As we approach Memorial Day weekend, summer is just around the corner, as is mosquito season. There has been a lot of discussion about what that means for public health this year as the Zika virus spreads in South America and the Caribbean and infected travelers return to the US. Most experts agree that we will likely see at least some local mosquito-borne transmission of this virus in the States this summer because we’ve seen similar outbreaks of dengue and chikungunya in years past.
Yet despite early warning of Zika arrival and our recent experiences with mosquito-borne outbreaks, little additional investment has been made here to support mosquito control, and Congress is currently balking at providing emergency funding to support Zika preparedness and response. Actually, most mosquito control districts in the US have faced drastic budget cuts over time or have been de-funded completely within the past few decades. This had allowed mosquitoes to proliferate, relatively unchecked in temperate areas of the country. For instance, the Aedes aegypti and albopictus species of mosquitoes, which transmit Zika, dengue, chikungunya and Yellow Fever, have expanded their range geographically to cover much more of the US than was previously thought.
Now, with the specter of Zika approaching, and no vaccine or treatment likely to come for many months or years, mosquito control is our best and only available option to address this problem right away. Yet, mosquito control isn’t easy. Even in places like Florida and Hawaii, where investment is relatively robust, there are other barriers to reducing Aedes mosquito populations and preventing disease transmission. Eliminating breeding is difficult because the mosquitoes can breed in very small amounts of water and in hidden locations. In addition, mosquitoes are beginning to become resistant to some insecticides and larvicides, rendering these control measures less effective than ever before. In response to these difficulties, there are a number of approaches being considered and tested around the world including new insecticides, public awareness campaigns, and introduction of sterile (genetically modified) mosquitoes to outcompete and thus reduce mosquito populations.
One genetically modified Aedes aegypti mosquito, created by Oxitec, is being considered by the FDA for a field trial in the Florida Keys. However, this effort has been delayed, primarily due to public resistance to releasing the mosquito. We were interested in learning more about how the residents of the Key West neighborhood think about this issue.
In order to find out more, our group fielded a survey to the affected neighborhood in Florida last summer (before Zika had raised its ugly head). The goal of our study was to get a better understanding about local knowledge, attitudes, and beliefs regarding GM mosquitoes, and to gain insight into more effective approaches to community engagement surrounding mosquito control and disease reduction efforts. Our results provide a pre-Zika baseline of community attitudes toward GM mosquitoes, that is, to the best of our knowledge, unique in the rapidly growing scientific literature on the Zika virus.
What we found was that among residents who responded, there was indeed significant opposition to GM mosquito use. Reasons for this opposition included general concern about GM mosquitoes, but also specific worries that GM mosquitoes could pass on modified genes to other mosquitoes, people, or animals; that introduction of these mosquitoes could have unforeseen and potentially harmful effects on the ecosystem; and that use of GM mosquitoes could lead to introduction of other GM products into the community. Many of the concerns expressed by residents have been countered with data and information from Oxitec and the Florida Keys Mosquito Control District (FKMCD), but residents were still not convinced. It is clear that a sustained dialogue with the community regarding the safety and efficacy of GM mosquitoes needs to occur. If and when GM mosquitos are introduced, the community needs to understand and be comfortable with the potential benefits, risks, and uncertainties.
When we examined opposition to GM mosquitoes more closely, we also found that both women and people who had never had personal experience with a mosquito-borne disease like dengue, were significantly more likely to oppose GM mosquitoes, indicating that the perceived risks of GM mosquito use in those groups outweighed the perceived risks of mosquito-transmitted diseases.
Now that Zika is becoming a major issue of concern, we think that public perception and attitudes toward GM mosquito use may be changing. So, this study is also valuable in providing baseline information from which to evaluate any changes in attitudes. With concern about health effects from Zika widely publicized in the US, risk perception has increased, and residents may be more likely to accept GM mosquito use than they were last summer. For example, a recent nation-wide survey by Purdue University indicated that a majority of surveyed Americans support the use of GM mosquitoes to control Zika in the US.
Follow-up studies to understand how community engagement efforts can be better designed and how risk perception influences community acceptance of new interventions like GM mosquitoes are in the works!