Detection of latent tuberculosis infection among migrant farmworkers along the US-Mexico border

BMC Infectious Diseases

Research Article

E. Oren¹  E. Barrett¹  M. H. Fiero¹  B. Anderson¹  F. Gonzalez-Salazar²  M. Nuῆez³ 

[1] Department of Epidemiology & Biostatistics, Mel and Enid Zuckerman College of Public Health, University of Arizona, P.O. Box 245211, 1295 N. Martin Ave., 85724, Tucson, AZ, USA;Mexican Social Security Institute, Juárez, México City, Mexico;University of Monterrey, Avenida Ignacio Morones Prieto 4500 Pte., Jesús M. Garza, 66238, San Pedro Garza García, NL, Mexico;Yuma County Health Services District, 2200 W 28th St, 85364, Yuma, AZ, USA;

关键词: Latent tuberculosis infection;    Interferon-gamma release assay;    Tuberculin skin test;    Migrants;   

DOI  :  10.1186/s12879-016-1959-3

 received in 2016-05-11, accepted in 2016-10-25,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundMigrant farmworkers are among the highest-risk populations for latent TB infection (LTBI) in the United States with numerous barriers to healthcare access and increased vulnerability to infectious diseases. LTBI is usually diagnosed on the border using the tuberculin skin test (TST). QuantiFERON-TB Gold In-Tube (QFT-GIT) also measures immune response against specific Mycobacterium tuberculosis antigens. The objective of this study is to assess the comparability of TST and QFT-GIT to detect LTBI among migrant farmworkers on the border, as well as to examine the effects of various demographic and clinical factors on test positivity.MethodsParticipants were recruited using mobile clinics on the San Luis US-Mexico border and tested with QFT-GIT and TST. Demographic profiles and clinical histories were collected. Kappa coefficients assessed agreement between TST and QFT-GIT using various assay cutoffs. Logistic regression examined factors associated with positive TST or QFT-GIT results.ResultsOf 109 participants, 59 of 108 (55 %) were either TST (24/71, 34 %) or QFT-GIT (52/106, 50 %) positive. Concordance between TST and QFT-GIT was fair (71 % agreement, ĸ = 0.38, 95 % CI: 0.15, 0.61). Factors associated with LTBI positivity included smoking (OR = 1.26, 95 % CI–1.01–1.58) and diabetes/high blood sugar (OR = 0.70, 95 % CI = 0.51–0.98).DiscussionTest concordance between the two tests was fair, with numerous discordant results observed. Greater proportion of positives detected using QFT-GIT may help avoid LTBI under-diagnosis. Assessment of LTBI status on the border provides evidence whether QFT-GIT should replace the TST in routine practice, as well as identifies risk factors for LTBI among migrant populations.

【 授权许可】

CC BY   
© The Author(s). 2016