Louse in the house
Headlice are about as loathed and feared as they are common – and they breed misconceptions to match. Christina Lanzito offers some answers to the head- scratching they generate.
Headlice: The thought of them alone is enough to make your scalp itch. They are a year- round scourge, and an international one. And there are almost as many misconceptions about the parasites as there are critters.
M J Eckert, a former school nurse who set up a business to offer an in- home lice treatment and removal service, says she once met a father who had used a highpowered shop vacuum on his son’s infested head, hoping to suck the problem away. Another family threw out a sleeper sofa in the middle of the night, convinced that it was the source of an intractable lice infestation. Neither approach worked.
First, some facts: The head louse is a six- legged wingless insect known as an ectoparasite, meaning that it makes its home on a host’s surface. It’s related to the body louse which, unlike the head louse, can carry disease. The animal needs blood and a warm environment to survive. That’s why it finds such comfort in the human scalp; it also likes to root itself in the nape of the neck and behind the ears.
Once it has set up shop, the insect lays pinhead- size tan or whitishcoloured eggs, known as nits. The mother louse excretes a kind of glue to cement the nits to the hair shaft, close to the scalp so its warmth can incubate them. They hatch about a week later into baby lice, called nymphs.
In a typical infestation, there are more nits than bugs since an adult louse will lay an average of five to 10 eggs a day and a newborn female needs only 10 days to become a mother. So the family tree grows quickly.
Headlice are undeniably gross. Eckert says she faces tears and panic from parents every day. ‘‘ Seeing [ lice] in their kid’s hair,’’ Eckert says, ‘‘ makes a normally sane person insane.’’
And yet, as New Zealand’s Ministry of Education points out on its website, ‘‘ a population is likely to host headlice most of the time. Infestation levels fluctuate for no apparent reason and sometimes headlice appear to be epidemic while at other times they appear to be absent.’’
They are not confined to schools, but can be spread through churches, supermarkets, sports fields and homes.
It doesn’t help that there’s such confusion about how the little beasts operate. Here are a few common myths:
get
lice if You’re more likely to you’re dirty.
‘‘ Headlice [ infestation] has nothing to do with hygiene,’’ says American paediatric infectiousdisease expert Andrew Bonwit. ‘‘ It has to do with whether the person was exposed to someone with headlice.’’ Bonwit says a louse doesn’t have discriminating tastes: It wants warmth for its eggs and a regular ‘‘ blood meal’’. It doesn’t matter if the dish is dirty or clean. Your pet can carry lice. Lice feed only on humans. Fleas and ticks are another story. Lice can jump and fly. No. They just crawl. That’s why kids are so much more likely than adults to have lice: They often touch heads when interacting, whether playing or talking or sleeping together at sleepovers ( which are top- notch settings for lice transmission). A few lice can quickly scuttle over hair to a new head while, say, kids press close to take photos, snuggle up to watch a movie or share a pillow. While adults can get lice from their children, they rarely are the family members to bring the bugs home. ( As Bonwit points out, ‘‘ In the typical office, there’s probably not a whole lot of hugging going on.’’)
Your house can get infested with lice.
While scientists
agree
that
lice almost always spread by crawling from head to head, they’re less sure how often they travel from head to pillow to head.
The bugs ‘‘ probably don’t voluntarily leave a scalp’’, says Dale Clayton, a lice expert and biology professor at the University of Utah in the United States. ‘‘ Because if you think about it, that’s dangerous for them. But they may get brushed off from time to time.’’
Eckert says she tries to reassure clients that ‘‘ lice are very good at holding on to hair’’.
‘‘ And they are not microscopic. You’re going to see them if they’re on a pillow.’’
She also says there’s no need to wash everything in a home where lice have been spotted; she’ll tell people to wash their bedding, not because there are bugs in the bed ( there probably aren’t – and if there are, they’re dying) but because lice leave droppings, which look like tiny dark specks.
‘‘ You don’t want to be sleeping on lice excrement,’’ she says.
You need special over- thecounter shampoos to get rid of the lice and nits.
Such shampoos can kill live lice – but not always and not all of them.
Many lice have developed resistance to the most common active ingredients, permethrin and pyrethrins. And they don’t kill all of the nits. In fact, use of these products has led to super lice, bugs that are developing a resistance to some insecticides.
‘‘ Evolutionary resistance gotten much worse in the past 20 years,’’ Clayton says.
When he grew up in the 1960s, he says, ‘‘ I never heard of anybody who had lice. Now they’re very, very common.’’
But Eckert says that, pesticide resistance or no, the key is ‘‘ meticulous combing’’ with a fine- toothed metal comb that removes the eggs from the hair shaft. You can suffocate lice. Eckert says she’ll show up for house calls and parents will come to the door with their child’s hair covered in petroleum jelly, wrapped in plastic and topped with a shower has 10 or cap. ‘‘ They read online somewhere that you can suffocate lice with Vaseline, olive oil or mayonnaise,’’ she says.
‘‘ They get dubious results at best, and it’s not going to kill the nits.’’
If you have lice, your head will be itchy.
Many people with lice don’t itch. For those who do, the itchiness may not begin until a few weeks into the infestation. Since head scratching isn’t always present as a warning sign, many experts suggest that parents do periodic lice checks on their children. Washington Post ( additional Fairfax NZ)
For background on headlice in New Zealand schools, go to the Ministry of Education webpage on the topic: http:// tinyurl. com/ 6b3xrcv.