Kaitlyn Bristowe, the recently crowned champion of ABC's "Dancing with the Stars," and her boyfriend Jason Tartick have Covid-19, she announced on Instagram.

Bristowe, an alum of "The Bachelor" franchise, shared the news alongside Tartick, who was also previously a contestant on "The Bachelorette.""Unfortunately, this is our Christmas card this year," Bristowe wrote. "We have Covid."

The couple was trying to quarantine ahead of the holidays so they could see family, Bristowe said. But they felt it was safe to have over one person who was being tested daily for work.

"The day we saw her, she became positive which we all found out the next day," she wrote. "Now, like many, we will spend Christmas by ourselves."

"We just want to let everyone know that we thought we were being safe, but covid is bigger than us," she added.

CNN Medical Analyst Dr. Leana Wen has said people should avoid indoor holiday gatherings with people not in their immediate households. But if people are going to get together indoors, the safest thing they can do is quarantine for 10 to 14 days prior to the gathering.

"This virus spreads inside so easily," she said. "There are measures that can reduce the spread, for example, opening all the windows and doors and having different families sit at different tables. But know that there is still going to be substantial risk."

In his own Instagram post, Tartick said, "You can never be too cautious and careful. There's no outthinking this god awful virus, lesson learned."CNN has reached out to Bristowe and Tartick for further comment.