Staying ahead in the fight against lice

 作者:轩辕硌砻     |      日期:2019-03-03 01:05:00
By Rachel Nowak FEW scientists go further than Stephen Barker to keep his experimental subjects content. A parasitologist at the University of Queensland in Brisbane, he studies head lice. These creatures only have one food source: blood. Human blood, to be precise, and they like it fresh. “It’s ironic,” says Barker. “They’re bastards to kill when they’re on people and bastards to keep alive when they’re not.” So when it comes to mealtimes, Barker tapes a pill box with the bottom removed to one of his legs, pops in the insects, and lets them tuck in. It is not a pleasant experience, he says. “You can feel the sting as each one bites – but it’s the only way to keep the suckers alive.” Head lice, nits, cooties, or Pediculus humanus – call them what you will, they may seem like a medieval health problem that we should have licked by now. But as beleaguered parents know, we are a long way from winning the war against head lice. Cases appear to be on the up in many countries, including the UK. Lice rapidly evolve resistance to the chemical insecticides used to kill them, while physical methods of removing the bloodsuckers are tiresome and time-consuming so are often not carried out properly. All it takes is one child with a few lice surviving for a whole school to be re-infested, so parents can face a never-ending battle. Fortunately a number of sophisticated new strategies against these parasites are on the horizon. We are discovering the louse genes responsible for insecticide resistance,