Do you hear the sirens? Hawaii is under a COVID-19 tsunami warning. The threat is imminent. Prevention is our most powerful tool and must be our first priority. We can choose to keep COVID-19 from inundating our state, if we act now.

I commend Gov. David Ige for requiring pretravel test results at the time of travel for trans-Pacific arrivals. This will strengthen the Safe Travels Program. But it will not keep the tsunami at bay. We must:

>> Declare a moratorium to the Safe Travels Program for the month of December, temporarily returning to a mandatory 14-day quarantine for all travelers — regardless of testing.

>> Continue aggressive daily prevention (masks, distancing, hand-washing, avoiding large gatherings), disease detection, disease containment and disease treatment.

>> Focus our holiday activities on local residents safely supporting local businesses.

The threat has never been greater. Mainland cases set daily worldwide records. The holidays are upon us, bringing travel and social gatherings. Community spread still predominates statewide, and will accelerate during the holiday season. Careful attention to preventive measures — especially mask-wearing — can help minimize that acceleration.

Improved testing access, case investigation and contact tracing capacity, isolation and quarantine facilities, and support services for those affected mean that we are better positioned than ever to manage community transmission. Our hospitals and health-care providers have gained experience caring for those with COVID-19.

No single test program, no matter the timing, can control COVID’s spread. Without definitive action to prevent disease, we are fighting a losing battle. Local resources are finite and outside help is literally an ocean away.

Encouraging travel to and from the mainland ensures a steady stream of newly introduced virus. Infected travelers spread disease to their households, coworkers, traveling companions, and hospitality and health-care workers. Inviting travel means inviting uncontrolled disease to our islands. Infectious diseases introduced from beyond our shores have repeatedly devastated Hawaii. We must heed those lessons, lest we allow history to repeat itself.

The biology of the SARS-CoV-2 virus is clear. It spreads easily, undeterred by hoping or waiting or wishing it away. When it takes hold, it increases exponentially — rising at a faster rate each day. Every case of COVID-19 that we prevent is one less test to run; one less case to investigate and isolate; one less group of contacts to trace and quarantine; and one less person at risk of hospitalization, long-term illness or a lonely death.

Hawaii is a rare exception to the national picture: Our disease rate is second only to Vermont’s as the lowest in the country. We cannot rely on our past successes or wait to see whether our cases rise as on the mainland. Preventing all travelers from mingling with others until a full 14-day incubation period has passed is the strongest preventive measure we can take. Doing so will save lives.

We are tired. Unfortunately, the peak of our fatigue coincides with an even more alarming peak of disease. We have worked so hard and sacrificed so much this year. Now is not the time to let down our guard. Caring for each other is Hawaii’s strength, but we cannot defeat this pandemic with individual actions alone.

A December mandatory quarantine for travelers will protect us through the end of the year. Then we can determine a prudent path forward. We will be well-positioned to rebuild and recover as it becomes safer to do so. When disease rates are stable or falling here and on the mainland, we can re-instate the Safe Travels Program. Vaccination of high-risk groups and health-care workers is slated to begin by early 2021. Widely available vaccines and their robust uptake will add a layer of safety. That will be the time to celebrate, gather, travel and welcome visitors. Let’s heed the sirens’ warning. Let’s prevent this tsunami while we can.

Janet M. Berreman, M.D., M.P.H., F.A.A.P., is Kauai District health officer.