In one scene from Harper Lee's novel, To Kill a Mockingbird, a teacher orders a dirty male student to go home to "get rid of the -- er, cooties," and one character calls the student "the filthiest human I had ever seen."

However moving the Lee story, the idea that lice is associated with filth is a myth, according to area nurses who work with children in schools and in summer camps.

"That's a misconception," says Crystal Nelson, lead nurse in the Hazelwood School District. "Lice have nothing to do with people not being clean. But there is that stigma."

Found on the head, lice live close to the scalp and feed on human blood several times a day, but they are not known to spread disease, according to the Centers for Disease Control and Prevention. A louse comes from an egg, or nit, laid by an adult female head louse. The nit later hatches and produces a nymph or immature louse, which matures into an adult within 12 days after hatching.

The CDC says parents might be able to detect a lice problem in some instances when a child has a tickling feeling of something moving in the hair or itching from bites of the louse. Other signs, the agency says, includes irritability and difficulty sleeping since head lice are most active in the dark, or sores resulting from scratching.

With the school term coming to a close, the next lice problem will show up when children head for summer camp, says Lisa Harnacker, manager of health services in the Parkway School District. Listen to the CDC's podcast about nitpicking, summer camp and head lice.

Unlike the lice scene in the novel, published more than half a century ago, teachers in modern classrooms don't embarrass the students suspected of having lice, Harnacker says.

"If we have to check a child's head, we do it very discreetly so that the other children aren't right there," she says. "Then we talk with individual parents. I talk all the time to parents whose children have had it, and it's very upsetting."

Since lice are not a reportable health condition, there are no exact figures on infestations, but at least 6 million cases are estimated annually. Regardless of the number, Harnacker says infestations are less of a public health concern than "a time-consuming nuisance. They are a great inconvenience for families because of the need to get rid of them. Children have to go home from school, and parents might have to take off from work." She and others say remedies include picking the nit from the hair shaft.

But nit picking and sending children home as soon as possible are another set of myths about head lice, according to the CDC. For just over a year, the CDC  has been saying that it isn't necessary to send children home from school if they have head lice, and that nitpicking can be overdone, citing the views of the American Association of Pediatrics and the national Association of School Nurses. Both groups advocate an end to the "no-nit" policy of requiring children to be free of nits before they return to school. 

The CDC says the "no-nit" policy should be discontinued because:

• Many nits are more than a fourth of an inch from the scalp, meaning they usually are not viable and are unlikely to hatch and become crawling lice. In addition, it says some nits may simply be empty shells or casings.

• Nits are cemeted to hair shafts and are very unlikely to be transferred successfully to other people.

• The burden of unnecessary absenteeism to the students, families and others outweighs the risks associated with head lice. It adds that misdiagnosis is common during nit checks by people with no medical background.

The lice problem varies from district to district. Nelson says a case might turn up "every couple of months," while Harnacker says head lice have shown up in nearly all Parkway elementary schools at some point during the school term. In addition, she says there's an occasional case where lice is passed on from a young sibling to a middle school or high school student.

Treatment varies as well, usually involving over-the-counter shampoos or prescription drugs. But there also are companies that offer treatment. The latest seems to be Bye Bye Bugz of Webster Groves. Owner Laura Eppolito uses an FDA-approved machine called the LouseBuster, developed at the University of Utah and marketed by a spinoff company called Larada Sciences. Eppolito completed training on the LouseBuster in December and now treats three or four customers a week.

"It's a cannister vacuum with a hose on it," she says."But it blows out heated air at a steady rate and force that hydrate the nits. It kills the nits and eggs." She says the heat is between 136 degrees and 138 degrees. Lice die when the temperature reaches 131 degrees, she says, adding that the heat isn't as intense as that coming from a hair dryer.

After about 30 minutes of treatment, she then spends about 30 more minutes combing the dead bugs from the hair. Her rate is $175 for a single treatment.

"It's 99 percent effective. Kids can go back to school the next day. After that, you're done. That's what parents really like because some treatments have several steps."

Eppolito got interested in lice treatment after her son came down with an infestation when at a summer camp in New Hampshire before the family moved back to St. Louis where she grew up.

"I am nurse and I've done a lot of head checks when I worked with kids at some of the camps," she says. "I didn't think much about treatment until my son had a case when he was about 9. I realized there weren't a lot of options and not many that guaranteed results."

In addition to building her LouseBuster business, she says she wants to work to dispel the myth among some that "if you have bugs in your hair, you must not be clean. In fact, lice prefer cleaner hair over dirtier hair, and they don't care how rich or poor you are."