A reduce and replace strategy for suppressing vector-borne diseases: insights from a deterministic model

PLoS One. 2013 Sep 4;8(9):e73233. doi: 10.1371/journal.pone.0073233. eCollection 2013.

Abstract

Genetic approaches for controlling disease vectors have aimed either to reduce wild-type populations or to replace wild-type populations with insects that cannot transmit pathogens. Here, we propose a Reduce and Replace (R&R) strategy in which released insects have both female-killing and anti-pathogen genes. We develop a mathematical model to numerically explore release strategies involving an R&R strain of the dengue vector Aedes aegypti. We show that repeated R&R releases may lead to a temporary decrease in mosquito population density and, in the absence of fitness costs associated with the anti-pathogen gene, a long-term decrease in competent vector population density. We find that R&R releases more rapidly reduce the transient and long-term competent vector densities than female-killing releases alone. We show that releases including R&R females lead to greater reduction in competent vector density than male-only releases. The magnitude of reduction in total and competent vectors depends upon the release ratio, release duration, and whether females are included in releases. Even when the anti-pathogen allele has a fitness cost, R&R releases lead to greater reduction in competent vectors than female-killing releases during the release period; however, continued releases are needed to maintain low density of competent vectors long-term. We discuss the results of the model as motivation for more detailed studies of R&R strategies.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes / genetics
  • Aedes / physiology*
  • Animals
  • Communicable Disease Control / methods*
  • Dengue / prevention & control*
  • Dengue / transmission*
  • Female
  • Genetic Engineering*
  • Insect Vectors / genetics
  • Insect Vectors / physiology*
  • Male
  • Models, Theoretical*
  • Time Factors