Health officials from Washington State in the US have reported that newly diagnosed cases of coronavirus caught the potentially deadly illness on purpose at "Covid-19 parties".
Walla Walla County health officials say people diagnosed with coronavirus have told county investigators they attended parties specifically organised to spread coronavirus in recent weeks.
Megan Debolt, the director of community health for Walla Walla County, said one of the parties with at least 20 attendees has so far resulted in two positive cases of Covid-19.
Immunity parties, also called pox or flu parties, are sometimes organised so children can catch diseases such as chickenpox from one another and gain immunity to an illness, news.com.au reports.
The discovery has alarmed health officials, who have been scrambling to contain a large outbreak of coronavirus at a meat processing plant near Pasco which has seen more than 700 workers test positive.
Walla Walla county so far has 94 confirmed cases of Covid-19, and the first of those infected sadly died this week, according to ABC4 KOMO News.
Debolt said while investigating the cases the residents said, "Oh, we were having a Covid party."
She said the county's health officials were now tracing the contacts of all those who attended the party.
"It's all of their contacts – up to 25 contacts per person is around 100 people that could have potentially been exposed," she said on Wednesday.
Researchers from Johns Hopkins University have dismissed the effectiveness of immunity parties similar to pox parties, warning that COVID-19 is up to 100 times more deadly than chickenpox.
"Some have entertained the idea of 'controlled voluntary infection', akin to the 'chickenpox parties' of the 1980s. However, Covid-19 is 100 times more lethal than the chickenpox," Professor David Dowdy, from the University's Department of Epidemiology, wrote.
Dowdy said that someone who goes to a Covid-19 party "would not only be substantially increasing their own chance of dying in the next month, they would also be putting their families and friends at risk".
Coronavirus is currently the leading cause of death in the United States, killing thousands of Americans every day. Currently, there have been over 1.26 million confirmed cases of coronavirus in the US and more than 74,000 people have died.
According to the University, at its peak chickenpox never killed more than 150 Americans a year.
Ms Debolt said the two confirmed cases have since expressed remorse after learning they'd endangered their friends and family.