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.     

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.     

Prevalence of tuberculin skin test positivity and conversions among healthcare workers in New York City during 1994 to 2001.

OBJECTIVE: To determine the prevalence of and risk factors for tuberculin skin test positivity and conversion among New York City Department of Health and Mental Hygiene employees. DESIGN: Point-prevalence survey and prospective cohort analysis. Sentinel surveillance was conducted from March 1, 1994, to December 31, 2001. PARTICIPANTS: HCWs in high-risk and low-risk settings for occupational TB exposure. RESULTS: Baseline tuberculin positivity was 36.2% (600 of 1,658), 15.5% (143 of 922) among HCWs born in the United States, and 48.5% (182 of 375) among HCWs not born in the United States. There were 36 tuberculin conversions during 2,754 observation-years (rate, 1.3 per 100 person-years). For HCWs born in the United States, the risk for tuberculin conversion was greater in high-risk occupational settings compared with low-risk settings (OR, 5.7; CI95, 1.7-19.2; P < .01). HCWs not born in the United States and those employed at the Office of the Chief Medical Examiner (OCME) were at high risk for baseline tuberculin positivity (OR, 3.2; CI95, 1.7-5.8; P < .001); OCME HCWs (OR, 4.7; CI95, 2.3-9.4; P < .001), those of Asian ethnicity (OR, 4.3; CI95, 1.4-13.5; P < .01), and older HCWs (OR, 1.0; CI95, 1.0-1.1; P < .05) were at a higher risk for conversion. CONCLUSIONS: Although the prevalence of tuberculin positivity decreased after the peak of the recent TB epidemic in New York City, the conversion rate among HCWs in high-risk occupational settings for TB exposure was still greater than that among HCWs in low-risk settings. Continued surveillance of occupational TB infection is needed, especially among high-risk HCWs.     

Epidemiological study of a tuberculosis case in a large manufacturing enterprise in Quebec]

OBJECTIVES: To determine the prevalence of tuberculosis infection related to a case of pulmonary and laryngeal tuberculosis in a workplace and to study PPD predictors. METHODS: The Mantoux skin test (PPD) was offered to all potentially infected contacts. Participants were asked to answer a questionnaire. RESULTS: Among 112 exposed employees, 92 (82.1%) were tested. At the 5 mm level, 65.2% of employees had positive tuberculin skin test (PPD). By controlling prior BCG and the degree of exposure, it showed a positive association between age and PPD (RC: 3.5; 95% CI: 1.25-10.03). When age and BCG were controlled, high exposure was statistically associated with PPD results (RC: 5.6; 95% CI: 1.25-24.68). CONCLUSION: The observed prevalence rate is probably related to the fact that the index case was very infectious and had contact in an enclosed area over a long period of time before withdrawal from work.     

Tuberculin reactivity in a population of schoolchildren with high BCG vaccination coverage.

OBJECTIVE: To investigate the influence of BCG vaccination or revaccination on tuberculin skin test reactivity, in order to guide the correct interpretation of this test in a setting of high neonatal BCG vaccination coverage and an increasing BCG revaccination coverage at school age. METHODS: We conducted tuberculin skin testing and BCG scar reading in 1 148 children aged 7-14 years old in the city of Salvador, Bahia, Brazil. We measured the positive effect of the presence of one or two BCG scars on the proportion of tuberculin skin test results above different cut-off levels (induration sizes of > or = 5 mm, > or = 10 mm, and > or = 15 mm) and also using several ranges of induration size (0, 1-4, 5-9, 10-14, and > or = 15 mm). We also measured the effects that age, gender, and the school where the child was enrolled had on these proportions. RESULTS: The proportion of tuberculin results > or = 10 mm was 14.2% (95% confidence interval (CI) = 8.0%-20.3%) for children with no BCG scar, 21.3% (95% CI = 18.5%-24.1%) for children with one BCG scar, and 45.0% (95% CI = 32.0%-58.0%) for children with two BCG scars. There was evidence for an increasing positive effect of the presence of one and two BCG scars on the proportion of results > or = 5 mm and > or = 10 mm. Similarly, there was evidence for an increasing positive effect of the presence of one and two scars on the proportion of tuberculin skin test results in the ranges of 5-9 mm and of 10-14 mm. The BCG scar effect on the proportion of results > or = 5 mm and > or = 10 mm did not vary with age. There was no evidence for BCG effect on the results > or = 15 mm. CONCLUSIONS: In Brazilian schoolchildren, BCG-induced tuberculin reactivity is indistinguishable, for results under 15 mm, from reactivity induced by Mycobacterium tuberculosis infection. BCG revaccination at school age increases the degree of BCG-induced tuberculin reactivity found among schoolchildren. This information should be taken into account in tuberculin skin test surveys intended to estimate M. tuberculosis prevalence or to assess transmission patterns as well as in tuberculin skin testing of individuals used as an auxiliary tool in diagnosing tuberculosis. Taking this information into consideration is especially important when there is increasing BCG revaccination coverage.     

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.     

Tuberculous infection in Saharia, a primitive tribal community of Central India

A cross-sectional tuberculin survey was carried out to estimate the prevalence of tuberculous infection and the annual risk of tuberculosis infection (ARTI) among children of Saharia, a primitive ethnic group in Madhya Pradesh, Central India. A total of 1341 children aged 1-9 years were subjected to tuberculin testing with 1 TU of PPD RT 23 and the reaction sizes were read after 72h. The proportion of BCG scar-positive children was 34.6%. The frequency distribution of children by reaction sizes indicated a clear-cut anti-mode at 11mm and a mode at 18mm at the right-hand side of the distribution. The prevalence of infection among children irrespective of BCG scar was estimated as 20.4% (95% CI 18.2-22.5%) and the ARTI was 3.9% (95% CI 3.5-4.3%). The corresponding figures were 21.1% (95% CI 18.3-23.8%) and 3.9% (95% CI 3.4-4.5%) among BCG scar-negative children and 19.0% (95% CI 15.4-22.5%) and 4.0% (95% CI 3.2-4.8%) among BCG scar-positive children. The findings of the present study show a high prevalence of tuberculous infection and high ARTI in this primitive ethnic group. There is an urgent need to further intensify tuberculosis control measures on a sustained and long-term basis in this area.     

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.     

传染病医院医务人员结核感染状况

目的了解传染病医院医务人员结核(TB)感染现况,探讨其感染TB的危险性及影响因素。方法对某传染病医院的全体医务工作者进行问卷调查和TB菌素纯蛋白衍化物（PPD）试验检测。结果该传染病医院全体职工TB感染发病率为48.18%。不同科室医务工作者的TB感染情况差异无统计学意义（P＞0.05）,不同工作年限、不同年龄、不同职称的医务工作者TB感染情况差异均有统计学意义（均P＜0.05）。文化程度、职称、目前居住情况、在结核感染门诊或病区的工作时间是TB感染的危险因素,其OR(95%CI)分别为1.70（1.03～2.80）、1.95（1.10～3.45）、1.84（1.03～3.28）、2.38（1.40～4.04）;个人防护是TB感染的保护因素［OR及OR95%CI为0.92（0.85～0.99）］。结论传染病医院的医务工作者是TB感染的高危人群,应加强自我防护意识,及早采取防护措施。     

Influenza vaccination of healthcare workers in the United States, 1989-2002.

OBJECTIVES: We sought to estimate influenza vaccination coverage among healthcare workers (HCWs) in the United States during 1989-2002 and to identify factors associated with vaccination in this group. The Advisory Committee on Immunization Practices (ACIP) recommends annual influenza vaccination for HCWs to reduce transmission of influenza to patients at high risk for serious complications of influenza. DESIGN: Analysis of cross-sectional data from 1989-2002 surveys conducted by the National Health Interview Survey (NHIS). The outcome measure was self-reported influenza vaccination in the past 12 months. Bivariate and multivariate analysis of 2002 NHIS data. SETTING: Household interviews conducted during 1989-2002, weighted to reflect the noninstitutionalized, civilian US population. PARTICIPANTS: Adults aged 18 years or older participated in the study. A total of 2,089 were employed in healthcare occupations or settings in 2002, and 17,160 were employed in nonhealthcare occupations or settings. RESULTS: The influenza vaccination rate among US HCWs increased from 10.0% in 1989 to 38.4% in 2002, with no significant change since 1997. In a multivariate model that included data from the 2002 NHIS, factors associated with a higher rate of influenza vaccination among HCWs aged 18-64 years included age of 50 years or older (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.1), hospital employee status (OR, 1.5; 95% CI, 1.2-1.9), 1 or more visits to the office of a healthcare professional in the past 12 months (OR, 1.5; 95% CI, 1.1-2.2), receipt of employer-provided health insurance (OR, 1.5; 95% CI, 1.1-2.1), a history of pneumococcal vaccination (OR, 3.9; 95% CI, 2.5-6.1), and history of hepatitis B vaccination (OR, 1.9; 95% CI, 1.4-2.4). Non-Hispanic black persons were less likely to be vaccinated (OR, 0.6; 95% CI, 0.5-0.9) than non-Hispanic white persons. There were no significant differences in vaccination levels according to HCW occupation category. CONCLUSIONS: Influenza immunization among HCWs reached a plateau during 1997-2002. New strategies are needed to encourage US HCWs to receive influenza vaccination to prevent influenza illness in themselves and transmission of influenza to vulnerable patients.     

The importance of addressing multidrug resistance and not assuming single-drug resistance in case-control studies.

BACKGROUND: Case-control studies analyzing antibiotic exposure as a risk factor for antimicrobial resistance usually assume single-drug resistance in the bacteria under study, even though resistance to multiple antimicrobials may be present. Since antibiotic selection pressures differ depending on the susceptibility profile of the antimicrobial-resistant bacteria, an accurate assessment of whether exposure to an individual antimicrobial is a risk factor for the emergence of resistance should distinguish between single-drug-resistant and multidrug-resistant bacteria. OBJECTIVE: To determine whether the exposures to individual antibiotics that were identified as independent risk factors in case-control studies differed depending on whether single-drug-resistant or multidrug-resistant bacteria were evaluated. DESIGN: Two retrospective case-control studies were performed with data on patients harboring Pseudomonas aeruginosa strains resistant only to ciprofloxacin (CRPA) and patients harboring P. aeruginosa strains resistant to ciprofloxacin and other antibiotics (multidrug-resistant P. aeruginosa [MDR-PA]). These 2 groups were compared with patients not harboring P. aeruginosa. SETTING: Two tertiary care hospitals. RESULTS: A total of 41 patients harboring CRPA and 151 patients harboring MDR-PA were identified and matched to 192 control subjects. By conditional logistic regression, independent risk factors associated with presence of CRPA were nonambulatory status (OR, 5.6 [95% confidence interval {CI}, 1.4-23]; P=.02) and prior ciprofloxacin exposure (OR, 5.0 [95% CI, 1.2-21]; P=.03). Independent risk factors for presence of MDR-PA were a Charlson score greater than 2 (OR, 3.3 [95% CI 1.8-6.0]; P<.001) and exposure to quinolones (OR, 2.8 [95% CI, 1.2-5.0]; P=.001), third- and fourth-generation cephalosporins (OR, 3.5 [95% CI, 1.7-7.1]; P<.001), imipenem (OR, 3.8 [95% CI, 1.2-12.1]; P=.02), and/or aminoglycosides (OR, 2.3 [95% CI, 1.04-5.1]; P=.04). CONCLUSION: There were substantial differences in exposure to individual antimicrobials between patients harboring CRPA and patients harboring MDR-PA. Future case-control studies addressing risk factors for single-drug-resistant bacteria should consider the complete susceptibility profile of the bacteria under investigation.     

Tuberculin reactivity in adults after 50 years of universal bacille Calmette-Guerin vaccination in Taiwan

We aimed to assess whether tuberculin reactivity in adults is affected by bacille Calmette-Guerin (BCG) vaccination after 50 years of universal BCG vaccination with 80-95% coverage. A community-based study on tuberculin reactivity in 619 participants was conducted in February 2000 in Keelung city, Taiwan. Information on BCG vaccination policies and annual risk of infection (ARI) in the underlying population was extracted from consecutive national prevalence surveys relating to the period 1952-1997. Compared with the expected ARI estimate, the standardized morbidity ratio of positive tuberculin response for vaccination in infancy was 2.2 (95% CI 0.3-15.5) for those aged <10 years. The corresponding figures for older age groups ranged from 3.6 (95% CI 2.2-5.9) for those aged 10-12 years to 0.7 (95% CI 0.5-0.9) for those aged 57-67 years. This suggests that the effect of BCG vaccination on positive tuberculin response in adults aged >30 years is probably negligible irrespective of age at vaccination or revaccination and that the tuberculin skin test can be used to diagnose TB in control programmes in countries with moderate or high incidence of TB.     

Risk factors for recovery of imipenem- or ceftazidime-resistant pseudomonas aeruginosa among patients admitted to a teaching hospital in Brazil.

BACKGROUND: The prevalence of resistance to imipenem and ceftazidime among Pseudomonas aeruginosa isolates is increasing worldwide. OBJECTIVE: Risk factors for nosocomial recovery (defined as the finding of culture-positive isolates after hospital admission) of imipenem-resistant P. aeruginosa (IRPA) and ceftazidime-resistant P. aeruginosa (CRPA) were determined. DESIGN: Two separate case-control studies were conducted. Control subjects were matched to case patients (ratio, 2:1) on the basis of admission to the same ward at the same time as the case patient. Variables investigated included demographic characteristics, comorbid conditions, and the classes of antimicrobials used. SETTING: The study was conducted in a 400-bed general teaching hospital in Campinas, Brazil that has 14,500 admissions per year. Case patients and control subjects were selected from persons who were admitted to the hospital during 1992-2002. RESULTS: IRPA and CRPA isolates were obtained from 108 and 55 patients, respectively. Statistically significant risk factors for acquisition of IRPA were previous admission to another hospital (odds ratio [OR], 4.21 [95% confidence interval {CI}, 1.40-12.66]; P=.01), hemodialysis (OR, 7.79 [95% CI, 1.59-38.16]; P=.01), and therapy with imipenem (OR, 18.51 [95% CI, 6.30-54.43]; P<.001), amikacin (OR, 3.22 [95% CI, 1.40-7.41]; P=.005), and/or vancomycin (OR, 2.48 [95% CI, 1.08-5.64]; P=.03). Risk factors for recovery of CRPA were previous admission to another hospital (OR, 18.69 [95% CI, 2.00-174.28]; P=.01) and amikacin use (OR, 3.69 [95% CI, 1.32-10.35]; P=.01). CONCLUSION: Our study suggests a definite role for several classes of antimicrobials as risk factors for recovery of IRPA but not for recovery of CRPA. Limiting the use of only imipenem and ceftazidime may not be a wise strategy to contain the spread of resistant P. aeruginosa strains.     

Tuberculosis in healthcare workers at a general hospital in Mexico.

OBJECTIVE: To determine the incidence rate of tuberculosis (TB) disease among healthcare workers (HCWs) at a general hospital. DESIGN: Retrospective analysis of TB cases among HCWs over the course of 5 years. SETTING: A 140-bed general hospital in Tijuana, Mexico. PARTICIPANTS: All hospital employees who developed TB during the 5-year period. RESULTS: From 1 January 1999 through 31 December 2003, 18 TB cases were diagnosed among the hospital personnel. During that period, the mean (+/- standard deviation) annual work force of the hospital was 819+/-21.7 employees. The TB incidence rate was 439.56 cases per 100,000 employees; this rate was 10.98 times higher than the rate for the general population of the city. The TB incidence rate for physicians was 860.21 cases per 100,000 employees, that for nurses was 365.85 cases per 100,000 employees, and that for physicians in training was 1,846.15 cases per 100,000 employees. Physicians in training had a higher risk of acquiring TB than did either physicians (relative risk, 2.14 [95% confidence interval, 1.34-35.66) or nurses (relative risk, 5.04 [95% confidence interval, 3.16-83.33). Three of the HCWs with TB disease were infected with a drug-resistant strain of Mycobacterium tuberculosis, and one of the infecting strains was multidrug resistant. Asymptomatic TB infection among HCWs was not addressed during this study. CONCLUSIONS: The TB incidence rate among the HCWs at the hospital is extremely high, compared with that in the general population. The implementation of infection control measures is an urgent priority, to reduce this occupational hazard.     

Vaccination technique, PPD reaction and BCG scarring in a cohort of children born in Guinea-Bissau 2000-2002

The rates of positive tuberculin skin test (TST) reactions and BCG scarring after BCG vaccination vary between studies and populations. Tuberculin reactivity and BCG scarring may be related to better child survival in low-income countries. We therefore studied determinants for TST reaction and scarring in Guinea-Bissau. In a cohort of children born in suburban Bissau from March 2000 to July 2002, we assessed a Mantoux test with Purified protein derivative (PPD) (SSI, 2 T.U.) at 2 (2689 children), 6 (N=2148) and 12 months (N=1638) of age, and BCG scar was assessed at 2 (N=2698) and 6 months (N=2225) of age. In a subgroup of the children the vaccination technique was monitored by direct observation of post-vaccination wheal and route of administration. Three different types of BCG vaccine supplied by the local Extended Programme on Immunization were used. At 6 months of age the rate of PPD reactors (>1mm) after BCG vaccination was 25% and the rate of scarring was 89%. One BCG strain was associated with fewer PPD reactors (OR=0.54 (0.31-0.91)) and BCG scars (OR=0.13 (0.05-0.37)) and larger post-vaccination wheals produced more PPD reactions (OR 1.21 (95% CI 1.02-1.43)) and BCG scars (OR 1.66 (1.24-2.21)). In the multivariable analyses of BCG-vaccinated children assessed at 6 months of age, monitoring of vaccination technique and type of BCG vaccine were important. This was not changed by control for other determinants, including sex, season, vaccination place, birthplace, ethnic group, low birth weight, place of residence, education and civil status of mother. We reason that vaccination technique and BCG strain are important for PPD reaction and scarring in response to BCG vaccination. Considering that these responses are associated with better infant survival, the importance of monitoring vaccination technique and of different BCG strains should be evaluated with respect to infant mortality.     

Effect of high-dose vitamin A supplementation on the immune response to Bacille Calmette-Guerin vaccine

BACKGROUND: Vitamin A supplementation (VAS) at birth has been associated with decreased mortality in Asia. Bacille Calmette-Guérin (BCG) vaccine is given at birth in tuberculosis-endemic countries. Previous studies suggest that VAS may influence the immune response to vaccines. OBJECTIVE: Our objective was to examine whether VAS influences the immune response to simultaneously administered BCG vaccine. DESIGN: Within a randomized trial of 50,000 IU vitamin A or placebo given with BCG vaccine at birth in Guinea-Bissau, 2710 infants were examined for BCG scar formation and delayed-type hypersensitivity (DTH) to purified protein derivative of Mycobacterium tuberculosis (PPD) at 2 and 6 mo of age. The ex vivo cytokine response to PPD was measured in 607 infants. RESULTS: At 2 mo of age, 39% (43% of the boys and 34% of the girls) responded to PPD. The prevalence ratio of a measurable PPD reaction for VAS compared with placebo recipients was 0.90 (95% CI: 0.80, 1.02) for all infants, 0.81 (95% CI: 0.69, 0.95) for boys, and 1.04 (95% CI: 0.86, 1.26) for girls. At 6 mo of age, 42% of the infants responded to PPD. No difference was observed between VAS and placebo recipients. The prevalence of BCG scar was not affected by VAS. The ex vivo interferon-gamma response to PPD was increased by VAS (means ratio: 1.40; 95% CI: 1.03, 1.91). CONCLUSIONS: VAS with BCG vaccination does not appear to interfere with the long-term immune response to BCG. However, VAS temporarily altered the DTH reaction to PPD in boys at 2 mo of age, suggesting sex differences in the immunologic response to VAS given with BCG. This trial was registered at www.clinicaltrials.gov as #NCT00168597.     

Enteric carriage of vancomycin-resistant Enterococcus faecium in patients tested for Clostridium difficile.

OBJECTIVE: To identify independent risk factors for enteric carriage of vancomycin-resistant Enterococcus faecium (VREF) in hospitalized patients tested for Clostridium difficile toxin. DESIGN: Retrospective case-cohort study. SETTING: Tertiary-care teaching hospital. PATIENTS: Convenience sample of 215 adult inpatients who had stool tested for C difficile between January 29 and February 25, 1996. RESULTS: 41 (19%) of 215 patients had enteric carriage of VREE Five independent risk factors for enteric VREF were identified: history of prior C difficile (odds ratio [OR], 15.21; 95% confidence interval [CI95], 3.30-70.10; P < .001), parenteral treatment with vancomycin for > or = 5 days (OR, 4.06; CI95, 1.54-10.73; P = .005), treatment with antimicrobials effective against gram-negative organisms (OR, 3.44; CI95, 1.20-9.87; P = .021), admission from another institution (OR, 2.95; CI95, 1.21-7.18; P =.017), and age > 60 years (OR 2.57; CI95, 1.13-5.82; P = .024). These risk factors for enteric VREF were independent of the patient's current C difficile status. CONCLUSIONS: Antimicrobial exposures are the most important modifiable independent risk factors for enteric carriage of VREF in hospitalized patients tested for C difficile.     

Tuberculosis in health care workers in Malawi.

Although sub-Saharan Africa has the highest rates of tuberculosis (TB) and human immunodeficiency virus (HIV) infection in the world, the rates of TB amongst its health care workers (HCWs) are poorly documented. We therefore conducted a country-wide investigation. All district/government and mission hospitals in Malawi that diagnose and care for TB patients were visited in order to obtain information on hospital-based HCWs and their incidence of TB in 1996. Hospital TB case loads, country-wide TB notification numbers and national population estimates for 1996 were obtained, which enabled TB case notification rates to be calculated. In 1996, 108 (3.6%) of 3042 HCWs from 40 hospitals were registered and treated for TB: 22 with smear-positive pulmonary TB (PTB), 40 with smear-negative PTB and 46 with extrapulmonary TB. The overall case fatality rate was 24%. Compared with the adult general population aged > or = 15 years, the relative risk [95% confidence interval (CI)] in HCWs of all types of TB was 11.9 [9.8-14.4], of smear-positive PTB 5.9 [3.9-9.0], of smear-negative PTB 13.0 [9.5-17.7] and of extrapulmonary TB 18.4 [13.8-24.6], P < 0.05. The 1996 hospital TB case load ranged from 29 to 915: there were no cases of TB in HCWs in hospitals whose case load was < or = 100 patients, while the TB case rate among HCWs was similar in hospitals with annual case loads of 101-300 or > 300. The annual risk of TB was high among all categories of HCW, especially clinical officers. This study shows a high rate of TB in HCWs in Malawi, and emphasizes the need for practical and affordable control measures for the protection of HCWs from TB in low-income countries.     

Outcomes for and risk factors associated with vancomycin-resistant Enterococcus faecalis and vancomycin-resistant Enterococcus faecium bacteremia in cancer patients.

OBJECTIVE: Vancomycin-resistant enterococci (VRE) are a major cause of nosocomial infection. We sought to compare vancomycin-resistant (VR) Enterococcus faecalis bacteremia and VR Enterococcus faecium bacteremia in cancer patients with respect to risk factors, clinical presentation, microbiological characteristics, antimicrobial therapy, and outcomes. METHODS: We identified 210 cancer patients with VRE bacteremia who had been treated between January 1996 and December 2004; 16 of these 210 had VR E. faecalis bacteremia and were matched with 32 patients with VR E. faecium bacteremia and 32 control patients. A retrospective review of medical records was conducted. RESULTS: Logistic regression analysis showed that, compared with VR E. faecalis bacteremia, VR E. faecium bacteremia was associated with a worse clinical response to therapy (odds ratio [OR], 0.3 [95% confidence interval (CI), 0.07-0.98]; P=.046) and a higher overall mortality rate (OR, 8.3 [95% CI, 1.9-35.3]; P=.004), but the VRE-related mortality rate did not show a statistically significant difference (OR, 6.8 [95% CI, 0.7-61.8]; P=.09). Compared with control patients, patients with VR E. faecalis bacteremia were more likely to have received an aminoglycoside in the 30 days before the onset of bacteremia (OR, 5.8 [95% CI, 1.2-27.6]; P=.03), whereas patients with VR E. faecium bacteremia were more likely to have received a carbapenem in the 30 days before the onset of bacteremia (OR, 11.7 [95% CI, 3.6-38.6]; P<.001). In a multivariate model that compared patients with VR E. faecium bacteremia and control patients, predictors of mortality included acute renal failure on presentation (OR, 15.1 [95% CI, 2.3-99.2]; P=.004) and VR E. faecium bacteremia (OR, 11 [95% CI, 2.7-45.1]; P<.001). No difference in outcomes was found between patients with VR E. faecalis bacteremia and control patients. CONCLUSIONS: VR E. faecium bacteremia in cancer patients was associated with a poorer outcome than was VR E. faecalis bacteremia. Recent receipt of carbapenem therapy was an independent risk factor for VR E. faecium bacteremia, and recent receipt of aminoglycoside therapy was independent risk factor for E. faecalis bacteremia.     

Factors associated with critical-care healthcare workers' adherence to recommended barrier precautions during the Toronto severe acute respiratory syndrome outbreak.

OBJECTIVE: To assess factors associated with adherence to recommended barrier precautions among healthcare workers (HCWs) providing care to critically ill patients with severe acute respiratory syndrome (SARS). SETTING: Fifteen acute care hospitals in Ontario, Canada. DESIGN: Retrospective cohort study. PATIENTS: All patients with SARS who required intubation during the Toronto SARS outbreak in 2003. PARTICIPANTS: HCWs who provided care to or entered the room of a SARS patient during the period from 24 hours before intubation until 4 hours after intubation. METHODS: Standardized interviews were conducted with eligible HCWs to assess their interactions with the SARS patient, their use of barrier precautions, their practices for removing personal protective equipment, and the infection control training they received. RESULTS: Of 879 eligible HCWs, 795 (90%) participated. In multivariate analysis, the following predictors of consistent adherence to recommended barrier precautions were identified: recognition of the patient as a SARS case (odds ratio [OR], 2.5 [95% confidence interval {CI}, 1.5-4.5); recent infection control training (OR for interactive training, 2.7 [95% CI, 1.7-4.4]; OR for passive training, 1.7 [95% CI, 1.0-3.0]), and working in a SARS unit (OR, 4.0 [95% CI, 1.8-8.9]) or intensive care unit (OR, 4.3 [95% CI, 2.0-9.0]). Two factors were associated with significantly lower rates of consistent adherence: the provision of care for patients with higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (OR for score APACHE II of 20 or greater, 0.4 [95% CI, 0.28-0.68]) and work on shifts that required more frequent room entry (OR for 6 or more entries per shift, 0.5 [95% CI, 0.32-0.86]). CONCLUSIONS: There were significant deficits in knowledge about self-protection that were partially corrected by education programs during the SARS outbreak. HCWs' adherence to self-protection guidelines was most closely associated with whether they provided care to patients who had received a definite diagnosis of SARS.