EDITORIAL – GM mosquitoes: What happened to the ‘Swat Team’?

The Zika virus is transmitted by Aedes aegypti mosquitoes.

In spring 2016, amid the maelstrom of fears over the Zika virus, the Cayman Islands government announced with considerable public fanfare that officials were partnering with a British firm to introduce a novel mosquito control method to the territory.

The strategy involves releasing genetically modified male Aedes aegypti mosquitoes to mate with wild females, producing offspring that do not survive into maturity.

It was hoped the new project, a collaboration between the Mosquito Research and Control Unit and Oxitec, would build upon promising results from a limited field test conducted in East End back in 2010.

“I am very proud to say that the Cayman Islands is the only other country in the world where this program will be taking place outside of Brazil, and we are once again leading the way in the advancement of mosquito control measures,” Premier Alden McLaughlin said in 2016.

Two years later, following legal challenges, protests, international publicity (positive and negative), and finally the release of millions of GM mosquitoes in West Bay … it seems the “buzz” surrounding Cayman’s Oxitec partnership has subsided to a low background hum. Hmmm …

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As we reported last week, the government has scaled back significantly immediate ambitions for the GM mosquito program.

Last fall, the government and Oxitec were close to a two-year, US$8 million commitment to expand the program across Grand Cayman. Since then, however, the government retreated, budgeting only CI$940,000 for the year, enough to (essentially) repeat the pilot deployment in West Bay that occurred from 2016 to 2017.

From the outside looking in, it’s difficult to conclude why the government has put the Oxitec program on cruise control. For the purposes of conjecture, here are some observations that may be germane:

  • The cost of the expanded GM mosquito rollout of US$8 million constituted a considerable portion of spending on mosquito control. The total MRCU budget for the next two years is about CI$15 million;
  • Emails obtained by the Compass seem to indicate differences in opinion among MRCU scientists over whether Oxitec’s method, while promising, achieves sufficient value for money;
  • Outside groups, such as U.S. nonprofit Genewatch, continue to exert pressure and express skepticism against the deployment of GM mosquitoes;
  • Over the past two years, the global paranoia about a Zika pandemic has waned, as nightmare scenarios of widespread microcephaly have largely failed to materialize;
  • In July, MRCU director Bill Petrie – the primary government champion for the Oxitec collaboration – departed Cayman to take up a similar position in Miami-Dade County. (There, authorities have just announced the launch of a mosquito suppression strategy – not with GM organisms – by releasing mosquitoes that have been purposefully infected with Wolbachia bacteria. Again, the hopes are the lab-bred mosquitoes will mate with wild females and produce offspring that will not survive to adulthood.)

It is worth noting that the Compass, and the general public, find ourselves in the position of hypothesizing as to our government’s motivations because of the lack of information proactively emanating from officials.

Indeed, even Oxitec, government’s partner for nearly a decade now, seems to have been caught off-guard by the decision not to expand the GM mosquito program.

In August, Oxitec’s regional manager Richard Adey wrote to government, “[W]e are delighted to be intensifying our work with the MRCU.”

In September, Mr. Adey told Cayman officials he was “surprised” that the decision to “expand our technique throughout Grand Cayman appears to have been revised.”

Whatever is going on (or not) between the government and Oxitec, what has not changed is that Cayman’s local population of Aedes aegypti mosquitoes are still lurking around homes and gardens, potentially carrying a host of dangerous diseases – including Zika, dengue, yellow fever, chikungunya, etc.

As we’ve written before, neither Zika nor any individual pathogen is the pre-eminent threat to public health in Cayman. “Public Enemy Number One” remains the Aedes aegypti mosquito itself.

Officials should be prepared and enabled to expend all resources necessary to eradicate this nemesis from our midst – involving a sustained war on all fronts, including aerial and ground-based spraying, public education and, sure, novel techniques – including, but not limited to – Oxitec’s GM mosquitoes and/or the Wolbachia approach.

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