Farmers, especially dairy farmers, could be putting their families at risk if they’re not cautious about cleanliness, according to an Ohio State University study.
For the study, researchers made four visits each to 52 rural households. Half were operating a dairy, sheep or beef cattle farm. Researchers collected samples and tested them for Listeria monocytogenes, a foodborne disease pathogen.
Although L. monocytogenes is widespread, it rarely causes illness – but when it does, the illness can be severe, as in the 2009 listeriosis outbreak at a Maple Leaf Foods plant in Toronto.
“Although we focused on looking for listeria, we actually were using it as a marker for any type of pathogen,” Jeffrey LeJeune, associate professor in the food animal health research program of Ohio State’s Agricultural Research and Development Center, said in a release.
Researchers took samples of food most likely to be contaminated with L. monocytogenes, including dairy products, leftovers, and ready-to-eat deli products.
They also collected samples from surfaces throughout the homes, including refrigerators, kitchen sinks, washing machines, and the bottoms of shoes or boots.
In farm households, they also took samples of work gloves. In non-farm households, they took samples from kitchen counters. The researchers also collected samples of both human and farm animal feces, since the organism can be found in the stools of infected animals and people.
Results showed that L. monocytogenes was much more likely to be found in farm households than non-farm rural homes. The chance of detecting L. monocytogenes at farm households was more than twice as great (54 per cent) than at non-farm rural households (23 per cent), primarily because of the fecal samples taken from farm animals.
Even more telling was when farm animal samples and food samples (which may have been contaminated at the store or otherwise outside of the household) were excluded from analysis. Then the odds of detecting L. monocytogenes in the home were 5.6 times higher at farm households.
In one farm household, a no-bake cookie tested positively for listeria of the same molecular fingerprint as was found in one of the farm animals.
“Farmers working with animals, particularly dairy cattle, need to take precautions not to carry contamination into the household,” said co-investigator Lydia Medeiros. “Clothing and shoes worn outside need to stay outside. And, since we found contamination on two washing machines, it may be a good idea to have a separate laundry area just for work clothes.”
LeJeune added that, although listeria showed up more in farm households than non-farm homes, it did appear in both.