The Economist: Zapping mosquitoes, and corruption

LIVE in a crowded South Asian city and a host of problems—smog, contagious disease, corruption—may plague you. Each winter, the air grows foul. The monsoon season brings mosquitoes, bloodsuckers capable of carrying nasties such as dengue and malaria. As cities expand and people are packed closer, they are more likely to pass on infections. Overwhelmed municipalities, especially if weakened by corruption, offer a weak response. In Lahore, Pakistan’s second-most populous city, there were 21,292 confirmed dengue patients in 2011, a particularly dire year. At least 350 of them died, victims of associated haemorrhages or shock.

The usual response is to send out fogging lorries to spray a choking mixture of insecticide (such as DDT) and kerosene to kill mosquitoes. Public officials also advise residents to drain every reservoir of water near their homes. Mosquito larvae flourish in puddles, even inside old tyres or old flower pots. But foggers sometimes spread their helpful poison too liberally, where no dengue-infected mosquitoes are present, or too rarely, perhaps neglecting poor neighbourhoods. Municipal workers skip puddle-hunting, or fail to tip chemicals into ponds to kill the larvae. Crooked workers sell their insecticides or refuse to spray without bribes from residents.

Full article on The Economist.