Iditarod officials contact tracing after positive virus test BECKY BOHRER, Associated Press FacebookTwitterEmail JUNEAU, Alaska (AP) — A musher taken out of the Iditarod Trail Sled Dog Race after testing positive for COVID-19 at a checkpoint is believed to have been exposed by a person who had been in his quarantine bubble before the race started, a doctor working on the race said Thursday. Dr. Jodie Guest, an epidemiologist working on the race, told reporters musher Gunnar Johnson and all other mushers tested negative on March 4 and all were also tested on Sunday, before the race start. On March 5, Johnson was in a vehicle with a person “who was part of two people in his bubble that he was quarantining with prior to the race, between his 14-day-before-the-race and his three-day-before-the-race test,” she said.