Anopheles mosquito surveillance in Madagascar reveals multiple blood feeding behavior and Plasmodium infection

PLoS Negl Trop Dis. 2019 Jul 5;13(7):e0007176. doi: 10.1371/journal.pntd.0007176. eCollection 2019 Jul.

Abstract

Background: The Madagascar National Strategic Plan for Malaria Control 2018 (NSP) outlines malaria control pre-elimination strategies that include detailed goals for mosquito control. Primary surveillance protocols and mosquito control interventions focus on indoor vectors of malaria, while many potential vectors feed and rest outdoors. Here we describe the application of tools that advance our understanding of diversity, host choice, and Plasmodium infection in the Anopheline mosquitoes of the Western Highland Fringe of Madagascar.

Methodology/principal findings: We employed a modified barrier screen trap, the QUadrant Enabled Screen Trap (QUEST), in conjunction with the recently developed multiplex BLOOdmeal Detection Assay for Regional Transmission (BLOODART). We captured a total of 1252 female Anopheles mosquitoes (10 species), all of which were subjected to BLOODART analysis. QUEST collection captured a heterogenous distribution of mosquito density, diversity, host choice, and Plasmodium infection. Concordance between Anopheles morphology and BLOODART species identifications ranged from 93-99%. Mosquito feeding behavior in this collection frequently exhibited multiple blood meal hosts (single host = 53.6%, two hosts = 42.1%, three hosts = 4.3%). The overall percentage of human positive bloodmeals increased between the December 2017 and the April 2018 timepoints (27% to 44%). Plasmodium positivity was frequently observed in the abdomens of vectors considered to be of secondary importance, with an overall prevalence of 6%.

Conclusions/significance: The QUEST was an efficient tool for sampling exophilic Anopheline mosquitoes. Vectors considered to be of secondary importance were commonly found with Plasmodium DNA in their abdomens, indicating a need to account for these species in routine surveillance efforts. Mosquitoes exhibited multiple blood feeding behavior within a gonotrophic cycle, with predominantly non-human hosts in the bloodmeal. Taken together, this complex feeding behavior could enhance the role of multiple Anopheline species in malaria transmission, possibly tempered by zoophilic feeding tendencies.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Anopheles / parasitology*
  • Anopheles / physiology*
  • Blood
  • Disease Vectors
  • Epidemiological Monitoring
  • Feeding Behavior*
  • Female
  • Host-Parasite Interactions
  • Humans
  • Madagascar
  • Malaria / prevention & control*
  • Malaria / transmission
  • Mosquito Control / methods*
  • Plasmodium / physiology

Grant support

Stipend support for R. E. Tedrow was provided by the United States Navy Health Services Collegiate Program. Additional support was provided to P. A. Zimmerman through the CWRU School of Medicine. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.