Background: Slaughterhouse workers are in direct contact with cattle nearly every day. The purpose of this study was to survey the presence and distribution of anti-Shiga toxin 1 (Stx1) immunoglobulin G (IgG) in slaughterhouse workers, enabling a study of the serologic response to this toxin while working in an area at high-risk of Stx-producing Escherichia coli (STEC) infection.
Methods: One thousand seven hundred and twenty-nine serum samples from healthy slaughterhouse employees were collected and surveyed by indirect enzyme-linked immunosorbent assay (ELISA).
Results: Among the 5 slaughterhouse positions, slaughterers had the highest distribution of anti-Stx1 IgG values by an ELISA. Based on the ELISA values, 25% (433/1729) of the workers had anti-Stx1 IgG. Slaughterers, residual products handlers, inspectors, livestock hygiene controllers, and grading testers had anti-Stx1 IgG-positive rates of 28%, 25%, 20%, 19%, and 17%, respectively. The ELISA values of anti-Stx1 IgG increased with increases in the number of years worked by slaughterers, but not by residual products handlers, inspectors, livestock hygiene controllers, or grading testers.
Conclusions: From these results, slaughterhouse workers are healthy and asymptomatic; slaughterers in particular are at high-risk for STEC exposure.