Vertebrate-Aedes aegypti and Culex quinquefasciatus (Diptera)-arbovirus transmission networks: Non-human feeding revealed by meta-barcoding and next-generation sequencing

PLoS Negl Trop Dis. 2020 Dec 31;14(12):e0008867. doi: 10.1371/journal.pntd.0008867. eCollection 2020 Dec.

Abstract

Background: Aedes aegypti mosquito-borne viruses including Zika (ZIKV), dengue (DENV), yellow fever (YFV), and chikungunya (CHIKV) have emerged and re-emerged globally, resulting in an elevated burden of human disease. Aedes aegypti is found worldwide in tropical, sub-tropical, and temperate areas. The characterization of mosquito blood meals is essential to understand the transmission dynamics of mosquito-vectored pathogens.

Methodology/principal findings: Here, we report Ae. aegypti and Culex quinquefasciatus host feeding patterns and arbovirus transmission in Northern Mexico using a metabarcoding-like approach with next-generation deep sequencing technology. A total of 145 Ae. aegypti yielded a blood meal analysis result with 107 (73.8%) for a single vertebrate species and 38 (26.2%) for two or more. Among the single host blood meals for Ae. aegypti, 28.0% were from humans, 54.2% from dogs, 16.8% from cats, and 1.0% from tortoises. Among those with more than one species present, 65.9% were from humans and dogs. For Cx. quinquefasciatus, 388 individuals yielded information with 326 (84%) being from a single host and 63 (16.2%) being from two or more hosts. Of the single species blood meals, 77.9% were from dogs, 6.1% from chickens, 3.1% from house sparrows, 2.4% from humans, while the remaining 10.5% derived from other 12 host species. Among those which had fed on more than one species, 11% were from dogs and humans, and 89% of other host species combinations. Forage ratio analysis revealed dog as the most over-utilized host by Ae. aegypti (= 4.3) and Cx. quinquefasciatus (= 5.6) and the human blood index at 39% and 4%, respectively. A total of 2,941 host-seeking female Ae. aegypti and 3,536 Cx. quinquefasciatus mosquitoes were collected in the surveyed area. Of these, 118 Ae. aegypti pools and 37 Cx. quinquefasciatus pools were screened for seven arboviruses (ZIKV, DENV 1-4, CHIKV, and West Nile virus (WNV)) using qRT-PCR and none were positive (point prevalence = 0%). The 95%-exact upper limit confidence interval was 0.07% and 0.17% for Ae. aegypti and Cx. quinquefasciatus, respectively.

Conclusions/significance: The low human blood feeding rate in Ae. aegypti, high rate of feeding on mammals by Cx. quinquefasciatus, and the potential risk to transmission dynamics of arboviruses in highly urbanized areas of Northern Mexico is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes / virology*
  • Animals
  • Arbovirus Infections / blood
  • Arbovirus Infections / transmission
  • Arbovirus Infections / veterinary*
  • Arboviruses / physiology*
  • Culex / virology*
  • DNA Barcoding, Taxonomic
  • Feeding Behavior
  • High-Throughput Nucleotide Sequencing
  • Host-Pathogen Interactions
  • Models, Biological
  • Mosquito Vectors / virology
  • Species Specificity
  • Vertebrates / blood
  • Vertebrates / virology*

Grants and funding

This work was performed under the auspices of CONACyT-MEXBOL (No. 295569) to MARP; IPN (SIP 20181120 and 20195706) to MARP, and a TAMU-CONACYT Collaborative Research Grant Program (2018-041-1) to MARP and GLH. AAA holds a doctoral scholarship from Consejo Nacional de Ciencia Y Tecnología (CONACYT), Mexico (291137/457158). Funding for LMHT and ARF was provided by the Department for Environment Food and Rural Affairs (DEFRA), Scottish Government and Welsh Government through grants SV3045 and the EU Framework Horizon 2020 Innovation Grant, European Virus Archive (EVAg, grant no. 653316). Funding for JGEF was provided by IPN (SIP 20196759, 20200873, and 20202442). PNDH would like to thank Canada First Research Excellence Fund and the government of Canada through Genome Canada and the Ontario Genomics Institute to the International Barcode of Life Project which also aided the work. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.