Annual Skin Testing Research Articles

A phthisiatrician’s report models during pediatric population screening for tuberculosis

For the early detection of tuberculosis infection, children in Russia undergo screening that is based on annual skin tests with tuberculosis allergens (Mantoux test or Diaskintest). To visit children’s educational establishments, one must have an application for admission, which shows the absence of tuberculosis. Alternative methods are used to diagnose tuberculosis infection when people refuse to undergo skin tests. The paper presents various patient models reflected in the clinical practice guidelines to make a phthisiatrician's report and to issue an application for admission, which contains possible recommendations.

Brief Report: Yield of Repeat Tuberculin Skin Testing for People Living With HIV in Brazil.

In Brazil, annual tuberculin skin tests (TSTs) are recommended for people living with HIV (PLWH) with CD4 >350, with tuberculosis preventive therapy provided on test conversion. We aimed to determine the yield of repeat TSTs for PLWH. Secondary analysis of the stepped-wedge, cluster-randomized THRio trial for isoniazid preventive therapy (IPT) to prevent tuberculosis (TB). We analyzed data from newly registered PLWH with negative baseline TST results. We calculated the number of TST conversions after 1 and/or 2 years among patients eligible for follow-up TSTs, the proportion of converters initiating IPT, and incidence of TB/death. Among 1770 PLWH with a negative baseline TST, 679 (38%) were female and median age was 36 years (IQR 29-43). Eighty-six (5%) developed TB or died within 1 year. Among 1684 eligible for a follow-up 1-year TST, 582 (35%) were tested and 53 (9%) were positive. Forty-nine converters (92%) started IPT. Of 529 patients with a negative 1-year TST, 7 (1%) developed TB or died over the following year. Of 522 patients eligible for a 2-year TST, 158 (30%) were tested and 13 (8%) were positive. Ten converters (77%) started IPT. Of 1102 patients who did not receive a 1-year TST, 33 (3%) developed TB or died. Of the 1069 patients eligible for a 2-year TST, 259 (24%) were tested and 34 (13%) were positive. Thirty converters (88%) started IPT. In this cohort of PLWH in Brazil, TST conversion was high among those retested, but only 48% received a follow-up TST within 2 years.

Latent tuberculosis infection in children and adolescents in Russia

BackgroundAfter the breakup of the Soviet Union, the annual incidence of tuberculosis (TB) in children 15–17 years of age increased in the Russian Federation from 16 per 100 000 population in 1992 to 37 per 100 000 in 2009, and new control measures were implemented. MethodsChildren were screened annually for TB exposure with a tuberculin skin test (TST) at age 1–8 years. If positive, they were investigated for active TB. If no active TB was found, they were treated with isoniazid for 4–6 months; they then underwent 6-monthly skin tests (which included two recombinant proteins) until negative and annual skin tests thereafter. From the age of 8 years, the yearly follow-up was performed using the skin test that included two recombinant proteins, either until they became negative, developed active TB, or turned 18 years. ResultsThe annual incidence of TB in Russian children decreased from 19.1 per 100 000 population in 2001 to 8.3 per 100 000 population in 2018. ConclusionsAnnual screening for TB exposure with treatment for latent or active TB has reduced the annual incidence of TB in Russian children aged 15–17 years to 1992 levels.

A case report of mono-sensitization to peanut component Ara h6

Peanut is the most common food allergen in the US, affecting 1-2 % of the population and studies show that it is still on the rise. Component testing has offered better insight into the likelihood of reactivity with exposure. Extensive literature shows Arachis hypogea (Ara h) 2 as being the most clinically significant component identified to correlate with reactivity with exposure to the peanut protein, however there is minimal research on the reactivity of Ara h6. This case report describes a patient with a clinical reaction to peanut as a toddler and subsequent positivity on annual skin testing with commercial peanut extract, likely confounded by positive birch with advancing age. Immuno CAP testing revealed a negative Ara h2 and positive Ara h6, describing mono-sensitization to Ara h 6 and high probability of clinical reactivity. The importance of this case is to raise awareness of other highly allergenic components in patients with peanut allergy.

Eliminating Annual Employee TST Testing: One Hospital's Story

Annual TST skin testing of all employees in the acute care setting is a labor intensive task that requires many steps; including mailing out reminder memos, administering the TST, initial documentation, reevaluation, and then final documentation. For staff members who require a second reminder letter, or forget to return for the reading, more time is required. After analyzing 5 consecutive years of data and review of NJ State TB Risk Assessment guidelines, our team concluded that we are designated a low risk facility for TB. Our hospital had no newly diagnosed TB patients, zero employee exposures, zero employee conversions and a total of 5 TB patients for the entire county.

Traffic-Related Pollutants and Wheezing in Children

Background and aims. Traffic related air pollutants from diesel engine exhaust are found in fine and ultrafine particulates. The Cincinnati Childrens Allergy and Air Pollution Birth Cohort Study was initiated to determine if early exposure to these pollutants increased risk for development of early atopic sensitization and allergic respiratory disease phenotypes in children. Materials and methods. Over 700 infants born to at least one atopic parent were recruited to participate in a birth cohort study. Participants received annual medical evaluations and skin testing to two foods and 15 aeroallergens from ages 1-4 and again at age seven. Indoor home assessments were conducted at age one. Outdoor traffic related air pollutant exposure was estimated using proximity and land use regression (LUR) modeling. Clinical outcomes were based upon case definitions for wheezing at ages one and three and allergic rhinitis at age three. Results. At age 1 exposure to stop and go traffic was associated with wheezing during infancy and recurrent wheezing was twice more likely among African-American infants. Exposure to high levels of elemental carbon attributable to traffic (ECAT) estimated with a LUR model predicted recurrent wheezing at age 1 as well as multiple wheezing phenotypes at age 3. Exposure to high levels of endotoxin combined with multiple dogs during the first year reduced risk for recurrent wheezing during the first year of life. Early sensitization to tree pollen aeroallergens in foods (egg white, milk) in infancy increased likelihood of allergic rhinitis during age 3. Conclusion. High exposure to traffic related air pollutants represent independent risk factors for wheezing during infancy and early childhood. Further studies are needed to explore long-term effects of traffic exposure on development of asthma in childhood. Scientific significance. Reduction and mitigation of exposure to traffic related air pollutants could reduce risk of respiratory illnesses during childhood.

Comparison of 5 IU and 10 IU tuberculin test results in patients on chronic dialysis

Immunocompromised patients such as those with end-stage kidney failure under-going hemodialysis (HD) are at increased risk of developing tuberculosis (TB). For this reason, routine TB screening of HD patients with tuberculin test has been recommended. The Center for Disease Control and Prevention (CDC) has recommended that patients with chronic renal failure should undergo annual skin testing for TB with tuberculin [purified protein derivative (PPD)], with an induration of ≥10 mm at 48 h depicting a positive reaction. The aim of this study was to compare the results of two different doses of PPD in dialysis patients. This descriptive and comparative multicenter study was performed on 255 patients on chronic dialysis in Tabriz, Iran. These patients did not have the PPD test done within the preceding one year. Patients were divided into two groups randomly and conventional or double-dose tuberculin test was performed using the Mantoux technique with 5 IU (group 1) and 10 IU (group 2) of PPD. Results were interpreted 48-72 h after injection. Patients were divided into those with less than 10 mm and those with ≥10 mm duration. Mean age was 44.6 ± 15 years (M/F = 1.5/1). The mean duration on dialysis was 39 ± 7 months. There was no significant difference regarding the age, gender, dura-tion on dialysis, causes of chronic kidney disease, erythrocyte sedimentation rate, C-reactive protein and serum albumin between the two groups. The mean induration was 4.6 mm and 7.7 mm in groups 1 and 2, respectively. There was induration ≥10 mm in 19.6% and 25.5% of group 1 and 2, respectively, which showed a significant difference (P <0.05). In conclusion, because of the high frequency of TB in dialysis patients, an annual tuberculin test may be recommended. Our study showed that the double-dose tuberculin test may be a better substitute to the conventional test in dialysis patients.

Infection Control Practices among Interventional Radiologists: Results of an Online Survey

To assess current infection control practices of interventional radiologists (IRs) in the context of recommendations by the Centers for Disease Control and Prevention and the Occupational Safety and Health Administration. From November 2006 to January 2007, members of the Society of Interventional Radiology (SIR) were invited to participate in an anonymous, online infection control questionnaire. A total of 3,019 SIR members in the United States were contacted via e-mail, and 1,061 (35%) completed the 57-item survey. Of the respondents, 283 (25%) experienced a needlestick injury within the previous year, most often as a result of operator error (76%). Less than 65% reported compliance with annual tuberculosis skin testing; notably, those who received a yearly reminder were much more likely to receive annual testing than those who did not (odds ratio, 19.0; 95% CI, 12.6-28.7; P < .05). During central venous catheter placement, only 56% wore gowns, 50% wore caps, and 54% used full barrier precautions. Only 19% reported routine hand washing between glove applications. More than 40% noted a change in infection control practices within the previous 5 years, citing new hospital guidelines and recommendations by a professional organization as the reasons for change. Only 44% had infection control training at the onset of their practice. IRs demonstrate a wide variety of infection control practices that are not in accordance with current guidelines. IRs were most likely to change infection control practice if required to do so by their own hospitals or a professional organization. SIR can play an important role in the prevention of health care-associated infection by reinforcing current infection control guidelines as they pertain to interventional radiology.

LOSS OF LEISHMANIN SKIN TEST ANTIGEN SENSITIVITY AND POTENCY IN A LONGITUDINAL STUDY OF VISCERAL LEISHMANIASIS IN BANGLADESH

Annual leishmanin skin test (LST) surveys were conducted in a visceral leishmaniasis-endemic Bangladeshi community from 2002 through 2004, using Leishmania infantum antigen from the same manufacturer and batch. In 2002, 530 (35%) of 1,532 had positive LST results; the prevalence increased with increasing age. The LST result was positive in 24 (51%) of 47, 18 (72%) of 25, and 11 (85%) of 13 kala-azar patients treated in the previous 1-11, 12-23, and 24-35 months. A positive LST result in 2002 was associated with protection against subsequent kala-azar (P < 0.0001). In 2003-2004, decreased antigen sensitivity was observed. Among 686 participants, 34% were LST-positive in 2002, 29% in 2003, and 19% in 2004. Of 63 cured kala-azar patients, 70% were positive in 2002, 53% in 2003, and only 30% in 2004. Among 171 participants tested with both antigens, L. infantum study antigen sensitivity was 70% compared with L. amazonensis antigen. Our data underscore the need for better production, standardization, and documentation of sensitivity, potency, and stability of leishmanin antigens.

Incidence of Tuberculin Skin Test Conversion Among HIV-Infected and -Uninfected Women

To define the incidence of tuberculin skin test (TST) conversion and to evaluate the yield of annual testing in an era of declining tuberculosis incidence rate in the United States. Annual TSTs were performed on initially TST-negative women (HIV infected, 995; uninfected, 260) from October 1995 through March 2002. A total of 4,622 repeat TSTs were performed during 5,530 person-years. The incidence of TST conversion was 0.8 case per 100 person-years for HIV-infected and 1.0 case per 100 person-years for uninfected women. Non-Hispanic blacks, women younger than 40 years of age, and HIV-infected women who had recently initiated active therapy were more likely to experience TST conversion. The incidence of conversion decreased over the course of the study from a peak of 21 cases per 937 tests in 1996 to 1 case per 179 tests in 2002 (P = 0.046 for trend). Twenty-one of 47 conversions occurred on the second TST, implying that boosting accounted for a number of conversions. The yield of annual skin testing diminished from 1996 to 2002. Our data suggest that repeating testing after initiation of HIV therapy, regardless of CD4 cell change, is warranted. If serial testing is undertaken, initial 2-step testing should be performed to allow for accurate interpretation of subsequent tests and earlier identification of persons with latent Mycobacterium tuberculosis infection.

Lipid Abnormalities During Saquinavir Soft-Gel???Based Highly Active Antiretroviral Therapy

Objective: To define the incidence of tuberculin skin test (TST) conversion and to evaluate the yield of annual testing in an era of declining tuberculosis incidence rate in the United States. Methods: Annual TSTs were performed on initially TST-negative women (HIV infected, 995; uninfected, 260) from October 1995 through March 2002. Results: A total of 4622 repeat TSTs were performed during 5530 person-years. The incidence of TST conversion was 0.8 case per 100 person-years for HIV-infected and 1.0 case per 100 person-years for uninfected women. Non-Hispanic blacks, women younger than 40 years of age, and HIV-infected women who had recently initiated active therapy were more likely to experience TST conversion. The incidence of conversion decreased over the course of the study from a peak of 21 cases per 937 tests in 1996 to 1 case per 179 tests in 2002 (P = 0.046 for trend). Twenty-one of 47 conversions occurred on the second TST, implying that boosting accounted for a number of conversions. Conclusions: The yield of annual skin testing diminished from 1996 to 2002. Our data suggest that repeating testing after initiation of HIV therapy, regardless of CD4 cell change, is warranted. If serial testing is undertaken, initial 2-step testing should be performed to allow for accurate interpretation of subsequent tests and earlier identification of persons with latent Mycobacterium tuberculosis infection.

Tuberculin Skin Test Results and the Booster Phenomenon in Two-Step Tuberculin Skin Testing in Hemodialysis Patients

Patients with chronic renal failure are at increased risk for tuberculosis (TB). Centers for Disease Control and Prevention (CDC) have recommended annual skin testing for TB, with tuberculin-purified protein derivative (PPD), in patients with chronic renal failure. Uremia alters the macrophage function, which can lead to anergy for skin tests. The aim of this prospective study was to determine the prevalence of positive tuberculin skin test (TST) and the booster effect of TST in hemodialysis patients living in a relatively underdeveloped portion of the country. Material and Methods. Patients were recruited from Van (Yuzuncu Yil University Hospital, Yuksek Ihtisas Hospital) and the Mus State Hospital). At the time of this study, a total of 143 patients were under hemodialysis treatment in these hemodialysis centers, and among them, 124 were included in the study. Informed consent was obtained before inclusion in the study. A positive PPD was an induration of >10 mm in response to five tuberculin units of PPD (RT23-Tween 80), at 72 h. TST-negative patients received a booster TST 10 days later, approximately 10 cm away from the previous intracutaneous injection. The test dose could not be increased due to unavailability of this kind of preparation. The test was performed and interpreted in the same way. Skin testing was performed in June and December 2003. Patients with known active TB are not included in the study. Testing was not done in hospitalized patients to rule out effects of other disease states. Results. Mean age of the patients was 45.3 +/- 16 (range 13-82) years. All patients were on HD treatment twice (n: 14) or three times (n: 110) weekly. Duration of dialysis before TST was 30 +/- 17 (12-84) months. With the first test (n: 14), 11.3% of the patients showed a positive reaction; the second test added (n: 15) 12.1% more TST-positive patients, reaching a total of (n: 29) 23.4% of the patients with a positive TST. The

Containment of active pulmonary tuberculosis in a long-term care/psychiatric center following exposure from a housekeeper

BACKGROUND: Diagnosis of tuberculosis (TB) disease in an employee requires broad and aggressive contact investigation and employee education to identify exposures and prevent further spread. A housekeeping employee (source) was diagnosed with active pulmonary tuberculosis in June 2004. The source was potentially infectious from January to May 2004, prior to diagnosis and treatment. Risk of transmission was relatively high due to AFB smear-positive, cavitary disease. METHODS: An exposure was defined as sharing an enclosed airspace with the source for more than 10 minutes. Infection control personnel identified employees who had unprotected exposure to the source using time cards, which indicated areas where the source worked. Exposed employees were screened using purified protein derivative (PPD) 10-12 weeks after exposure; employees that were previously PPD positive completed questionnaires regarding signs and symptoms of TB. Screened employees also received training on TB detection and prevention and a TB fact sheet that was developed. An exposed employee with a PPD of 5mm or more was considered TB infected. TB infected employees had chest x-rays to rule out active disease and were offered treatment to prevent development of TB disease. RESULTS: Time card analysis indicated source assignment in the following areas: emergency room and outpatient clinic, six mental health inpatient units, four nursing home care units, geriatric long-term care unit, acute medical unit, research building, and police station. A total of 303 employees were exposed and were PPD skin tested. Two EMS employees and a nurse converted for a conversion rate of ∼1%. Their contacts with the source included riding in a car and singing in a chorus. These employees were treated with a 9-month course of isoniazid. Annual TB skin testing has not identified further cases. CONCLUSION: An employee with active TB can expose many medical center employees and patients to the infection prior to detection. Widespread contact investigation is effective in identifying exposed employees and preventing the spread of TB in a healthcare facility.

Tuberculin Skin Test Results and the Booster Phenomenon in Two-Step Tuberculin Skin Testing in Hemodialysis Patients

Patients with chronic renal failure are at increased risk for tuberculosis (TB). Centers for Disease Control and Prevention (CDC) have recommended annual skin testing for TB, with tuberculin-purified protein derivative (PPD), in patients with chronic renal failure. Uremia alters the macrophage function, which can lead to anergy for skin tests. The aim of this prospective study was to determine the prevalence of positive tuberculin skin test (TST) and the booster effect of TST in hemodialysis patients living in a relatively underdeveloped portion of the country. Material and Methods. Patients were recruited from Van (Yuzuncu Yil University Hospital, Yuksek Ihtisas Hospital) and the Mus State Hospital). At the time of this study, a total of 143 patients were under hemodialysis treatment in these hemodialysis centers, and among them, 124 were included in the study. Informed consent was obtained before inclusion in the study. A positive PPD was an induration of >10 mm in response to five tuberculin units of PPD (RT23-Tween 80), at 72 h. TST-negative patients received a booster TST 10 days later, ~ 10 cm away from the previous intracutaneous injection. The test dose could not be increased due to unavailability of this kind of preparation. The test was performed and interpreted in the same way. Skin testing was performed in June and December 2003. Patients with known active TB are not included in the study. Testing was not done in hospitalized patients to rule out effects of other disease states. Results. Mean age of the patients was 45.3 ± 16 (range 13–82) years. All patients were on HD treatment twice (n: 14) or three times (n: 110) weekly. Duration of dialysis before TST was 30 ± 17 (12–84) months. With the first test (n: 14), 11.3% of the patients showed a positive reaction; the second test added (n: 15) 12.1% more TST-positive patients, reaching a total of (n: 29) 23.4% of the patients with a positive TST. The mean induration of the positive TST was 16 ± 4 mm in the first test and 15 ± 3 mm in the second. Five (17.2%) of the patients with positive PPD and two of the patients (2.1%) with negative PPD results subsequently developed active TB within 12 months. Conclusion. We found a significant booster effect in our hemodialysis patients using TST-2. Repeat PPD test with the same dosage could detect positive patients more than twofold higher. Among positive PPD patients, TB incidence is considerably high.

Tuberculosis screening in dialysis patients--is the tuberculin test effective?

Patients with end-stage renal disease are at increased risk for tuberculosis (TB). The Centers for Disease Control and Prevention (CDC) has recommended annual skin testing for TB, with tuberculin-purified protein derivative (PPD), in patients with chronic renal failure. The aim of this study was to identify the incidence and prevalence oftuberculin positivity and assess the utility of the tuberculin test in an inner city dialysis population. All patients on chronic hemodialysis at a center affiliated to the University of Chicago, who were tuberculin-tested between 1997 and 2000 or had previously documented PPD positivity precluding retesting, were included. Demographics, comorbidity, and tuberculin and anergy reactivity were recorded. A positive PPD was an induration of > 10 mm in response to 5 tuberculin units of PPD, and anergy an induration of < 2 mm in response to the anergy antigens (Candida and Mumps), at 48 h. PPD-positive patients were compared with PPD-negative patients; Fisher's exact test and t-test were used, p < 0.05 was considered significant. Of 131 patients at the dialysis center, 118 were studied. The remaining 13 refused consent to PPD testing. 41 (35%) were PPD-positive, 77 (65%) were negative. Of the 77 PPD-negative patients, 62 (81%) were anergic. None of the PPD-positive patients had clinical or radiographic signs of active TB. Only 20 patients received INH prophylaxis, the others refused or had contraindications to therapy. The conversion rate ranged from 3 - 8% per year. Demographics, nutritional parameters, comorbidity and adequacy of dialysis did not help predict PPD positivity. There is a high prevalence of PPD positivity and anergy among dialysis patients. As the diagnostic utility of the time-tested PPD test is unclear in an anergic dialysis population, the need for a high index of suspicion for active tuberculosis and timely diagnostic work up should be reinforced and not replaced by total dependence on the tuberculin test.

Mycobacterial infections in cattle in the Czech Republic during 1990-1999

In the nineties, cattle stocks gradually decreased from 3 506 222 head of cattle in 1990 to 1 657 337 head in 1999. Skin testing of cattle was carried out annually using bovine tuberculin. Animals for sale were also simultaneously tested with avian tuberculin. In records from 1991 to 1999 a total of 14 611 393 bovine tuberculin skin tests and 611 405 simultaneous avian tuberculin skin tests are registered. A total of 1 457 (0.01%) animals reacted positively with bovine tuberculin and 1 790 (0.29%) with avian tuberculin. In the period monitored a total of 7 268 274 head of cattle were slaughtered and given veterinary hygienic examinations. Statistical data on the post-mortem detection of tuberculous lesions have been available for nine years since 1992 when tuberculous lesions were found in 1 186 (0.019%) out of 6 273 441 slaughtered animals. Mycobacteria were isolated from the organs of only 561 (17.5%) out of 3 202 culturally examined animals. M. bovis only was isolated from 48 (8.6%) animals originating from seven herds (two infected herds in 1991, 1992 and 1994 and one infected herd in 1995): four outbreaks were detected by annual skin testing, one outbreak by movement tuberculin skin testing and two outbreaks by the detection of tuberculous lesions at slaughter. M. avium complex strains of serotypes 1, 2 and 3 and of genotypes IS901+ and IS1245+ were isolated from 331 (59.0%) animals and strains of serotypes 4 to 6, 8 to 11 and 21 and of genotypes IS901- and IS1245+ were isolated from 132 (23.5%) animals. Potentially pathogenic bacteria of the M. chelonae, M. terrae, M. phlei and M. fortuitum species were isolated from 50 (8.9%) animals. Neither miliary nor generalised tuberculosis was found in any of the animals. Between 1996 and 1999, the proportion of cattle in which tuberculous lesions were recorded decreased.

Ability of caregivers to read delayed hypersensitivity skin tests in children exposed to and infected by HIV

Objectives: To identify whether nonmedical home caregivers (parents, guardians) could accurately interpret the results of delayed hypersensitivity skin tests in children, thereby obviating the need for a return visit for a professional reading. Methods: Patients who were enrolled in the Pediatric Pulmonary and Cardiac Complications of HIV (P 2C 2HIV) study were given annual skin tests to tuberculin purified protein derivative, Candida, and tetanus as part of the study protocol. Caregivers were instructed verbally about how to read and measure erythema and induration. They were given written instructions to take home as well and were asked to return in 48 to 72 hours for the professional reading. On the morning of their return visit, they were to read the skin tests and record the results before coming to the clinic. Results: When compared with readings by professional staff, caregivers had a high percentage of false-negative readings for both Candida (24%) and tetanus (41%) skin tests. These false-negative readings did not correlate with age, gender, race, or educational level of the caregivers. Conclusions: The high percentage of false-negative readings by the caregivers emphasizes the need for professional reading of delayed hypersensitivity skin tests. J Pediatr Health Care. (2000). 14, 50–55.

Tuberculosis control in the New York State Department of Correctional Services: A case management approach

In the New York State Department of Correctional Services (DOCS), the incidence of tuberculosis (TB) increased from 43 per 100,000 persons in 1985 to 225 per 100,000 in 1991. To combat this increase in cases, the NYSDOCS enhanced its collaborative efforts with the New York State Department of Health and the Division of Parole, developing a comprehensive TB control program. This control program focuses on prevention and containment of disease. Policies and directives were developed on the basis of epidemiologic principles, which include surveillance and detection. To assist the NYSDOCS in the implementation of the TB control program statewide, a team of infection control nurses was established in July 1992. A case management approach was used, and TB registry was developed. Each case of active and suspected TB was monitored closely to ensure appropriate containment, identification, and treatment measures. Transfers within the state system also were monitored to promote continuity. Discharge planning coordination with the DOCS, Division of Parole, and Department of Health is facilitated by the infection control nurses. Directly observed preventive therapy and directly observed therapy is used for inmates. Staff and inmates are provided education that addresses mandatory annual skin testing, diagnosis, containment procedures, disease process, and treatment modes. Implementation of this comprehensive TB control program in NYSDOCS has strongly contributed to reducing the incidence of TB. In 1997, the incidence rate was 61 TB cases per 100,000 persons—a 73% decrease since 1991. The conversion rate for staff and inmates has steadily declined since 1993. No new outbreaks have occurred in NYSDOCS since 1993. (AJIC Am J Infect Control 1998;26:534-8)

Varied approaches to tuberculosis control in a multihospital system.

To document the actual tuberculosis (TB) control policies and procedures in a nonoutbreak setting in a variety of hospitals. To determine if any particular practices are linked to higher rates of employee tuberculin skin-test conversion. Survey of hospital occupational health and infection control practitioners for the year 1994 regarding hospital TB policies. Review of hospital records to verify the number of patients with TB at each hospital and to verify the number of employees with positive tuberculin skin tests. Smoke-stick testing of negative-pressure ventilation rooms. A 13-hospital health system in the Midwest. Hospitals ranged in size from 40 to 1,208 beds (median 220) and employed 150 to 6,500 workers (median 875). There were seven rural and six urban centers, including four teaching hospitals. All 13 hospitals had TB control plans, and all performed annual tuberculin skin testing on employees. Annual skin-test positivity rates ranged from 0% to 1.0% (median 0.3%). Negative-pressure ventilation rooms were available in 11 hospitals. The percentage of negative-pressure rooms with effective negative pressure ranged from 44% to 100% (median 95%). Three of the 13 hospitals used high-efficiency particulate air (HEPA) masks as primary personal respiratory protection, and 8 used dust-mist or dust-mist-fume masks. We found no relation between the type of face mask used, number of functional negative-pressure rooms, or hospital TB risk category, and employee skin-test conversion rates. Considerable variation existed in the TB control policies and procedures between hospitals, but employee TB skin-test conversion rates were low in all settings.

The Cost-effectiveness of Preventing Tuberculosis in Physicians Using Tuberculin Skin Testing or a Hypothetical Vaccine

Tuberculin skin testing using the purified protein derivative is recommended as part of a tuberculosis control program for health care workers. However, compliance with skin testing programs has been poor and their cost-effectiveness is unknown. A Markov-based decision analysis was performed to determine the cost-effectiveness of tuberculin skin testing over the entire lifetimes of physicians who are now in medical school. Assumptions were deliberately chosen to present a conservative estimate of cost-effectiveness. Indirect costs were not included. Annual testing cost $29,000 per life-year saved and $39,000 per case of pulmonary tuberculosis prevented. In contrast, particulate respirators have been shown to cost millions of dollars per case prevented. Skin testing every 6 months was cost-effective in a subpopulation at high risk of infection (> or = 1.8-fold). During their entire lifetimes, physicians now in medical school can expect to avert 137 cases of pulmonary tuberculosis, prevent 7 tuberculosis deaths, and save 182 life-years because of skin testing programs. Improved compliance with annual skin testing and prophylactic isoniazid could more than triple this benefit. If available, a moderately effective vaccine would be even more cost-effective than tuberculin skin testing programs. Tuberculin skin testing is cost-effective and should be an integral part of any tuberculosis control program. Vaccination may one day be a feasible and cost-effective alternative to skin testing programs.