the respective reliability of MSA and PSA vis-à-vis expert opinion. Seven experts determined the content validity index (CVI) of MSA. MSA and PSA were used to prioritize the TB contact of 108 subjects, and we compared the result with the risk assessed by the experts. The respective Kappa agreements between MSA and PSA and the experts were used to assess reliability. The result of the content validity index revealed that MSA had I-CVI > 0.83 for all questions and an S-CVI/Ave above 0.90 for all factors. The Kappa agreement of contact priority between MSA and the experts was 0.80; it was 0.58 between PSA and the experts. MSA can, thus, be used to prioritize contact with tuberculosis in Srinagarind Hospital. MSA is a valid risk communication tool for aerosol-generating procedures. Further study should be conducted in other hospitals, and the number of participants should be increased in order to come to a concrete result.

Tuberculosis among prisoners & health care workers

TB in prisons and among HCW is a major public health concern in countries having high burden of disease. Prompt detection of TB is must in prisons by screening on entry, passive screening, mass screening and contact screening via clinical evaluation, smear microscopy and chest X-rays. The new rapid diagnostic methods - True-NAAT, CBNAAT and Line Probe Assay are important tools in the diagnosis. Implementation of effective preventive measures at every steps in various settings, along with airborne infection control and protective measures for staff must be ensured.

Serial testing of health care workers for tuberculosis infection: A prospective cohort study

Health Care Workers (HCW) may have an occupational risk of latent tuberculosis infection (LTBI) and TB disease. The objective of this study was to evaluate the performance of the 2-step strategy: tuberculin skin test (TST) followed by confirmation with Interferon (IFN)-γ- release assays (IGRAs) in HCW. A secondary objective was to determine the factors related to conversions and reversions. HCW at risk of occupational exposure who attended the Occupational Department of the Hospital Germans Trias i Pujol were included during the study period (2013-2016). All professionals testing negative for LTBI were included in a cohort study. These workers were followed up with the administration of a TST and an IGRA quantification at least one year after inclusion in the study. Workers with positive TST, regardless of the results of the IGRA tests, were followed-up with an IGRA. 255 workers were enrolled in the study and 108 workers from the same cohort were followed up. During the follow-up period, seven workers presented TST test conversion. One of these conversions was also confirmed by an IGRA test. There were 2 conversions of cases only testing positive with the IGRA. There have been only 2 reversions of cases testing negative with the IGRA. In this study, not all TST conversions were confirmed when using the IGRA test, which highlights the importance of the 2-step strategy. We have detected a low number of conversions and reversions. Our conclusions should be confirmed in studies with a longer follow-up time.

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.

Risk factors of delayed isolation of patients with pulmonary tuberculosis

OBJECTIVES

The aim was to examine the rate of delayed or no isolation of hospitalized patients with pulmonary tuberculosis (TB) and the causes for isolation failure.

METHODS

This retrospective study included patients with pulmonary TB at a university-affiliated hospital in South Korea between January 2015 and June 2018 after excluding those with a stay ≤2 days and those who only visited the emergency department. Patients who were not isolated for ≥3 days were classified as the delayed or no isolation group. We compared the clinical findings and diagnostic test results, between patients managed with delayed or no isolation (D-isolation) and timely isolation (T-isolation).

RESULTS

Of 486 patients with pulmonary TB, 222 patients were included. In 106 cases (47.7%), isolation was delayed or not applied, while in 116 cases, isolation was applied in a timely manner. Typical findings of TB were seen on the chest X-rays of 87 (75.0%) patients in the T-isolation group versus 25 (23.6%) patients in the D-isolation group (p < 0.001). Other factors significantly associated with delayed or no isolation on univariate analyses were older age, admission route (emergency room vs. other), admitting department, negative acid-fast bacilli (AFB) stain, and negative MTB PCR. On multivariate analysis, admission through an outpatient clinic, admission to a department other than infectious diseases or pulmonology, an atypical chest X-ray finding and negative sputum AFB stains were risk factors for isolation failure.

DISCUSSION

Delayed or no isolation of patients with pulmonary TB was attributed mainly to atypical radiological findings and negative findings of direct TB diagnostic tests.

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.

Late boosting phenomenon in TST conversion among health care workers

BACKGROUND

Available information is insufficient to guide determination of whether tuberculin skin test (TST) conversions of health care workers (HCWs) within 2 years of two-step testing are related to occupational exposures or to other causes, including late boosting.

AIMS

To describe the epidemiologic factors of TST conversion in HCWs, comparing early TST conversion (≤2 years after two-step testing) with late conversion to possibly distinguish late boosting phenomenon from occupational TST conversion.

METHODS

Retrospective analysis of a database of TSTs of HCWs from 1 January 1998, through 31 May 2014, in the United States Midwest.

RESULTS

In total, 40142 HCWs had 197932 tests over the 16 years, with 123 conversions (conversion rate: 0.3%; 95% CI 0.3-0.4%). Among 61 HCWs with a negative two-step TST, 30 (49%) were found to have early TST conversion within 2 years; 31 (51%) had late conversion, with likely occupational exposure but no identifiable community risks. Persons with early conversion were more likely to be born outside the USA (89% versus 57%; P < 0.05), had a higher rate of prior bacille Calmette-Guérin (BCG) vaccination (89% versus 52%; P < 0.05) and had no identifiable risk factors for conversion (63% versus 58%; P < 0.05).

CONCLUSIONS

Early conversions among HCWs after negative two-step TST are associated with various nonoccupational factors, including international birth and BCG vaccination history. Therefore, conversion is not a reliable indicator of recent tuberculosis contact in this population, and two-step TST is insufficient to discount a delayed boosting response for HCWs.

Prevalence and risk factors for latent tuberculosis infection among healthcare workers in Nampula Central Hospital, Mozambique

BACKGROUND

Healthcare workers in high tuberculosis burdened countries are occupationally exposed to the tuberculosis disease with uncomplicated and complicated tuberculosis on the increase among them. Most of them acquire Mycobacterium tuberculosis but do not progress to the active disease - latent tuberculosis infection. The objective of this study was to assess the prevalence and risk factors associated with latent tuberculosis infection among healthcare workers in Nampula Central Hospital, Mozambique.

METHODS

This cross-sectional study of healthcare workers was conducted between 2014 and 2015. Participants (n = 209) were administered a questionnaire on demographics and occupational tuberculosis exposure and had a tuberculin skin test administered. Multivariate linear and logistic regression tested for associations between independent variables and dependent outcomes (tuberculin skin test induration and latent tuberculosis infection status).

RESULTS

The prevalence of latent tuberculosis infection was 34.4%. Latent tuberculosis infection was highest in those working for more than eight years (39.3%), those who had no BCG vaccination (39.6%) and were immunocompromised (78.1%). Being immunocompromised was significantly associated with latent tuberculosis infection (OR 5.97 [95% CI 1.89; 18.87]). Positive but non-significant associations occurred with working in the medical domain (OR 1.02 [95% CI 0.17; 6.37]), length of employment > eight years (OR 1.97 [95% CI 0.70; 5.53]) and occupational contact with tuberculosis patients (OR 1.24 [95% CI 0.47; 3.27]).

CONCLUSIONS

Personal and occupational factors were positively associated with latent tuberculosis infection among healthcare workers in Mozambique.

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.

Screening for Tuberculosis in Health Care Workers: Experience in an Italian Teaching Hospital

Health care workers (HCW) are particularly at risk of acquiring tuberculosis (TB), even in countries with low TB incidence. Therefore, TB screening in HCW is a useful prevention strategy in countries with both low and high TB incidence. Tuberculin skin test (TST) is widely used although it suffers of low specificity; on the contrary, the in vitro enzyme immunoassay tests (IGRA) show superior specificity and sensitivity but are more expensive. The present study reports the results of a three-year TB surveillance among HCW in a large teaching hospital in Rome, using TST (by standard Mantoux technique) and IGRA (by QuantiFERON-TB) as first- and second-level screening tests, respectively. Out of 2290 HCW enrolled, 141 (6.1%) had a positive TST; among them, 99 (70.2%) underwent the IGRA and 16 tested positive (16.1%). The frequency of HCW tested positive for TB seems not far from other experiences in low incidence countries. Our results confirm the higher specificity of IGRA, but, due to its higher cost, TST can be considered a good first level screening test, whose positive results should be further confirmed by IGRA before the patients undergo X-ray diagnosis and/or chemotherapy.

Preventing the Transmission of Tuberculosis in Health Care Settings: Administrative Control

It is well established that health care workers (HCWs) have a considerably higher risk of occupationally acquired tuberculosis (TB). To reduce the transmission of TB to HCWs and patients, TB infection control programs should be implemented in health care settings. The first and most important level of all protection and control programs is administrative control. Its goals are to prevent HCWs, other staff, and patients from being exposed to TB, and to reduce the transmission of infection by ensuring rapid diagnosis and treatment of affected individuals. Administrative control measures recommended by the United States Centers for Disease Control and Prevention and the World Health Organization include prompt identification of people with TB symptoms, isolation of infectious patients, control of the spread of the pathogen, and minimization of time spent in health care facilities. Another key component of measures undertaken is the baseline and serial screening for latent TB infection in HCWs who are at risk of exposure to TB. Although the interferon-gamma release assay has some advantages over the tuberculin skin test, the former has serious limitations, mostly due to its high conversion rate.

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.

Indicators to assess the quality of programs to prevent occupational risk for tuberculosis: are they feasible?

OBJECTIVE

to analyze the feasibility of quality indicators for evaluation of hospital programs for preventing occupational tuberculosis.

METHOD

a descriptive cross-sectional study. We tested indicators for evaluating occupational tuberculosis prevention programs in six hospitals. The criterion to define feasibility was the time spent to calculate the indicators.

RESULTS

time spent to evaluate the indicators ranged from 2h 52min to 15h11min 24sec. The indicator for structure evaluation required less time; the longest time was spent on process indicators, including the observation of healthcare workers' practices in relation to the use of N95 masks. There was an hindrance to test one of the indicators for tuberculosis outcomes in five situations, due to the lack of use of tuberculin skin test in these facilities. The time requires to calculate indicators in regarding to the outcomes for occupational tuberculosis largely depends upon the level of organizational administrative structure for gathering data.

[Guidelines for the prevention and control of tuberculosis in health care workers]

Tuberculosis remains one of the communicable diseases that cause increased morbidity and mortality worldwide. With an incidence rate of 13,04 per 100,000 population, Spain ranks third among the most affected European countries. These data show a tendency to decrease meaning that it may go unnoticed with the potential to miss the appropriate preventive measures in a suspected case. In centers where patients are treated with tuberculosis, health care worker presents risk of transmission. This risk is higher in some areas or work units. The Occupational health physicians' services, which monitorize the health of health care workers, use different strategies in order to prevent and detect tuberculosis infection. The national guidelines include the tuberculin skin test as a screening test for tuberculosis infection with mention of new diagnostic tests based on the in vitro detection of gamma interferon (IGRA) for certain cases. The purpose of this guide is to establish common criteria for IGRA tests, as a supplementary aid to the tuberculin skin test in health care workers, from the evidence available today. Recommendations for its use have been adapted to the different situations faced by the professionals involved in monitoring the health of health workers.