[ZH] As researchers struggle to understand what makes infection with COVID-19 so mild in some cases, and so deadly in others, we have kept a close eye out for any new links between symptoms different strains of the virus. And on Wednesday we noticed new comments from South Australia's top health official who warned that a particularly deadly strain of SARS-CoV-2 is circulating in the state.
Chief Health Officer Professor Nicola Spurrier explained that the reason for the recently imposed six-day lockdown is the fact that "this particular strain has had certain characteristics" she said.
The State of South Australia, which became home to this dramatic scene yesterday, is also bracing for the risk that this new strain could spread more quickly, in addition to being more deadly. Professor Spurrier said a typical generation, or stage, of the virus was only about three days.
"We also know, because of that characteristic, that what we call a generation, is only about three days and a generation is when one case is passing it on to the next level, and then that (next) level, so if they pass it on to two people, they will pass it on to another lot of people, and that is your third generation," she said.
Already, the virus has progressed to the fifth generation, she said.
"At the moment in SA we have done contact tracing to the fourth generation but the fifth generation is out there in our community and at the moment we are contact tracing to get on to that generation and that is the Woodville pizza bar."
Authorities have traced the local outbreak to a pizza shop in Parafield. The cluster began with a worker at Peppers Warmouth, which is being used as a quarantine hotel, was infected with the virus.
By tracing the spread of certain strains of the virus, researchers in the US have hypothesized that the virus was spread to New York from Europe, before moving to the rest of the country east of the Mississippi, while other strains colonized China and the west.
Though SA's infection rate remains muted, officials have reported two new cases today, taking the total to 22, while another 12 people are still under investigation.
But as residents rush to get tested, we can't help but wonder if public health officials might be playing up the strain angle to coax people into obeying the state's six day lockdown.