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

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.

Wolbachia: endosymbiont of onchocercid nematodes and their vectors

“…Similarly, use of other endosymbionts along with Wolbachia will help to accelerate the control of D. immitis through the use of genetically engineered Asaia bacteria for the expression of WSP from their Wolbachia endosymbionts [ 80 ]. However, the untoward effects of Wolbachia such as irreversible biological effects and reversal outcome on disease transmission [ 162 ] should be properly addressed before clinical trials. Successful introduction of Wolbachia infections in Anopheles gambiae, Anopheles stephensi and C. sonorensis cell lines may give a breakthrough in the control of malaria, African horse sickness, Schmallenberg, bluetongue and epizootic hemorrhagic disease.…”

Acquisition of Adaptive Traits via Interspecific Association: Ecological Consequences and Applications

“…Investigation of the mechanisms underlying such dynamics (e.g., modes of signaling between host and pathogen cells) might reveal ways to evaluate and mitigate the risks to humans, wildlife, and crops associated with coinfecting pathogens [36,37]. Additionally, since A. aegypti is a known vector of disease in humans and other animals [38], deeper understanding of when and how pathogens employ exogenous barricades within this particular host to exclude competitors could lead to human and animal health-related applications that complement existing approaches to modifying vectors to control disease [39].…”

Mosquito Larvicidal Activity of DNA Capped Colloidal Silver Nanoparticles

“…Rapid spreading of highly invasive mosquitoes and the diseases spread by them are responsible for killing more people than all the wars in history. [2][3] Nowadays several insecticides namely, DDT, organophosphorus, dieldrin, fenithothion and propoxur were widely used for mosquito prevention and control. Constant use of chemical insecticides leads to undesirable consequences including ecological imbalance and extinction of non-target organisms in the environment [4][5].…”