The spread of the Zika virus has caused as much of an uproar in public health as it has divided us on how to combat it. While governments and organizations have scrambled to find the most effective way to stop the spread of Zika, others have been creating new technologies and refining older methods to fight the root of the problem: the Aedes genus of mosquitoes. Even now with the virus’ spread declining, it’s important to understand our fighting capabilities against it should it – or any similar virus – return in the near future.
Most cases of the virus have been transmitted from human to human (through direct contact of body fluids), but the main culprits behind the spread of Zika (and numerous other diseases) are Aedes aegypti and Aedes albopictus, the former species of mosquito coming from Asia and latter from Africa. The first notable emergence of the virus in this recent epidemic dates back to around 2013, while its initial identification was in 1947.
Zika is usually not life threatening, but has no cure, commercially available vaccine, or simple prevention outside of bug spray and sexual abstinence, posing a huge challenge to the medical industry in terms of how and why it has been able to spread so fast. As of now, there is also no widely accepted strategy on fighting the mosquito effectively. However, there are a number of possible solutions being developed in hopes of finally stopping the spread of both mosquito and disease.
Researchers in Australia have been experimenting with artificially infecting the Aedes aegypti mosquito with a strain of bacteria called Wolbachia, which has been proven to stop the spread of the Dengue virus. Although the Aedes aegypti mosquitoes recently gained notoriety from spreading Zika, they have always been carriers of deadly disease such as yellow fever and chikungunya. What makes this project intriguing isn’t its immediate usefulness (which it has little in terms of directly fighting Zika) but instead its implication in using artificial biological means to curb the spread of mosquitoes, a possibility that will definitely need to be explored further in the future.
One of the more promising methods of obliterating mosquito populations lies in genetic modification, with Oxitec spearheading the effort on biologically engineering the Aedes aegypti mosquito. The company created an engineered mosquito (called OX513A) that contains added genes which produce a protein that inhibits cellular function and kills the mosquito. The protein can be “switched” on and off with an antidote, which is given to host mosquitoes so that they may live long enough to go and mate with females, while their offspring die shortly after birth. The strain of mosquitoes has gained approval and recommendations from the World Health Organization and the US Food and Drug Administration, along with hosting several successful trials in Brazil, Panama, and the Cayman Islands.
A new trial is set to take place in the Florida Keys after gaining approval from both Monroe County and its residents. While the engineered mosquitoes have been in development for years, there is some caution in determining what long term effects they can bring, if any. The FDA recently declared that the trial will have no significant impacts on the environment, but the widespread application of the engineered mosquito is still some time away.
The traditional and current primary tool to combat mosquito populations are insecticides, although their overall effectiveness has slightly deteriorated thanks to mosquitoes gaining increased resistance to the chemicals used. In turn, greater amounts of insecticides (and pesticides) are needed to actually kill the bugs, creating a feedback loop where the more chemicals used, the greater resistance the bugs gain. Many fear that this current strategy will create “super strains” of mosquitoes that are unaffected by any conventional pesticides. Insecticides also fail to kill mosquito populations that dwell within human occupied spaces, such as inside of someone’s house or furniture.
The greater current concern in insecticide spraying however, is its impact on the environment. One of the major insecticides used for aerial spraying in Miami Dade County, Dibrom (which has been sprayed for decades), has been protested against in the South Beach and Wynwood areas. In South Carolina, aerial spraying in response the outbreak have alarmingly killed millions of honey bees (an endangered species), in a state with no known Zika cases attributed to mosquitoes.
The less popular method of using mosquito traps is now on the table as several companies have started a new wave of innovation in how these traps work. In2care has created a trap that is unique in the fact it really doesn’t trap mosquitoes. Instead, it contaminates female mosquitoes with two bio agents – a larvicide that is spread to nearby breeding sites once the female leaves the trap, and a fungus that kills the mosquito after a few days – both of which are EPA approved.
Microsoft on the other hand is helping to develop a trap that doesn’t quite kill mosquitoes, but instead gives information through infrared readings on what types of mosquitoes enter it, helping to collect data and track different breeds in local areas that can potentially carry deadly diseases. The trap currently does not have the capability to differentiate mosquito breeds, but is being taught and programmed to as they collect more data in field tests.
A project in Brazil, dubbed “The Mosquito Killer Billboard,” has been developed to act as a trap and at the same time as a social awareness tool. The billboard which resides on sidewalks, immolates Human odor through spraying lactic acid and CO2, which apparently attracts mosquitoes in a 2.5 km area. Pedestrians can stroll on by and witness the mosquitoes trapped inside, with a message in the backdrop reading “This billboard kills hundreds of mosquitoes everyday.” The entire design is also open patented, allowing anyone or any municipality to replicate it as encouraged by its creators.
The effectiveness of this billboard trap however, is yet to be determined as it has only been installed in two separate locations within Rio de Janeiro. There is concern that it could actually be more destructive than beneficial, as attracting mosquitoes to high population areas may lead them to bite humans around the billboards instead of getting trapped inside of them.
In an effort to understand the Zika Virus more than necessarily fight it, new tactics for tracking the spread of the virus have emerged from the digital world. Using apps on your smart phones, research projects like Kinsa (based in Silicon Valley) and Kidenga (University of Arizona) are collecting health information from users on a global scale to give insight of how mosquitoes spread diseases in local areas, along with any other major illnesses.
Perhaps the most interesting application of the smartphone is to directly cure the virus instead of prevent it. #OpenZika (using IBM’s World Community Grid) is doing exactly that, using your smartphone or computer as one node in a greater pool of thousands of devices to create and solve experimental calculations based on chemical research conducted by the team on the virus.
The threat of Zika in South Florida has temporarily subsided thanks to the cool and dry winter months, but spring and summer are just around the corner and the heat and humidity will very likely accompany a resurgence in Zika cases. That’s not to mention another fundamental problem that arose a year ago when the virus first hit Florida: a lack of funding and attention from legislatures at both state and federal levels, even with the international pressure to act. Political issues aside, without the proper tools and methods to fight the virus, our current strategies will be a waste of time and will prove useless in the event something more dire arrives.
For more information of the spread of Zika:
For more information on the Aedes aegypti and Aedes albopictus species of mosquito:
For more information on the use and consequences of insecticides:
For more information on the Wolbachia bacteria:
For more information on the Oxitec bio-engineered mosquito:
For more information on the traps being used and developed:
For more information on the digital applications being used: