What happens when we modify mosquitoes for disease prevention? A systematic review

Emerg Microbes Infect. 2020 Feb 11;9(1):348-365. doi: 10.1080/22221751.2020.1722035. eCollection 2020.

Abstract

The release of modified mosquitoes to suppress/replace vectors constitutes a promising tool for vector control and disease prevention. Evidence regarding these innovative modification techniques is scarce and disperse. This work conducted a systematic review, gathering and analysing research articles from PubMed and Biblioteca Virtual em Saúde databases whose results report efficacy and non-target effects of using modified insects for disease prevention, until 2016. More than 1500 publications were screened and 349 were analysed. Only 12/3.4% articles reported field-based evidence and 41/11.7% covered modification strategies' post-release efficacy. Variability in the effective results (90/25.7%) questioned its reproducibility in different settings. We also found publications reporting reversal outcomes 38/10.9%, (e.g. post-release increase of vector population). Ecological effects were also reported, such as horizontal transfer events (54/15.5%), and worsening pathogenesis induced by natural wolbachia (10/2.9%). Present work revealed promising outcomes of modifying strategies. However, it also revealed a need for field-based evidence mainly regarding epidemiologic and long-term impact. It pointed out some eventual irreversible and important effects that must not be ignored when considering open-field releases, and that may constitute constraints to generate the missing field evidence. Present work constitutes a baseline of knowledge, offering also a methodological approach that may facilitate future updates.

Keywords: Vector-borne diseases; Wolbachia; genetically modified mosquitoes; transgenesis.

Publication types

  • Systematic Review

MeSH terms

  • Animals
  • Animals, Genetically Modified*
  • Gene Transfer, Horizontal
  • Mosquito Control / methods*
  • Mosquito Vectors / genetics*
  • Mosquito Vectors / microbiology
  • Wolbachia

Grants and funding

We thank to Fundação para a Ciência e Tecnologia (FCT) for the funding through the following projects: PTDC/IVC – ESC T/2486/2014, UID/Multi/04413/2019, WARDEN – PTDC/SAU-PUB/30089/2017.