Tuberculin skin test screening practices among US colleges and universities

CONTEXT: Concern about transmission of Mycobacterium tuberculosis on college campuses has prompted some schools to institute tuberculin skin test screening of students, but this screening has never been evaluated. OBJECTIVE: To describe tuberculin skin test screening practices and results of screening in colleges and universities in the United States. DESIGN AND SETTING: Self-administered mail and telephone questionnaire in November and December 1995 to a stratified random sample of US 2-year and 4-year colleges and universities. MAIN OUTCOME MEASURES: Type of tuberculin screening required; types of schools requiring screening; number and rate of students with positive skin test results and/or diagnosed as having tuberculosis. RESULTS: Of the 3148 US colleges and universities, 624 (78%) of 796 schools surveyed responded. Overall, 378 schools (61%) required tuberculin screening; it was required for all new students (US residents and international students) in 161 (26%) of 624 schools, all new international students but not new US residents in 53 (8%), and students in specific academic programs in 294 (47%). Required screening was more likely in 4-year vs 2-year schools, schools that belonged to the American College Health Association vs nonmember schools, schools with immunization requirements vs schools without, and schools with a student health clinic vs those without (P<.001 for all). Public and private schools were equally likely to require screening (64% vs 62%; P=.21). In the 378 schools with screening requirements, tine or multiple puncture tests were accepted in 95 (25%); test results were recorded in millimeters of induration in 95 (25%); and 100 (27%) reported collecting results in a centralized registry or database. Of the 168 (27%) of 624 schools accepting only Mantoux skin tests and reporting results for school years 1992-1993 through 1995-1996, 3.1% of the 348 368 students screened had positive skin test results (median percentage positive, 0.8%). International students had a significantly higher case rate for active tuberculosis than US residents (35.2 vs 1.1 per 100000 students screened). CONCLUSIONS: Widespread tuberculin screening of students yielded a low prevalence of skin test reactors and few tuberculosis cases. To optimize the use of limited public health resources, tuberculin screening should target students at high risk for infection.     

A tuberculin screening and isoniazid preventive therapy program in an inner-city population

As tuberculosis transmission decreases, case rates decline and an increasing proportion of cases arises from the pool of persons with latent infection. Elimination of tuberculosis will require preventing disease from developing in infected persons. From 1994 to 1996 the Atlanta TB Prevention Coalition conducted a community-based tuberculin screening and isoniazid preventive therapy project among high-risk inner-city residents of Atlanta, Georgia. We established screening centers in outpatient waiting areas of the public hospital serving inner-city residents, the city jail, clinics serving the homeless, and with outreach teams in neighborhoods frequented by drug users. All services were provided free. A total of 7,246 persons participated in tuberculin testing; 4,701 (65%) adhered with skin test reading, 809 (17%) had a positive test, 409 (50%) fit current guidelines for isoniazid preventive therapy, 84 (20%) we intended to treat completed therapy. The major limitations of this community-based tuberculin screening and preventive therapy project were the low proportion of infected individuals who were eligible for isoniazid preventive therapy and the poor adherence with a complete regimen among those we intended to treat. For community-based programs to be efficacious, preventive therapy regimens that are of shorter duration and safe for older persons will need to be implemented.     

Mutations in the iduronate-2-sulfatase gene in five Norwegians with Hunter syndrome

OBJECTIVES: Adolescents with human immunodeficiency virus (HIV) infection are at increased risk for tuberculosis (TB), underscoring the importance of early identification of TB infection. The goals of this study were to assess the factors associated with the completion of evaluations for TB in a cohort of HIV-positive adolescents and young adults and to describe the prevalence of Mycobacterium tuberculosis infection and adherence to antituberculous treatment regimens. METHODS: A retrospective chart review was done for all HIV-positive adolescents and young adults, ages 13 to 21 years (n = 49), seen in a comprehensive care program from January 1991 through December 1992. Data collected included CD4 cell count, HIV clinical status, living situation, substance use history, and the completion of an annual evaluation for TB infection. The evaluation consisted of a tuberculin skin test (Mantoux test), using an intraepidermal injection of 0.1 mL of 5 tuberculin units of purified protein derivative (PPD) and a simultaneous Merieux multitest anergy panel. Chi-square analysis was used to assess the association between the completion of the evaluation for TB and both living status and substance use. RESULTS: Thirty-one (63%) of 49 patients completed evaluations for TB. Of the 31 completed evaluations, 18 were assessed by clinic staff on site, and 13 were assessed by other medical or trained nonmedical observers through community networking efforts. Neither homelessness nor illicit substance use were factors in the completion of the evaluation. Six (19%) of the 31 patients had positive PPD skin test results. Three had medical histories and chest radiographs suggesting active TB, and all were hospitalized for at least 2 weeks. Two had positive cultures for M tuberculosis, although the third also responded clinically to antituberculous therapy. All three were otherwise asymptomatic for HIV infection, with only moderately depressed CD4 cell counts. All three were homeless and used crack cocaine. After the initial treatment as inpatients, none completed treatment within the prescribed time period. CONCLUSIONS: The completions of the evaluations for TB were greatly facilitated by community networking, but innovative strategies to enhance both screening and treatment programs, such as training youth service providers in the community to read PPD skin tests, expansion of directly observed therapy services, and youth-centered programs for housing and substance use, need further development. The high prevalence of TB in the cohort underscores the need for providers to increase efforts to identify cases of TB infection among adolescents and young adults and to incorporate HIV risk assessment, counseling, and testing into their practices routinely.     

Detection of HIV infection in pulmonary tuberculosis patients

Well documented 112 pulmonary tuberculosis patients were studied for the prevalence of human immunodeficiency virus (HIV) seropositivity by using two antibody screening tests along with western blot test. Nineteen of the pulmonary tuberculosis patients were HIV seropositive, 12 were acid-fast bacillus smear positive; 12 patients were tuberculin skin test positive and 15 patients were culture positive. As the incidence of HIV infection is increasing in India, it is observed that patients co-infected with HIV and TB are also on the rise. Recognition of the dual infection and taking adequate steps to deal with this epidemic are needed.     

Tuberculosis screening and compliance with return for skin test reading among active drug users

OBJECTIVES: This study assessed the independent and combined effects of different levels of monetary incentives and a theory-based educational intervention on return for tuberculosis (TB) skin test reading in a sample of active injection drug and crack cocaine users. Prevalence of TB infection in this sample was also determined. METHODS: Active or recent drug users (n = 1004), recruited via street outreach techniques, were skin tested for TB. They were randomly assigned to 1 of 2 levels of monetary incentive ($5 and $10) provided at return for skin test reading, alone or in combination with a brief motivational education session. RESULTS: More than 90% of those who received $10 returned for skin test reading, in comparison with 85% of those who received $5 and 33% of those who received no monetary incentive. The education session had no impact on return for skin test reading. The prevalence of a positive tuberculin test was 18.3%. CONCLUSIONS: Monetary incentives dramatically increase the return rate for TB skin test reading among drug users who are at high risk of TB infection.     

Tuberculosis of the ankle in childhood: clinical, roentgenographic and computed tomography findings

We report on three Italian children who presented with unilateral ankle tuberculosis (TB) consecutively during a short time period and in the same geographical area. A 6-year-old-girl with a family history of TB had limited mobility of the right leg at age 9 months; Mantoux test and radiographs at that age yielded normal findings. When severe right tibiotarsal swelling, reddening, pain and restriction of motion became apparent at age 4.6 years, the typical lesions of TB were evident on radiographs and computed tomographic (CT) scans. Mantoux test and synovial biopsy confirmed TB. A three-drug regimen of treatment proved useless: articular cartilage destruction and diffuse osteosclerosis ensued. Only a four-drug prolonged regimen of treatment proved to be somewhat effective. A 5-year-old girl had a 6-month history of painless swelling and limited mobility of the ankle; radiographs and CT showed osteopenia with marginal erosion of cartilages. A 14-month-old boy presented with a 2-week history of painless swelling ankle. Radiographs showed decreased bone density of talocalcanear bones. Mantoux test and synovial biopsy confirmed TB in both patients; treatment with a three-drug regimen greatly reduced symptoms. A careful suspicion of the diagnosis of tuberculosis is paramount in children with chronic or subacute monoarticular arthritis, even in absence of a positive tuberculin test or abnormalities on chest radiograph. When negative early on, the tuberculin test should be repeated after 6 weeks of arthritis, and a needle biopsy of the synovium is required in those children with monoarticular arthritis and a positive tuberculin test. Careful therapy is necessary to avoid sequelae that may lead to severe osteoarticular damage.     

A prospective study of the risk of tuberculosis among HIV-infected patients

OBJECTIVE: To evaluate the risk of developing active tuberculosis (TB) in a cohort of HIV-1-infected patients. METHODS: Prospective longitudinal follow-up of 839 HIV-infected patients, of whom 505 (60%) were parenteral drug users and 269 (32%) homosexual men. Tuberculin skin tests were performed at baseline and annually thereafter. Prophylaxis with isoniazid (300 mg daily for 9 months) was offered to those with a positive tuberculin test (induration > or = 5 mm). Diagnosis of TB was accepted if it could be confirmed microbiologically (acid-fast bacilli seen in Ziehl-Neelsen stains or grown in Lowenstein-Jensen cultures) or pathologically (presence of caseating granulomas) and patients had consistent clinical manifestations. RESULTS: Active TB developed in 23 out of the 733 (3.1%) patients with a negative tuberculin skin test after a mean follow-up of 16 +/- 11 months (range, 2-52 months), with an estimated cumulative probability of 1.5 and 7% after 1 and 3 years, respectively (or 2.4 per 100 patient-years). None of the 87 patients with a negative tuberculin test but a positive Multitest developed TB. Conversely, 106 patients had a positive tuberculin skin test (97 at baseline and nine who converted during follow-up). Active TB developed in seven out of the 26 not receiving prophylaxis or in whom prophylaxis had to be discontinued (16.2 per 100 patient-years), in four out of 61 patients 3-27 months after having completed 9 months of prophylaxis with isoniazid (8.9 per 100 patient-years) and in none of the 19 still receiving isoniazid. When TB was diagnosed, the mean CD4 lymphocyte count of the 34 patients who developed it during follow-up was 77 +/- 103 x 10(6)/l (range, 1-400 x 10(6)/l). CONCLUSIONS: Among HIV-infected patients in whom the tuberculin skin test is negative, the risk of developing active TB is sufficient to consider prophylaxis if the CD4 count falls below 400 x 10(6)/l, at least in those patients with skin anergy living in high-risk geographical areas such as Spain. When the tuberculin skin test was positive, isoniazid (9 months) provided a 45% protection beyond the period of its administration.     

Tuberculin skin testing of hospitalized patients

OBJECTIVES: We sought to define the prevalence of tuberculin skin test (TST) positivity in a group of newly hospitalized patients, to identify risk factors for positive tests, and to examine the impact of testing on infection control practices. DESIGN: Unblinded cohort study over 5 days in July 1992. SETTING: A 1,000-bed university-affiliated hospital. PATIENTS: All patients admitted (excluding obstetric patients and newborns) were interviewed. Patients without a history of tuberculosis (TB) or a positive TST were offered a TST with Candida and tetanus controls. RESULTS: Of 346 patients offered the test, 21 (6%) had a prior history of TB or a positive TST, and 36 (10%) declined to participate; 279 of the remaining 289 completed the study. Anergy was demonstrated in 94 (33.7%) of 279 patients. New positive TSTs were identified in 19 (10.3%) of 185 nonanergic patients. Of the 19 TST-positive patients, 6 (32%) had infiltrates on chest radiographs and were evaluated for active TB. One patient was treated empirically for active TB, and five received isoniazid prophylaxis. Risk factors for a new positive TST included age (odds ratio [OR], 1.56 per decade of life; P = .021), African American race (OR, 4.81; P = .008), alcohol abuse (OR, 5.53; P = .005), and peptic ulcer disease (OR, 4.53; P = .017). Risk factors for anergy included admission to a surgical service (OR, 2.1; P = .006), current use of steroids (OR, 2.65; P = .005), and human immunodeficiency virus (HIV) infection (OR, undefined; P = .034). CONCLUSIONS: Despite a high rate of anergy, routine tuberculin skin testing identified a substantial number of patients with TB infection who might otherwise have gone unrecognized.     

Infection of sheep with adult and larval Ostertagia circumcincta: gastrin

OBJECTIVE: To determine the prevalence, incidence and risk factors for Mycobacterium tuberculosis infection, as well as to assess TB knowledge and attitudes, among a group of known drug users in a city with low TB incidence (11.3 per 100,000 in 1995). METHODS: Patients of an urban drug treatment facility enrolled in opioid substitution, opioid antagonist and other drug treatment programs were screened for TB, including tuberculin skin testing and standardized data collection on TB risk factors. A subsample of clients was interviewed about TB knowledge and attitudes. RESULTS: Between 1 June 1995 and 31 May 1996, 1055 individuals were screened. The prevalence of infection was 15.7% (CI: 13.2-18.2%). PPD positivity was associated with older age (per annum, OR = 1.08, CI: 1.05-1.11), non-white race (OR = 2.81, CI: 1.72-4.60), foreign birth (OR = 4.24, CI: 2.35-7.62) and a history of injecting drug use (OR = 1.89, CI: 1.14, 3.12). The incidence of infection was 2.9 per 100 person-years (CI: 1.8-4.7). Thirty-two per cent of 79 drug users interviewed about TB knowledge and attitudes thought TB could be prevented by bleaching or not sharing needles/syringes. Fifty-one per cent thought anyone with a positive TB skin test was contagious. CONCLUSION: M. tuberculosis infection was common in this population and associated with injecting drugs and several demographic factors. The incidence of new infection was relatively low. In this non-endemic environment, the detection and treatment of latent infection are important aspects of TB control. Misconceptions about TB transmission were also widespread in this population. Drug treatment programs can play a key role by undertaking screening programs that educate about TB and identify infected subjects who would benefit from preventive therapy.     

Rates of tuberculosis infection in healthcare workers providing services to HIV-infected populations. Terry Beirn Community Programs for Clinical Research on AIDS

OBJECTIVE: To assess the prevalence of tuberculosis (TB) or a positive skin test in healthcare workers (HCWs) providing services to human immunodeficiency virus (HIV)-infected individuals and to determine prospectively the incidence of new infections in this population. DESIGN: This prospective cohort study enrolled 1,014 HCWs working with HIV-infected populations from 10 metropolitan areas. Purified protein derivative (PPD) tuberculin skin tests were placed at baseline and every 6 months afterwards on those without a history of TB or a positive PPD. Demographic, occupational, and TB exposure data also were collected. SETTING: Outpatient clinics, hospitals, private practice offices, and drug treatment programs providing HIV-related healthcare and research programs. PARTICIPANTS: A voluntary sample of staff and volunteers from 16 Community Programs for Clinical Research on AIDS units. RESULTS: Factors related to prior TB or a positive skin test at baseline included being foreign-born, increased length of time in health care, living in New York City, or previous bacille Calmette-Guerin vaccination. The rate of PPD conversion was 1.8 per 100 person years of follow-up. No independent relation was found between the amount or type of contact with HIV-infected populations and the risk of TB infection. CONCLUSION: These data provide some reassurance that caring for HIV-infected patients is not related to an increased rate of TB infection among HCWs in these settings.     

Autofluorescence guided biopsy for the early diagnosis of bladder carcinoma

To assess whether there is increased risk of tuberculous infection in children who traveled to or had a household visitor from a country having a high prevalence of tuberculosis, we conducted a case-control study. Children younger than 6 yr of age who had a tuberculin skin test read at public health clinics in areas of California that have a high prevalence of tuberculosis were enrolled. Of the 953 children who had a skin test read, 72 (7.6%) had a positive reaction. By multiple logistic regression analysis, children who had traveled in the 12 mo before the skin test were 3.9 times more likely to have a positive skin test than were children who had not traveled (95% confidence interval [CI], 1.9 to 7.9). Among children born in the United States, those who had traveled were 4.7 times more likely to have a positive skin test (95% CI, 2.0 to 11.2). Children who had a household visitor from a country having a high prevalence of tuberculosis were 2.4 times more likely to have a positive skin test than were those who did not have a visitor (95% CI, 1.0 to 5.5). These data indicate that travel to a country that has a high prevalence of tuberculosis or having a visitor from such countries increase the risk of tuberculous infection among young children. Physicians and tuberculosis control programs should incorporate questions about travel and visitors into their evaluations, and children with a history of extended travel should have a tuberculin skin test.     

Tuberculin tests in school leavers in canton Berne , Neuenburg and Wallis 1992/1993

To determine the prevalence of tuberculosis infection in Switzerland, standardized tuberculin tests using 2 units of tuberculin Berna PPD RT 23, administered by specially trained personnel, were performed on school leavers in 3 Swiss cantons in 1992/1993. Of the 7036 school leavers, averaging 15 years of age, only 294 (4.18%) were not BCG-vaccinated. Non-vaccinated persons had tuberculin test indurations > 15 mm in 2.04% (6663 BCG vaccinated persons in 1.14%). Calculations of potentially influential factors using stepwise ordinal polychotomous regression showed that tuberculin test indurations are significantly larger after BCG vaccination, as well as with increasing age at immigration from high prevalence tuberculosis countries. Indurations were smaller with increasing time passed since BCG vaccination, as well as in females. Pets at home did not significantly influence the size of tuberculin reactions. Theoretically the positive predictive value of tuberculin tests in Switzerland is small because of the low tuberculosis prevalence. From our data the maximal prevalence of infection in 15-year-olds is estimated at 0.91% (2.48% in the non-vaccinated) in Swiss and 2.54% (9.77% in the non-vaccinated) in foreign born school children. These rates, higher than extrapolated from previous studies, are comparable to data from other industrialized countries. They do not warrant a change in BCG vaccination policy in Switzerland, which since 1987 requires BCG vaccination in children immigrating from countries with high tuberculosis prevalence only.     

Results of screening for tuberculosis in foreign-born persons applying for adjustment of immigration status

As part of the required screening process of illegal aliens applying for adjustment of status by the Immigration and Naturalization Service, 7,573 persons were evaluated for tuberculous infection by the Denver Department of Health and Hospitals from May 1987 through December 1988. Applicants were screened with tuberculin skin testing, chest radiographs, or both. Review of 6,520 charts that were available found that 4,840 applicants had tuberculin skin tests, of which 2,039 (42 percent) were > or = 10 mm and 1,528 had further evaluation at the Denver Metro Tuberculosis Clinic. Seventy-five percent of the applicants were between the ages of 15 and 34 years, and 91 percent were from Mexico. Evidence of past or current tuberculous infection on chest radiograph was present in 273 (17 percent) and 16 (7 percent) had sputum cultures obtained that identified four new cases of active tuberculosis. Isoniazid preventive therapy (IPT) was recommended to 1,029 applicants, of whom 29 (3 percent) were 35 years of age or older; 716 (70 percent) completed at least six months of treatment. We conclude that there is a high prevalence of tuberculous infection in foreign-born persons applying for adjustment of immigration status, but a low prevalence of clinically apparent tuberculosis. This population is an excellent target for IPT, which can be achieved with good success. Proactive screening and preventive therapy is likely to significantly reduce tuberculosis reactivation and morbidity, prevent secondary infection of contacts, and be cost-effective.     

The cost-effectiveness of preventing tuberculosis in physicians using tuberculin skin testing or a hypothetical vaccine

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.     

Impact of policy and practice on the effectiveness of contact screening for tuberculosis

BACKGROUND: Screening for tuberculosis is conducted because TB is a disease of public health importance that can be prevented if screening is followed by isoniazid prophylaxis for infected individuals. Screening alone is not effective unless that screening is rational and systematic and is followed by prevention where appropriate. Our aim was to consider whether the TB contact screening guidelines are evidence-based and appropriate, how well these guidelines are implemented, and how policy and practice impact on prevention. METHODS: A cohort of 1,142 recent contacts screened in 1991 in Victoria, Australia, was studied. We evaluated the appropriateness of the screening guidelines and how well they were implemented and how the combination of these two factors impacted on the efficacy of the screening program. RESULTS: The screening guidelines required updating and were not evidence-based. Chest radiograph (CXR) was overused and was the sole screening tool for nearly 40% (449/1,142) of contacts. Eighty percent of repeat CXRs were done following a normal initial study. Skin testing was underused. In nearly 60% (658/1,142) of all contacts, the presence or absence of infection could not be determined because a skin test was not done and the CXR, if done, was clear. Only 22% (38/175) of identified, eligible contacts received isoniazid preventive therapy. CONCLUSIONS: Lack of evidence-based guidelines, as well as poor adherence to guidelines, resulted in an inefficient program. This problem may not be unique to the study setting, but cannot be identified without systematic program evaluation, for which we have provided a model.     

Efficacy of control measures in preventing nosocomial transmission of multidrug-resistant tuberculosis to patients and health care workers

OBJECTIVE: To assess the efficacy of control measures in decreasing nosocomial transmission of multidrug-resistant tuberculosis. DESIGN: Retrospective cohort study. SETTING: A teaching hospital in New York City. POPULATION: 40 patients hospitalized with multidrug-resistant tuberculosis (case-patients) and health care workers receiving tuberculin skin testing. INTERVENTIONS: Centers for Disease Control and Prevention (CDC) 1990 guidelines for preventing transmission of tuberculosis, including 1) prompt isolation and treatment of patients with tuberculosis; 2) rapid diagnostic techniques for processing Mycobacterium tuberculosis specimens; 3) negative-pressure isolation rooms; and 4) molded surgical masks for health care workers. MEASUREMENTS: Proportion of case-patients with nosocomially acquired tuberculosis and rate of tuberculin skin test conversion among health care workers before and after implementation of control measures. RESULTS: The proportion of patients with multidrug-resistant strains of M. tuberculosis decreased after the interventions (10 of 70 [14%] compared with 30 of 95 [32%] patients before the intervention; relative risk [RR], 0.5; 95% CI, 0.2 to 0.9). Before onset of multidrug-resistant tuberculosis, case-patients in the intervention period were as likely to be hospitalized on high-risk wards containing patients with tuberculosis (4 of 10 compared with 17 of 30 patients; RR, 0.7; P = 0.5) but were less likely to be exposed to another case-patient with tuberculosis (1 of 10 compared with 20 of 30 patients; RR, 0.2; P = 0.003). Tuberculin skin test conversion rates for health care workers assigned to wards housing patients with tuberculosis were lower in the intervention period than in the preintervention period (4 of 78 [5%] compared with 15 of 90 [17%] conversions; P = 0.02), decreasing to levels observed for workers assigned to other wards (4 of 78 [5%] compared with 9 of 228 [4%] conversions; P = 0.7). CONCLUSIONS: Implementing control measures reduced nosocomial transmission of multidrug-resistant strains to patients and health care workers.     

Tuberculosis surveillance practices in long-term care institutions

OBJECTIVES: To identify the tuberculosis (TB) skin-testing practices of long-term care facilities for the elderly in Toronto, Ontario. DESIGN: A telephone survey using a 25-item questionnaire. SETTING: Twenty-nine nursing homes (NHs) and 26 Homes for the Aged (HFAs) in metropolitan Toronto. RESULTS: Thirty-one percent of facilities (17 of 55) had no formal tuberculin skin-testing program, including 52% of NHs (15 of 29) versus 8% of HFAs (2 of 26; P = 0.001). Ninety-two percent of HFAs (24 of 26), compared with 45% of NHs (13 of 29), obtained preadmission or admission skin-test status of residents (P = 0.0005). Annual testing was performed at 46% of HFAs (12 of 26) and 27% of NHs (8 of 29; P = 0.28). Of facilities that carried out any skin testing, 64% of HFAs (16 of 25) versus 32% of NHs (6 of 19) measured induration to establish test positivity (P = 0.068). Fifty-two percent of HFAs (13 of 25), compared with 21% of NHs (4 of 19), recorded the actual size of induration in the patient record (P = 0.085). Only 28% of HFAs (7 of 25) and 21% of NHs (4 of 19) correctly defined a positive tuberculin skin test. CONCLUSIONS: TB surveillance practices in long-term care institutions in Toronto are inadequate and often yield results that do not predict the risk of infection and cannot be used to investigate outbreaks. Tuberculin skin-testing practices were better at HFAs, which are subject to provincial legislation regarding TB surveillance, than at NHs, which are not subject to this legislation. Staff at HFAs and NHs require education regarding tuberculin skin-testing policies and procedures.     

Tuberculosis control in health care workers: an algorithmic approach

Health care workers have always been at risk for contracting tuberculosis (TB) from patients with active disease. In addition, health care workers who have active TB pose a risk for transmitting TB to patients. As a result, institutions that employ health care professionals must adopt programs to reduce the probability of transmission of TB to their employees or their patients. This article discusses the new guidelines for preventing TB issued by the Centers for Disease Control and Prevention and suggests approaches for adapting the guidelines to the needs of individual institutions. It emphasizes the importance of skin testing for early detection, correct interpretation of the tests, the approaches to determining who should be tested, and the relative frequency with which employees should be tested. It presents algorithms to assist employee health and infection control personnel in screening current and prospective employees, and in responding to positive and negative test results, and the booster effect.     

Screening for gonorrhea and chlamydia by DNA amplification in adolescents attending middle school health centers. Opportunity for early intervention

GOAL: To determine prevalence and incidence of Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) infection and assess risk factors predictive for such infections in a middle school-based clinic sample. STUDY DESIGN: 170 female students and 43 male students making 256 and 47 visits, respectively, > or = 30 days apart, in urban middle school clinics for primary care screening, reproductive health, or illness/injury were routinely asked to provide urine specimens for GC and CT ligase chain reaction testing if sexually active in the preceding 3-month period. Information regarding prior sexually transmitted diseases, reason for visit, and sexual risk behaviors was obtained. RESULTS: GC: 11.4% of female student and 2.1% of male student tests were positive. Incidence was 34.0 cases/1,000 person months (95% Confidence interval [CI]: 19.5-67.5). Median time to first positive and repeat positive test was 4.6 and 2.6 months, respectively. For CT: 16.4% of female student and 2.1% of male student tests were positive. Incidence was 57.5 cases/1,000 person months (95% CI: 35.2-93.8). Median time to first positive and repeat positive CT test was 6.0 and 4.8 months, respectively. Assessed risk factors failed to specify a candidate screening population. CONCLUSION: These data suggest that all sexually active adolescent girls in this high risk setting should be offered testing for GC and CT at least twice per year, regardless of age or other sexual risk behaviors and that STD control efforts in high risk middle schools should be encouraged.