Feb 7, 2005 (CIDRAP News) The use of gloves by fast-food restaurant workers might be expected to result in cleaner food, but that isn't necessarily the case, according to a recent study published in the Journal of Food Protection.
Testing of flour tortillas bought at about 140 fast-food restaurants in Tulsa, Okla., and Wichita, Kan., showed that those handled by gloved workers were more than twice as likely to have coliform bacteria on them as were those handled by gloveless workers, the report says. However, the number of samples was not large enough to make the difference statistically significant. A finding of coliform bacteria (a general term for intestinal microbes) indicates that pathogenic bacteria could be present.
"Overall, the results of this study suggest that use of gloves by food handlers does not reduce bacterial contamination of foods and might even increase the risk of microbial contamination," says the report by Robert A. Lynch and colleagues at the University of Oklahoma Department of Occupational and Environmental Health in Oklahoma City.
The researchers collected 371 flour tortillas at restaurants from four fast-food chains in the two cities and tested them for bacteria. When ordering the food, the investigators observed whether or not the workers wore gloves, among other details. The researchers also collected 82 unopened packages of tortillas from the four chains and tested them to assess the background level of bacteria present before handling.
Gloves were used on 93% of 172 samples collected in Kansas, where gloves are required by state law, but on only 5% of 191 samples collected in Oklahoma, where they are not, the report says.
Overall, testing showed coliform bacteria on 6.5% (24 of 359) of samples for which data were complete. The coliform rate for samples prepared with gloved hands was 9.6%, versus 4.4% for samples handled without gloves. Though the sample was too small to show a significant difference, each of the two rates fell outside the other's 95% confidence interval, which suggests that a true difference is not unlikely, the report says.
The researchers found low rates of contamination when they tested for particular bacterial species: 0.3% (1 of 371 samples) for Escherichia coli, 2.2% (8 of 371) for Staphylococcus aureus, and 0.5% (2 of 371) for Klebsiella species. The investigators did not actually count bacterial organisms, however. No potentially pathogenic microbes were found on the unopened tortilla samples.
The authors write that the higher coliform bacteria rate associated with gloves suggests that food workers were not using gloves properly. "We observed several instances in which previously used gloves were reused, and we never observed glove wearers changing gloves in the midst of food preparation," they state. "Given the levels of surface bacteria that have been reported in food service settings, it is not surprising that organisms were transferred to the food that were tested."
They also say that food managers and workers prefer to use gloves because glove use is easier to monitor than handwashing is. However, "It has often been found that glove use provides a false sense of security because food handlers misuse gloves or neglect washing their hands when gloves are worn," the article concludes.
Lynch RA, Phillips ML, Elledge BL, et al. A preliminary evaluation of the effect of glove use by food handlers in fast food restaurants. J Food Prot 2005;68(1):187-90 [Abstract]