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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  In the final phase of China’s national programme to eliminate malaria by 2020, it is vitally important to monitor the resistance of malaria vectors for developing effective vector control strategies. In 2017 Shanghai declared that it had eliminated malaria; however, the insecticide resistance status of the primary malaria vector  Anopheles sinensis  remains unknown.    Methods  We examined the pyrethroid and organophosphate resistance of  An. sinensis via  a bioassay of two populations from the Chongming District of Shanghai. The voltage-gated sodium channel ( VGSC ) and acetylcholinesterase 1 ( ace-1 ) genes were partially sequenced to examine the association between resistance phenotype and target site genotype. In addition, the geographical distribution, polymorphism and genotype frequencies of insecticide resistance genes were examined using samples collected during routine mosquito surveillance in 2016 and 2017 from Chongming, Songjiang, Jiading and Qingpu Districts.    Results  In Chongming District, the  An. sinensis  population near Dongtan National Nature Reserve showed resistance to pyrethroids, sensitivity to organophosphate, no knockdown resistance ( kdr ) mutations in the  VGSC  gene, and a low frequency (1.71%) of the  ace-1  119S allele. An  An. sinensis  population near the Chongming central area (CM-Xinhe population) showed high resistance to pyrethroids and organophosphates and high frequencies of  kdr  1014F and 1014C (80.73%) and  ace-1  119S (85.98%) alleles. A significant association was detected between the homozygous  kdr  mutation 1014F/1014F and pyrethroid resistance in the CM-Xinhe population, indicating that the  kdr  mutation is probably recessive. Eight  kdr  genotypes with 1014F and 1014C substitutions were detected in the four surveyed districts of Shanghai. TTT and GGC/AGC were the dominant  kdr  allele and  ace-1  genotype, respectively, and were prevalent in most Shanghai  An. sinensis  populations.    Conclusions  On the basis of our assessment of insecticide resistance gene mutations in Shanghai, we identified a  kdr  mutation-free population in Chongming Dongtan. However, high frequencies of target-site mutations of insecticide resistance genes were observed in most areas of Shanghai. Bioassays of  An. sinensis  populations in the central Chongming District indicated the high insecticide resistance status of  An. sinensis  populations in Shanghai. We accordingly recommend a restriction on insecticide usage and development of effective integrated pest/vector management interventions to support disease control efforts.

parasites and vectors

Resistance to pyrethroid and organophosphate insecticides, and the geographical distribution and polymorphisms of target-site mutations in voltage-gated sodium channel and acetylcholinesterase 1 genes in Anopheles sinensis populations in Shanghai, China