Honolulu Mayor Kirk Caldwell is questioning the effectiveness of a surveillance testing program meant to be a key safety net in the safe reopening of Hawaii tourism.

In a letter Tuesday to Lt. Gov. Josh Green, just days before the start of the study next week, the mayor questioned how the state would ensure a randomized sample, which is needed to accurately assess how much coronavirus may be coming into the state despite pre-travel testing that allows travelers to bypass the mandatory 14-day quarantine if they get a negative COVID-19 result 72 hours before their departure to Hawaii.

Details of the surveillance program, which will be voluntary, have not yet been unveiled to the county mayors, who are each developing their own post-travel testing programs for added security.

“We’ve been informed by members of the medical community that collecting this type of random sample will be a difficult task, which is why it is vital we be provided more details on this program so that we can relay these details to the public. Knowing how well this pre-travel testing program is working to keep COVID-19 out of our state is crucial to fighting this virus,” Caldwell wrote, adding that the City and County of Honolulu would “explore additional protocols to protect the health and safety of its visitor industry workers and the broader community” if the positivity rate was found to be greater than the 1 in 1,000 visitors projected as tourism reopens.

Caldwell and Green will likely be competing against each other in the governor’s race in two years.

“This is a time where public trust is vital to our effort to control this virus as we continue to open up our island economy,” Caldwell added.

The pilot program was created as an additional layer of security amid growing concerns that one pre-travel test per traveler won’t be enough to prevent a surge in infections, which have plateaued at about 100 cases a day, a significantly higher baseline than in the early months of the pandemic. The program will select a sample of 10% of incoming passengers.

“All the mayors will get details of the study from our team of scientists led by epidemiologist DeWolfe Miller when they are ready to present it,” Green told the Honolulu Star-Advertiser. “I anticipate that will be done shortly but do not want to micromanage their work, understandably.”

Details of the program, including where selected individuals will be tested and how they will be contacted, are still being worked out. Positive test results will be shared with travelers and the state Department of Health. Anyone positive will immediately be contacted and ordered to quarantine per state rules.

Hawaii recorded 10 new coronavirus deaths — seven of which occurred between Aug. 15 and Sept. 30 — and 101 new infections statewide, bringing the totals since the start of the pandemic to 183 fatalities and 13,674 cases. The latest deaths include five on Maui, three on the Big Island and two on Oahu.

Separately, Hilo Medical Center reported the Big Island’s COVID-19 death toll has risen to 38 people, after a fourth person from the Life Care Center in Hilo died. The state has yet to verify 20 reported coronavirus deaths by Hilo Medical Center.

Miller, the lead epidemiologist heading the surveillance program, said the program will give the state a valid estimate of infection through a “representative sampling of people coming off the planes.”

“We’re ramping up, then we’re going to be operational with 20,000 tests-plus very soon. We don’t know how many people are going to be coming on these planes,” said Miller, who is not being compensated for his work. “We’re offering people the opportunity to participate in the study to give us the necessary information to evaluate whether one test is safe for Hawaii or not. I will feel safe after we complete the study and have the results.”