Alternative vector control methods to manage the Zika virus outbreak: more haste, less speed

As stated by Laith Yakob and Thomas Walker,1Yakob L Walker T Zika virus outbreak in the Americas: the need for novel mosquito control methods.Lancet Glob Health. 2016; 4: e148-e149Summary Full Text Full Text PDF PubMed Scopus (127) Google Scholar the need for efficient and novel mosquito control methods in the context of the Zika virus outbreak is undisputed. However, technologies such as Release of Insects carrying Dominant Lethal genes (RIDL) are not flawless. Transgenic Aedes aegypti larvae die if they are not fed with a diet supplemented with an antibiotic (tetracycline). However, deprivation of the mosquitoes from the antibiotic results in 5% survival of transgenic larvae,2Curtis Z Matzen K Oviedo MN et al.Assessment of the impact of potential tetracycline exposure on the phenotype of Aedes aegypti OX513A: implications for field use.PLoS Negl Trop Dis. 2015; 9: e0003999Crossref Scopus (15) Google Scholar resulting in the uncontrolled diffusion of the transgene in large-scale deployment in the field. Moreover, tetracycline is widespread in surface waters in countries where the Zika virus is rapidly progressing, including Brazil.3Locatelli MAF Sodré FF Jardim WF Determination of antibiotics in Brazilian surface waters using liquid chromatography–electrospray tandem mass spectrometry.Arch Environ Contam Toxicol. 2011; 60: 385-393Crossref PubMed Scopus (127) Google Scholar By contrast, the Sterile Insect Technique (SIT) is safe and is undergoing field validation against A aegypti and Aedes albopictus, but has received little attention to date. SIT does not raise public opposition or require regulatory approvals and no intellectual property issues are involved. Most importantly, the released sterilised insects cannot become established in nature. We believe that the SIT could be further boosted by use of sterile males as conveyors of biocides to their wild counterparts.4Bouyer J Lefrançois T Boosting the sterile insect technique to control mosquitoes.Trends Parasitol. 2014; 30: 271-273Summary Full Text Full Text PDF PubMed Scopus (59) Google Scholar A European project, titled Revolutionizing insect control, was launched in 2016 to study the dispersion of densovirus (a species-specific natural entomopathogenic virus)5Carlson J Suchman E Buchatsky L Densoviruses for control and genetic manipulation of mosquitoes.Adv Virus Res. 2006; 68: 361-392Crossref PubMed Scopus (90) Google Scholar from sterile males to wild females and then to their larval habitats as a result of their skipping oviposition behaviour (figure). This strategy might enlarge the effect of the SIT, offering unprecedented opportunities for the control of Zika virus and other mosquito-borne diseases. Although transgenic mosquitoes might be exciting to the media, more biosafe alternatives should not be neglected. We declare no competing interests. This project has been selected for funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement No 682387—REVOLINC). This Correspodence reflects only the authors' views and the Agency is not responsible for any use that may be made of the information it contains. Alternative vector control methods to manage the Zika virus outbreak: more haste, less speed – Authors' replyIn response to our Comment1 promoting the development of novel approaches to controlling Aedes aegypti, Christophe Boëte and R Guy Reeves argue for the continued reliance on current techniques—mosquito breeding site management and adulticidal spraying—to contain the current Zika virus outbreak. We agree that inclusion of these more traditional approaches might be justified as part of a wider, integrated, vector management programme. However, current vector control strategies for A aegypti do not appear to be stopping the rapid increase in the number of dengue cases in recent decades in Brazil (figure).