Nosocomial transmission of Mycobacterium tuberculosis from an extrapulmonary site.

OBJECTIVE: To assess the extent of nosocomial transmission and risk factors associated with tuberculin skin test (TST) conversions among healthcare workers (HCWs) exposed to a patient with genitourinary Mycobacterium tuberculosis. DESIGN: Retrospective cohort study of exposed HCWs. SETTING: A 275-bed community hospital in Middle Tennessee. PARTICIPANTS: A total of 128 exposed HCWs and the index patient, who required drainage of a prostatic abscess and bilateral orchiectomy and expired after a 27-day hospitalization. Disseminated tuberculosis was diagnosed at autopsy. METHODS: Contact tracing was performed on exposed HCWs. Logistic regression was used to identify independent risk factors associated with TST conversion. RESULTS: A total of 128 HCWs were exposed to the index patient. There was no evidence of active pulmonary tuberculosis throughout the patient's hospitalization; TST conversions occurred only among HCWs who were exposed to the patient during or after his surgical procedures. A total of 12 (13%) of 95 exposed HCWs who were previously nonreactive had newly positive TST: 6 of 28 nurses, 3 of 3 autopsy personnel, 2 of 17 respiratory therapists, and 1 of 12 surgical staff. By logistic regression, irrigation or packing of the surgical site was the only independent risk factor associated with TST conversion among nurses (odds ratio, 9; 95% confidence interval, 1.2-67; P=.03). CONCLUSION: Manipulation of infected tissues of the genitourinary tract can result in nosocomial transmission of tuberculosis.     

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

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

Measures to control an outbreak of pertussis in a neonatal intermediate care nursery after exposure to a healthcare worker.

BACKGROUND: Hospitalized premature infants are particularly vulnerable to morbidity and mortality from pertussis. Effective prevention and investigative and control measures are not well described. OBJECTIVE: To identify the source of nosocomial pertussis in a 2-month-old premature infant in a neonatal intermediate care nursery (ICN) and to critically review the investigation and outbreak control measures. SETTING: An ICN and a neonatal intensive care unit. METHODS: We queried healthcare workers (HCWs) and family members about cough illness and contacted potentially exposed patients to determine whether they had symptoms of pertussis. Culture and polymerase chain reaction (PCR) testing for Bordetella pertussis were performed by the hospital laboratory with specimens collected from symptomatic patients and HCWs. Levels of pertussis toxin immunoglobulin G antibodies were measured in HCWs with cough of at least 14 days' duration at a public health laboratory. Extensive control measures were instituted. RESULTS: Four ICN HCWs met the clinical case definition for presence of pertussis. Serologic test results were positive for 3 of the HCWs. The primary case patient was a 36-year-old HCW with a cough illness of 3-weeks' duration that was accompanied by paroxysms, whoop, posttussive emesis, and pneumothorax. Among the 4 affected HCWs, the duration of cough illness prior to identification of the infant index patient ranged from 11 to 25 days. Outbreak control measures included isolation of the infant case patient, furlough and treatment of symptomatic HCWs, administration of chemoprophylaxis to contacts, and surveillance for additional cases. Seventy-two infant patients and 72 HCWs were exposed and were given antibiotic prophylaxis. One additional case of pertussis, confirmed by PCR and culture, occurred in a resident physician who declined prophylaxis; she had cared for the index patient but had no contact with symptomatic HCWs. CONCLUSION: HCWs or patients may serve as the source of pertussis in nosocomial outbreaks, which can result in substantial morbidity and outlay of resources for control measures. Our review suggested that a diagnosis of pertussis should be an early consideration for HCWs with cough illness. Targeted pertussis immunization of HCWs, employee health policies that provide for testing and furlough of HCWs with prolonged cough, and monitoring of HCWs for compliance with infection control measures could reduce the morbidity and costs associated with pertussis outbreaks. These measures will require evaluation of their effectiveness.     

Comparing the performance of QuantiFERON-TB Gold and Mantoux test in detecting latent tuberculosis infection among Iranian health care workers

Objectives  

The risk of transmission of Mycobacterium tuberculosis from patients with tuberculosis to health care workers (HCWs) has been well documented but little is known about the prevalence of latent tuberculosis infection (LTBI) in Iranian HCWs. The aim of this study was to determine the prevalence of LTBI among HCWs by using IFNgamma-release assay and compare the results with those of tuberculin skin test (TST).     

In-hospital contact investigation among health care workers after exposure to pulmonary tuberculosis in an intermediate tuberculosis prevalence area: A prospective study

We carried out in-hospital contact investigations of patients with pulmonary tuberculosis and analyzed the prevalence of latent tuberculosis infection (LTBI) among health care workers (HCWs) after TB exposure. A prospective study was conducted of 872 HCWs who were exposed to 55 index cases diagnosed with active pulmonary TB. HCWs after TB exposure were evaluated both TST and chest X-ray at the time of enrollment and 12 weeks after exposure; 625 HCWs (71.6%) underwent both initial assessments; 41 HCWs (6.6%) had a positive TST result. After 12 weeks, 71.1% of HCWs with initial negative TST (n = 415) underwent a second assessment. Ten HCWs had TST conversion. One HCW (0.2%) developed active pulmonary TB. In multivariable analysis, age over 30 years was associated with TST conversion (p = .02). Point prevalence of latent TB was 6.6%, and incidence of LTBI was estimated as 2.4 per 100 HCWs. Strict infection control measures should be emphasized in intermediate TB-burden, BCG-vaccinated countries, especially in HCWs with high risk for TB exposure.     

Tuberculin skin testing among healthcare workers in the University of Malaya Medical Centre, Kuala Lumpur, Malaysia.

OBJECTIVES: To determine the occupational risk of Mycobacterium tuberculosis infection among healthcare workers (HCWs) and to examine the utility of tuberculin skin testing in a developing country with a high prevalence of bacille Calmette-Guerin vaccination. DESIGN: Tuberculin skin test (TST) survey. SETTING: A tertiary-care referral center and a teaching hospital in Kuala Lumpur, Malaysia. PARTICIPANTS: HCWs from medical, surgical, and orthopedic wards. INTERVENTION: Tuberculin purified protein derivative RT-23 (State Serum Institute, Copenhagen, Denmark) was used for the TST (Mantoux method). RESULTS: One hundred thirty-seven (52.1%) and 69 (26.2%) of the HCWs tested had indurations of 10 mm or greater and 15 mm or greater, respectively. Medical ward HCWs were at significantly higher risk of a positive TST reaction than were surgical or orthopedic ward HCWs (odds ratio, 2.18; 95% confidence interval, 1.33 to 3.57; P = .002 for TST positivity at 10 mm or greater) (odds ratio, 2.61; 95% confidence interval, 1.44 to 4.70; P = .002 for TST positivity at 15 mm or greater). A previous TST was a significant risk factor for a positive TST reaction at either 10 mm or greater or 15 mm or greater, but a duration of employment of more than 1 year and being a nurse were only significantly associated with a positive TST reaction at a cut-off point of 15 mm or greater. CONCLUSIONS: HCWs at the University of Malaya Medical Centre had an increased risk for M. tuberculosis infection that was significantly associated with the level of occupational tuberculosis exposure. A TST cut-off point of 15 mm or greater may correlate better with M. tuberculosis infection than a cut-off point of 10 mm or greater in settings with a high prevalence of bacille Calmette-Guerin vaccination.     

Mycobacterium tuberculosis transmission in a newborn nursery and maternity ward--New York City, 2003

Evaluating young children recently exposed to airborne Mycobacterium tuberculosis is a public health priority. If infected, children aged <2 years are at high risk for severe tuberculosis (TB) disease (e.g., TB meningitis). In December 2003, infectious pulmonary TB disease was diagnosed in a foreign-born nurse working in the newborn nursery and maternity ward of a New York City hospital (hospital A); the nurse had declined treatment for latent TB infection (LTBI) after testing positive 11 years earlier. An investigation including medical evaluation of contacts in the nursery and maternity ward was conducted by the Bureau of TB Control (BTBC) at the New York City Department of Health and Mental Hygiene, hospital A, and CDC. This report summarizes the results of that investigation, which determined that approximately 1,500 patients had been exposed to the nurse but the majority could not be located for evaluation. Among those who were tested, four infants had positive tuberculin skin test (TST) results, likely attributable to recent transmission of M. tuberculosis. The findings emphasize the difficulty of conducting contact investigations in certain settings and the importance of effective LTBI testing and treatment programs for health-care workers (HCWs) to prevent TB disease and subsequent health-care--associated transmission.     

Occupational risk of Mycobacterium tuberculosis infection in hospital workers

We conducted a 4-year (1/89–12/92) retrospective cohort study among employees at a large metropolitan hospital where a nosocomial outbreak of multidrug-resistant tuberculosis (TB) had occurred. We compared the risk of tuberculin skin test (TST) conversion among employees who worked on wards where patients with culture-confirmed TB were cared for (“exposed”) with the risk among employees who worked on wards with no such patients (“unexposed”). Exposed employees had a higher 4-year risk of TST conversion (14.5%) than unexposed employees (1.4%) (adjusted relative risk 13.4; 95 percent confidence interval 5.1–35.2). Exposed employees had significantly higher risks of conversion than unexposed employees during 1989–91, but not for 1992. Among the exposed, ward clerks had a risk of conversion (15.6%) only slightly lower than nurses (18.2%). We conclude that employees who worked in areas where patients with active M. tuberculosis infection were cared for, including workers who did not provide direct patient care, had a higher risk of TST conversion than employees who did not work in these areas. Reasons for the decline in risk over time include outbreak termination, fewer admissions of patients with TB, implementation of effective infection control measures, and possible resistance to infection in some members of the study population. Am. J. Ind. Med. 32:528–534, 1997. © 1997 Wiley-Liss, Inc.     

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.     

Improving hand sensibility in vibration induced neuropathy: A case-series

Introduction

Results of systematic screening of healthcare workers (HCWs) for tuberculosis (TB) with the tuberculin skin test (TST) and interferon-γ release assays (IGRA) in a Portuguese hospital from 2007 to 2010 are reported.

Methods

All HCWs are offered screening for TB. Screening is repeated depending on risk assessment. TST and QuantiFERON Gold In-Tube (QFT) are used simultaneously. X-ray is performed when TST is > 10 mm, IGRA is positive or typical symptoms exist.

Results

The cohort comprises 2,889 HCWs. TST and IGRA were positive in 29.5%, TST-positive but IGRA-negative results were apparent in 43.4%. Active TB was diagnosed in twelve HCWs - eight cases were detected during screening and four cases were predicted by IGRA as well as by TST. However, the progression rate in IGRA-positive was higher than in TST-positive HCWs (0.4% vs. 0.2%, p-value 0.06).

Conclusions

The TB burden in this cohort was high (129.8 per 100,000 HCWs). However, the progression to active TB after a positive TST or positive IGRA was considerably lower than that reported in literature for close contacts in low-incidence countries. This may indicate that old LTBI prevails in these HCWs.     

Results of five-year systematic screening for latent tuberculosis infection in healthcare workers in Portugal

Introduction  

The risk of tuberculosis (TB) in healthcare workers (HCWs) is related to its incidence in the general population, and increased by the specific risk as a professional group. The prevalence of latent tuberculosis infection (LTBI) in HCWs in Portugal using the tuberculin skin test (TST) and the interferon-γ release assays (IGRA) was analyzed over a five-year period.     

Tuberculosis transmission in a renal dialysis center--Nevada, 2003

Among persons with chronic renal failure, infection with Mycobacterium tuberculosis is more likely to progress to tuberculosis (TB). Chronic renal failure is an immunocompromising condition associated with cutaneous anergy, which can result in a false-negative tuberculin skin test (TST) result. In 2003, a health-care worker (HCW) (i.e., a hemodialysis technician) in an outpatient renal dialysis center in Nevada became ill with pulmonary TB, exposing more than 400 patients and other employees. The HCW had a previous positive TST result but never received treatment for TB infection. This report summarizes the results of a contact investigation, which suggested that the HCW had transmitted M. tuberculosis to 29 patients and 13 employees. The findings underscore the need for TB screening and treatment of TB infection for all HCWs and patients at high risk.     

Latent tuberculosis in nursing professionals of a Brazilian hospital

Tuberculosis (TB) is considered an occupational disease among health-care workers (HCWs). Direct contact with TB patients leads to an increased risk to become latently infected by Mycobacterium tuberculosis. The objective of this study is to estimate the prevalence of latent M. tuberculosis minfection among nursing professionals of a hospital in Rio Grande do Sul, Brazil, assessed by tuberculin skin test (TST). From November 2009 to May 2010, latent M. tuberculosis infection was assessed by TST in 55 nursing professionals. Epidemiological information was collected using a standardized questionnaire. A positive TST result (> or = 10 mm) was observed in 47.3% of the HCWs tested. There was no significant difference in TST positivity when duration of employment or professional category (technician or nurse) was evaluated. The results of this work reinforce the need for control measures to prevent latent M. tuberculosis infection among nursing professionals at the hospital where the study was conducted.     

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

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

婴儿结核性脑膜炎与家庭接触感染的临床特点及相关分析

目的对家庭成员为传染源与婴儿结核性脑膜炎的相关性及其早期诊断进行临床分析。方法对我院近8年收治的有结核病接触史的婴儿结核性脑膜炎患儿33例的早期临床特点及疗效进行分析。并以同期收治的1～3岁幼儿结核性脑膜炎患者作对照。结果婴儿结核性脑膜炎患儿有家庭成员结核病接触者发病率为48.5%,而对照组仅为7.7%。婴儿结核性脑膜炎患儿有卡介苗接种占75.8%,但疗效欠佳,治愈率仅36.4%;后遗症发生率36.4%,两项与对照组比效有显著性差异(p<0.05)。结论家庭密切接触是婴儿患结核性脑膜炎的高危因素,其父母为主要传染源,值得高度重视。可以把有结核病接触史、发热、意识障碍、抽搐等临床特点作为判断婴儿结脑疑似病例的依据。     

Evaluation of a western blot test as a potential screening tool for occupational exposure to Mycobacterium tuberculosis in health care workers

Health care workers (HCWs) have a higher than average risk for contracting Mycobacterium tuberculosis (MTB) infection and tuberculosis (TB). No markers of MTB-exposure are available, and TB risk assessment is performed by tuberculin screening, identifying individuals with acquired MTB infection. This study evaluated a western blot (WB) anti-M. bovis A60 complex antibody as a MTB-exposure marker. WB reactivity was evaluated on 127 exposed and 28 non-exposed HCWs from four divisions of the Policlinico Hospital of Modena, and 140 non-exposed bacille Calmette-Guérin-vaccinated controls. Excess of occupational TB risk according to the Occupational Safety and Health Administration (OSHA) was calculated in each division. WB-positivity (%) was: (1) significantly higher in exposed HCWs compared with non-exposed (72% vs 25%, P < 0.00001), (2) highly related (r = 0.99) to OSHA risk excess in all divisions, (3) higher than non-exposed in HCWs with short (< 5 years) MTB-exposure (purified protein derivative [PPD], P > 0.18; WB, P < 0.04). PPD-positivity (%) was higher than controls only in HCWs with longer (> 5 years) MTB-exposure. The study suggests that the WB antibody might represent a more sensitive biological marker of MTB contact among exposed HCWs, related to the level of TB risk and detectable earlier than the PPD skin test, thus providing new tools for TB risk assessment in health care facilities.     

综合性医院医务工作者结核分枝杆菌感染现状及职业防护

目的了解综合性医院医务工作者结核分枝杆菌（TB）感染现状及职业防护措施,分析影响因素,为综合性医疗机构结核病职业防护管理策略提供科学依据。方法采用横断面研究方法对河南省郑州市中心医院各临床科室医务工作者进行社会人口学特征、健康状况和职业防护方式的问卷调查和结核菌素皮肤试验（TST）。TB感染的影响因素分析采用单变量logistic回归和多变量逐步logistic回归,将单变量logistic回归分析中P〈0.10的变量纳入多变量logistic回归模型。采用SPSS 17.0软件对数据进行统计分析。结果 325名临床相关科室的医务工作者中,结核分枝杆菌感染率为34.2%,未发现现症肺结核患者。经多因素logistic回归分析发现,临床工作岗位（OR=2.26,95%CI：1.33~3.83）、艾滋病门诊、病房工作史（OR=6.39,95%CI：1.26~32.51）和早餐习惯（OR=3.87,95%CI：1.40~10.73）是医务工作者结核分枝杆菌感染的影响因素。结论综合性医疗机构医务工作者是结核分枝杆菌感染的重点人群,尤其应该重视其中某些高风险科室的医院感染预防控制,建立常态化的医务工作者结核分枝杆菌感染状态的体检监测制度和医疗机构内部结核病院内感染控制的评估机制。     

The association of family continuity with infant health service use

Purpose: Continuity of care is a fundamental component of family medicine that has been shown to improve health care quality. Family continuity, when different family members are seen by the same clinician or practice, has not been well studied. Methods: We performed a retrospective cohort study of Medicaid enrollees in Oregon using administrative data. Infants were determined to have family continuity if they received well-baby care at the same clinic as that in which their mothers received prenatal care. Results: Of the 1591 infants identified for participation in this study, 749 (47.1%) had family continuity. Infants had a mean of 4.55 well-child visits, 1.23 emergency department visits, and 0.17 hospitalizations in the first 13 months of life. Multivariate analyses found that infants with family continuity had increased numbers of well-child visits (relative risk, 1.05; P = .041), increased numbers of emergency department visits (relative risk, 1.36; P < .0001), and no difference in the number of hospitalizations (relative risk, 0.85; P = .282) when compared with infants without family continuity. CONCLUSIONS: Family continuity, when measured at the clinic level, is associated with a variable effect on infant health service use. This finding suggests that clinic-level continuity is not sufficient for achieving all the benefits of continuity.