Every indication is that the sacrifices Mainers have made and the precautions they have taken, perhaps with a little luck, have kept COVID-19 in check. But that doesn’t mean it isn’t around.

Mount Desert Island Hospital in Bar Harbor last week said it had been contacted by at least 35 out-of-state tourists who were carrying the disease on the island. Many of them had taken a COVID-19 test in their home states before coming to Maine, but because of delays in results only found out they were positive after they got here — and after they had moved about the communities there. The remainder were assumed positive because of their close contacts with the others.

Spokespeople from the two largest hospital networks in the state, MaineHealth and Northern Light Health, told the Press Herald they knew of no such incidents at their hospitals, but said that it is possible they had occurred. A hospital in York County said they had heard such stories anecdotally “many times.”

Of course, the hospitals would only know if they were contacted by the tourists themselves. There are any number of scenarios under which someone with the virus could have come here and spent time without anyone here knowing. And the Press Herald reported recently that nonresidents were testing positive at a rate four times that of residents.

The number of infected visitors, however, is still very small, and there are no indications yet that an out-of-state tourist has spread the virus here.

It’s encouraging, too, that most visitors come to Maine from states that have taken the pandemic seriously, and where preventative measures are widely accepted as the way of life now.

But we should assume that what happened in Bar Harbor has happened elsewhere in the state. Health officials and hospitals need to keep a close eye on cases in the coming weeks to see if there is any increase related to summer tourism. The state should be prepared to track out-of-state cases, which pose a challenge for the contact tracers who are tasked with identifying people who have been around someone with the virus.

And, as always, it’s best to act as if COVID-19 is around even if the chances are low that an infected person is nearby. We know that measures such as physical distancing, face coverings, ventilation and cleanliness can keep the virus from spreading.

Making those small sacrifices can help everyone, out-of-state tourists and Mainers alike, enjoy the summer to the extent possible, without jeopardizing Maine’s status as one of the safest places to be in terms of COVID-19 — and putting at risk months of hard work.