Public Response to a Proposed Field Trial of Genetically Engineered Mosquitoes in the United States

Despite an increase in vector-borne diseases in the United States, there has been public opposition to novel vector control methods, particularly those that leverage advances in genetic engineering.¹ In 2016, the US Food and Drug Administration (FDA) invited public comments on a draft environmental assessment² for a proposed field trial of a genetically engineered mosquito (OX513A) designed to suppress wild-type Aedes aegypti mosquitoes, which can transmit diseases such as Zika, dengue, and chikungunya. Trials of OX513A in other countries have demonstrated reductions in numbers of A aegypti.³

The environmental assessment indicated the trial would be unlikely to adversely affect the environment in Key Haven, Florida, the proposed trial site. We assessed public response to this proposed trial based on the content of public comments submitted to the FDA because the views expressed in such public forums may influence testing and deployment. In addition, given that individual informed consent for such environmental interventions is not feasible, efforts to understand and respond to public concerns are critical for maintaining public trust in public health activities.⁴

The study was deemed exempt by the University of California, San Diego, institutional review board. Transcripts of comments from self-selected respondents to docket FDA-2014-N-2235 between March 11, 2016, and May 16, 2016, were obtained through the Freedom of Information Act. Content analysis was used to classify each comment as opposed, neutral, or supportive of the trial, and thematic analysis using both inductive and deductive approaches was conducted to identify additional themes in the data. To assess reliability, a primary rater coded all comments and a secondary rater coded a random 10% for each code (κ = 0.98 for opposed, neutral, and supportive classifications). Comments that included respondent zip code were geocoded and linked to publicly available geographic and sociodemographic data.⁵ Using SPSS Statistics (IBM), version 23, the Mood median test and χ² test for trend were used to analyze characteristics of comments and themes. A 2-sided P value less than .05 was considered significant.

Of 2649 comments submitted to the FDA, 2624 were analyzed after quality control. Median word count was 57.0 and 82.8% were from individuals. Most comments (74.8%) were opposed, 3.6% were neutral, and 21.6% were supportive of the trial (Table 1). Themes identified were ecological safety (51.2%), human health implications (67.3%), genetically modified organisms generally (65.1%), and mistrust of government or industry (23.6%). The greatest differences between comments opposing vs supporting were for human health (61.4% opposing comments vs 86.8% supporting comments; difference, −25.4%) and mistrust of government or industry (30.1% opposing comments vs 1.4% supporting comments; difference, 28.7%). Zip codes were available from 1125 comments (42.9%). Opposition was significantly associated with zip codes with micropolitan areas, higher elevations, lower average house values, and lower household incomes (Table 2).

This study found that members of the public who responded to a federal document had predominately negative views on the use of genetically engineered mosquitoes. Even though this group is unlikely representative of the general public,⁶ the vocal minority who have expressed views on this topic have influenced whether and where field trials may go forward, and therefore, it is worthwhile to understand those views. In August 2016, the FDA concluded that the proposed trial of OX513A would be unlikely to harm the environment. Due to opposition from the residents of Key Haven, Florida, however, the local mosquito control board did not approve the trial. Instead, 2 nonbinding referendums were put on the November ballot, 1 for Key Haven residents (35% in favor), and 1 for all of Monroe County (58% in favor). The mosquito control board then approved the trial but moved the trial site to another Monroe County location.

The associations observed between some demographic factors and opposed views might inform approaches to future public engagement strategies regarding the use of genetically engineered mosquitoes. Limitations of the study include the self-selected response and lack of information on respondent-level covariates. Future studies that incorporate representative sampling and evaluate educational attainment, media coverage, and proximity to A aegypti are required.

Accepted for Publication: June 23, 2017.

Corresponding Author: Cinnamon S. Bloss, PhD, Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr, Mail Code 0811, La Jolla, CA 92093-0811 (cbloss@ucsd.edu).

Author Contributions: Dr Bloss had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Bloss, Stoler.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Bloss, Bietz, Cheung.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Bloss, Stoler, Bietz, Cheung.

Obtained funding: Bloss.

Administrative, technical, or material support: Bloss, Stoler, Brouwer, Cheung.

Supervision: Bloss, Bietz.

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Bloss reports grant funding from the National Institutes of Health’s National Human Genome Research Institute. No other disclosures were reported.

Funding/Support: This work was supported by the 2016 Carmel Prize for Research Excellence from the Western Societies of Medicine (Dr Bloss).

Role of the Funder/Sponsor: The sponsor had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Additional Contributions: We thank the members of the public who posted their views to docket FDA-2014-N-2235. We also thank undergraduates Derek Deng, Rasheed Al Kotob, and Julia Herskovic (University of California, San Diego) for their assistance with data coding, as well as Robert Friedman, PhD (J. Craig Venter Institute), and Michael Kalichman, PhD (University of California, San Diego), for their insights regarding the initial code selection process. Rasheed Al Kotob was compensated for his work. All others listed were not compensated for their contributions.