Occupational transmission of Mycobacterium tuberculosis to health care workers in a university hospital in Lima, Peru

Latent tuberculosis infection (LTBI) in health-care workers: a cross-sectional study at a northern Peruvian hospital

Background

Healthcare workers (HCWs) have a higher risk of latent tuberculosis infection (LTBI) and active tuberculosis than the general population. In HCWs, the risk of tuberculosis infection depends on the local tuberculosis prevalence, HCWs' characteristics, the healthcare facility, and prevention and control measures. We aimed to estimate the prevalence and risk factors for LTBI in HCWs at a northern Peruvian hospital.

Methods

This study had two phases: (1) a cross-sectional phase involving recruitment, history taking, and sampling for the Interferon-Gamma Release Assays (IGRA test), and (2) a prospective follow-up of IGRA-positive participants. We enrolled direct and non-direct patient caregivers among HCWs. We defined an LTBI case if the IGRA test was positive and clinical, laboratory, and radiological evaluations for active tuberculosis were negative.

Results

We recruited 308 participants between November 2022 and May 2023. The mean age was 38.6 ± 8.3 years. Over 75% of the participants were female. The most common job category was technicians (30.5%), physicians (22.7%), nurses (20.5%), and other HCWs groups (17.5%). Most participants worked in hospital wards (28.2%), diagnostics departments (16.9%), and critical care departments (15.6%). The LTBI prevalence among HCWs was 17.86% (95% CI 13.84-22.70). In multivariate analysis, after adjusting for age, time working in our hospital, and family history of tuberculosis, males had a higher risk of LTBI (aPR 1.69, 95% CI 1.01-2.77) than females. Working for more than 10 years increased the risk of LBTI (aPR 2.4, 95% CI 1.44-3.97) compared to working for ≤10 years. Even further, participants who had worked for more than 20 years had an aPR of 4.31 (95% CI 1.09-13.65) compared to those with ≤10 years. Similarly, occupational exposure increased the risk of LTBI (aPR 2.21, 95% CI 1.27-4.08) compared to those HCWs not occupationally exposed.

Conclusion

The LTBI prevalence in HCWs at a northern Peruvian hospital was lower compared to other Peruvian cities. Males, more experienced, and occupational exposed HCWs are at higher risk of LTBI. LTBI prevalence in Peruvian HCWs is still high. More studies are needed to address some aspects this study has not examined.

The characteristics of occupational tuberculosis risk in healthcare workers

BACKGROUND

Tuberculosis (TB) remains to be one of the most common causes of morbidity worldwide, but the discourse of its prevention has disproportionately singled out the occupational risks that affect healthcare workers. In this research, we aimed to: (1) investigate the underlying factor structure of Risk Characteristics (RC), specifically the risk of nosocomial TB transmission in health care facilities; (2) estimate the effects of work-related determinants and RC on risk perception; and (3) compare occupational risk perception of contracting TB with expert risk assessment.

METHOD

A paper-based questionnaire was administered to 179 health care workers (HCWs) working at 10 public health centres and two hospitals in Surabaya, Indonesia. We analysed our data using exploratory factor analysis (EFA) to unravel the latent structure of RC and structural equation modelling (SEM) to identify determinants of risk perceptions.

RESULTS

EFA revealed a two-factor solution for nine qualitative RC: controllability of damage and knowledge-evoked dread. Our SEM analysis found evidence that the controllability aspect of the TB risk was a more profound determinant in predicting risk perception than knowledge-evoked dread, implying that HCWs might benefit from training aims to increase their beliefs on the controllability of TB risk despite its severity.

CONCLUSION

Although further research is necessary, our study highlights the importance of addressing occupational risk perceptions in health facilities, encouraging HCWs to become more active in advocating for the necessary allocation of resources for their workplaces, and raising communities' awareness of TB transmissions.

QuantiFERON-TB Gold plus testing for the detection of LTBI among health care workers in major TB hospitals of the Northern Kyrgyz Republic

Background

Health care workers (HCW) are at increased risk of TB infection due to their close contact with infected patients with active TB. The objectives of the study were (1) to assess the prevalence of LTBI among HCW in the Northern Kyrgyz Republic, and (2) to determine the association of LTBI with job positions or departments.

Methods

HCWs from four TB hospitals in the Northern Kyrgyz Republic were tested with the interferon-gamma release assay (IGRA) Quantiferon-TB Gold plus (QFT) for the detection of an immune response to TB as marker of TB infection. Age was controlled for as a confounder. Univariate and multivariable analysis were performed using logistic regression to assess the association of the risk factors (job position, and department) with having a QTF positive result. Firth’s penalized-likelihood estimates were used to account for the small-sample size. Pairwise comparisons using the Bonferroni correction (conservative) and comparisons without adjusting for multiple comparisons (unadjusted) were used to identify the categories where differences occurred.

Results

QFT yielded valid results for 404 HCW, with 189 (46.7%) having a positive test. In the National Tuberculosis Center there was an increased odds to have a positive QFT test for the position of physician (OR = 8.7, 95%, CI = 1.2–60.5, p = 0.03) and laboratory staff (OR = 19.8, 95% CI = 2.9–135.4, p < 0.01) when administration staff was used as the baseline. When comparing departments for all hospitals combined, laboratories (OR 7.65; 95%CI 2.3–24.9; p < 0.001), smear negative TB (OR 5.90; 95%CI 1.6–21.8; p = 0.008), surgery (OR 3.79; 95%CI 1.3–11.4; p = 0.018), and outpatient clinics (OR 3.80; 95%CI 1.1–13.0; p = 0.03) had higher odds of a positive QFT result than the admin department. Fifteen of the 49 HCW with follow-up tests converted from negative to positive at follow-up testing.

Conclusions

This is the first report on prevalence and risk factors of LTBI for HCW in the Kyrgyz republic, and results indicate there may be an increased risk for LTBI among physicians and laboratory personnel. Further research should investigate gaps of infection control measures particularly for physicians and laboratory staff and lead to further improvement of policies.

The Prevalence and Demographic Risk Factors for Latent Tuberculosis Infection (LTBI) Among Healthcare Workers in Semarang, Indonesia

Purpose

To determine the prevalence and demographic risk factors for latent tuberculosis infection (LTBI) among healthcare workers in Semarang, Indonesia.

Methods

A cross-sectional study involving 195 healthcare workers from 34 primary health centers was conducted from August to October 2019. The relationship between independent variables and dependent variables was analyzed using a multivariable logistic regression analysis.

Results

The prevalence of LTBI among healthcare workers in this study was 23.6%. Comorbidities were the only risk factor for LTBI identified among other risk factors (OR=3.39, 95% CI: 0.99–11.62, p=0.04). Other demographic factors such as age (OR=0.93, 95% CI: 0.45–1.92, p=0.839), gender (OR=0.79, 95% CI: 0.23–2.72, p=0.708, smoking habits (OR=2.54, 95% CI: 0.52–12.38, p=0.247), and length of work (OR=1.43, 95% CI: 0.70–2.91, p=0.331) were not significant risk factors for LTBI.

Conclusion

Healthcare workers suffering from comorbidity have a high risk for tuberculosis infection, and should not work in areas where they would be exposed to patients with tuberculosis. Healthcare workers need to apply occupational safety standards during contact with TB patients or specimens to minimize the disease transmission.

Incidence of Newly Diagnosed Tuberculosis among Healthcare Workers in a Teaching Hospital, Thailand

BACKGROUND

Data on the incidence of new onset tuberculosis (TB) infection among healthcare workers (HCWs) in Thailand was scarce and not current.

OBJECTIVES

To determine the incidence of TB, as well as the impact of TB on HCWs in a teaching hospital in Bangkok, Thailand.

METHODS

A time series cross-sectional study was conducted at Ramathibodi Hospital, Bangkok, Thailand. It was a teaching hospital with 9,562 employees. Medical records of personnel with TB infection between October 1st, 2010 and September 30th, 2015 were reviewed to determine the newly diagnosed TB infection. The personnel who were treated in fiscal year 2015 were interviewed about work-related issues, health status and the impact of TB.

FINDINGS

In five years, 109 personnel were diagnosed with new onset TB disease. The infection rates were 2.04, 1.97, 2.85, 2.53, and 1.35 per 1,000 persons in 2011, 2012, 2013, 2014, and 2015, respectively. The most prevalent type of TB infection was pulmonary TB. The infection rate in males was higher than in females. Pharmacists had the highest proportion of infected personnel. The second highest rate of infection was in support staff related to patient care. Twenty personnel were interviewed. Most of them worked in patient care units with central-type air-conditioning system without negative-pressure rooms for TB patients. Contracting TB had an impact on productivity at work, health (physically, mentally and socially) and incomes.

CONCLUSIONS

Ramathibodi HCWs had higher rate of TB infection than the general Thai population, but the incidence was noted to be decreasing from 2013 to 2015. HCWs suffered from the impact of TB on their lives in multiple ways. Due to the adverse impact of TB on the health and welfare of its employees, hospital administration should apply effective preventive measures and develop a compensation system for HCWs infected with TB.

Prevalence and risk factors of tuberculosis in developing countries through health care workers

In the last two decades, tuberculosis (TB) have threatened the public across the globe and continuing new TB cases and their transmission pooled with the global emergence of drug-resistant strains present an enduring occupational risk for health care workers (HCWs). Since last decade, government and funding agencies has given a significant amount of funds to tackle the problem of TB infection among medical staff or HCW in hospitals of developing countries, but the effects of these efforts have not yet been reported. Working environments are the major risk factors for TB infections among the HCW in hospital settings. Twenty-two high burden countries endorsed to the preponderance of worldwide tuberculosis cases in 2015. Urgent preventive strategies and mediations are needed to ensure the safety and sustained availability of these exquisite healthcare resources. This timeline review will provide the theoretical basis of high TB burden among the HCW which can be used for further improvement in strategies for the prevention of TB infections in hospital settings and provide a reliable basis for improving the personal health of HCW or medical staff.

Hospital-based tuberculosis control activities in five cities of Latin America

Objective. To generate actionable insights for improving TB control in urban areas by describing the tuberculosis (TB) control activities of hospitals in five cities in Latin America.

Methods. A descriptive study of hospital-based TB control activities was conducted in 2013–2015 using a cross-sectional survey designed by the Pan American Health Organization and administered in Guatemala City, Guatemala; Guarulhos, Brazil; Bogotá, Colombia; Lima, Peru; and Asunción, Paraguay. Data were analyzed using Chi-squared, Fisher exact tests, and the Mantel–Haenszel test for Risk Ratios, as necessary (P < 0.05).

Results. While variation among cities existed, most hospitals (91.3%) conducted acid-fast bacilli smears for TB diagnosis and had a quality control process (94.0%), followed national TB guidelines (95%), and reported TB cases to the respective health authorities (96%). Additionally, TB treatment was offered free of charge almost universally (97.1%). However, only 74.2% of hospitals were supervised by the national or local TB programs; 52.8% followed up on the outcome of referrals; and 39.1% offered full ambulatory TB treatment, with 68.7% using Directly-Observed Therapy.

Conclusion. The study underscored strengths and weaknesses in specific areas for TB control activities in hospitals and highlighted the importance and complexity of coordinating efforts among private and public hospitals and the various stakeholders. Local TB programs and health authorities should use these results to enhance the quality of TB-related actions in hospitals in similar settings.

Prevalence and associated risk factors of latent tuberculosis infection among undergraduate and postgraduate dental students: A retrospective study

To estimate the prevalence of latent tuberculosis (TB) infection (LTBI) in Italian dental students exposed to the same occupational risks as dental health care personnel and to evaluate potential risk factors, a cross-sectional study was conducted on undergraduate and postgraduate students. After clinical evaluation, students were given a tuberculin skin test; in those found positive, an interferon-γ release assay (IGRA) was conducted. Of the 281 students enrolled, 10 were only TST positive; 8 were TST or/and IGRA positive. We found that participants testing positive at TST and/or IGRA, a group in which the risk of false LTBI positives is minimal, were older and had been studying longer. Although the prevalence of LTBI among dental students in our study was low, a risk of acquiring a work-related infection exists even in a country with a low incidence of TB. Thus, dental students should be screened to catch LTBI early on.

Predictors of low prevalence of latent tuberculosis infection among Egyptian health care workers at intensive care and bronchoscopy units

Aim: Latent tuberculosis infections (LTBI) contain a significant reservoir for future epidemics. Screening of health care workers (HCWs) in a high-risk tuberculosis (TB) environment is an important strategy in TB control. The study aimed to assess the prevalence of LTBI among high risk Egyptian HCWs and to assess infection associated risk factors. Methods: Fifty-two HCWs who work at intensive care unit (ICU), bronchoscopy unit, and chest diseases department were tested for LTBI using both tuberculin skin test (TST) and Quantiferon TB Gold in-tube test (QFT). Risk factors for infection, knowledge of HCWs towards different aspects of TB infection and agreement between TST and QFT were also evaluated. Results: Prevalence of LTBI in this study was 13.5% by QFT and TST. It was 13.6% by TST alone and 10.3% by QFT alone. There was good concordance between both tests (Kappa=0.713). There was a statistically significant association between prevalence of LTBI and age of staff ≥30 yr (p=0.002), period of working experience (p=0.006) and working at the Bronchoscopy Unit (p=0.001). The total knowledge of HCWs towards different aspects of TB infection was generally good. Conclusion: Although the participants in the current study were among high risk HCWs, the prevalence of LTBI was low. Bacille Calmette-Guerin (BCG) vaccination, young age, short employment duration, good knowledge and a good infection control were the predictors of low risk of contracting TB at our hospitals. The risk of TB infection in resource-limited countries can be reduced with simple continuous educational and administrative infection control programmes.

Strengthening TB infection control in specialized health facilities in Romania--using a participatory approach

INTRODUCTION

In 2012, the tuberculosis (TB) notification rate among Romanian TB facility doctors and nurses was 7.2 times higher than in the general population. This indicates that transmission is ongoing inside TB facilities and that TB infection control measures are insufficient. To help prevent nosocomial TB transmission a project was implemented that aimed at providing nationwide tailor-made technical assistance in TB infection control (TB-IC) in TB treatment facilities, including the development of TB infection control plans. The objective of the present article is to describe the implementation of the project and to discuss successes and challenges.

STUDY DESIGN

The project was an implementation study using two methods of evaluation: (1) a cross sectional questionnaire study; and (2) collection of information, during the training, on challenges related to infection control and to the project implementation.

METHODS

The project team developed a TB facility infection control (TB-IC) plan template, together with the Romanian experts. The template was discussed and agreed upon with the experts at a meeting and thereafter distributed by email to all TB facilities. Afterwards, a training of trainers (TOT) seminar was organized which included the provision of information about different training methods, as well as information about TB-IC. The TOT was followed by training for key TB-IC providers. Information about use of the TB-IC template was gathered through a self-administered questionnaire sent to all participants of the expert meeting and the training (42 people). Additionally, non-systematized discussions were held on broader challenges in TB-IC implementation during the training.

RESULTS

Within the project 42 key TB-IC service providers were trained in TB-IC, including 9 who were trained at a TOT seminar. The trainees were specialists working at the national level, such as country TB coordinators, or at the TB facility level: TB doctors, epidemiologists, laboratory specialists and maintenance engineers. Out of 42 key TB-IC service providers who were trained, only eighteen responded to the questionnaire (no reminders were sent). Out of these, 14 had used the TB-IC plan template after the project team disseminated it to them by email. The remaining four TB-IC service providers indicated that they were planning to use the template to develop or update their facility TB-IC plans. Related to the use of TB-IC plan template, the following broader challenges in TB-IC were identified: a lack of authority of the individuals responsible for TB-IC to implement the TB-IC measures, lack of training among facility epidemiologists on TB, underdeveloped system for reporting TB in healthcare workers, difficulties with triage of the TB suspects, and poor facility infrastructure hampering implementation of TB-IC measures.

DISCUSSION

Implementing TB-IC plans in Romanian health care facilities proved to be challenging, mainly due to the fact that the national infection control plan for TB was not yet adopted at the time of project implementation, and therefore there was neither a regulatory framework to support TB facility-IC planning nor any related budget allocations for the implementation of the facilities' TB-IC plans. Nonetheless, most respondents who answered the questionnaire (18 of 42 responded) indicated that they had started using the TB-IC plan template, which represents a full package of infection control measures that, when implemented effectively and in its entirety, may be expected to reduce nosocomial transmission. The study's limitations are: very low survey response rate, thus there is a likelihood of responder bias.

Tuberculosis in Healthcare Workers: A Matched Cohort Study in Taiwan

Background

Proportional mortality ratio data indicate that healthcare workers (HCWs) have an elevated tuberculosis (TB) mortality. Whether this is caused by an increased TB incidence, a worse TB treatment outcome, or a combination of effects, remains unclear. To elucidate the hazard components of occupational TB, we assessed TB incidence and TB treatment outcome among HCWs in Taiwan.

Methods

We compared the incidence of active TB among HCWs at a major medical center in Taiwan with that of Taiwan general population in 2004–2012. We also compared the TB treatment outcome of HCWs with that of age/sex-matched non-HCW patients treated at the same hospital, as well as that of nationally registered TB patients.

Results

The standardized TB incidence ratio of the HCWs was 1.9 (95% confidence interval [CI]: 1.2–2.9), compared with the general population. HCWs with pulmonary TB (n = 30) were less likely to have underlying diseases, delay in diagnosis, delay in treatment, or side effects of treatment, compared with age/sex-matched non-HCW TB patients (n = 120) (all Ps<0.05). The TB treatment outcome of HCWs was significantly better than that of non-HCW patients (TB-related mortality: 0.0% vs. 5.8%, P = 0.008, Mantel-Haenszel test). The standardized TB-related mortality rate was 1.08% [95% CI: 0.96% - 1.20%] for all of the nationally registered TB patients in Taiwan.

Conclusions

HCWs are at increased risk of active TB, compared with general population. To mitigate this occupational hazard, more efforts need to be directed towards the prevention of nosocomial TB transmission. Healthy worker effect, more rapid diagnosis, and less delay in treatment contribute to a lower TB-related mortality in HCWs.

Latent Tuberculosis Infection and Associated Factors among Health Care Workers in Kigali, Rwanda

INTRODUCTION

Data are limited regarding tuberculosis (TB) and latent TB infection prevalence in Rwandan health facilities.

METHODS

We conducted a cross-sectional survey among healthcare workers (HCWs) in Kigali during 2010. We purposively selected the public referral hospital, both district hospitals, and randomly selected 7 of 17 health centers. School workers (SWs) from the nearest willing public schools served as a local reference group. We tested for latent TB infection (LTBI) using tuberculin skin testing (TST) and asked about past TB disease. We assessed risk of LTBI and past history of TB disease associated with hospital employment. Among HCWs, we assessed risk associated with facility type (district hospital, referral hospital, health center), work setting (inpatient, outpatient), and occupation.

RESULTS

Age, gender, and HIV status was similar between the enrolled 1,131 HCWs and 381 SWs. LTBI was more prevalent among HCWs (62%) than SWs (39%). Adjusted odds of a positive TST result were 2.71 (95% CI 2.01-3.67) times greater among HCWs than SWs. Among HCWs, there was no detectable difference between prevalence of LTBI according to facility type, work setting, or occupation.

CONCLUSION

HCWs are at greater risk of LTBI, regardless of facility type, work setting, or occupation. The current status of TB infection control practices should be evaluated in the entire workforce in all Rwandan healthcare facilities.

Prevalence of latent tuberculosis infection and associated risk factors among 3,374 healthcare students in Italy

Introduction

The risk of tuberculosis (TB) in healthcare personnel (HCP) is related to its incidence in the general population. Healthcare students involved in clinical training could be exposed to occupational risks similar to those that HCP face. The prevalence of latent tuberculosis infection (LTBI) among undergraduate healthcare students with different working seniority in Italy was analysed.

Methods

A cross-sectional study under a screening programme for LTBI among undergraduate and postgraduate students attending Medical School at the Second University of Naples was conducted between January 2012 and December 2013 with clinical evaluations, tuberculin skin testing (TST) and, in positive TST students, Interferon-γ release assays (IGRA). Putative risk factors for LTBI were assessed by means of a standardised questionnaire.

Results

3,374 students attending the Medical School of the Second University of Naples were submitted to a screening programme for TBC. 3,331 performed TST as a first-level test and 43 performed a Quantiferon test (QFT). 128 students were TST-positive and continued the diagnostic work with QFT, which was positive in 34 students. Of the 43 subjects who took the QFT as a first-level test only 1 was positive. In 35 students positive to the QFT test we formulated the diagnosis of LTBI by clinical and radiographic results. A correlation was found between age, non-Italian born persons, studying age, post-medical school status and LTBI.

Conclusions

The prevalence of LTBI among healthcare students in our study was very low. In countries with a low incidence of TB, the screening programmes of healthcare students can be useful for early identification and treatment of sporadic cases of LTBI.

Electronic supplementary material

The online version of this article (doi:10.1186/s12995-014-0034-5) contains supplementary material, which is available to authorized users.

Performance of QuantiFERON-TB Gold In-Tube test and Tuberculin Skin Test for diagnosis of latent tuberculosis infection in BCG vaccinated health care workers

Background

Tuberculin skin test (TST) has been used for years as an aid in diagnosing latent tuberculosis infection (LTBI) but it suffers from a number of well-documented performance and logistic problems. Quantiferon-TB Gold In Tube test (QFT-GIT) has been reported to have better sensitivity and specifity than TST. In this study, it was aimed to compare the performance of a commercial IFN-γ release assay (QFT-GIT) with TST in the diagnosis of HCWs at risk for latent TB infection in BCG vaccinated population.

Material/Methods

Hundred healthy volunteer health care workers were enrolled. All were subjected to TST and QFT-GIT. Results were compared among Health Care Workers (HCWs) groups in terms of profession, workplace, working duration.

Results

TST is affected by previous BCG vaccinations and number of cases with QFT-GIT positivity is increased in accordance with the TST induration diameter range. QFT-GIT result was negative in 17 of 32 TST positive (≥15 mm) cases and positive in 4 of 61 cases whose TST diameters are between 6–14 mm, that is attritutable to previous BCG vaccination(s). It was negative in all cases with TST diameters between 0–5 mm.

HCWs with positive QFT-GIT results were significantly older than the ones with negative results. Furthermore duration of work was significantly longer in QFT-GIT positive than in negative HCWs.

Conclusions

There was a moderate concordance between QFT-GIT and TST, when TST result was defined as positive with a ≥15 mm diameter of induration. We suggest that QFT-GIT can be used as an alternative to TST for detection of LTBI, especially in groups with high risk of LTBI and in population with routine BCG vaccination program.

Spatial and temporal analyses to investigate infectious disease transmission within healthcare settings

Background

Healthcare-associated infections (HCAIs) cause significant morbidity and mortality worldwide, and outbreaks are often only identified after they reach high levels. A wide range of data is collected within healthcare settings; however, the extent to which this information is used to understand HCAI dynamics has not been quantified.

Aim

To examine the use of spatiotemporal analyses to identify and prevent HCAI transmission in healthcare settings, and to provide recommendations for expanding the use of these techniques.

Methods

A systematic review of the literature was undertaken, focusing on spatiotemporal examination of infectious diseases in healthcare settings. Abstracts and full-text articles were reviewed independently by two authors to determine inclusion.

Findings

In total, 146 studies met the inclusion criteria. There was considerable variation in the use of data, with surprisingly few studies (N = 22) using spatiotemporal-specific analyses to extend knowledge of HCAI transmission dynamics. The remaining 124 studies were descriptive. A modest increase in the application of statistical analyses has occurred in recent years.

Conclusion

The incorporation of spatiotemporal analysis has been limited in healthcare settings, with only 15% of studies including any such analysis. Analytical studies provided greater data on transmission dynamics and effective control interventions than studies without spatiotemporal analyses. This indicates the need for greater integration of spatiotemporal techniques into HCAI investigations, as even simple analyses provide significant improvements in the understanding of prevention over simple descriptive summaries.

Implementation of tuberculosis infection control in health facilities in Mukono and Wakiso districts, Uganda

Background

Tuberculosis infection control (TBIC) is rarely implemented in the health facilities in resource limited settings. Understanding the reasons for low level of implementation is critical. The study aim was to assess TBIC practices and barriers to implementation in two districts in Uganda.

Methods

We conducted a cross-sectional study in 51 health facilities in districts of Mukono and Wakiso. The study included: a facility survey, observations of practices and eight focus group discussions with health workers.

Results

Quantitative: Only 16 facilities (31%) had a TBIC plan. Five facilities (10%) were screening patients for cough. Two facilities (4%) reported providing masks to patients with cough. Ventilation in the waiting areas was inadequate for TBIC in 43% (22/51) of the facilities. No facility possessed N95 particulate respirators.

Qualitative: Barriers that hamper implementation of TBIC elicited included: under-staffing, lack of space for patient separation, lack of funds to purchase masks, and health workers not appreciating the importance of TBIC.

Conclusion

TBIC measures were not implemented in health facilities in the two Ugandan districts where the survey was done. Health system factors like lack of staff, space and funds are barriers to implement TBIC. Effective implementation of TBIC measures occurs when the fundamental health system building blocks -governance and stewardship, financing, infrastructure, procurement and supply chain management are in place and functioning appropriately.

Latent tuberculosis infection screening for laboratory personnel using interferon-γ release assay and tuberculin skin test in Korea: an intermediate incidence setting

BACKGROUND

Though recent reports have indicated a higher prevalence of latent tuberculosis infection (LTBI) in laboratory personnel than in other healthcare workers, these studies included only a limited number of laboratory personnel.

METHODS

We have thus focused on the laboratory personnel, who had a high level of exposure to specimens from patients with TB. We recruited 173 laboratory personnel and performed QuantiFERON-TB Gold In-Tube test (QFT-G) and tuberculin skin test (TST).

RESULTS

QFT-G was positive in 21.4% of the enrolled laboratory personnel, and TST was positive in 33.3%. The agreement between the two tests was fair (κ = 0.234). In multivariate analyses, household contactwith TBpatients (P = 0.013), the laboratory sections of microbiology (P = 0.045) and chemistry/immunology (P = 0.014) were shown to be significantly associated with positive QFT-G results.

CONCLUSION

Our data show a high prevalence of TST and QFT-G positivity in laboratory personnel and emphasize the importance of LTBI screening for laboratory personnel. In BCG-vaccinated populations with an intermediate incidence setting, QFT-G seems to be superior to TST as a screening tool for the detection of LTBI. Further study, including results of follow-up tests will be helpful for confirmation of our findings.

Risk factors for tuberculosis among health care workers in South India: a nested case-control study

OBJECTIVE

The epidemiology of tuberculosis (TB) among health care workers (HCWs) in India remains under-researched. This study is a nested case-control design assessing the risk factors for acquiring TB among HCWs in India.

STUDY DESIGN AND SETTINGS

It is a nested case-control study conducted at a tertiary teaching hospital in India. Cases (n = 101) were HCWs with active TB. Controls (n = 101) were HCWs who did not have TB, randomly selected from the 6,003 subjects employed at the facility. Cases and controls were compared with respect to clinical and demographic variables.

RESULTS

The cases and controls were of similar age. Logistic regression analysis showed that body mass index (BMI) <19 kg/m(2) (odds ratio [OR]: 2.96, 95% confidence interval [CI]: 1.49-5.87), having frequent contact with patients (OR: 2.83, 95% CI: 1.47-5.45) and being employed in medical wards (OR: 12.37, 95% CI: 1.38-110.17) or microbiology laboratories (OR: 5.65, 95% CI: 1.74-18.36) were independently associated with increased risk of acquiring TB.

CONCLUSION

HCWs with frequent patient contact and those with BMI <19 kg/m(2) were at high risk of acquiring active TB. Nosocomial transmission of TB was pronounced in locations, such as medical wards and microbiology laboratories. Surveillance of high-risk HCWs and appropriate infrastructure modifications may be important to prevent interpersonal TB transmission in health care facilities.

Manifestations of tuberculosis stigma within the healthcare system: the case of Sekondi-Takoradi Metropolitan district in Ghana

OBJECTIVES

To explore the manifestations of tuberculosis (TB) stigma within the healthcare system.

METHOD

Twenty-one individual interviews (16 females and 5 males) and six focus groups (1 with health managers, 1 with staff providing services for TB patients, and 4 with general staff) were conducted among healthcare workers (HCWs) and the generated data analysed using grounded theory principles and procedures.

RESULTS

TB stigma manifests in three broad and inter-related ways within the healthcare system: behaviour towards TB patients; attitudes towards TB work; and administrative procedures and policies of healthcare mangers. Healthcare workers expressed fear of infection when interacting with TB patients; a fear which intensifies after the confirmation of the diagnosis. For fear of infection, they shuned, avoided, and advocated the segregation of TB patients at home and in the hospitals. They sometimes maltreated the patients, and accused and blamed them for deliberately infecting others. Posting to TB units/wards is viewed as a punishment, with majority indicating refusal to work there or be trained as TB nurse/doctor. They maintained that those working at TB units should be given incentives. Health managers also situated TB units/wards in isolated parts of the hospital, and do not provide adequate tools, equipment, support and supervision for those offering TB services.

CONCLUSIONS

Fear of infection underlies the stigmatisation of TB by HCWs and worsen by administrative procedures and policies of healthcare managers. To help minimise TB stigma, a national guideline for the prevention of TB in HCWs should be developed as this may help protect them and alleviate their fear of infection. Rewarding and motivating HCWs involved in TB control may also improve their attitudes towards TB and those suffering from the disease. Furthermore, interventions to reduce TB stigma should be put in place, and the effects these may have on TB treatment outcomes investigated.

Occupational respiratory infections

PURPOSE OF REVIEW

In the last decade, descriptions of outbreaks of extensively drug-resistant strains of tuberculosis (TB) have increased concern about the nosocomial transmission of TB - a potentially life-threatening occupational respiratory infection. In addition, outbreaks of avian influenza caused by an H5N1 virus, severe acute respiratory syndrome caused by a coronavirus A and the recent pandemic caused by an H1N1 influenza virus have heightened concern about occupational infectious illnesses among workers in healthcare and agriculture.

RECENT FINDINGS

The last decade has witnessed extensive research into the modes, patterns, determinants and extent of transmission of these illnesses. The most important findings regarding risk, determinants and preventive measures of these occupational infections and recent guidelines are reviewed in this article.

SUMMARY

Administrative, personal and engineering measures to control respiratory infection are effective and should be implemented in healthcare facilities. The use of N95 personal respirators by healthcare workers who are caring for pulmonary TB and viral respiratory infections patients is strongly recommended. Vaccination against influenza (including H1N1) is effective and strongly recommended for healthcare workers. Ultraviolet germicidal irradiation is underused at present, despite good evidence of safety and efficacy in elimination of airborne respiratory infectious agents including TB.

Comparison of the interferon- gamma release assay and the tuberculin skin test for contact investigation of tuberculosis in BCG-vaccinated health care workers

Health care workers are at increased risk of Mycobacterium tuberculosis infection. The tuberculin skin test (TST) is frequently false positive in BCG-vaccinated health care workers. QuantiFERON-TB GOLD (QFT-G) is a sensitive and specific interferon-gamma release assay unaffected by BCG vaccination. This study compared TST and QFT-G in the diagnosis of latent TB infection in BCG-vaccinated health care workers. 39 health care workers exposed to a smear-positive TB patient were enrolled. Initial TST was positive in 33 (84.6%) cases, but only 4 (10.2%) cases using QFT-G. TST conversion occurred in 2/6 (33.3%), compared to 4/32(12.5%), cases using QFT-G. A higher proportion of QFT converters was associated with intimate contact, although not reaching statistical significance. Face-to-face contact >1 h was significantly associated with QFT-G conversion >or=0.7 IU/ml (OR 8.63, 95%CI 1.08-69.07, p=0.04). Agreement between TST and QFT-G was 18.0%, (kappa: -0.03). Concordance between TST and QFT (>or=0.35 IU/ml) conversion was 40.0%(kappa=-0.40), and 60.0%(kappa=0.00) if QFT >or=0.7 IU/ml was used. Agreement increased with increasing TST cut-offs. TST is not useful in contact investigation among BCG-vaccinated health care workers, in an area with intermediate burden of TB. QFT may provide additional information for the diagnosis and strategic management of preventive treatment of LTBI in BCG-vaccinated health care workers in a country with intermediate burden of TB.

Tuberculosis among health-care workers in low- and middle-income countries: a systematic review

BACKGROUND

The risk of transmission of Mycobacterium tuberculosis from patients to health-care workers (HCWs) is a neglected problem in many low- and middle-income countries (LMICs). Most health-care facilities in these countries lack resources to prevent nosocomial transmission of tuberculosis (TB).

METHODS AND FINDINGS

We conducted a systematic review to summarize the evidence on the incidence and prevalence of latent TB infection (LTBI) and disease among HCWs in LMICs, and to evaluate the impact of various preventive strategies that have been attempted. To identify relevant studies, we searched electronic databases and journals, and contacted experts in the field. We identified 42 articles, consisting of 51 studies, and extracted data on incidence, prevalence, and risk factors for LTBI and disease among HCWs. The prevalence of LTBI among HCWs was, on average, 54% (range 33% to 79%). Estimates of the annual risk of LTBI ranged from 0.5% to 14.3%, and the annual incidence of TB disease in HCWs ranged from 69 to 5,780 per 100,000. The attributable risk for TB disease in HCWs, compared to the risk in the general population, ranged from 25 to 5,361 per 100,000 per year. A higher risk of acquiring TB disease was associated with certain work locations (inpatient TB facility, laboratory, internal medicine, and emergency facilities) and occupational categories (radiology technicians, patient attendants, nurses, ward attendants, paramedics, and clinical officers).

CONCLUSIONS

In summary, our review demonstrates that TB is a significant occupational problem among HCWs in LMICs. Available evidence reinforces the need to design and implement simple, effective, and affordable TB infection-control programs in health-care facilities in these countries.

Risk of tuberculin conversion among healthcare workers and the adoption of preventive measures

BACKGROUND

In industrialised countries, occupational tuberculosis among healthcare workers (HCWs) is re-emerging as an important public health issue. To prevent and control tuberculosis transmission, several institutions have issued and implemented recommendations and practice guidelines.

OBJECTIVES

To estimate the annual rate of tuberculosis infection (ARTI; per 100 person-years) among HCWs in Turin, the capital of the Piedmont region of Italy, to identify factors associated with variations in the ARTI and to evaluate the efficacy of the regional guidelines to prevent and control tuberculosis.

METHODS

The study was conducted between 1997 and 2004 on a cohort of HCWs. The tuberculosis infection was diagnosed through tuberculin skin testing (TST) conversion and defined as an induration increase of at least 10 mm from a previous negative TST. The ARTI and the hazard ratio for each at-risk subgroup, categorised according to working activities and settings, was estimated using exponential survival models. The efficacy of the regional guidelines was estimated by stratifying the analysis according to the moment of the implementation of the guidelines (before/after).

RESULTS

The 2182 study participants were drawn from the dynamic cohort. The overall adjusted ARTI was 1.6 (95% CI: 1.3 to 1.9)/100 person-years. Different workplaces (eg, administrative and infectious diseases inpatient services) and occupations (eg, clerical and medical workers) were associated with significantly different ARTIs, ranging between 0.62 and 2.62 and between 0.61 and 1.71, respectively, whereas the TST conversion risk differed by about 16-68% and 30-60%, respectively. The implementation of the guidelines coincided with overall ARTI reductions of 1.3/100 person-years, and concurrently the variations between ARTIs of different occupations and workplaces disappeared.

CONCLUSIONS

The occupational risk categories for targeting the surveillance and prevention of tuberculosis transmission among HCWs were identified, and the introduction of preventive measures was observed to be effective in decreasing the overall risk of tuberculosis infection among HCWs.

Gamma delta T cell responses associated with the development of tuberculosis in health care workers

This study evaluated T cell immune responses to purified protein derivative (PPD) and Mycobacterium tuberculosis (Mtb) in health care workers who remained free of active tuberculosis (HCWs w/o TB), health care workers who went on to develop active TB (HCWs w/TB), non-health care workers who were TB free (Non-HCWs) and tuberculosis patients presenting with minimal (Min TB) or advanced (Adv TB) disease. Peripheral blood mononuclear cells (PBMC) were stimulated with Mtb and PPD and the expression of T cell activation markers CD25+ and HLA-DR+, intracellular IL-4 and IFN-gamma production and cytotoxic responses were evaluated. PBMC from HCWs who developed TB showed decreased percentages of cells expressing CD8+CD25+ in comparison to HCWs who remained healthy. HCWs who developed TB showed increased gammadelta TCR+ cell cytotoxicity and decreased CD3+gammadelta TCR- cell cytotoxicity in comparison to HCWs who remained healthy. PBMC from TB patients with advanced disease showed decreased percentages of CD25+CD4+ and CD25+CD8+ T cells that were associated with increased IL-4 production in CD8+ and gammadelta TCR+ phenotypes, in comparison with TB patients presenting minimal disease. TB patients with advanced disease showed increased gammadelta TCR+ cytotoxicity and reduced CD3+gammadelta TCR- cell cytotoxicity. Our results suggest that HCWs who developed TB show an early compensatory mechanism involving an increase in lytic responses of gammadelta TCR+ cells which did not prevent TB.

Risk of tuberculous infection among healthcare workers in a tertiary-care hospital in Ankara, Turkey

OBJECTIVE

To determine risk factors for tuberculin skin test (TST) positivity among healthcare workers (HCWs).

DESIGN

Two-step TST was performed in 2002.

SETTING

Tertiary-care hospital in Ankara, Turkey.

PARTICIPANTS

A sample of 491 hospital HCWs were included. Information related to demographics, profession, work duration, department, and individual and family history of tuberculosis (TB) was obtained by a structured questionnaire.

RESULTS

Four hundred eight (83%) had two-step TST positivity. On multivariate analysis, male physicians (relative risk [RR], 1.5; 95% confidence interval [CI95], 1.23-1.69; P = .001), nurses (RR, 1.5; CI95, 1.29-1.66; P = .005), radiology technicians (RR, 1.7; CI95, 1.35-1.73; P = .002), laboratory technicians (RR, 1.6; CI95, 1.3-1.74; P = .007), and male housekeepers (RR, 1.6; (HCWs). CI95, 1.38-1.7; P < .001) had a higher risk than did female physicians. Among laboratory technicians, radiology technicians had the highest TST positivity (85%). HCWs working for less than 1 year (RR, 0.8; CI95, 0.72-0.98; P = .027) had a lower risk of infection. The HCWs having bacille Calmette-Guerin vaccination (RR, 1.12; CI95, 1.08-1.45) had higher TST positivity.

CONCLUSION

Male physicians, nurses, and laboratory technicians had increased risk of Mycobacterium tuberculosis infection in this setting, but community exposure likely accounted for most infections.

Elevation of procalcitonin level in patients with pulmonary tuberculosis and in medical staff with close patient contact

BACKGROUND

Several studies have shown that serum procalcitonin levels increase conspicuously in acute and systemic inflammatory diseases. However, there is insufficient information concerning its activity in chronic infectious diseases such as tuberculosis. In this study, we aimed to assess serum level of procalcitonin in patients with active pulmonary tuberculosis and in medical staff at high risk due to close patient contact (high-risk staff).

METHODS

For this purpose, 30 patients (6 female, 24 male) and 20 staff (8 female, 12 male) were evaluated. Twenty eight healthy blood donors (9 female, 19 male) made up the control group.

RESULTS

Serum procalcitonin level in patients with tuberculosis was 0.76 +/- 0.20 ng/mL. Procalcitonin levels in active tuberculosis patients and staff were not significantly different (p=0.381); however, differences between active tuberculosis patients and control group were significant (p<0.001). In addition, serum procalcitonin levels were also different in staff and control groups (p<0.001).

CONCLUSIONS

This study showed that procalcitonin levels increased both in patients with pulmonary tuberculosis and in the staff. This result considered that procalcitonin could be a good indicator of inflammation in patients with chronic diseases and in persons exposed to long-lasting infections.

Factors associated with tuberculin conversion in Canadian microbiology and pathology workers

The risk of occupational tuberculosis (TB) infection and associated factors was estimated among all microbiology and pathology technicians and compared with a sample of nonclinical personnel in 17 Canadian acute care hospitals. Participants underwent tuberculin skin testing and completed questionnaires. Prior skin tests and vaccinations and all patients with TB hospitalized in the preceding 3 years were reviewed. Of the work areas where direction of air flow and air changes per hour were measured, only 51% were adequately ventilated. Among participating lab workers the average annual risk of tuberculin conversion was 1.0%. This was associated with lower hourly air exchange rates (16.7 versus 32.5 in workers with no conversion, p < 0.001) work in pathology (adjusted odds ratio [OR]: 5.4; [95% confidence interval: 1.3, 22], higher proportion of patients with missed diagnosis in the first 24 hours (per 20% increase-OR: 2.0; [1.3, 3.2], treatment delayed 1 week or more (per 20% increase-OR: 2.0; [3.2, 3.2]), and higher mortality (per 20% increase-OR: 2.5; [1.1, 5.6]). We conclude that laboratory workers, with no direct patient contact, have increased risk of tuberculin conversion in hospitals where a greater proportion of patients with TB die, or have delayed, or missed diagnosis, although this may be modified by workplace ventilation.