Revisiting The Issues With Pre-Travel Testing and COVID-19

As the State of Hawaiʻi pushes forward with plans to implement a pre-travel COVID-19 screening protocol, I must revisit a point I previously raised when this planning was ongoing at the Hawaiʻi State Legislature. RT-PCR tests are NOT accurate when administered on non-symptomatic patients, and non-symptomatic carriers of COVID-19 are still contagious, and they can become symptomatic after arrival to Hawaiʻi. For those that missed it, Governor Ige announced on 6.24.2020 that: “Out-of-state travelers arriving in Hawai‘i must get a PCR test prior to arrival from any testing location approved by the Hawai‘i State Department of Health. Evidence of a negative test result must be provided upon arrival in Hawai‘i. Without this, passengers arriving from out-of-state will be subject to the 14-day quarantine. No testing will be provided upon arrival at the airport.” This was directly addressed in the post I made a month ago on the issues with pre-travel checks that rely on RT-PCR was unclear, but as the point was missed, let me try again: On the first day of infection the chance of detecting COVID-19 is exactly 0%! (95% CI, 0% to 0%). 72hrs after infection the chance of detecting COVID-19 is very roughly 33%, with a wide margin of error! (95% CI, 6% to 73%). Those figures are based upon this study that looked at false-negative rates with RT-PCR tests (https://www.acpjournals.org/doi/10.7326/M20-1495). Even when PCR tests are used on patients with symptoms, the most common test has a false-negative rate reported to be ~30%! (https://www.medrxiv.org/content/10.1101/2020.05.27.20114736v1.full.pdf+html) AT BEST the likelihood of the pre-travel tests producing false-negative results could be roughly 67%, but likely considerably worse, up to approaching 100%... The 14 day quarantine is both one of the strongest mitigation measures against COVID-19 rapidly coming to our islands, and one of the measures that has severely impacted the economy. The removal of the mandatory quarantine needs to be sound to not risk situations we are seeing across the mainland with clusters of infection. The idea of adding thermal imaging and other scanning metrics at Hawaiʻi airports as an added layer of protection from infected travelers has some merit, but it too relies on patients presenting with a few common symptomatic conditions at time of arrival. As commonly accepted, COVID-19 takes on average 5 days before presenting symptoms. It also requires people having not taken a fever suppressor prior to screening, such as taking two Tylenol on the plane. I am quite interested in research that the Department of Health is using to guide the chosen pre-travel protocol, other than citing anecdotes of countries that have a similar system in place. The need to reopen the economy to travel does not make the proposed protocol more sound, and does not provide a layer of security that the public can rely upon, based upon the data available. The pandemic is not over, SARS-CoV-2 has not really changed. We can overcome this virus and reactivate the economy, but that will not be accomplished by ignoring the research. Journalists - Ask Dr. Green, Dr. Anderson, and Dr. Park about the research they have on the accuracy of RT-PCR tests on pre-symptomatic and asymptomatic patients. Ask how false-negative rates will play into the pre-check system. Ask how well the thermal imaging will perform if someones takes two Tylenols a hour before arrival in Hawaiʻi.