Global health number crunchers, led by Seattle’s Institute for
Health Metrics and Evaluation, have determined after an
exhaustive survey of medical and demographic records in 22 sub-
Saharan African countries that treated bed nets do protect
against malaria. Duh, you say. You might well think it’s a no-
brainer to ask if handing out hundreds of millions of
insecticide-treated bed nets in sub-Saharan Africa helps to
reduce malaria. But it’s not. To begin with, there are lots of
things that can — and do — reduce the incidence of malaria
deaths and illnesses. There is the practice of indoor household
spraying of insecticide, which has been increased along with the
massive campaign to distribute insecticide-treated nets (ITNs).
There also seems to be a routine ebb-and-flow of malaria
severity in the tropics. The disease, like many things in
nature, tends to alternate between severe and mild cycles. It’s
not clear why. And there was this confusing report recently,
about the unexplained decline in mosquito population