English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Background  The widespread emergence of resistance to pyrethroids is a major threat to the gains made in malaria control. To monitor the presence and possible emergence of resistance against a variety of insecticides used for malaria control in Rwanda, nationwide insecticide resistance surveys were conducted in 2011 and 2013.    Methods  Larvae of  Anopheles gambiae sensu lato  mosquitoes were collected in 12 sentinel sites throughout Rwanda. These were reared to adults and analysed for knock-down and mortality using WHO insecticide test papers with standard diagnostic doses of the recommended insecticides. A sub-sample of tested specimens was analysed for the presence of knockdown resistance ( kdr ) mutations.    Results  A total of 14,311 mosquitoes were tested and from a sample of 1406 specimens, 1165 (82.9%) were identified as  Anopheles arabiensis  and 241 (17.1%) as  Anopheles gambiae sensu stricto . Mortality results indicated a significant increase in resistance to lambda-cyhalothrin from 2011 to 2013 in 83% of the sites, permethrin in 25% of the sites, deltamethrin in 25% of the sites and DDT in 50% of the sites. Mosquitoes from 83% of the sites showed full susceptibility to bendiocarb and 17% of sites were suspected to harbour resistance that requires further confirmation. No resistance was observed to fenitrothion in all study sites during the entire survey. The  kdr  genotype results in  An. gambiae s.s.  showed that 67 (50%) possessed susceptibility (SS) alleles, while 35 (26.1%) and 32 (23.9%) mosquitoes had heterozygous (RS) and homozygous (RR) alleles, respectively. Of the 591  An. arabiensis  genotyped, 425 (71.9%) possessed homozygous (SS) alleles while 158 (26.7%) and 8 (1.4%) had heterozygous (RS) and homozygous (RR) alleles, respectively. Metabolic resistance involving oxidase enzymes was also detected using the synergist PBO.    Conclusion  This is the first nationwide study of insecticide resistance in malaria vectors in Rwanda. It shows the gradual increase of insecticide resistance to pyrethroids (lambda-cyhalothrin, deltamethrin, permethrin) and organochlorines (DDT) and the large presence of target site insensitivity. The results demonstrate the need for Rwanda to expand monitoring for insecticide resistance including further metabolic resistance testing and implement an insecticide resistance management strategy to sustain the gains made in malaria control.

Susceptibility of Anopheles gambiae to insecticides used for malaria vector control in Rwanda