Dozens Contract Covid-19 After Abundance 360 Conference

A technology executive in California has apologized for hosting a conference in Culver City after which two dozen attendees and staff members at the event tested positive for the coronavirus.

The executive, Peter H. Diamandis, was among those who contracted the coronavirus. He hosted the conference — an annual summit for a paid-membership group called Abundance 360 — indoors in late January, with a total of about 80 attendees, panelists and members of the support staff.

The gathering flouted guidance from public health officials in Los Angeles County, who had repeatedly urged people to avoid excess travel or public mingling. At the time of the conference, Southern California was just coming down from a surge in coronavirus cases, and many hospitals were still overwhelmed.

Mr. Diamandis, the founder of the X Prize Foundation, a nonprofit group that awards cash prizes for technological innovation, said in a blog post on Friday that he was “deeply sorry.” He added that safety protocols for the event — including repeated Covid-19 testing for attendees, none of whom showed positive results at the time — had created a false sense of security, leading people to be less vigilant about masks and distancing.

“I was wrong,” Mr. Diamandis said, adding that masks, physical distancing and vaccines were the best ways to fight the virus. “I hope others can learn from my mistakes.”

According to Mr. Diamandis, hundreds of people attended the conference virtually, and some asked if they could attend physically. The X Prize office in Culver City, which borders Los Angeles, was turned into a studio space, and Mr. Diamandis’s Instagram posts from the event show him sharing a colorfully lit stage with panelists, some on video calls and others in person.

Mr. Diamandis said that the people who attended the event had been asked to share negative test results for the coronavirus before they arrived, and that workers and attendees were tested repeatedly at the event, yielding more than 450 negative results.

“I trusted that an immunity bubble was a ‘real thing,’” Mr. Diamandis said.

But two days after the studio production ended, he said, a member of his staff tested positive. He sent emails to inform attendees, urging them to isolate and get tested again.

On Friday, he wrote that at least 24 people had been infected. MIT Technology Review, which reported on the gathering last week, found that 32 people associated with the conference or more might have been infected.

A general membership in Abundance 360 costs $12,500 annually, according to the organization’s online materials, and MIT Technology Review reported that attendees of the January event paid upward of $30,000 each. When the conference began on Jan. 23, California had a strict stay-at-home order in place; it was lifted two days later.

On Tuesday, state and county health officials did not immediately respond to questions about whether Mr. Diamandis could be fined or otherwise disciplined.

Mr. Diamandis, who has a medical degree from Harvard Medical School and whose entrepreneurial ventures include a coronavirus vaccine development company and a competition to improve Covid-19 testing technology, said in an emailed statement on Tuesday that “none of the 24 cases of Covid were serious and virtually all have fully recovered — including myself.”

He added that as a scientist with a medical degree, “I have a special responsibility to learn from mistakes, lead by example and use the resources at my disposal to make a positive difference and improve the health and safety of everyone on this planet.”

He said he was doubly committed to fighting the virus but did not answer questions about the cost of tickets to the January event, or about whether there had been any response from state or local officials.

Many people see a negative coronavirus test as permission to socialize without taking precautions, but doctors and scientists say this is dangerously misguided.

Some types of tests, especially the ones that deliver rapid results, do not reliably detect low levels of the virus and can mislabel infected people “negative.” And even the best tests cannot see into the future: People can contract the coronavirus after a negative test result.

According to Mr. Diamandis, attendees took P.C.R. tests, which are molecular tests processed using a technique called polymerase chain reaction. These tests are considered relatively reliable, but they are not perfect. (Antigen tests, which are meant to detect pieces of coronavirus proteins rather than their genetic materials, tend to deliver results faster than molecular tests but are worse at identifying coronavirus cases.)

The P.C.R. tests created a false sense of security, according to Mr. Diamandis’s blog post. “We did not make it a requirement to wear masks 100 percent of the time at the studio,” he said. “This is definitely one of my biggest failings and one of the most important lessons learned.”

Those lessons — especially about relying too much on test results — hit home for Mr. Diamandis after he got sick himself.

“Once it was clear that I personally had contracted Covid-19 (which sucks as much as everyone says it does), I tested myself with rapid P.C.R. and rapid antigen every day, twice per day, for several consecutive days,” he wrote. “I was flabbergasted that NONE of the tests turned up positive.”

Four days into his quarantine, a P.C.R. spit test finally detected the virus, Mr. Diamandis said.

He also noted that one group of people at the Culver City event — the 35 audiovisual experts who ran the live broadcast — wore masks throughout the production process and did not report any positive test results.

“There were NO COVID cases amongst this group,” Mr. Diamandis wrote. “Bottom line again: Masks work.”