China links COVID outbreak to man’s jog through a park; Scientists skeptical - Ars Technica

The CCDC claims that genetic data links all the cases together, showing that patient zero was the source of the 39 infections.

Specifically, they report that 29 of the 39 cases had "the exact same gene sequencing as Patient Zero; 5 cases had a mutation site added to Patient Zero’s gene sequence; and the other 5 cases could not be sequenced because of unqualified specimens." But there is no sequencing data included with the report, and it's unclear what sequencing was actually done to support their claims.

"If they had sequence data that showed 29 cases had identical genomes to 'patient zero,' that would suggest that all the cases came from a single source," virologist Angela Rasmussen told Ars.

The CCDC also offers a puzzling explanation of how the jogging patient zero came to be infected in the first place.

The plane, meanwhile, wasn't disinfected after their flight, and the Chongqing man boarded the next day and sat (in seat 33K) near where three of the infected passengers had been sitting (seats 34A, 34C, 34H).

But patient zero was infected with BA.2.76, which was circulating in Tibet, which led the CCDC to conclude a connection.

"I think it’s also very dubious that 'patient zero' was infected on that plane," Rasmussen said.

"I noticed that the prior flight with the passengers that were supposedly the source of the infection came from Chongqing—that could suggest cryptic spread of BA.2.76 in Chongqing, not (just) Tibet as the paper claims.

In this case, if a whole bunch of people in Chongqing have BA.2.76, the sequencing data might just point to a much larger outbreak in Chongqing, but you’d need the actual sequencing data to really figure out what’s going on.