Context. —Cases of tuberculosis (TB) in the United States have declined for 4 consecutive years, but cases among foreign-born persons account for an increasing percentage. Objective. —To describe the risk of tuberculosis among foreign-born persons with respect to their length of residence in the United States. Design. Cross-sectional analysis of national surveillance data. Setting. —The United States. Patients. —All verified TB cases reported to the Centers for Disease Control and Prevention between 1986 and 1994. Main Outcome Measure. —Stratum-specific incidence rates of TB by age, place of birth, length of residence, age at arrival in the United States, or combinations of these variables. Results. —Several groups of persons from countries with a high prevalence of TB had incidence rates higher than 20 per 100 000 person-years more than 20 years after arrival. Among long-term residents, those who arrived in the United States after their fifth birthday had incidence rates of TB 2 to 6 times higher than those of similar age who arrived before their fifth birthday. A total of 45% of the TB cases were among persons younger than 35 years and an additional 18% were among persons who arrived in the United States before their 35th birthday. Conclusions. —Imported Mycobacterium tuberculosis infection (active or latent) is responsible for most TB cases among foreign-born persons in the United States. Detection of active cases among recent arrivals is the main priority in these populations, but many cases were in persons who arrived in the United States before the age of 35 years that could potentially have been avoided with preventive therapy. Elimination of TB in the United States may not be feasible using available diagnostic and treatment modalities without increased efforts to address the global burden of this disease.

https://jamanetwork.com/HttpHandlers/ArticlePdfHandler.ashx?journal=jama&articleId=417786&pdfFileName=jama_278_4_038.pdf

Long-term Risk of Tuberculosis Among Foreign-born Persons in the United States

American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America: Controlling Tuberculosis in the United States

There is little published information regarding treatment completion, safety, and efficacy of rifampin administered daily for 4 months-a recommended alternative to 9 months of isoniazid for therapy of latent tuberculosis infection. In an open-label randomized trial at a university-affiliated respiratory hospital, consenting patients whose treating physician had recommended therapy for latent tuberculosis infection were randomized to daily self-administered rifampin for 4 months or daily self-administered isoniazid for 9 months. Of 58 patients randomized to rifampin, 53 (91%) took 80% of doses, and 50 (86%) took more than 90% of doses within 20 weeks compared with 44 (76%) and 36 (62%) who took 80 and 90%, respectively, of doses of isoniazid within 43 weeks (relative risks: 80% of doses, 1.2 [95% confidence interval: 1.02, 1.4]; 90% of doses, 1.4 [1.1, 1.7]). Adverse events resulted in permanent discontinuation of therapy for two (3%) patients taking rifampin, and for eight (14%) patients taking isoniazid. Three patients developed drug-induced hepatitis--all were taking isoniazid. Total costs of therapy were significantly higher for isoniazid. In conclusion, completion of therapy was significantly better with 4 months of rifampin and major side effects were somewhat lower. Further studies are needed to assess the safety and efficacy of the 4-month rifampin regimen.

/pdf/treatment-completion-and-costs-of-a-randomized-trial-of-5978lnzdug.pdf

Treatment Completion and Costs of a Randomized Trial of Rifampin for 4 Months versus Isoniazid for 9 Months

Although tuberculosis (TB) screening of immigrants has been conducted for over 50 yr in many industrialized countries, its cost- effectiveness has never been evaluated. We prospectively compared the yield and cost-effectiveness of two immigrant TB screening programs, using close-contact investigation and passive case detection. Study subjects included all immigration applicants undergoing radiographic screening, already arrived immigrants requiring surveillance for inactive TB, and close contacts of active cases resident in Montreal, Quebec, Canada, who were referred from June 1996 to June 1997 to the Montreal Chest Institute (MCI), a referral center specializing in respiratory diseases. For all subjects seen, demographic data, investigations, diagnoses, and therapy were abstracted from administrative data bases and medical charts. Estimated costs of detecting and treating each prevalent active case and preventing future active cases, based on federal and provincial health reimbursement schedules, were compared with the costs for passively diagnosed cases of active TB. Over a period of 1 yr, the three programs detected 27 cases of prevalent active TB and prevented 14 future cases. As compared with passive case detection, close-contact investigation resulted in net savings of $815 for each prevalent active case detected and treated and of $2,186 for each future active case prevented. The incremental cost to treat each case of prevalent active TB was $39,409 for applicant screening and $24,225 for surveillance, and the cost of preventing each case was $33,275 for applicants and $65,126 for surveillance. Close-contact investigation was highly cost effective and resulted in net savings. Immigrant applicant screening and surveillance programs had a significant impact but were much less cost effective, in large part because of substantial operational problems.

https://www.atsjournals.org/doi/pdf/10.1164/ajrccm.162.6.2001111

Comparison of cost-effectiveness of tuberculosis screening of close contacts and foreign-born populations.

All adult immigrant applicants to Canada undergo chest radiographic screening for tuberculosis (TB). Tuberculin skin testing could reduce the number of chest X-rays, and identify more candidates for prophylaxis. We modeled the cost-effectiveness of chest radiography and tuberculin skin testing for TB prevention over a 20-yr time frame, among three simulated cohorts of 20-yr-old immigrants. Compared with no screening, radiographic screening prevented 4.3% of expected active TB cases in the highest risk cohort (50% TB-infected, 10% human immunodeficiency virus [HIV] seroprevalence), and 8.0% in the lowest risk cohort (5% TB-infected, 1% HIV seroprevalence). Tuberculin skin testing further reduced the expected incidence 8.0% and 4.0%, respectively. Compared with no screening, radiographic screening cost $3,943 Canadian per active TB case prevented in the highest risk cohort, and $236,496 per case prevented in the lowest risk group. Compared with radiographic screening, mass tuberculin skin testing cost $32,601 per additional case prevented in the highest risk group, and $68,799 per additional case prevented in the lowest risk group. Chest radiographic screening of young immigrants from countries with a high prevalence of TB is a relatively inexpensive means of TB prevention. Tuberculin skin testing is considerably less cost-effective. For immigrants from low-prevalence countries, both interventions are extremely costly with negligible impact. The cost-effectiveness of either strategy would be greatly enhanced by increased adherence to chemoprophylaxis recommendations. Radiographic screening of groups with a high prevalence of tuberculous infection will then likely save money.

https://www.atsjournals.org/doi/pdf/10.1164/ajrccm.161.3.9902005

Tuberculosis screening of immigrants to low-prevalence countries. A cost-effectiveness analysis.

Objective. —To compare tuberculin screening of all kindergartners and high school entrants (screen-all strategy) vs screening limited to high-risk children (targeted screening). Design. —Decision, cost-effectiveness, and cost-benefit analyses. Setting and Subjects. —Students in a large urban and rural county. Definitions. —High risk of tuberculous infection was defined as birth in a country with a high prevalence of tuberculosis. Low risk was defined as birth in the United States. Outcome Measures. —Tuberculosis cases prevented per 10000 children screened. Net costs, net cost per case prevented, benefit-cost ratio, and incremental cost-effectiveness. Results. —The screen-all strategy would prevent 14.9 cases per 10 000 children screened; targeted screening would prevent 84.9 cases per 10000 children screened. The screen-all strategy is more costly than no screening; the benefit-cost ratio is 0.58. Targeted screening would result in a net savings; the benefit-cost ratio is 1.2. Screening all children is cost saving only if the reactor rate is 20% or greater. The cost per additional case prevented for screening all children compared with targeted screening ($34 666) is more than twice as high as treatment and contact tracing for a case of tuberculosis ($16392). Conclusions. —Targeted screening of schoolchildren is much less costly than mass screening and is more efficient in prevention of tuberculosis. (JAMA. 1995;274:613-619)

Judy Lessler

Papers

School-Based Screening for Tuberculous Infection: A Cost-Benefit Analysis

A Cost-Benefit Analysis