Latent tuberculosis among Latino migrant farmworkers in Connecticut

It is estimated that the prevalence rate of latent tuberculosis infection (LTBI) for the United States general population is less than 5%. The prevalence of LTBI among Connecticut migrant workers has not been reported. This study was designed to determine the prevalence of a positive tuberculin skin test (TST), a potential measure of LTBI in migrant workers, at one Connecticut farm.

A two-step standardized TST was performed on farmworkers recruited in a migrant clinic setting. Those with negative results on the first-step were offered the second. Workers with positive results were referred to community health centers for assessment and examined by a physician investigator.

Seventy-nine male workers were recruited from a population of approximately 200. Of these, 57 consented to the first-step TST, and 26% tested positive. Over 96% of the 57 tested workers were from Mexico. None had symptoms or signs of active tuberculosis.

This study suggests that a high percentage of asymptomatic Connecticut Latino migrant farmworkers have LTBI. This finding has public health implications for TB control strategies in the state.