By Barbara Goldberg

(Reuters) – The first COVID-19 outbreak among firefighters battling the enormous Bootleg fire in Oregon has put nine of them in quarantine as weather forecasters on Friday warned that relentlessly dry weather will persist over the weekend.

With the 400,389-acre blaze 40% contained, nine firefighters out of a 2,389-person force tested positive for coronavirus and were placed in quarantine with mild symptoms, said Stefan Myers, fire information spokesman for the Bootleg fire.

“We expect them all to make a full recovery,” Myers told Reuters.

Safety measures to stop virus spread, including social distancing at all four fire camps, appeared to be working for the most part.

“We are really heartened by the fact that there weren’t more firefighters exposed. They have to perform on a daily basis and that does lead to the possibility for exposure,” Myers said.

Citing privacy laws, he declined to comment on the age, gender and vaccination status of the nine people who are “quarantining away from the main body of the fire camp as to make sure they are isolated but also recovering.”

The so-called Bootleg fire, which was first reported July 6 in the Fremont-Winema National Forest some 250 miles south of Portland, was ignited by lightning but smoldered for days before it was detected.

Air quality amid the smoky blaze on Friday appeared to improve over all but two of 11 fire stations, authorities said. However, dry weather was expected to persist through the weekend, ramping up risk.

“There is really no relief in sight,” said Bob Oravec, lead forecaster with the National Weather Service in College Park, Maryland. “The fire weather will continue.”

On Friday, the fire remained most active on the northern and eastern portions, authorities said.

“The fire continues to throw challenges at us, and we are going to continue to stay vigilant, work hard and adapt,” Joe Hessel, incident commander for the Oregon Department of Forestry Incident Management Team said in a statement.

(Reporting by Barbara Goldberg in New York; Editing by Mark Potter)