Human antibody response to Anopheles saliva for comparing the efficacy of three malaria vector control methods in Balombo, Angola

PLoS One. 2012;7(9):e44189. doi: 10.1371/journal.pone.0044189. Epub 2012 Sep 24.

Abstract

Human antibody (Ab) response to Anopheles whole saliva, used as biomarker of Anopheles exposure, was investigated over a period of two years (2008-2009), in children between 2 to 9 years old, before and after the introduction of three different malaria vector control methods; deltamethrin treated long lasting impregnated nets (LLIN) and insecticide treated plastic sheeting (ITPS)--Zero Fly®) (ITPS-ZF), deltamethrin impregnated Durable (Wall) Lining (ITPS-DL--Zerovector®) alone, and indoor residual spraying (IRS) with lambdacyhalothrin alone. These different vector control methods resulted in considerable decreases in all three entomological (82.4%), parasitological (54.8%) and immunological criteria analyzed. The highest reductions in the number of Anopheles collected and number of positive blood smears, respectively 82.1% and 58.3%, were found in Capango and Canjala where LLIN and ITPS-ZF were implemented. The immunological data based on the level of anti-saliva IgG Ab in children of all villages dropped significantly from 2008 to 2009, except in Chissequele. These results indicated that these three vector control methods significantly reduced malaria infections amongst the children studied and IRS significantly reduced the human-Anopheles contact. The number of Anopheles, positive blood smears, and the levels of anti-saliva IgG Ab were most reduced when LLIN and ITPS-ZF were used in combination, compared to the use of one vector control method alone, either ITPS-DL or IRS. Therefore, as a combination of two vector control methods is significantly more effective than one control method only, this control strategy should be further developed at a more global scale.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angola
  • Animals
  • Anopheles / immunology*
  • Antibodies / blood
  • Antibodies / immunology*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin G / immunology
  • Male
  • Mosquito Control / methods
  • Public Health Surveillance
  • Saliva / immunology*

Substances

  • Antibodies
  • Immunoglobulin G

Grants and funding

This study received funding support from Diabetes Australia Research Trust Southern Australia (DART S.A.) and Drame PM was supported by a post-doctoral fellowship from “Fondation Infectiopôle Sud”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.