A Second Chance to Tackle African Malaria Vector Mosquitoes that Avoid Houses and Don't Take Drugs

Sometimes history gives us a second chance by repeating itself. The timely and lucid modeling analysis presented by Phillip Eckhoff in this issue1 reminds us all that the challenges and opportunities faced by the malaria control community today remain remarkably similar to those of our predecessors who undertook the Global Malaria Eradication Campaign (GMEP). The anti-malarial drugs we use in 2013 are relatively new to the front lines but they are still overwhelmingly used in the same way for reactive clinical management of symptomatic cases.2 Long-lasting insecticidal nets (LLINs) now offer a proven alternative to indoor residual spraying (IRS) as the front-line vector control tool of the GMEP era but both approaches target mosquitoes within the same indoor environment and evidence that combining the two yields incremental benefits remains mixed.3–7 Although efficacious vaccines against malaria now exist and their expected impacts are simulated here,1 the protection they confer is partial and may wane8 as naturally acquired immunity fades9 and/or naturally acquired skin stage infections induce immunotolerance of pre-erythrocytic stages.10 Therefore, the fundamental properties, applications, and limitations of “off-the-shelf” intervention options available to control program managers today have not dramatically changed since the heyday of GMEP optimism half a century ago.11 And neither have the most fundamental knowledge gaps we face. The white arrows in Figure 1 crudely illustrate the impacts of intervention strategies we have reasonable experience and understanding of (suppression of high transmission with LLINs or IRS and elimination of sparse residual human parasite reservoirs with drugs), whereas the dark arrows illustrate those we urgently need to develop and learn about through trial and error (long-term resistance management, programmatic-scale vector control outdoors or at source, elimination of mosquito-to-human transmission during the dry season with vaccines, novel vector control tools, or chemoprophylaxis).