The impact of pyrethroid resistance on the efficacy and effectiveness of bednets for malaria control in Africa

• Published in: eLife Vol. 5
• Main Authors: Churcher, Thomas S, Lissenden, Natalie, Griffin, Jamie T, Worrall, Eve, Ranson, Hilary
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 22-08-2016; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: Africa; Animals; Anopheles - physiology; bednets; Bioassays; Biological Assay - statistics & numerical data; Clinical trials; Culicidae; Epidemiology; Epidemiology and Global Health; Health aspects; Humans; Infection control; Insecticide Resistance - physiology; Insecticide-Treated Bednets - statistics & numerical data; Insecticide-Treated Bednets - supply & distribution; Insecticides; Malaria; Malaria - prevention & control; Malaria - transmission; Mathematical models; Methods; Models, Statistical; Mortality; mosquito; Mosquito Control - methods; Mosquito Vectors - physiology; Mosquitoes; Nets; Nitriles; Observations; Permethrin; Pesticide resistance; Pesticide Synergists - supply & distribution; Piperonyl butoxide; Piperonyl Butoxide - supply & distribution; Population; Prevention; Public health; Pyrethrins; pyrethroid resistance; Pyrethroids; Seasonal variations; Sensitivity analysis; United States > US; global health; pyrethroid resistance; epidemiology; P. falciparum; bednets; malaria; mosquito
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/elife.16090

Long lasting pyrethroid treated bednets are the most important tool for preventing malaria. Pyrethroid resistant Anopheline mosquitoes are now ubiquitous in Africa, though the public health impact remains unclear, impeding the deployment of more expensive nets. Meta-analyses of bioassay studies and experimental hut trials are used to characterise how pyrethroid resistance changes the efficacy of standard bednets, and those containing the synergist piperonyl butoxide (PBO), and assess its impact on malaria control. New bednets provide substantial personal protection until high levels of resistance, though protection may wane faster against more resistant mosquito populations as nets age. Transmission dynamics models indicate that even low levels of resistance would increase the incidence of malaria due to reduced mosquito mortality and lower overall community protection over the life-time of the net. Switching to PBO bednets could avert up to 0.5 clinical cases per person per year in some resistance scenarios.