GE Mosquitoes To Be Released in Florida!

Photo: Natural Society

Oxitech, a UK biotechnology firm, is planning the first US release of genetically engineered (GE) mosquitoes!  Who ever heard of those?  The release is planned this month in the Florida Keys!  Since the US is not a party to the Cartegena Protocol on BioSafety which governs international biotech regulation, it is unclear which US agency, if any, will review the firm’s biotech assessment.

5,000 – 10,000 GE mosquitoes will be released in an undisclosed 36-acre location supposedly near the Key West Cemetery, across the street from my girlfriend’s house!  I wonder if my girlfriend or any of the Key West residents were asked their opinions about this or consented?  Mosquitoes don’t just eat other mosquitoes and they are a part of the food chain so the GE ones will be devoured by other animal species, or worse, they will bite animals and humans!

What amount of testing has been done on the results of these toxic chemicals being introduced into the human body through bites or what will happen when this one strain of mosquito disappears…will another, more dangerous strain take its place?   Those who remember the “love bug” research and subsequent release of those bugs understand how these GE mosquitoes can easily multiply to cover an unimaginable  area.

Read the full article from Friends of the Earth yourself and add your thoughts in the comment section.  I don’t believe I am the only one alarmed by this “experiment”!

One thought on “GE Mosquitoes To Be Released in Florida!

  1. NOTE: The following is an Issue Brief released by Friends of the Earth on Dec. 21, 2011. Comments and clarifications are inserted in the original text by the Florida Keys Mosquito Control District (FKMCD) and Oxitec Limited of Oxford, England. Statements of interest are in yellow, comments by FKMCD and Oxitec are italicized.

    Genetically engineered mosquitoes in the U.S.
    The UK biotechnology company Oxitec has developed a genetically engineered mosquito in an attempt to reduce mosquito populations and in turn limit the spread of disease such as dengue fever. This mosquito, Aedes aegypti (OX513A), has been engineered to survive only in the presence of tetracycline — a common antibiotic used in agriculture production and sewage treatment.
    The GE mosquitoes are bred in a lab until adulthood, after which the males are released into the wild. In theory, the males will mate and then die off while their tetracycline-dependent gene passes onto their offspring. The offspring die early on in life — in the late larvae or pupae stage — and the mosquito population in a given area will theoretically be suppressed. These GE mosquitoes are not in fact sterile as some news reports claim but are engineered to pass on an “autocidal” gene that kills their offspring.1

    FKMCD: There is no layman’s term for “passes on an autocidal gene that kills offspring.” Sterile is the closest common term, but we agree is not sufficient because the public generally takes “sterile” to mean, “will not produce any eggs”. Since our primary audience is the general public, we have decided to use the words “modified mosquito” in future communications.

    Oxitec: Use of the term ‘sterile’; OX513A is sterile in very much the same sense as radiation-sterilized insects are sterile. Radiation induces [random] lethal mutations in the DNA of the sperm, these lead to death of [most of] the offspring. The two, fairly subtle, differences between this and our system is that death occurs as pupae rather than as embryos, and that death can be prevented by providing tetracycline to the larvae. Neither of these is fundamental to use of the term ‘sterile’. Arguably radiation-sterilized insects are not ‘sterile’ either, in a strict sense of the word (= agametic sterility), but sterile, and Sterile Insect Technique have been used in this context for decades, including in Florida in the context of fruit fly control. A short, easily recognised and easily-understood term to characterise the mosquitoes is desirable; both to make clear what we are not doing (e.g. releasing wild type mosquitoes) and some key aspect of what we are doing. Oxitec therefore uses this term, while also ensuring that its technical literature is precise. RIDL is itself an acronym for Release of Insects carrying a Dominant Lethal, which is unambiguous and would be another alternative, though not so immediately understandable to most people. The mosquitoes are modified in various useful ways, so ‘modified’ is clearly correct, and has been frequently used by Oxitec and others to describe these mosquitoes in the past; this is FKMCD’s current preferred descriptor.

    Oxitec has been quick to move ahead with field releases of its genetically engineered mosquitoes.
    The first-ever field releases of GE mosquitoes took place between 2009 and 2010 in the Cayman Islands, a British Overseas Territory, when three million mosquitoes were released.2 Malaysia was the second country to host Oxitec’s experiments at the end of 2010 and six thousand more GE mosquitoes were released there.3 Between February and June 2011 more than 33,000 GE mosquitoes were then released in Brazil.4

    Oxitec: Oxitec has been working on this technology for the past 10 years. The strain used in the Cayman trial was developed in 2002 and has been independently tested all over the world and numerous laboratory studies have been conducted to prove the technology works.
    According to Oxitec, results from the Cayman trials showed a reduction in Aedes aegypti populations of 8 percent.5

    FKMCD: This is likely a typo on FoE’s part – it should read “80 percent”. (Please note that an 80% reduction Ae. aegypti in two months is very impressive\for any type of control method…we at FKMCD have not been able to get high reductions like this using heavy pesticide applications, monthly home inspections and a huge public involvement program).
    Despite misleading reports published on the journal Nature’s website that “the controlled release of male mosquitoes genetically engineered to be sterile has successfully wiped out dengue fever in a town of around 3,000 people, in Grand Cayman,”6 (emphasis added) the mosquitoes are in fact not sterile and Oxitec never successfully eradicated dengue fever from any population. Dengue is not endemic in the Cayman Islands (only occasional cases occur in travelers).7 The company has only shown its technology can reduce mosquito populations in the immediate term in controlled settings. Oxitec has not proven such population reductions lead to disease eradication.

    Oxitec: Oxitec has never claimed that we have successfully wiped out dengue fever; the article was written independently and was not correct. Suppression of the target mosquito population was the intended trial endpoint, which was successfully met. There is a strong desire to suppress Aedes aegypti in the Cayman Islands to prevent the risk of dengue transmission; this is forward-looking and preventative, not a response to current transmission.

    However, more generally, all current dengue control relies on mosquito population reduction. This includes FKMCD’s program! To argue, as FoE do here, that population suppression is not a legitimate method of disease control is a head-on challenge to that paradigm. How else does FoE propose to control dengue? One method they advocate is community-based source reduction, which itself is exclusively aimed at mosquito population suppression.
    Genetically engineered mosquitoes: Coming to the U.S.
    Recent reports have exposed Oxitec’s plan to release its GE mosquitoes in the Florida Keys. According to Michael Doyle, director of the Florida Keys Mosquito Control District, Oxitec intends to release 5,000 to 10,000 GE mosquitoes over a two week period and release them into an undisclosed 36-square-acre block area as early as January 2012 — likely near the Key West Cemetery.

    Oxitec: A two-week release will not lead to population suppression, rather it will show us how many mosquitoes are out there, how many sterile males we need to release to suppress them etc., which we will then do (probably by adjusting release rates in a second, consecutive release period).

    FKMCD: We can assure the reader that there is no attempt being made to hide information. It might help to explain the Catch-22 of publicizing potential field trials. To illustrate, we regularly publicize truck and air spraying for mosquitoes in our District. Poor weather often postpones the treatments, and often for several days in a row. Sometimes we cancel the treatment altogether, sometimes it occurs on a following night, sometimes treatment areas are combined or shrunk due to changes in our trap counts. The public is always displeased, and often confused, about why we didn’t treat “as planned.” This trial is similar for the following reasons:
    1. We do not have permission to do the releases, so cannot honestly publicize a treatment location until we are reasonably sure it will happen.
    2. Field trials like this require that the “treated” and “untreated” areas need to have similar numbers of adult Ae. aegypti at the start of the test. Wild mosquito populations change weekly – and sometimes drastically. Our past data gives us a general idea of which city blocks we can use for the test, but only traps set in the weeks prior to an actual release will determine the exact blocks to be treated.
    For the record, the tentative treatment area is approximately 6 x 6 city blocks, between the Key West Cemetery and Garrison Bight Marina.
    The trial is expected to last about two months. The mosquitoes will be dusted with a fluorescent powder for identification purposes and then trapped to see how far they are flying. If the male mosquito population declines, the trial will be considered a success.8

    Oxitec and FKMCD: “Male” is likely a typo by the author of the referenced Keynoter article; it should be “female”. To clarify; the first two week release is to show us how many mosquitoes are present which subsequently informs us how many males we would have to release to achieve suppression of the female population (females bite and transmit disease, male do not). The suppression trial will last somewhere between 4-6 months.
    While attempts to limit the spread of disease are laudable, there are many regulatory, environmental and ethical challenges facing the release of GE mosquitoes in the U.S. and there are even more unanswered questions.
    Regulatory gaps
    Despite the fact that the Florida Keys Mosquito Control District and Oxitec are planning their trial as early as 2012 it is unclear which federal agency would regulate the field release of GE mosquitoes.
    Originally, Oxitec and the Florida government agencies assumed the U.S. Department of Agriculture would regulate GE mosquitoes as it has other GE insects such as the first-ever release of a GE insect, a fluorescent pink bollworm.9 But in October 2011 the USDA issued a statement concluding Oxitec’s mosquito was outside its jurisdiction since it supposedly didn’t pose a threat to animal health. 10
    In the statement, the USDA suggested that Oxitec reach out to other federal agencies — such as the Fish and Wildlife Service, the Centers for Disease Control and the Food & Drug Administration. It is unclear which agency will claim authority, if any, but the FDA could play a major role in any decision since it has authority over genetically engineered animals (such as a GE salmon currently being considered for human consumption), which it regulates through laws written for new animal drugs. In this instance, the engineered genes would be considered the animal drug.

    Oxitec: Oxitec has been talking to federal agencies since 2008 to determine the requirements for field use of our mosquitoes (which agency, what informational requirements, etc.). The outcome of consultations with the agencies was indeed that USDA-VS would take the lead and we duly applied to them. They concluded that our technology is safe and that they have no basis to regulate it. This would require a credible potential threat to animal health, which they simply didn’t see (while recognizing that Aedes aegypti itself IS a threat to animal health). Their no-jurisdiction letter suggested that we might like to contact other federal agencies; it now seems that FDA will get involved whereas we had previously thought otherwise (i.e. we thought other agencies would follow the lead of USDA-VS).
    Oversight by the FDA is important because release of GM mosquitoes is a medical experiment that could have effects on human health. But as a 2004 report by the Pew Initiative on Food and Biotechnology points out, if the FDA does regulate the release of GE mosquitoes it may not “have the expertise to assess the full range of environmental effects that could arise from the release of [GE] insects, including, for example, risks to plants, an expertise housed in other agencies like [USDA’s Animal and Plant Health Inspection Service] or the Department of the Interior.”11 Any agency that does have final regulatory authority over the field release of GE mosquitoes should be required to consult other relevant agencies and public stakeholders before making any final decision on whether GE mosquitoes should be released into the environment. The FDA’s track record on consulting other agencies as it considers approval for GE salmon is less than encouraging.12

    FKMCD: A successful project will likely have positive effects on human health (ie., reduction of a dangerous disease.) I am not aware of any way that this technique could be detrimental to human health. We have a choice of not doing anything, which creates a definite human risk, or doing something, which appears to have little or no human risk.

    Oxitec: This is a key point; it is in no sense a medical experiment. Genewatch has for some time been trying to push this idea as a campaigning tactic. Their hope is to try to impose the whole panoply of medical protocols that have built up around human subjects and individual interventions in the context of drugs and vaccines (individual informed consent, opt-out etc.). But this is completely inappropriate for our situation, which is analogous to building a sewage treatment plant for public health, or perhaps to putting iodine in salt, or calcium in flour (though perhaps less direct human contact than these last two!).
    In a representative democracy, approval for such interventions is through decisions by elected representatives, often (and preferably) with opportunity for input from the public but no individual veto or opt-out, which would make little sense in such circumstances.
    Baroness O’Neill has described as ‘anti-democratic’ the notion that one individual dissenting from a public health intervention in an area should have a veto power over the entire activity (this is the logical consequence of applying an individual-informed-consent paradigm, which is why Genewatch and FoE are so keen to push it)
    Additionally, the U.S. is not a Party to the Cartagena Protocol on Biosafety to the Convention on Biological Diversity13 which governs international regulation, including transboundary movement of genetically engineered organisms. Since the mosquito eggs will be shipped from the United Kingdom to the U.S. it is unknown how the Cartagena Protocol will apply to the field release of GE mosquitoes. Oxitec will be required to provide environmental assessments to the U.S. government before the shipment of the mosquito eggs — as mandated by the Protocol. But it is unclear which U.S. authority, if any, will publish, review and consult on this assessment.

    FKMCD and Oxitec: The US state and federal regulators will decide. The US will do whatever risk assessments etc. it feels necessary as it has no Cartagena obligations. There is a requirement in the UK, as it is a signatory to the Cartagena Protocol, that Oxitec informs the US government prior to the first shipment for release into the environment.
    Environmental risks
    The behavior of these mosquitoes and the risks they pose to human health and the environment are hard to predict, leaving the public with more questions than answers.
    One threat is that a significant decline in the Aedes aegypti mosquito population could have unintended consequences on the local ecosystem and food chain. Mosquitoes are an important source of food for many fish, birds and other insects that would need to find another food source if Aedes aegypti were to disappear. The impacts a decline in Aedes aegypti population would have on the food chains in Florida have yet to be studied.

    FKMCD: We fully agree with FoE’s concern for potential impacts on the food chain.(We would be very hesitant to use this technique on any species that is a significant food source for other animals). However, Ae. aegypti is an invasive species that in many people’s view has almost negligible value as a food source because its larvae live in “unnatural” human containers away from most predators. In addition, the adults are very sparse compared to many other insects in the same trophic level.
    A decline in Aedes aegypti could also leave an ecological niche to be filled by other, possibly more harmful pests. For example the Asian Tiger mosquito, Aedes albopictus, is considered one of the most invasive species in the world and carries many diseases including dengue fever and the West Nile virus.14

    FKMCD and Oxitec: This is an insightful question, and deserves more attention. A few important points:
    1. Ae albopictus is a poor dengue vector compared to Ae. aegypti;
    2. Ae. albopictus is a poor West Nile virus vector;
    3. Ae. albopictus has replaced Ae. aegypti already in much of Florida, but less so as you travel southwards in the state. There is good reason to believe that some aspect of natural Keys ecology prevents Ae. albopictus from establishing here. Is it the presence of Ae. aegypti? Perhaps, but the worst case scenario in #4, below.
    4. The replacement of Ae. aegypti by Ae. albopictus elsewhere has not been associated with any evident negative public health impact. Indeed deliberate introduction of Ae. albopictus has been proposed as a public health intervention (to suppress Ae. aegypti). Therefore if Ae. albopictus does establish itself in Key West it is not expected to be any more harmful than Ae. aegypti.
    While the Asian Tiger mosquito has not yet been found in the Florida Keys,15it could spread to the island if other mosquito populations decline as it has spread across many parts of the U.S. This could mean the spread of more disease and increased use of pesticides. The impacts from other, potentially more dangerous insects taking over the ecological niche left by Aedes aegypti have yet to be studied.

    FKMCD: While introduction of Ae. albopictus could hypothetically increase the possibility of some diseases, we already have a clear and present danger here now. Which is worse, a hypothetical problem (with no strong evidence of its appearance) or a confirmed present problem?

    FKMCD: Pesticide levels would not be likely to increase any more than they are already. Ae. aegypti control and Ae. albopictus control are very similar. It would be highly unlikely for any other species to fill the Ae. aegypti niche.
    Ethical concerns
    The release of GE mosquitoes as an attempt to curb the spread of disease should be considered a medical trial and must follow the strict laws and guidelines in place to protect human subjects in medical trials. Central to ethics on human subject trials is the idea of free and informed consent.

    FKMCD: Our position is that the proposed releases are no more a medical trial than traditional spraying with pesticides, citizens spraying Raid in their homes, or any other attempt to reduce insect populations. The implication made by FoE is that there is some inherent danger to humans, which to our knowledge, is not true. . .
    Oxitec: The individual-informed-consent paradigm is simply not applicable or appropriate for public health interventions with non-targeted (e.g. area-wide) benefits.
    According to paragraph 24 of the World Medical Association’s Declaration of Helsinki – Ethical Principles for Medical Research Involving Human Subjects, the cornerstone of human research ethics:
    In medical research involving competent human subjects, each potential subject must be adequately informed of the aims, methods, sources of funding, any possible conflicts of interest, institutional affiliations of the researcher, the anticipated benefits and potential risks of the study and the discomfort it may entail, and any other relevant aspects of the study. The potential subject must be informed of the right to refuse to participate in the study or to withdraw consent to participate at any time without reprisal. Special attention should be given to the specific information needs of individual potential subjects as well as to the methods used to deliver the information. After ensuring that the potential subject has understood the information, the physician or another appropriately qualified individual must then seek the potential subject’s freely-given informed consent, preferably in writing. If the consent cannot be expressed in writing, the non-written consent must be formally documented and witnessed16 (emphasis added).
    Unfortunately, Oxitec has already shown a disregard of the importance of free and informed consent. The first releases of GE mosquitoes took place in the Cayman Islands — first a small-scale trial in 2009 followed by the release of three million GE mosquitoes in 2010. According to Genewatch UK, the Cayman experiments were not revealed to the public until one month after the initial release and “no public consultation was undertaken on potential risks and informed consent was not sought from local people.”17

    Oxitec: The Cayman trial was not unannounced; prior to the Cayman trial the national newspaper (Cay Compass) published an article about the use of genetically modified mosquitoes in vector control. MRCU used its standard practices to inform stakeholders, including householders of the trial, which also included many one to one discussions where stakeholders could ask questions based on the information received. Locally it was well known that the mosquitoes were genetically modified. There have been no reports of any negative consequences to either human health or the environment from this activity.
    Equally troubling is that the Cayman Islands — a territory of the United Kingdom — does not have any biosafety laws and is not covered by either the Cartagena Protocol on Biosafety or the Aarhus Convention on Access to Information, Public Participation in Decision-making and Access to Justice in Environmental Matters, despite the UK being a Party to these treaties.18 These conventions would have required publication of and consultation on an environmental risk assessment prior to the release of GE mosquitoes. Instead, the only regulatory requirements were a local permit from the Cayman Islands Agriculture Department and a notification that GE mosquito eggs were shipped internationally. Neither of these documents appears to have been published.19

    Oxitec: The trial was carried out in accordance with all the appropriate Cayman regulations, which were determined following briefing sessions with several Government ministries. Governments have the sovereign right to decide on their own regulatory requirements for such technologies.
    In fact, the lack of public consultation for the Cayman experiments has been strongly criticized by one of Oxitec’s powerful collaborators, the Gates Foundation. Anthony James, the lead investigator on the Gates team, said that he would “never” release genetically engineered mosquitoes the way Oxitec did in Grand Cayman.20
    Despite public outcry over the unannounced Cayman field trials, Oxitec again released GE mosquitoes in Malaysia in 2010. According to an open letter sent to the Malaysian government from civil society organizations around the world, the public was only made aware of a field release trial of GE mosquitoes by a press release dated January 25, 2011 — more than one month after the trial began on December 21, 2010. This is despite press reports as late as January 4, 2011 in the Malaysian press claiming the trials had been postponed. “It therefore appears,” the letter stated, “that neither the local communities nor the Malaysian public at large knew that these trials had occurred.”21 A larger trial, scheduled for an inhabited area, has not yet taken place.

    Oxitec: There is no evidence of concern, let alone outcry, from people at the actual release site. Oxitec and the Cayman Mosquito control team were there, 5 days a week for 6 months, providing information as requested and noting concerns. Almost no negative comments were received – none about genetic engineering. A local newspaper conducted a poll which indicated two out of three supported, and that online poll was open to all inhabitants and overseas readers, not just those at the trial site where we had focused our communications (the trial site has at most 2% of the population of the island).
    Such a track record does not bode well for the Florida Keys community that will be the center of the first field release of GE mosquitoes in the United States. Community members must be informed throughout the process through a number of mechanisms — including the establishment of local institutional review boards and ethics committees and hosting of community meetings and public forums — and community members must have a right to leave the field trial area22 or demand the halt of the experiment entirely if they so decide.

    FKMCD: The Florida Keys Mosquito Control District has many competent staff that publicize and educate at will. Indeed many information events and newspaper/radio reports have already publicized the upcoming trial to local people and officials.
    Are genetically engineered mosquitoes a real solution?
    Misleading claims that Oxitec’s mosquitoes are sterile23 make it appear as if the company’s technology is a foolproof way to bring an end to mosquito-borne diseases. Unfortunately, its system has many problems that raise serious questions about the viability of GE insects as a way to limit the spread of disease.
    As discussed, Oxitec’s technology does not make its mosquitoes sterile; rather, they are engineered to be dependent on tetracycline and die in its absence. In fact, 3 to 4 percent of Oxitec’s mosquitoes survived into adulthood in the lab in the absence of tetracycline despite supposedly carrying the lethal gene.24 25 If there is contamination with the commonly used antibiotic tetracycline in the environment, survival rates might be much higher.

    FKMCD: This is an important point. Lab mosquitoes are “pampered,” (i.e., are raised in ideal conditions) and we need to do tests to see if 3-4% would survive in the wild. We doubt many would survive tough field conditions, but that remains to be tested.
    Tetracycline in the environment is very unlikely. Most Ae. aegypti habitat is from rainwater and in contained places. This can be tested also.

    Oxitec: A small percentage do survive to be adults in the laboratory. Even if they survive in the wild they will still pass on the gene to their offspring and they will die. The gene will quickly disappear from the population if releases are stopped. If this same percentage survived in the wild – and we have no evidence of that – it really makes no difference. The target population will still be suppressed (would need much higher survival to stop the method from working). The transgene will still disappear very rapidly from the environment if not maintained by periodic release of more males. The issue of people being bitten by GM mosquitoes is already addressed for obvious precautionary reasons in case of (e.g.) accidental release of females; the number generated even if there were low-percentage survival of offspring would be small (e.g. relative to the pre-intervention wild female population).

    Additionally, Oxitec claims it only plans to release male GE mosquitoes into the environment since it’s the female mosquito that bites humans and therefore spreads diseases such as dengue fever. But its process of sorting males and females is also not guaranteed. The sorting is conducted by hand and could result in up to 0.5 percent of the released insects being female.26 This would raise new human health concerns as people could be bit by GE mosquitoes. It could also hamper efforts to limit the spread of dengue fever.

    Oxitec: The actual figure for female releases in the Cayman trial was 0.03% of females released compared to males. This represents a tiny proportion of the number of females found in the wild. Reducing the mosquito population by over 80% (as shown by the Cayman trials) should have a significant effect on dengue transmission which will have a large effect on human health.
    For there to be a difference – even given the low exposure rates – would require a specific chain of events/circumstances, none of which in fact apply:
    1. One or both of the two proteins expressed by the transgene would have to be toxic.
    2. They would have to be secreted into the saliva and for this they would have to be expressed in the salivary glands
    In fact both proteins have been expressed in a very wide range of organism, including mammals, with no ill effects. We have to express one of them at extremely high levels to affect the mosquito – think about the relative concentration that could be transmitted to a human by a mosquito bite. And they are intracellular proteins, not secreted ones. Finally, they are not expressed in the salivary glands at detectable levels.
    Oxitec has been handling this strain in the lab since 2002. As you know, from time to time mosquito researchers get bitten by their mosquitoes (records are kept of bites routinely for Health and Safety reasons), so we have certainly had numerous people bitten by these mosquitoes over the years because for breeding purposes we do have females in large numbers. No negative effects on human health (or anything else) have been observed.

    Mosquitoes reproduce continually and Oxitec readily admits it will need to continually release GE mosquitoes in a given area in order to keep populations low.27

    FKMCD: This need for repeated releases seems very practical; it doesn’t promise a magic bullet. Many insect control techniques, when they are first introduced, are overly optimistic in how they can overcome Mother Nature.

    In fact, Oxitec does not expect its technology to lead to population collapses; rather, it states it is only able to decrease existing mosquito populations by approximately 80 percent.28 This claim is based on unpublished results from the Cayman Islands.

    In reality it remains unknown whether population suppression using this approach would be effective in the long term or over larger areas. Continual releases would need to occur every month or every few weeks, with upwards of a million mosquitoes per release. This is why Oxitec has suggested that 100 million to a billion GE mosquitoes should be stockpiled for each project.29

    FKMCD: We agree that it is unknown whether this strategy will work over large areas. But the simple fact is that the only way to learn that is to test modified male mosquito releases over a large area. There is no way to simulate field conditions in a lab.
    This is problematic for a number of reasons. First, any environmental assessment of a full-scale field release of GE mosquitoes cannot simply look at the risks from one release; rather, the impacts of releasing millions of mosquitoes on a continual basis must be fully assessed.
    Second, this system locks communities and nations into a permanent scheme of repeated ongoing payments to Oxitec once releases begin since Oxitec’s mosquitoes are patented.

    FKMCD: True, but if this approach is denied by regulators, or does not work, FKMCD will be repeatedly making ongoing payments to someone anyway– chemical companies most likely.

    The company stands to make significant profits if countries and communities must make continuous payments to it.

    FKMCD: In fact, it appears that this method would be more cost effective, and more environmentally friendly than conventional chemical techniques.
    These payments would presumably continue endlessly unless the community wanted the release of GE mosquitoes to stop in which case disease prevalence could rise when conventional mosquito populations rebound. The company has yet to provide data on what would happen to mosquito populations or prevalence of disease if releases were halted.

    FKMCD: There are several true points here – namely, if releases stopped conventional populations would likely return to current levels and disease risk would return to current levels. Simply put, everything would likely return to the present situation, which is not good. There is no need for new data because the current situation is the likely result.
    Concern also exists around the possibility of the dengue virus to evolve and become more virulent in response to the introduction of GE mosquitoes.30 The fact is that the virulence and spread of disease combined with mosquito population levels and behavior involve incredibly complex systems and difficult to predict in advance. Significantly more research is needed on these and other potentially unintended consequences of the introduction GE mosquitoes.

    FKMCD: We agree with the complexity part of this. We are unlikely to ever fully know the impacts of this technique, or our current techniques. But we don’t fully understand or know the effects of our insecticides that are released into the environment for mosquito control, or the effects of dumping larval-filled containers, for that matter. Anything we do can result in a change in mosquito behavior or physiology. We take small risks every day in the hope of reducing big risks tomorrow.
    Oxitec: This issue applies much more severely to some of the interventions FoE proposes as alternatives. Most people will agree that dead mosquitoes can’t transmit dengue; hence population suppression is a rather ‘clean’ approach in this regard. But the Wolbachia strategy they propose as one alternative is much more complex. There you would have three elements (mosquitoes, Wolbachia and viruses) all co-adapting in the field, outside your control. The Wolbachia group has recently found – though not published – that these mosquitoes fed on blood from dengue patients are not fully refractory, rather they see titer-dependent breakthrough. This may therefore select for viruses with higher titers in human blood, which is unlikely to be desirable from a public health perspective. And that’s just one of several predictable evolutionary changes.
    Researchers do not know much about the correlation between population levels of Aedes aegypti and dengue fever infection in humans. According to a 2002 article in Science, the density of Aedes aegypti populations is at best weakly correlated with human infection rates. This is due to the fact that mosquitoes “persist and effectively transmit dengue virus even at very low population densities because they preferentially and frequently bite humans.” 31 Additionally, any introduction of GE mosquitoes that does not eradicate a population could lead to increased survivability of the dengue virus and increased risk of human infection.32

    FKMCD: This is true. We do not know for certain what reduction in mosquito population will prevent dengue transmission. However, we are interested in any technique that has some potential to reduce populations to nearly zero. Will it work that well? We don’t know, but if it doesn’t we will stop and go back to current methods.
    Genetically engineered mosquitoes are not the only tool available to try and limit the spread of dengue fever and other diseases. Community-based programs that educate communities about dengue prevention and low-cost ways to prevent mosquitoes from breeding are one way disease rates can be brought down. Community-based dengue prevention programs have been found to be successful across the world. For example, a 2006 study found that a community-based educational program in Sri Lanka was effective in increasing understanding and active involvement in mosquito control and disease prevention.33 As the World Health Organization has stated, “community is the key to dengue prevention.”34 While community-based programs are not the only answer they do show that sometimes solutions can be low-cost, low-risk social innovations rather than expensive, patented technologies.

    FKMCD: We agree that community-based programs are a good tool. Our District has already been employing a very intensive public education program for over 2 years in conjuction with the local health department. The Key West public is overwhelmingly supportive of personal responsibility for reducing mosquitoes (Key West survey, Feb. 2011), but a large proportion of Key West homes still produce high numbers of Ae. aegypti. The average house index is above 10% much of the season. See our website for weekly House Indexes and maps.

    Oxitec: Has anyone stopped dengue transmission by this method, where is the evidence? Community-based programs are part of an overall strategy, but with current technology they can only be part of the answer (at best).
    Bed nets may be a relatively cheap and effective way to prevent the spread of dengue fever.
    FKMCD: Given our close work with the citizens here, we are certain that use of bed nets in Key West would be almost universally rejected.
    Oxitec: Bed nets do not work in most cases with Ae. aegypti, it is a day biting mosquito.
    Preliminary results from a trial in Haiti found that insecticide-treated bed nets led to an immediate drop in dengue-carrying mosquito populations, despite the fact that these mosquitoes bite during the day.35 Treating other household materials with insecticides, such as window curtains and water jar-covers, was successful in significantly reducing Aedes aegypti numbers in a study conducted in Venezuela.36
    FKMCD: While an immediate drop in Ae. aegypti is encouraging, it is a common misunderstanding that a drop in population results in a drop in disease transmission. This is simply not the case with Ae. aegypti. It takes very, very few infected females to maintain active dengue transmission, so populations have to drop drastically for long periods of time to effect a measurable change in transmission. The proposed releases, at least theoretically, seem to have a better chance at doing that than current techniques.
    Recent research has even found that infecting mosquitoes with the common bacteria, Wolbachia pipientis, completely prevents the dengue virus from growing in mosquitoes. Field trials in a remote part of Australia found that after releasing 300,000 infected adult mosquitoes, nearly all the wild mosquitoes tested were infected with the bacteria ten weeks later.37

    Oxitec: Wolbachia may one day be an option but it has several critical issues that need addressing;

    • The irreversible nature of the releases, once Wolbachia has been released into the environment it cannot be stopped from spreading.
    • There is no containment so the Wolbachia can easily spread outside a trial area.
    • Wolbachia will interact and evolve with the Aedes population in unknown and unpredictable ways; it is not naturally infected with Wolbachia this has been performed in the laboratory.
    • Wolbachia can spread between species with unknown consequences.
    • The effect is dependent on the strain of Wolbachia infection and the underlying genetic or biochemical basis for resistance is unknown.
    • Aedes albopictus is naturally infected with two strains of Wolbachia yet is still a competent vector.
    • Post release stewardship and liability are high as there is no way to contain a trial (in theory you can spray an area with insecticides but we all know how effective that will be!).
    • This claim that Wolbachia completely prevents the dengue virus id not true, at least for the strain they released. It does block in an artificial lab assay, but only partially when given blood from dengue-infected patients. Worryingly, breakthrough seems to be titre-dependent, potentially leading to selection for more virulent strains of virus if this approach were used.

    While such experiments may carry their own unique risks (human health risks due to exposure to insecticides, mosquitoes growing a resistance to those insecticides,38 and unknown risks from the Wolbachia bacteria) they illustrate that there exists innovative ways to tackle dengue fever that do not involve expensive and risky genetic engineering technologies. In the end there will likely be no single “silver bullet” in fighting dengue fever since insect populations and the spread of disease are part of a much more complex ecosystem that will require numerous approaches in which communities are not just consulted but are integral actors.

    Oxitec and FKMCD: We all agree that there is no “silver bullet” RIDL has always been proposed as part of an integrated vector management strategy.
    Despite Oxitec’s claims, questions still remain as to whether GE mosquitoes are safe for the environment, safe for people or are even effective in fighting the spread of dengue fever. While the goal of limiting the spread of disease is laudable, too many questions remain to allow the release of genetically engineered mosquitoes in the U.S.
    The federal government and the state of Florida must be open and transparent throughout any deliberations on whether or not to allow Oxitec to release GE mosquitoes in Key West or anywhere in Florida. Our government must require the company to obtain the free and informed consent of the Florida community before any trial is allowed to move forward and mechanisms should be made available to halt the experiment if the community demands. Oxitec must not be allowed to repeat its mistakes in the Cayman Islands and Malaysia where it released mosquitoes without public knowledge or consent.
    Comprehensive and independent analyses of the risks GE mosquitoes may pose to the environment and human health must be conducted and released to the public with ample time for review before any trial begins. These assessments must look at:

    • The ecological risks of released GE mosquitoes including the risk of disrupting food chains or providing a new ecological niche more dangerous insects to take the place of Aedes aegypti;

    Oxitec: The risk to the food chain or predators is predicted to be low. The aim of the FKMCD has been to remove Aedes aegypti from Key West using standard mosquito control methods (i.e. insecticides). These methods have not proved successful and do impact many more species than just Aedes aegypti because insecticides do not discriminate between insects. Oxitec’s technology will only remove Aedes aegypti and not any other species of mosquito. Aedes aegypti is not a Keystone species and is not a native species and it tends to breed in small pools of water without other predators; removal of this insect from the ecosystem is likely to have no to minimal impact on any other species. It will however remove any chance of dengue transmission in Key West.

    • The risks of releasing biting females;

    Oxitec: The risk of the small number of RIDL females released (0.03) is predicted to be low. Theoretically being bit by a GE mosquito would not differ from being bit by any other kind of mosquito.

    • The risks associated with mosquitoes surviving into adulthood if tetracycline is present in the surrounding environment;

    Oxitec: The risk of tetracycline being present in the same environment of the mosqutioes is low; most Ae. aegypti habitat is from rainwater.

    • The risk from the unintentional release of GE mosquitoes into the environment due to a natural disaster, wear-and-tear or human error;

    Oxitec: All RIDL mosquitoes carry the RIDL gene so there offspring will die. Female mosquitoes are destroyed as pupae (before they reach adults) in the factory so release of females is highly unlikely. Strict quality control procedures will be in place to reduce human error to a minimum.

    • Potential adverse impacts the release of GE mosquitoes may have on the ability of dengue fever to evolve and become more virulent or the likelihood of the released mosquitoes leading to increases in disease transmission;

    Oxitec: RIDL functions like any insecticide or conventional control programme as it reduces the number of mosquitoes present in the wild. The technology is not designed to change or affect the dengue virus transmission other than by reducing the number of mosquitoes able to transmit the disease. Therefore the risk of increased disease transmission is extremely low and no more than conventional methods of control.

    • The full range of impacts from releasing millions of mosquitoes on a regular basis;

    Oxitec: This is inherently part of the regulatory process and the function of trials.

    • The consequences of ending a GE mosquito program would have for mosquito populations and disease, as well as the economic impacts on countries and communities that are indefinitely dependent on Oxitec for GE mosquito eggs to fight dengue fever; and

    FKMCD: We will be repeatedly making ongoing payments to someone – chemical companies mostly. There is no more a problem with this technique than when we treat with conventional insecticides currently.

    • Alternatives to using GE mosquitoes as a way to limit the spread of dengue fever such as bed nets, community-based prevention programs and other biological tools that do not depend on expensive and risky genetic engineering technologies. Additionally, Oxitec must be legally liable in case something goes wrong with the field release of its GE mosquitoes. If its actions harm the environmental or public health, Oxitec must be legally responsible for the damages and must compensate the communities. It must also be required to repair the damage it caused to the greatest extent possible.

    Oxitec: Alternatives are available and can and will be used in combination with RILD. RIDL is a method of controlling insects and it can be used as part of an integrated programme to a) control the dengue mosquito and then b) keep an area clear from re-infestation. A customer [vector control team] could use our approach as part of an IVM programme to control the mosquito, then it could carry on with low level releases – or stop – or just use monitoring – or could return to chemicals. We would recommend low level releases going forward but the customer can do what they want.
    Until such studies have been independently completed and made available to the public, it is premature to allow the release of GE mosquitoes in the U.S. or elsewhere.
    Oxitec: Much data is already available from lab studies and previous field trials. The purpose of these trials is to provide additional data.
    The burden of proof rests with Oxitec to show the public its mosquitoes are safe. Until that burden of proof is met GE mosquitoes must remain inside the lab.

    Oxitec and FKMCD agree with this sentiment. It is the remit and authority of the regulatory agencies to analyse the evidence and reach such a determination. Until they have enough evidence and analysis to conclude that a given action, e.g. release under defined conditions of modified mosquitoes, poses negligible risk to human health or the environment, they will not allow it and the mosquitoes will indeed remain inside the lab.

    1 Morgan, Curtis. “Key West Mosquito Control Could Go Sci-fi.” Miami Herald, 11 Nov. 2011. .
    2 Oxitec and the Mosquito Control Unit Cayman Islands Government. Open Field Trial Demonstrates Effectiveness of RIDL® System for Suppressing a Target Wild Mosquito Population. 4 Nov. 2010. Web. .
    3 “Genetically Modified Mosquitoes Released in Malaysia Sparks Fears of Uncontrollable New Species | Mail Online.” Daily Mail, 26 Jan. 2011. Web. .
    4 Number based on calculations provided in: “Oxitec June 2011 Newsletter.” Oxitec, June 2011. Web. .
    5 “March 2011 Newsletter.” Oxitec, Mar. 2011. Web. .
    6 “ GM Mosquitoes Wipe out Dengue Fever in Trial.” Nature News Blog. Nature, 11 Nov. 2011. Web. .
    7 Cayman Islands Government. Dengue Prevention Campaign.,2327966&_ dad=portal&_schema=PORTAL
    8 McCarthy, Ryan. “Mosquito Control to Breed Mosquito-Killing Mosquitoes.” 12 Nov. 2011. Web. 13 Dec. 2011. .
    9 The GE pink bollworm, also produced by Oxitec, was the first-ever genetically engineered insect to be released in the U.S. Mil¬lions of GE pink bollworms already been released in cotton fields in Yuma County, Arizona.
    10 Morgan, Curtis. “Key West Mosquito Control Could Go Sci-fi.” Miami Herald, 11 Nov. 2011. .
    11 Bugs in the System? Issues in the Science and Regulation of Genetically Modified Insects. Rep. Pew Initiative on Food and Biotechnology, Jan. 2004. .
    12 “Troubling Emails Reveal Federal Scientists Fear FDA Approval of Genetically Engineered Salmon: “Maybe They [the FDA] Should Watch Jurassic Park.” Food & Water Watch, 15 Nov. 2010. Web. .
    13 Convention information available at:
    14 “100 of the World’s Worst Invasive Alien Species.” Global Invasive Species Database. Invasive Species Specialist Group, Nov. 2004. Web. .
    15 O’Neara, G. F. The Asian Tiger Mosquito in Florida. Rep. University of Florida IFAS Extension, July 2005. .
    16 “World Medical Association Declaration of Helsinki – Ethical Principles for Medical Research Involving Human Subjects.” World Medical Association. Web. .
    17 Genewatch UK. British Overseas Territory Used as Private Lab for GM Mosquito Company. 14 Dec. 2010. Web. .
    18 Convention information available at:
    19 Oxitec’s Genetically-modified Mosquitoes: In the Public Interest? Rep. Genewatch UK, Dec. 2010. Web.
    20 GM Mosquito Trial Strains Ties in Gates-Funded Project. Science Insider. 16 November 2010.
    21 “Open Letter on the Release of GM Mosquitos in Malaysia.” 9 Feb. 2009. Web. .
    22 Macer, Darryl. “Ethical, Legal and Social Issues of Genetically Modifying Insect Vectors for Public Health.” Insect Biochemistry and Molecular Biology 35.7 (2005): 649-60.
    23 Oxitec and the Mosquito Control Unit Cayman Islands Government. Open Field Trial Demonstrates Effectiveness of RIDL® System for Suppressing a Target Wild Mosquito Population. 4 Nov. 2010. Web. .
    24 Phuc , H.K., Andreasen, M.H., Burton, R.S., Vass, C., Epton, M.J., Pape, G., Fu, G., Condon, K.C., Scaife, S., Donnelly, C.A., Cole¬man, P.G., White-Cooper, H. and Alphey, L. (2007) Lateacting dominant lethal genetic systems and mosquito control. BMC Biology 5:11.
    25 Phuc , H.K., Andreasen, M.H., Burton, R.S., Vass, C., Epton, M.J., Pape, G., Fu, G., Condon, K.C., Scaife, S., Donnelly, C.A., Cole¬man, P.G., White-Cooper, H. and Alphey, L. (2007) Lateacting dominant lethal genetic systems and mosquito control. BMC Biology 5:11.
    26 Harris AF, Nimmo D, McKemey AR, Kelly N, Scaife S, Donnelly CA, Beech C, Petrie WD, Alphey L (2011) Field Performance of Engineered Male Mosquitoes. Nature Biotechnology. 29(11):1034-1037
    27 “Aedes Aegypti OX513A.” Oxitec. Web. .
    28 Pollack, Andrew. “Concerns Are Raised About Genetically Engineered Mosquitoes.” New York Times, 30 Oct. 2011. Web. .
    29 Oxitec’s Genetically-modified Mosqitoes: In the Public Interest? Rep. Genewatch UK, Dec. 2010. Web.
    30 Medlock, J., Luz, Paula M., Struchiner, Claudio J., and Galvani, Alison P. (2009) The Impact of Transgenic Mosquitoes on Den¬gue Virulence to Humans and Mosquitoes. The American Naturalist 174, 565-577.
    31 Scott, T. W., Takken, W., Knols, B. G., & Boete, C. (2002). The ecology of genetically modified mosquitoes. Science, 298(5591), 117-119.
    32 Ibid.
    33 Yasuoka, Junko, Thomas W. Mangione, Andrew Spielman, and Richard Levins. “Impact of Education on Knowledge, Agricul¬tural Practices, and Community Actions for Mosquito Control and Mosquito-Borne Disease Prevention in Rice Ecosystems in Sri Lanka.” American Journal of Tropical Medicine and Hygiene 72.6 (2006): 1034-042.
    34 “Dengue/DHF – FAQ.” World Health Organization – Regional Office for Southeast Asia. Web. .
    35 Lenhart, Audrey, Nicolas Orelus, Rachael Maskill, Neal Alexander, Thomas Streit, and P.J. McCall. “Insecticide-treated Bednets to Control Dengue Vectors: Preliminary Evidence from a Controlled Trial in Haiti.” Tropical Medicine & International Health 13.1 (2008): 56-67.
    36 Vanlerberghe V, Villegas E, Oviedo M, Baly A, Lenhart A, et al. (2011) Evaluation of the Effectiveness of Insecticide Treated Materials for Household Level Dengue Vector Control. PLoS Negl Trop Dis 5(3): e994. doi:10.1371/journal.pntd.0000994
    37 Gilbert, Natasha. “Bacterium Offers Way to Control Dengue Fever : Nature News.” Nature, 24 Aug. 2011. Web. .
    38 Kelland, Kate. “Mosquito Resistance to Bednets Fuels Malaria Worries.” Reuters, 18 Aug. 2011. Web. .


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