Louisa Messenger (Environmental and Occupational Health) co-published an article titled, "Effectiveness of long-lasting insecticidal nets with pyriproxyfen-pyrethroid, chlorfenapyr-pyrethroid, or piperonyl butoxide-pyrethroid versus pyrethroid only against malaria in Tanzania: final-year results of a four-arm, single-blind, cluster-randomised trial," in The Lancet Infectious Diseases.

New classes of long-lasting insecticidal nets (LLINs) containing two active ingredients have recently been recommended by WHO in areas where malaria vectors are resistant to pyrethroids. This policy was based on evidence generated by the first two years of the researchers' published trial in Tanzania. This article reports the final third-year trial findings which are necessary for assessing the long-term effectiveness of new classes of LLIN in the community and the replacement intervals required.