The depth of skepticism among scientists at the Mosquito Research and Control Unit about the success of genetically modified mosquitoes in Grand Cayman is revealed in a cache of internal emails released following an open records request.

Both Alan Wheeler, assistant director at the unit, and Fraser Allen, who at the time was the unit’s research manager, expressed serious doubts about the impact of the technology in controlling natural populations of the disease-spreading insects. They also expressed concerns about the claims being made on its behalf by British biotech firm Oxitec.

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The concerns of both men appear to have contributed to government’s decision to walk back on plans for an US$8 million national rollout of the technology.

Though neither the MRCU nor Oxitec has commented in detail on their current plans, the emails suggest that a rerun of the initial West Bay trial release has been sanctioned to help government to determine if and how to use the technology in the long term.

In a series of emails dating back to April last year, Mr. Wheeler and Mr. Allen suggest the unit was moving too fast on the controversial project. They consistently argue that the GM mosquito technique has not definitively proved its effectiveness in the field and that more data is needed.

Both men wrote to then MRCU director Bill Petrie and ministry of health officials in April 2017, disputing Oxitec’s data and calling for a more scientific approach to information gathering.

“We all need to be looking at the data that is being collected; we cannot just take Oxitec’s word that it is working,” Mr. Wheeler wrote.

Mr. Allen also cautioned that independently verified data was needed before an islandwide rollout of the technology was contemplated

“I’m throwing up caution flags for discussion prior to a big commitment,” he wrote in an email citing concerns over the validity of Oxitec’s results.

The scientists also questioned the wisdom of making such a large financial commitment to “one technology,” arguing that any operational rollout of GM mosquitoes should be on a much smaller scale than was being contemplated at that time. They suggested any rollout should focus largely on West Bay and George Town, and that GM mosquitoes should only be used in combination with other suppression methods.

The pilot deployment in West Bay was largely self-funded by Oxitec, though government did make payments to the company to extend that trial beyond its original deadline.

In a series of internal emails released this week by U.K. campaign group GeneWatch, which made the Freedom of Information request, Mr. Wheeler argued against any payments to Oxitec, suggesting they are benefiting from the trial as much as the MRCU.

In one email, in April 2017, he argued that the resources being put into the project were hampering the unit’s effectiveness.

“I am also rather disappointed that MRCU has signed a $400,000 extension of the project as I am firmly of the opinion that the Oxitec program is still in the development stage and MRCU should not be paying for an as-yet unproven technique. $400,000 could have expanded our traditional control program by 13 staff for 1 year, which would have allowed us to treat all problem yards across the island on a once-weekly basis,” he wrote.

He went on to argue, in further emails to his colleagues at MRCU and ministry staff, that the unit was so short-staffed, it could not conduct its full schedule of yard-by-yard ground control patrols.

“Our established and proven control methods are being neglected and it appears that we have put all our eggs in one basket and see Oxitec as the only solution.”

Following the departure of Bill Petrie as MRCU director that summer, Mr. Allen, in emails to ministry staff in August, endorsed Mr. Wheeler’s view that further proof is needed of the effectiveness and value for money of the GM mosquito technique.

He proposed a compromise involving a new trial deployment in West Bay, which appears to be the path the MRCU eventually followed. The emails suggested “production issues” and other logistical problems impacted the initial trial, and that a new test deployment was needed for the MRCU staff to be satisfied that it works.

“I don’t think we are ready to make the big leap in 2018,” Mr. Allen wrote in August 2017. “By deferring for a year we can also examine other combined control methods and outline a more structured approach on our terms and within our comfort levels.

“The future dollar figures they suggest may also become invalid if we look at other pathways, whilst incorporating Oxitec where we see fit.”

Doubts over Oxitec’s claims about the success of the technology came to a head in October 2017, when the Compass reported a 62-percent suppression rate from data in the MRCU’s annual report on the project.

Among the emails, Mr. Wheeler argued that Oxitec, not the MRCU, authored that document, and that this suppression rate was not endorsed by the MRCU.

“The MRCU Annual Report was actually written by Oxitec and we remain divided upon the level of suppression achieved,” he wrote in an email to ministry staff.

“The information given is incorrect and goes against our current logic for requesting a repeat of the release. MRCU was expecting to see a reduction in the region of 90%+ as had been reported in all other Oxitec releases. This was not achieved and the figure of 62% reduction is also not accepted by MRCU.”

No response to those concerns from Oxitec is apparent in the email chain. However, Oxitec’s Richard Adey did explain the suppression rate data in an email to ministry officials in September of last year, in which he argued that a 61-percent suppression rate was achieved for at least part of the trial period. He acknowledged that this was not achieved consistently throughout the project, but attributed this to logistical problems unconnected with the efficacy of the technology.

As the negotiations continued, the emails suggested Mr. Wheeler, in particular, was keen to abandon the partnership with Oxitec altogether.

In one internal email responding to Oxitec’s request for further payment to extend the trial deployment, he wrote, “I really think we have reached the end of the line with Oxitec and should not be wasting anymore time on this. Now I need a cigarette.”

Though the email chain does not tell the whole story, a compromise position appears to have been reached for a new trial deployment to take place in West Bay in order to obtain clear data.

In response to questions from the Compass on the email release this week, a government spokeswoman said new MRCU director Jim McNelly was bringing himself “up to speed” on the data from the project so far. She said a more substantive response would be sent this week.

Asked about the future of the GM mosquito program, she said, “MRCU and Oxitec have finalized negotiations and will soon begin rollout of a programme that aims to evaluate Oxitec’s potential for inclusion within MRCU’s Integrated Mosquito Management Programme.”

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