Reemergence of Anopheles funestus as a vector of Plasmodium falciparum in western Kenya after long-term implementation of insecticide-treated bed nets.
Historically, the malaria vectors in western Kenya have been Anopheles funestus, Anopheles gambiae s.s., and Anopheles arabiensis. Of these species, An. funestus populations declined the most after the introduction of insecticide-treated bed nets (ITNs) in the 1990s in Asembo, and collections of An. funestus in the region remained low until at least 2008. Contrary to findings during the early years of ITN use in Asembo, the majority of the Anopheles collected here in 2010 and 2011 were An. funestus. Female An. funestus had characteristically high Plasmodium falciparum sporozoite rates and showed nearly 100% anthropophily. Female An. funestus were found more often indoors than outdoors and had relatively low mortality rates during insecticide bioassays. Together, these results are of serious concern for public health in the region, indicating that An. funestus may once again be contributing significantly to the transmission of malaria in this region despite the widespread use of ITNs/long-lasting insecticidal nets (LLINs).
Department of Entomology, Michigan State University, East Lansing, Michigan; Department of Biomedical Science and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kenya; Centre for Global Health Research, Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya; Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia; Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan.
Robert S
RS
McCann
Eric
E
Ochomo
M Nabie
MN
Bayoh
John M
JM
Vulule
Mary J
MJ
Hamel
John E
JE
Gimnig
William A
WA
Hawley
Edward D
ED
Walker
D000818:Animals; D000852:Anopheles / Q000145:classification / Q000469:parasitology*; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000145:classification / Q000469:parasitology*; D057148:Insecticide-Treated Bednets; D007630:Kenya; D016778:Malaria, Falciparum / Q000635:transmission*; D010963:Plasmodium falciparum; D034101:Sporozoites