A Novel Assay for Simultaneous Assessment of Mammalian Host Blood, Mosquito Species, and Plasmodium spp. in the Medically Important Anopheles Mosquitoes of Madagascar

Am J Trop Med Hyg. 2019 Mar;100(3):544-551. doi: 10.4269/ajtmh.18-0782.

Abstract

Anopheles mosquitoes vary in habitat preference, feeding pattern, and susceptibility to various measures of vector control. Consequently, it is important that we identify reservoirs of disease, identify vectors, and characterize feeding patterns to effectively implement targeted control measures. Using 467 anopheline mosquito abdomen squashes captured in Madagascar, we designed a novel ligase detection reaction and fluorescent microsphere assay, dubbed Bloodmeal Detection Assay for Regional Transmission (BLOODART), to query the bloodmeal content, identify five Anopheles mosquito species, and detect Plasmodium infection. Validation of mammalian bloodspots was achieved by preparation and analysis of known hosts (singular and mixed), sensitivity to degradation and storage method were assessed through mosquito feeding experiments, and quantification was explored by altering ratios of two mammal hosts. BLOODART identifications were validated by comparison with mosquito samples identified by sequenced portions of the internal transcribed spacer 2. BLOODART identification of control mammal bloodspots was 100% concordant for singular and mixed mammalian blood. BLOODART was able to detect hosts up to 42 hours after digestion when mosquito samples were stored in ethanol. A mammalian host was identified in every field-collected, blood-fed female Anopheles mosquito by BLOODART. The predominant mosquito host was cow (n = 451), followed by pig (n = 26) and human (n = 25). Mixed species bloodmeals were commonly observed (n = 33). A BLOODART molecular identification was successful for 318/467 mosquitoes, with an overall concordance of 60% with all field-captured, morphologically identified Anopheles specimens. BLOODART enables characterization of large samples and simultaneous pathogen detection to monitor and incriminate disease vectors in Madagascar.

MeSH terms

  • Animals
  • Anopheles / genetics
  • Anopheles / parasitology*
  • Feeding Behavior*
  • Fluorescent Antibody Technique
  • Host Specificity
  • Humans
  • Madagascar
  • Mammals / blood*
  • Plasmodium / isolation & purification*
  • Species Specificity