In the United States, ants may carry the larva of the liver fluke, a flatworm that attaches itself to the livers of mammals and feeds on their blood. You can’t get this parasite from eating food touched by an ant - you have to actually eat an ant carrying fluke larva.
Welcome to the SDMB, sommy.
The item you’re commenting on is not a Straight Dope column by Cecil Adams but rather a Straight Dope Staff Report by SDSAB member Doug. Consequently, I’ll move this thread to the Comments on Staff Reports Forum.
It is appreciated if you can provide a link to the item when posting a thread in the comments forums. The staff report in question is Are ants disease-carriers?