Use of anthropophilic culicid-based xenosurveillance as a proxy for Plasmodium vivax malaria burden and transmission hotspots identification

PLoS Negl Trop Dis. 2018 Nov 12;12(11):e0006909. doi: 10.1371/journal.pntd.0006909. eCollection 2018 Nov.

Abstract

Vector-borne diseases account for more than 17% of all infectious diseases, causing more than one million deaths annually. Malaria remains one of the most important public health problems worldwide. These vectors are bloodsucking insects, which can transmit disease-producing microorganisms during a blood meal. The contact of culicids with human populations living in malaria-endemic areas suggests that the identification of Plasmodium genetic material in the blood present in the gut of these mosquitoes may be possible. The process of assessing the blood meal for the presence of pathogens is termed 'xenosurveillance'. In view of this, the present work investigated the relationship between the frequency with which Plasmodium DNA is found in culicids and the frequency with which individuals are found to be carrying malaria parasites. A cross-sectional study was performed in a peri-urban area of Manaus, in the Western Brazilian Amazon, by simultaneously collecting human blood samples and trapping culicids from households. A total of 875 individuals were included in the study and a total of 13,374mosquito specimens were captured. Malaria prevalence in the study area was 7.7%. The frequency of households with at least one culicid specimen carrying Plasmodium DNA was 6.4%. Plasmodium infection incidence was significantly related to whether any Plasmodium positive blood-fed culicid was found in the same household [IRR 3.49 (CI95% 1.38-8.84); p = 0.008] and for indoor-collected culicids [IRR 4.07 (CI95%1.25-13.24); p = 0.020]. Furthermore, the number of infected people in the house at the time of mosquito collection was related to whether there were any positive blood-fed culicid mosquitoes in that household for collection methods combined [IRR 4.48 (CI95%2.22-9.05); p<0.001] or only for indoor-collected culicids [IRR 4.88 (CI95%2.01-11.82); p<0.001]. Our results suggest that xenosurveillance can be used in endemic tropical regions in order to estimate the malaria burden and identify transmission foci in areas where Plasmodium vivax is predominant.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anopheles / genetics
  • Anopheles / parasitology*
  • Anopheles / physiology
  • Blood / parasitology
  • Brazil / epidemiology
  • Cost of Illness
  • Cross-Sectional Studies
  • DNA, Protozoan / blood
  • DNA, Protozoan / isolation & purification
  • Epidemiological Monitoring
  • Family Characteristics
  • Female
  • Gastrointestinal Tract / parasitology
  • Humans
  • Incidence
  • Malaria, Vivax / blood
  • Malaria, Vivax / epidemiology*
  • Malaria, Vivax / parasitology
  • Malaria, Vivax / transmission*
  • Mosquito Vectors / genetics
  • Mosquito Vectors / parasitology*
  • Mosquito Vectors / physiology
  • Plasmodium vivax / genetics
  • Plasmodium vivax / isolation & purification
  • Plasmodium vivax / pathogenicity
  • Plasmodium vivax / physiology*
  • Prevalence

Substances

  • DNA, Protozoan

Grants and funding

This work was supported by National Counsel of Technological and Scientific development (CNPq), Coordination for the Improvement of Higher Education Personnel (CAPES) and Research Support Foundation of Amazonas (FAPEAM) through PPSUS and PAPAC projects supported this study. Bill & Melinda Gates Foundation has also funded this study through TransEpi Project. PFPP and MVGL are level 1 fellows from CNPq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.