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

Early within the morning of August 16, a 41-year-old man from Chongqing Municipality in west central China received up and went jogging alongside a lake in a neighborhood out of doors park – some one thing that ought to have been nice, if not banal. , exit. However what actually occurred throughout that 35-minute jaunt has now sparked worldwide alarm and debate, with some scientists doubting China’s startling story.

In line with the Chinese language Middle for Illness Management and Prevention, the unmasked man contaminated 33 unmasked park guests and two unmasked park workers with the omicron coronavirus subvariant BA.2.76 throughout his quick run. The company claimed the transmission occurred throughout fleeting out of doors encounters as he walked previous individuals on a four-metre-wide pathway. Many extra have been contaminated with none shut encounters. Twenty of the 33 park-goers contaminated had been contaminated by merely visiting out of doors areas of the park that the jogger had beforehand handed by way of, together with an entrance gate. The 2 contaminated employees, in the meantime, rapidly unfold the an infection to 4 different co-workers, bringing the full variety of outbreaks within the jogger’s park to 39.

To help these uncommon findings, the CCDC cited case interviews, park surveillance pictures and genetic knowledge on SARS-CoV-2, which might have linked the circumstances however are notably lacking from the report.

The report’s claims, if correct, would recommend {that a} vital replace is required for our present understanding of SARS-CoV-2 transmission dangers. Though out of doors transmission is thought to be doable, it’s thought-about a lot much less possible than indoor transmission, the place virus particles can cling in stagnant air and accumulate in enclosed areas over time. time. Out of doors encounters which can be transient are significantly not thought-about a major threat, as huge volumes of transferring air rapidly disperse infectious doses of virus particles. For a similar motive, SARS-CoV-2 shouldn’t be thought to linger within the threatening clouds outdoors within the wake of an contaminated individual.

For now, consultants outdoors China aren’t revising their considering on transmission dangers, citing lacking genetic knowledge from the report and different questionable findings.

Lacking knowledge

Given China’s strict “zero COVID” technique, the CCDC flatly dismissed the chance that the infections had been a part of an undetected outbreak within the better neighborhood, calling publicity to the jogger (aka “affected person zero”) of “solely doable publicity”.

The CCDC says genetic knowledge hyperlinks all of the circumstances collectively, displaying that affected person zero was the supply of all 39 infections. Particularly, they report that 29 of the 39 circumstances had “precisely the identical genetic sequencing as affected person zero; 5 circumstances had a mutation web site added to affected person zero’s genetic sequence; and the opposite 5 circumstances couldn’t be sequenced. attributable to unqualified specimens”. However there is not any sequencing knowledge included within the report, and it is unclear what sequencing was truly carried out to again up their claims.

“If that they had sequence knowledge displaying that 29 circumstances had genomes similar to ‘affected person zero,’ that will recommend that each one the circumstances got here from a single supply,” virologist Angela Rasmussen instructed Ars. Rasmussen is a analysis scientist on the Vaccine and Infectious Illness Group on the College of Saskatchewan and affiliated with the Georgetown College Middle for International Well being Science and Safety.

“However,” she stated, “it is unclear whether or not they did full genome sequencing of all circumstances, what sequencing platform they used (Illumina vs. Nanopore), and many others.” The report solely mentions “gene sequencing”, which can solely recommend partial genome sequencing, not “entire genome sequencing” which would definitely point out a direct hyperlink between the circumstances. With out understanding the info and sequencing strategies, it’s unattainable to verify whether or not the jogger was the supply.

The CCDC additionally presents a complicated clarification of how Jog’s affected person zero received contaminated within the first place.

affected person zero

In line with the CCDC, the person was contaminated following a wave of “publicity to contaminated airline environments”. The person had traveled from Chongqing to the northern metropolis of Hohhot on August 11 and returned to Chongqing on August 13, three days earlier than his jog. Neither flight had recognized circumstances of SARS-CoV-2 on board that would clarify the human’s an infection. However, the airplane he took for the return journey had carried 4 SARS-CoV-2 constructive passengers the day past, August 12.

On August 12, 4 passengers from Tibet flew from Chongqing to Hohhot and later examined constructive in Hohhot. The airplane, in the meantime, was not disinfected after their flight, and the Chongqing man boarded the following day and sat (in seat 33K) close to the place three of the contaminated passengers had been seated (seats 34A, 34C, 34H). It’s unclear how people might have been contaminated this fashion – SARS-CoV-2 shouldn’t be recognized to persist within the air for such lengthy durations, and transmission from contaminated surfaces is uncommon. Furthermore, the report doesn’t point out that different passengers on the flight had been additionally contaminated, together with individuals who had been truly seated in the identical seats because the passengers from Tibet. However affected person zero was contaminated with BA.2.76, which was circulating in Tibet, main the CCDC to make a connection.

“I believe it is also very uncertain that ‘affected person zero’ received contaminated on that airplane,” Rasmussen stated. “I observed that the earlier flight with the passengers who had been believed to be the supply of the an infection had been from Chongqing – this may recommend cryptic unfold of BA.2.76 to Chongqing, not (solely) Tibet because the paper claims On this case, if a complete bunch of individuals in Chongqing have BA.2.76, the sequencing knowledge may simply level to a a lot bigger outbreak in Chongqing, however you’d want the precise sequencing knowledge to essentially perceive what is going on on. .

“Backside line: any assertion about what the info truly reveals relies on the precise inclusion of the info within the doc,” she stated. “In any other case it is simply hypothesis.”