A.L.
Been there... our kids have had worms pretty much each time we took them overseas. They are easily treated WITH PROPER DIAGNOSIS (like Dawn said, there are several kinds, and they require different medications). I think you should take the child to the doctor and you probably should be prepared to gather a stool sample so they can identify which worm it is, unless there is only one kind commonly in your area and the medical folks say they don't need a sample. If they do need a sample, it may take a day or so to get the sample and diagnosis, however don't stress about it--worms are not fatal/damaging in the short run. To avoid infection, he does need to wash his hands well, especially before eating and not put raw veggies/fruits/unpeeled seeds/etc in his mouth. Also, going without shoes can lead to infection. Good luck!