Four Lanai residents tested positive for COVID-19 on Tuesday, state health officials announced. They are the first to have documented infections on the island since the pandemic began.

One person works in the health care field but does not work directly with patients, according to the Department of Health. Three of the residents work together, but their place of work was not released.

All four people are currently isolating, health officials said.

At least one of the residents diagnosed is believed by officials to have contracted the virus while traveling.  No other details were offered about the cases.

The Hawaii Department of Health’s Maui District Health Office is conducting contact tracing and investigating how the infections originated.

Earlier this year there were two other Lanai residents confirmed to contract COVID-19, but they were off island and stayed elsewhere to avoid introducing the virus to the island, according to Hawaii News Now. Fewer than 3,000 people live on Lanai and the island has limited medical resources.

Drive-thru COVID-19 testing by appointment will be held at the old Dole Administration Building on Oct. 24 from 9 a.m. to 1 p.m. for people 15 and older.