A new report has shown just how transmissible the Omicron strain of coronavirus is after a man jogging through a park infected 39 people on his run.
The report by China CDC Weekly revealed how 'Patient zero' in the Chongqing municipality jogged for 35 minutes at a local park while also unmasked, and potentially exposed the virus to approximately 2,836 people at the park, with 38 out of the 39 people testing positive not wearing masks.
The man went running on August 16, 2022, after flying back to Chongqing on August 13. On his initial flight to Hohhot city on August 11, there were four positive passengers and he had only felt fatigue on August 15, not thinking much of it.
American Physician and epidemiologist Dr Bob Morris posted on social media about the new report, noting that "nothing beats a surveillance state for contact tracing".
"Using surveillance videos, Chinese CDC investigators identified 256 people who passed within a meter of Patient zero as he jogged through the park without a mask. 13 (5%) were infected. He infected another 20 out of 20,496 park visitors while running without known close contact."
The report stated in total 39 people tested positive to SARS-CoV-2; 33 visitors and two park cleaners. The two cleaners then passed the virus on to four colleagues.
None of the people at the park had been previously exposed to reported cases or travelled to regions with Covid cases.
"Of 34 cases that could be sequenced, 29 had exact sequence match to patient zero and 5 had one mutation," Dr Morris said.
Warning for outdoor transmission of Covid
Along with other medical professionals who shared the stats, Dr Morris encouraged people to see the "overwhelming evidence of outdoor transmission of Omicron".
"Outdoor transmission has been suspected for a long time," epidemiologist and health economist Dr Eric Feigl-Ding said on Twitter. "Just been hard to prove in Western countries with the lack of detailed contact tracing. Many fleeting transmission been found at outdoor stadiums previously."
He also gave Australian examples of "fleeting exposure" such as a woman in her 70s sitting outside a Sydney cafe last year that a Covid case had visited, leading the NSW Government to re-introduce a mask mandate for five days.
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