Fewer than 1 in 1,000 travelers infected with COVID-19 slipped through the cracks of Hawaii’s travel testing program, state officials said on Tuesday, announcing the results of a post-travel testing study created to supplement Hawaii’s Safe Travels program.

The testing, which was conducted Oct. 19 to Nov. 2, found 10 confirmed positive cases of COVID-19 out of 11,027 tests conducted, for a rate of 0.091%, the Hawaii Emergency Management Agency said in a news release.

The post-travel surveillance testing quantifies what has long been assumed: that some people would slip through the cracks of a pre-travel testing system designed to reduce the risk posed by travelers infected with COVID-19. The state’s Safe Travels program lets travelers skip a 14-day quarantine upon arrival in Hawaii by showing proof of a negative COVID-19 test within a few days of departing for the islands.

The question has been how many would slip through the cracks. The rate – less than 1 in 1,000 – is lower than the rate in the general population in Hawaii, which is closer 1 in 700, said Lt. Gov. Josh Green, who has been in charge of designing and implementing the state’s pre-travel testing program.

“So far, the numbers are good,” Green said. “It’s what we had hoped for, that the Safe Travels pre-test would keep us safe.”

The post-travel surveillance testing study arose amidst criticism by some local government officials who called for two tests: a pre-travel test and a test upon arrival in Hawaii, perhaps combined with a short quarantine period. Green devised the post-travel test to determine how many infected people were traveling to Hawaii after testing negative.

“We’re actually doing this to make sure the Safe Travels program is working,” Green said.

To that end, the study gave a second test to a representative sample of people who participated in the Safe Travels Hawaii pre-travel testing program. The second test was voluntary, free and administered one to four days after the test subject’s arrival in Hawaii.

The state has partnered with pharmacies, health care facilities and hotel properties to conduct testing on Oahu, Kauai and Hawaii island. The following are testing and sharing data for the study: Premier Medical Group, Hawaii Pacific Health, The Queen’s Health Systems, Doctors of Waikiki, Kaiser Permanente, Adventist Health Castle, The Resort Group and select Walgreens locations.

The relatively low number of cases brought into the state is manageable, Green said, and worth the trade-off for the economic benefit of reopening the tourism industry.

“This is a very close reflection of what we saw in other places, like Tahiti,” Green said.