- In January 2018, lab-bred Aedes aegypti mosquitoes carrying wolbachia bacteria were released in South Miami, Florida
- It was the first phase of the Miami-Dade County Mosquito Reduction Test Program, which will release more wolbachia mosquitoes each week for several months — 666 million in all
- If preventing Zika was their aim, government officials missed the boat on this one; although Miami-Dade County was previously designated as a Zika cautionary area, that designation was removed June 2, 2017
- No Zika virus disease cases have been reported with illness onset in 2018 in the U.S., while in 2017 there were only four cases of Zika virus reported that were presumably acquired via local mosquitoes (two in Florida and two in Texas)
- There is a major push to combat mosquito-borne diseases in the continental U.S. with the use of lab-made and GE mosquitoes, even though in the U.S. mosquito-borne illnesses are not a grave threat, especially compared to other major public health crises like the opioid epidemic
In January 2018, lab-bred Aedes aegypti mosquitoes carrying wolbachia bacteria were released in South Miami, Florida. It was the first phase of the Miami-Dade County Mosquito Reduction Test Program, which targeted a one-half square-mile treatment area that received the altered mosquitoes and a corresponding control area within the city.
After initial monitoring, more wolbachia mosquitoes will be released into South Miami each week for several months1 — 666 million in all2 — with the ultimate goal of reducing mosquito populations and their potential for disease transmission.
The project is being conducted by the Miami-Dade County Mosquito Control & Habitat Management Division in collaboration with MosquitoMate, Inc., which created the technology. They’ve already been tested in Key West, Florida, (although due to Hurricane Irma, results of the tests are still pending),3 Kentucky, California and New York. Interest in releasing lab-made mosquitoes has peaked in recent years in response to the Zika virus scare, which has since petered out in the U.S.
If preventing Zika was their aim, government officials missed the boat on this one. Although Miami-Dade County was previously designated as a Zika cautionary area, that designation was removed June 2, 2017.4 No Zika virus disease cases have been reported with illness onset in 2018 in the U.S., according to the U.S. Centers for Disease Control and Prevention (CDC), while in 2017 there were only four cases of Zika virus reported that were presumably acquired via local mosquitoes (two in Florida and two in Texas).5
If Zika virus isn’t even circulating in the area, it’s unclear how the government plans to measure the “success” of their mosquito release in order to definitively say whether or not it’s helping anything. It’s curious timing, to say the least, unless there are some unknown beneficiaries behind the scenes.
Interestingly, the Daily Mail reported, “MosquitoMate also collaborated with Verily Life Sciences, an offshoot of Google’s parent company Alphabet Inc., and Fresno County’s Consolidated Mosquito Abatement District, this past summer to release the bacteria-infected mosquitoes in Fresno, California.”6
What Are Lab-Made Wolbachia Mosquitoes?
MosquitoMate’s lab-bred male mosquitoes are infected with wolbachia bacteria, which is naturally occurring in up to 60 percent of insect species, but not in Aedes aegypti mosquitoes. When the male wolbachia mosquitoes mate with female mosquitoes in the wild (which do not carry the bacteria), the resulting eggs do not hatch, which means the number of Aedes aegypti mosquitoes in the area should ultimately decrease.7
Male mosquitoes don’t bite humans, but rather feed off flower nectar. Female mosquitoes are the ones that require meals of blood in order to develop and lay eggs. Their bites are at best an itchy nuisance and, at worst, can transmit serious diseases like malaria, yellow fever, dengue, encephalitis, chikungunya and West Nile virus. This is why MosquitoMate only releases male mosquitoes.
That said, in the case of the wolbachia mosquitoes, once they’re released (and they already have been), there’s no stopping them from mingling with wild mosquitoes. While this may help to reduce the spread of certain viruses (although this remains to be seen), it may also have other unintended, as yet unknown consequences.
Mosquitoes infected with wolbachia were also released in Brazil and Colombia in 2017 as part of The Eliminate Dengue research program, an $18 million project funded in part by the Bill and Melinda Gates Foundation.
The altered mosquitoes were tested in open trials in dengue-affected communities since 2011, but not to the level as the 2017 tests, which released the insects in large, heavily populated urban areas. It took decades for researchers just to figure out how to introduce wolbachia into Aedes mosquito eggs, but once they did they started experimenting with releasing them into the wild.
Field tests suggest the bacteria spread to the vast majority of local mosquitoes, and as Eliminate Dengue said, is a “self-sustaining” system8 — which is both the point and the problem.
There’s No Failsafe With Wolbachia Bugs
In some cases, experimental GE mosquitoes have been genetically engineered to die in the absence of the antibiotic tetracycline (which is introduced in the lab in order to keep them alive long enough to breed). They were designed this way assuming they would not have access to that drug in the wild, a failsafe (though not a perfect one, especially since antibiotics are now showing up in waterways) to ensure that the GE insects could theoretically be removed from the environment if necessary.
This isn’t the case with wolbachia mosquitoes; now that they’re released, there’s no going back. While MosquitoMate’s wolbachia mosquito program involves only male insects, other programs exist that are releasing both females and males with the bacteria.
The World Mosquito Program is among them, which notes a potential problem with the male-only route: “This technique requires the release of a large number of male mosquitoes to reduce the overall mosquito population. As with insecticides, this technique would need to be reapplied over time as the population of mosquitoes gradually returns.”9
There’s also the potential ramifications to the ecosystem, which can occur whenever any species is removed or drastically reduced. While mosquitoes are primarily viewed as a nuisance and vector for deadly diseases like malaria, there may be “undesirable side effects” of eradicating them entirely, according to Florida University entomologist Phil Lounibos, Ph.D. BBC News reported:
“ … [Lounibos] says mosquitoes, which mostly feed on plant nectar, are important pollinators. They are also a food source for birds and bats while their young — as larvae — are consumed by fish and frogs. This could have an effect further up and down the food chain … He warns that mosquitoes could be replaced by an insect ‘equally, or more, undesirable from a public health viewpoint.’ Its replacement could even conceivably spread diseases further and faster than mosquitoes today.”
The World Mosquito Program operates under the premise that mosquitoes with wolbachiaare less able to transmit diseases to people. By releasing both male and female mosquitoes with wolbachia, the idea is to establish the bacteria in the entire mosquito population, which they say can occur over a small number of generations.
While male mosquitoes with wolbachia and female mosquitoes without it cannot successfully reproduce, male wolbachia mosquitoes that mate with female wolbachia mosquitoes produce offspring that also contain the bacteria. In addition, when female wolbachia mosquitoes mate with males without it, the offspring will still have wolbachia. According to the program:10
“[T]he World Mosquito Program’s Wolbachia method is unique because it is self-sustaining and does not need to be continually reapplied, making it an affordable, self-sustaining, long-term solution.
Our method reduces the ability of mosquitoes to transmit dengue, Zika and chikungunya on to people, without suppressing mosquito populations and potentially affecting ecosystems. We are currently adapting our approach for use in large, urban environments and targeting a cost of US$1 per person.”
GE Mosquitoes Also on the Horizon
Biotech company Oxitec has also created and is seeking to release genetically engineered (GE) mosquitoes in the U.S. to fight Zika. The mosquitoes have been genetically engineered to carry a “genetic kill switch,” such that when they mate with wild female mosquitoes, their offspring inherit the lethal gene and cannot survive. To achieve this feat, Oxitec has inserted protein fragments from the herpes virus, E. coli bacteria, coral and cabbage looper moth into the insects.
The GE mosquitoes have proven lethal to native mosquito populations in tests in the Cayman Islands and Brazil, but as pointed out by Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston to USA Today, the GE mosquitoes have not been shown to reduce rates of diseases such as Zika (nor, as mentioned, is Zika virus widespread in the U.S.).11The GE mosquitoes may also prove to be too expensive for areas that are plagued with mosquito-borne diseases.
In addition, the potential exists for these foreign genes, which hop from one place to another, to infect human blood by finding entry through skin lesions or inhaled dust. Such transmission could potentially alter the human genome by creating “insertion mutations” and other unpredictable types of DNA damage.12
The U.S. Food and Drug Administration (FDA), which was previously reviewing the GE mosquitoes, initially stated that GE mosquitoes will not have a significant impact on the environment, but was reportedly interested in how the “genetic kill switch” would behave in the wild and whether it could humans or other animals.13
In October 2017, the FDA then transferred the power for regulatory approval over to the EPA, after apparently categorizing the GE mosquitoes as pesticides rather than drugs to prevent disease.14 The GE mosquitoes haven’t been released in the U.S. — yet. Although the FDA had approved their release in the Florida Keys as part of a 22-month trial, this is currently on hold, pending notice from the EPA. The switch could pave the way for their eventual release, however. Wired reported:15
“The switch from FDA to EPA oversight means an end to Oxitec’s endless waiting. That’s because the EPA is required by federal law to review new pesticides ‘as expeditiously as possible,’ which the statute defines as within 12 months after the submission of an application … [Derric Nimmo, an Oxitec scientist who leads the company’s work in the US] hopes to get permission to go ahead with releases in the next six months, just in time for … [the 2018] mosquito season.”
How Big of a Problem Are Mosquito-Borne Diseases in the US?
There is a major push to combat mosquito-borne diseases in the continental U.S. with the use of lab-made and GE mosquitoes. While it’s clear that some areas worldwide are in the midst of epidemic levels of mosquito-borne disease, such as malaria, with 91 countries experiencing ongoing transmission,16 is this the case in the U.S.? Quite the contrary. According to the CDC:
- Dengue: “Dengue rarely occurs in the continental United States.”17
- Chikungunya: In 2016 and 2017, “No locally-transmitted cases have been reported from U.S. states.”18
- Eastern equine encephalitis virus (EEEV): EEEV “is a rare illness in humans, and only a few cases are reported in the United States each year.”19
- Zika virus: Only four cases of (presumably) locally acquired cases were reported in 2017.20
This isn’t to say that health threats from mosquitoes shouldn’t be taken seriously; they’re often described as the “world’s deadliest animal” for a reason. However, in the U.S. mosquito-borne illnesses are not a grave threat, especially compared to other major public health crises like the opioid epidemic. Further, even if they were, there may be better methods to combat them than releasing questionable lab-made or GE mosquitoes.
It’s important to remember that malaria once occurred in the U.S. but was eliminated without the use of mosquito “pesticides.” How? Karl Tupper of Pesticide Action Network (PAN) North America said in a press release:21
“It was improved sanitation, environmental management and access to health care that beat malaria in the U.S. … Rising standards of living were also key — bringing things like screened windows to rural areas in the southern states of the U.S. where the malaria problem was the worst.”
For now, it makes sense to avoid the past panic over mosquitoes, as was seen with the Zika fraud and, instead of releasing altered mosquitoes into the environment — with largely unknown consequences — take sensible measures to avoid getting bitten. Wear long sleeves and pants if you know you’ll be outdoors in a mosquito-prone area and use natural insect repellants (not synthetic chemical versions), like cinnamon leaf oil, citronella essential oil or catnip oil, if necessary.
If mosquitoes are bothering you in your backyard, a house fan can keep them away while you’re outdoors, as can the strategic planting of marigolds, which mosquitoes tend to stay away from.
Draining standing water, including pet bowls, gutters, garbage and recycling bins, spare tires, bird baths, children’s toys and anything else where even small amounts of water can pool, is also important to encourage mosquitoes to live elsewhere. This is where mosquitoes breed, so if you eliminate standing water you’ll eliminate many mosquitoes. Finally, try installing a bat house, as mosquitoes are one of their favorite meals.
– Sources and References
- 1, 7 Miami-Dade County, Wolbachia Mosquito Release
- 2 Efficient Gov February 5, 2018
- 3 Fox News January 30, 2018
- 4 U.S. CDC, Advice for people living in or traveling to South Florida
- 5, 20 U.S. CDC, Zika virus, 2017 case counts in the U.S.
- 6 Daily Mail January 30, 2018
- 8, 9, 10 EliminateDengue.com, Wolbachia
- 11 USA Today May 25, 2016
- 12 Institute of Science in Society August 12, 2010
- 13, 14, 15 Wired October 17, 2017
- 16 World Health Organization, Malaria Fact Sheet
- 17 CDC, Dengue
- 18 CDC, Chikungunya virus in the United States
- 19 CDC, Eastern Equine Encephalitis
- 21 PAN International April 18, 2011