Elimination &ITNs Bill Brieger | 13 Mar 2013 11:53 am
What Goes Around – Net Protection and Malaria Elimination
In 1998 Fred Binka and colleagues published an article that showed the value of living near someone with an insecticide treated net (ITNs), even if you did not have your own net. They documented a 6.7% increase in likelihood of malaria mortality in children for each 100 meter shift away from a house with ITNs the non-user was located.
Then Otten et al. looked at the effects of a short campaign in 2006 to distribute ITNs to children during immunization campaigns and ACTs through CHWs in Rwanda. Eight months later 60% ITN coverage was documented. The interventions resulted in a greater than 50% decline in inpatient malaria cases and outpatient laboratory confirmed malaria cases among children even with less than optimal intervention coverage.
Now, these hints of success in net use have been modeled mathematically to achieve a more realistic target for net coverage instead of relying solely on arbitrary estimates like 80% or 85%. Agusto and colleagues have published their findings which propose that, “If 75% of the population were to use bed-nets, malaria could be eliminated.â€
“We conclude that more data on the impact of human and mosquito behavior on malaria spread (are) needed to develop more realistic models and better predictions.† Of particular concern is learning more about how human handling and mishandling of nets affect these estimates.
So what progress toward this potential target of 75% have we made? The attached chart was derived recent from Malaria Indicator and Demographic and Health Surveys. Except for the preliminary results of the Tanzania survey, most countries were not even close to the RBM target of 80% coverage for 2010, let alone a slightly more modest 75%. A frustrating trend is the fact that even in households that posses at least one net, children are not sleeping under them.
Now that we have more realistic targets, planning should be easier. Even so after all the push towards universal coverage since 2009, we still have a long way to go to reach targets, let alone talk of elimination.