L.S.
I would talk to the teacher face to face, and when my daughter was in public school, I had been known to confront the parents who sent sick children to school as well. I didn't win any popularity contests, but what would typically happen is that my oldest would catch something at school, and bring it home to the baby, who was asthmatic. The whole time that my daughter was in public school, I spent my days working and going to college, then hanging out in the emergency room at night with one or both of the children. That year, the little one even got double pneumonia and ended up in the hospital. It was not a pleasant time for us, and removing them from school improved their health tremendously. I know that homeschooling is not an option for everybody, but I would make it known to the teachers and the parents that they need to teach their children some manners and also keep them home when they are sick.