I am going to start a series of blog posts on lice. I thought I would write a little bit about their biology and how to get rid of them, for all the parents out there.
Head lice have not been found to transmit disease. They do not infect dirty people more than clean people and some really old studies found that lice will actually leave a sick person for a healthy person, fortunately we don’t do those types of experiments on people anymore. Head lice do not survive if they fall off the host (yep that’s you), in fact most head lice will be dead within 9-14 hours. Lice cannot even move round unless they are on hair. This means they are not likely to be in your bed, on your floors, on your stuffed animals or anywhere in your house except on your kids heads. Studies that have looked for lice in hats, bedding, combs etc. have found almost no evidence that lice are transmitted this way. In fact, the worst and most common issue with head lice is the itching caused by the bite from the louse.
Although they can infect anyone, lice are most common on children aged 3-12 and are widely spread throughout our school systems. Because lice move from head to head we have essentially set up a system that is perfect for these little buggers. We put a bunch of little people who don’t have any personal boundaries into a small area. Have you ever watched kids in a playground? They jump all over each other. If you are a parasite that spreads when people put their heads together this is the ideal system.
According to the World Health Organization, it is thought that around 10-20% of children are infested worldwide. In the United States alone, approximately 6-12 million infestations occur every year. Although these data are really hard to get so these numbers are estimates.
Parents have attacked this problem using every method from shaving their child’s head to covering the entire scalp with petroleum jelly, vinegar, and even toxic chemicals like kerosene. We have been evolving with lice for millions of years, and we are still struggling to understand and eradicate these parasites.
How to get rid of them?
There are a number of options. Many chemicals are available you can buy to put on your kids heads. As unappealing as this sounds it is a very common method. Unfortunately, lice around the world are evolving resistance to these pesticides so there is a chance it will not work, and the more we use them the more we promote resistance in these lice.
Manually removing the lice is an option. In fact the term “nit-picking” actually refers to doing just that. Nits are louse eggs so the term comes from picking lice and their eggs off peoples heads. This can take a long time and requires much patience. Missing a single louse may cause the infection to return. Lice tend to stay close to the base of the scalp, and the eggs are glued onto the hairs, using a louse comb and carefully going through small sections of the hair is the best method. If the eggs are found far from the base of the scalp (on longer hair) these are likely a hatched eggs that do not have a louse in it anymore or are not viable because they need the heat from the scalp to be incubated.
My most recent favorite method is the Louse-Buster. This is a machine that essentially blows hot air on the lice and dries them out until they die. It works on lice and eggs and it is unlikely they will be able to evolve resistance to being dried out. This has to be done by a trained professional so there is a company that will come out and blow-dry your kids heads for you.