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Volume 23, Number 5—May 2017

Insecticide-Treated Nets and Protection against Insecticide-Resistant Malaria Vectors in Western Kenya

Eric Ochomo1Comments to Author , Mercy Chahilu1, Jackie Cook, Teresa Kinyari, Nabie M. Bayoh, Philippa West, Luna Kamau, Aggrey Osangale, Maurice Ombok, Kiambo Njagi, Evan Mathenge, Lawrence Muthami, Krishanthi Subramaniam, Tessa Knox, Abraham Mnavaza, Martin James Donnelly, Immo Kleinschmidt, and Charles Mbogo
Author affiliations: Kenya Medical Research Institute (KEMRI), Kisumu, Kenya (E. Ochomo, M. Chahilu, A. Osangale, M. Ombok); London School of Hygiene and Tropical Medicine, London, UK (J. Cook, P. West, I. Kleinschmidt); University of Nairobi, Nairobi, Kenya (T. Kinyari); US Centers for Disease Control and Prevention–Kenya, Nairobi (N.M. Bayoh); KEMRI, Nairobi (L. Kamau, E. Mathenge, L. Muthami); Ministry of Health, Nairobi (K. Njagi); Liverpool School of Tropical Medicine, Liverpool, UK (K. Subramaniam, M.J. Donnelly); World Health Organization, Geneva, Switzerland (T. Knox, A. Mnavaza); University of Witwatersrand, Johannesburg, South Africa (I. Kleinschmidt); KEMRI, Kilifi, Kenya (C. Mbogo); KEMRI–Wellcome Trust, Nairobi (C. Mbogo)

Main Article

Table 4

Incidence of malaria parasite infection in low– and high–insecticide resistance clusters by year, Kenya, 2013 and 2014*

Insecticide resistance
No. children
No. malaria episodes
Total follow-up time, person-years
Incidence, infections/person-year (95% CI)

RR (95% CI)
p value
RR (95% CI)
p value
Low resistance 290 114 51.6 2.2 (1.8–2.7) 1.0 1.0
High resistance 311 116 59.2 2.0 (1.6–2.4) 0.9 (0.5–1.6) 0.70 0.9 (0.5–1.6) 0.68
Per 10% increase in
mosquito mortality

1.0 (0.7–1.5)

1.0 (0.7–1.5)
Low resistance 433 224 80.7 2.8 (2.4–3.2) 1.0 1.0
High resistance 460 222 80.9 2.7 (2.4–3.1) 1.0 (0.7–1.4) 0.96 0.8 (0.5–1.2) 0.33
Per 10% increase in
mosquito mortality 1.0 (0.9–1.1) 0.90 1.1 (0.9–1.2) 0.24

*In 2013, low resistance was defined as mortality >88% and high resistance as mortality <88%. In 2014, low resistance was defined as mortality >67% and high resistance as mortality <67%. RR, rate ratio.

Main Article

1These authors contributed equally to this article.

Page created: April 14, 2017
Page updated: April 14, 2017
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