Prevalence of latent tuberculosis infection among tuberculosis laboratory workers in Iran

Epidemiology of Latent Tuberculosis in Moroccan Healthcare Workers: Prevalence Patterns and Predisposing Factors

BACKGROUND

Among occupational hazards in healthcare settings, latent tuberculosis infection (LTBI) ranks as a major concern, particularly threatening healthcare workers (HCWs) in nations grappling with intermediate to high tuberculosis (TB) rates. Our study was conducted in Morocco, a country characterized by widespread Bacillus Calmette-Guérin (BCG) vaccination and a moderate TB burden of 93 cases per 100,000 inhabitants in 2022. We examined both the prevalence of LTBI among Moroccan HCWs and its various risk factors.

METHODS

A cross-sectional study was conducted from August 2022 to October 2024 in two Moroccan hospitals. One hundred forty-seven HCWs were recruited and screened for LTBI using the QuantiFERON-TB Gold In-Tube (QFT-GIT) test. Data on demographics, occupational characteristics, and potential risk factors were collected through standardized questionnaires. Statistical analysis included univariate and multivariate logistic regression to identify factors associated with LTBI.

RESULTS

The overall prevalence of LTBI was 32.65% (48/147). Multivariate analysis identified several independent risk factors: male gender (OR: 2.84; 95% CI: 1.54-5.22; p<0.001), age above 50 years (OR: 4.58; 95% CI: 1.50-13.90; p=0.007), smoking status (OR: 4.07; 95% CI: 1.63-10.14; p=0.003), and family history of TB (OR: 4.71; 95% CI: 1.33-16.65; p=0.016). Notably, neither specific work areas nor job categories were identified as significant risk factors in the final multivariate model.

CONCLUSIONS

The observed LTBI prevalence among HCWs in Morocco demonstrates concordance with epidemiological data from comparable intermediate-burden nations. The elucidation of predisposing factors, with particular emphasis on non-occupational determinants, underscores the imperative for implementing systematic surveillance protocols and World Health Organization (WHO)-sanctioned infection prevention measures within healthcare facilities. These epidemiological findings provide an empirical foundation for the formulation and optimization of TB control strategies specifically tailored to the occupational health needs of Morocco's healthcare workforce.

Prevalence of modifiable risk factors of tuberculosis and their population attributable fraction in Iran: A cross-sectional study

BACKGROUND

The mycobacterium tuberculosis (Mtb) is necessary for the morbidity of tuberculosis (TB), but it is insufficient. Many risk factors increase the risk of disease among infected people. We aimed to estimate the prevalence of modifiable risk factors of TB and their related population attributable fraction (PAF) in the marginal population of Markazi province in Iran.

DESIGN

In this cross-sectional study, the prevalence of the modifiable risk factors of TB was estimated. We designed and validated a questionnaire to determine the risk factors. The measures of association for the modifiable risk factors of TB were obtained via the review of published literature. We calculated the PAF for each modifiable risk factor.

RESULTS

Out of the 1275 calculated sample size, 1146 people participated in this study, and the participation rate was 89.9%. The mean age was 39.26. Out of 1146 participants, 76% did not know anything regarding TB. The highest prevalence was related to the lack of physical activity (58.73%), lack of fish consumption (50.79%), lack of red meat consumption (21.20%), and secondhand smoke (19.02%). The highest PAF was related to secondhand smoke; this value based on the crude relative risk (RR) and crude odds ratio (OR) was 24.54% and 23.44%, respectively. Based on crude hazard ratio (HR) and crude OR, the PAF for smoking was 14.81% and 11.19%, respectively. PAF for lack of BCG vaccination based on the crude OR was 14.79%.

CONCLUSION

Based on this study's results, poor nutrition, secondhand smoke, smoking, lack of BCG vaccination, and diabetes are the main prevalent modifiable risk factors for TB. The highest PAF for TB was related to secondhand smoke, smoking, lack of BCG vaccination, and diabetes.

Mycobacterium tuberculosis infection and disease in healthcare workers in a tertiary referral hospital in Bandung, Indonesia

Background

Healthcare workers (HCWs), especially in high tuberculosis (TB) incidence countries, are at risk of Mycobacterium tuberculosis infection and TB disease, likely due to greater exposure to TB cases and variable implementation of infection control measures.

Aim

We aimed to estimate the prevalence of tuberculin skin test (TST) positivity, history of TB and to identify associated risk factors in HCWs employed at a tertiary referral hospital in Bandung, Indonesia.

Methods

A cross-sectional study was conducted from April to August 2018. A stratified sample of the HCWs were recruited, screened by TST, assessed for TB symptoms, history of TB disease and possible risk factors. Prevalence of positive TST included diagnosis with TB after starting work. HCWs with TB disease diagnosed earlier were excluded. Survey weights were used for all analyses. Possible risk factors were examined using logistic regression; adjusted odds ratios and 95% confidence intervals (CI) are presented.

Results

Of 455 HCWs recruited, 42 reported a history of TB disease (25 after starting work) and 395 had a TST result. The prevalence of positive TST was 76.9% (95% CI 72.6-80.8%). The odds increased by 7% per year at work (95% CI 3-11%) on average, with a rapid rise in TST positivity up to 10 years of work and then a plateau with around 80% positive.

Discussion

A high proportion of HCWs had a history of TB or were TST positive, increasing with longer duration of work. A package of TB infection control measures is needed to protect HCWs from Mycobacterium tuberculosis infection.

Prevalence and incidence of tuberculosis in health workers: A systematic review of the literature

OBJECTIVE

To identify the prevalence and incidence of tuberculosis in health workers.

METHOD

Systematic literature review, according to the protocol of the Joanna Briggs Institute and report following PRISMA guidelines. Primary studies containing data on the incidence or prevalence of active or latent tuberculosis infection in health workers were considered.

RESULTS

2,310 potentially relevant studies were identified in ten databases, of which 24 were included. The prevalence of latent tuberculosis varied between 0.1% and 62.0%, and the annual incidence rate varied from 1.4% to 11.4%. A meta-analysis combining data from the studies identified the prevalence as 28% (95% CI 21-36). Occupational risk factors are related to direct contact with patients having active tuberculosis, and more years of professional experience.

CONCLUSIONS

Evidences show that tuberculosis is an important occupational problem in health care; however, there are still gaps in information about the epidemiology of tuberculosis in health workers, mainly related to the risk factors.

Prevalence of latent tuberculosis infection among health workers in Afghanistan: A cross-sectional study

BACKGROUND

About 26% of the world's population may have latent tuberculosis infection (LTBI). Health care workers are a high-risk category because of their professional exposure.

METHODS

This cross-sectional study assessed the LTBI burden among health care workers in Afghanistan, a high-TB-burden country. We selected health facilities using a systematic sampling technique and invited all workers at the targeted health facilities to participate. Participants were interviewed about sociodemographic and exposure variables and received tuberculin skin tests for LTBI.

RESULTS

Of the 4,648 health care workers invited to participate, 3,686 had tuberculin skin tests. The prevalence of LTBI was found to be 47.2% (1,738 workers). Multivariate analysis showed that a body mass index of ≥ 30 and marriage were associated with an increased risk of LTBI. Underweight (body mass index of ≤ 18 and below) and normal body mass index had no association with increased risk of LTBI.

CONCLUSION

LTBI is high among health care workers in Afghanistan. We recommend instituting infection control measures in health facilities and screening workers for timely TB diagnosis.

Meta-analysis of latent tuberculosis in healthcare workers in Iran: a retrospective review

BACKGROUND

Here we review the status of latent tuberculosis (LTB) in Iranian healthcare workers (HCWs).

METHODS

A literature search was conducted using keywords according to the Preferred Reporting Items for Systematic Review and Meta-Analyses instructions. Cross-sectional studies published from 1 January 2000 through 1 January 2019 were retrieved. Meta-analysis was performed using Comprehensive Meta-Analysis software using the random effects model, Cochran's Q and I2 tests. Publication bias was estimated by funnel plot and Egger's linear regression test.

RESULTS

Among 774 articles retrieved in the primary literature search, 21 studies met the eligibility criteria. No publication bias was observed among the included studies (p=0.07). The prevalence of LTB ranged from 7% to 63% in Iranian HCWs from different geographical areas. The overall combined prevalence of LTB among Iranian HCWs was 30.9% (95% confidence interval 24.2 to 38.5). Also, 52.4% of the included studies showed a significant correlation between occupation and LTB incidence (p<0.05).

CONCLUSIONS

The prevalence of LTB was high among Iranian HCWs. This requires developing comprehensive information databases and surveillance systems for detecting LTB among HCWs. It is also essential to periodically screen for LTB in HCWs to provide a timely diagnosis of the infection. It is recommended to perform a tuberculin skin test, a useful tool for screening and treatment of LTB, on an annual basis in HCWs.

Prevalence of Latent Tuberculosis Infection in the Middle East and North Africa: A Systematic Review

OBJECTIVE

Data on the prevalence of latent tuberculosis infection (LTBI) in Middle Eastern and North African countries are scarce. We aimed to review all relevant published data in countries belonging to this region to determine the overall prevalence of LTBI in the Middle East and North Africa (MENA) region.

METHODS

In this systematic review PubMed and Google Scholar databases were searched for observational, prospective, retrospective, cross-sectional, and cohort studies providing prevalence data of LTBI in any MENA country. Studies fulfilling the search criteria were incorporated in the review. Overall prevalence of LTBI with 95% confidence intervals (CI) was calculated using the random-effects model; heterogeneity was assessed using I 2 statistics. Gender and age group-based subgroup analyses were performed to evaluate the basis of heterogeneity.

RESULTS

The total number of overall LTBI studies identified was 956, of which 31 studies from ten countries within the MENA region were included that represented 12,439 subjects. The overall prevalence was 41.78% (95% CI 31.18% to 52.78%, I 2 = 99.31%). By gender-based subgroup analysis, the prevalence of LTBI was 33.12% (95% CI 18.97% to 49.04%, I 2 = 99.25%) and 32.65% (95% CI 19.79% to 47%, I 2 = 98.89%) in males and females, respectively, while in the age-based subgroup analysis, the prevalence of LTBI was 0.44% (95% CI -0.05% to 0.9%), 3.37% (95% CI 2.23% to 4.74%, I 2 = 0%), and 43.81% (95% CI 33.09% to 54.82%, I 2 = 99.18%) for children, adolescents, and adults, respectively.

CONCLUSION

This systematic review reveals a high prevalence of LTBI in the MENA region; enhanced LTBI surveillance and prompt infection prevention steps are urgently needed to prevent active tuberculosis, this would help achieve the World Health Organization End TB Strategy 2035, and the United Nations Sustainable Development Goals 2030 target in the MENA region.

Occupational Tuberculosis Among Laboratory Workers in South Africa: Applying a Surveillance System to Strengthen Prevention and Control

Background: Tuberculosis (TB) is recognized as an important health risk for health workers, however, the absence of occupational health surveillance has created knowledge gaps regarding occupational infection rates and contributing factors. This study aimed to determine the rates and contributing factors of active TB cases in laboratory healthcare employees at the National Health Laboratory Service (NHLS) in South Africa, as identified from an occupational surveillance system. Methods: TB cases were reported on the Occupational Health and Safety Information System (OHASIS), which recorded data on occupation type and activities and factors leading to confirmed TB. Data collected from 2012 to 2019 were used to calculate and compare TB risks within NHLS occupational groups. Results: During the study period, there were 92 cases of TB identified in the OHASIS database. General workers, rather than skilled and unskilled laboratory workers and medical staff, had the highest incidence rate (422 per 100,000 person-years). OHASIS data revealed subgroups that seemed to be well protected, while pointing to exposure situations that beckoned policy development, as well as identified subgroups of workers for whom better training is warranted. Conclusions: Functional occupational health surveillance systems can identify subgroups most at risk as well as areas of programme success and areas where increased support is needed, helping to target and monitor policy and procedure modification and training needs.

Is latent tuberculosis infection challenging in Iranian health care workers? A systematic review and meta-analysis

Background

The high chances of getting latent tuberculosis infection (LTBI) among health care workers (HCWs) will an enormous problem in low and upper-middle-income countries.

Method

Search strategies were done through both national and international databases include SID, Barakat knowledge network system, Irandoc, Magiran, Iranian national library, web of science, Scopus, PubMed/MEDLINE, OVID, EMBASE, the Cochrane library, and Google Scholar search engine. The Persian and the English languages were used as the filter in national and international databases, respectively. Medical Subject Headings (MeSH) terms was used to controlling comprehensive vocabulary. The search terms were conducted without time limitation till January 01, 2019.

Results

The prevalence of LTBI in Iranian’s HCWs, based on the PPD test was 27.13% [CI95%: 18.64–37.7]. The highest prevalence of LTBI in Iranian’s HCWs were estimated 41.4% [CI95%: 25.4–59.5] in the north, and 33.8% [CI95%: 21.1–49.3] in the west. The lowest prevalence of LTBI was evaluated 18.2% [CI95%: 3.4–58.2] in the south of Iran. The prevalence of LTBI in Iranian’s HCWs who had work-experience more than 20 years old were estimated 20.49% [CI95%: 11–34.97]. In the PPD test, the prevalence of LTBI in Iranian’s HCWs who had received the Bacille Calmette–Guérin (BCG) was estimated 15% [CI95%: 3.6–47.73]. While, in the QFT, the prevalence of LTBI in Iranian’s HCWs in non-vaccinated was estimated 25.71% [CI95%: 13.96–42.49].

Conclusions

This meta-analysis shows the highest prevalence of LTBI in Iranian’s HCWs in the north and the west probably due to neighboring countries like Azerbaijan and Iraq, respectively. It seems that Iranian’s HCWs have not received the necessary training to prevent of TB. We also found that BCG was not able to protect Iranian’s HCWs from TB infections, completely.

Latent tuberculosis infection in healthcare workers in low- and middle-income countries: an updated systematic review

Healthcare workers (HCWs) are at increased risk of latent tuberculosis (TB) infection (LTBI) and TB disease.We conducted an updated systematic review of the prevalence and incidence of LTBI in HCWs in low- and middle-income countries (LMICs), associated factors, and infection control practices. We searched MEDLINE, Embase and Web of Science (January 1, 2005-June 20, 2017) for studies published in any language. We obtained pooled estimates using random effects methods and investigated heterogeneity using meta-regression.85 studies (32 630 subjects) were included from 26 LMICs. Prevalence of a positive tuberculin skin test (TST) was 14-98% (mean 49%); prevalence of a positive interferon-γ release assay (IGRA) was 9-86% (mean 39%). Countries with TB incidence ≥300 per 100 000 had the highest prevalence (TST: pooled estimate 55%, 95% CI 41-69%; IGRA: pooled estimate 56%, 95% CI 39-73%). Annual incidence estimated from the TST was 1-38% (mean 17%); annual incidence estimated from the IGRA was 10-30% (mean 18%). The prevalence and incidence of a positive test was associated with years of work, work location, TB contact and job category. Only 15 studies reported on infection control measures in healthcare facilities, with limited implementation.HCWs in LMICs in high TB incidence settings remain at increased risk of acquiring LTBI. There is an urgent need for robust implementation of infection control measures.