Latent tuberculosis infection screening in foreign-born populations: a successful mobile clinic outreach model

Abstract

Objectives: We evaluated the efficacy of a mobile medical clinic (MMC) screening program for detecting latent tuberculosis infection (LTBI) and active tuberculosis.

Methods: A LTBI screening program in a MMC in New Haven, Connecticut, used medical surveys to examine risk factors and tuberculin skin test (TST) screening eligibility. We assessed clinically relevant correlates of total (prevalent; n = 4650) and newly diagnosed (incident; n = 4159) LTBI from 2003 to 2011.

Results: Among 8322 individuals, 4159 (55.6%) met TST screening eligibility criteria, of which 1325 (31.9%) had TST assessed. Similar to LTBI prevalence (16.8%; 779 of 4650), newly diagnosed LTBI (25.6%; 339 of 1325) was independently correlated with being foreign-born (adjusted odds ratio [AOR] = 8.49; 95% confidence interval [CI] = 5.54, 13.02), Hispanic (AOR = 3.12; 95% CI = 1.88, 5.20), Black (AOR = 2.16; 95% CI = 1.31, 3.55), employed (AOR = 1.61; 95% CI = 1.14, 2.28), and of increased age (AOR = 1.04; 95% CI = 1.02, 1.05). Unstable housing (AOR = 4.95; 95% CI = 3.43, 7.14) and marijuana use (AOR = 1.57; 95% CI = 1.05, 2.37) were significantly correlated with incident LTBI, and being male, heroin use, interpersonal violence, employment, not having health insurance, and not completing high school were significantly correlated with prevalent LTBI.

Conclusions: Screening for TST in MMCs successfully identifies high-risk foreign-born, Hispanic, working, and uninsured populations and innovatively identifies LTBI in urban settings.

FIGURE 1—

Tuberculin skin test screening algorithm for latent tuberculosis infection on the Community Health Care Van mobile medical clinic (n = 7484), New Haven, Connecticut, 2003–2011. Note. TB = tuberculosis; TST = tuberculin skin test. ^a459 additional patients who did not meet TST screening eligibility underwent TST screening and are not reported here.

FIGURE 2—

Newly diagnosed and previously diagnosed latent tuberculosis infection by US-born and top-4 foreign-born countries of origin. Note. LTBI = latent tuberculosis infection. Puerto Rico is shown separately because it has significantly higher incidence and prevalence than the US mainland. Newly diagnosed LTBI (incident LTBI = new TST-positive) plus prevalent LTBI (previous TST-positive) equals total prevalent LTBI (all TST-positive). ^aP < .01 for newly diagnosed LTBI for all foreign countries compared with United States. ^bP < .01 for previously diagnosed LTBI for Mexico, Jamaica, and Ecuador compared with the United States; P < .17 for Puerto Rico and Guatemala compared with the United States.