The majority of the houseguests entered in early February, and were unaware of the pandemic.
The majority of the houseguests had entered the house over a month ago, when the first cases of coronavirus outside of China were being reported. Four new residents who joined the show on March 9 were just reportedly told not to talk about coronavirus.
The premise of Big Brother depends on the houseguests being completely isolated from the outside world and not having communication with anybody not in the house, all while they are under constant surveillance.
Coronavirus, which was declared a pandemic last week, can be fatal in the most extreme cases. Germany now has more than 6,000 cases and 13 deaths -- and after fan backlash earlier this week, host Jochen Schropp finally told the cast in a live special on Tuesday what was going on outside the Big Brother House.
"Please don’t get scared. Let me just explain why we are sitting behind a glass wall," he began, separated from the cast by a protective barrier. Schropp then explained that "a disease called COVID-19 had spread across the world."
Schropp assured the houseguests that their families were healthy and showed them a video of what has happened in the past several weeks. He tried not to panic the cast -- but some burst into tears.
A 26-year-old nurse named Michelle noted that her 55-year-old mother had a preexisting lung disease and said that she was concerned for her elderly patients. Schropp tried to comfort the crying houseguests before a doctor joined him to answer their questions about the virus. "Please calm down. Everything's OK," he said.
Cast members were then shown video messages from their family and friends -- who reassured them that they're OK, and encouraged them to stay on Big Brother. "This might be the safest place in Germany," one joked.
Tuesday's special isn't the first time Big Brother has had to interrupt the game due to a major worldwide event. In 2001, producers interrupted season two of the U.S.'s Big Brother to tell the contestants about 9/11.
For more on how coronavirus has affected the entertainment world, watch the video below.