The entomologists are scratching their heads as to the cause, but they speculate it may have to do with fourth-grade girls affinity for hugging each other, combing each other s hair and otherwise sharing physical contact. Koehler oversaw the study. Between 6 million and 12 million children are afflicted with head lice nationally each year, according to previous studies. Although the pests do not carry any diseases, they cause discomfort and may result in missed school as children are kept at home until the problem is controlled. Outbreaks are common in the fall, when children return to school, but head lice are a problem year-around, health officials say.
Many children respond to treatment quickly and without much problem.
But some children are chronically infested, or are unable to eliminate the pests despite repeated treatment. Koehler said school officials should take that information into account when screening children and trying to combat outbreaks. If they can focus in on the children most likely to have lice, they can save time and are more likely to have an impact on the problem quickly. While previous studies of the shampoos relied on tests of the products in laboratory conditions, Scherer removed lice from the 52 infested children immediately after they had been shampooed and monitored their fate. Teri Hardwick-Allen, a school nurse at Norton Elementary School, said that jibes with her experience trying to rid children of lice.