"As Covid-19 Surges, the Big Unknown Is Where People Are Getting Infected
The U.S. and Europe struggle to identify where coronavirus infections are occurring, making it hard to impose targeted restrictions"
"Western nations face a big challenge in fighting the Covid-19 pandemic: Ten months into the health crisis, they still know little about where people are catching the virus.
The problem is becoming more acute as new cases are breaking records in the U.S. and Europe and pressure grows on authorities to impose targeted restrictions on places that are spreading the virus, rather than broad confinement measures that are wreaking havoc on the economy.
In Germany, authorities say they don’t know where 75% of people who currently test positive for the coronavirus got it. In Austria, the figure stands at 77%. In Spain, the health ministry said that it was able to identify the origin of only 7% of infections registered in the last week of October. In France and Italy, only some 20% of new cases have been linked to people who previously tested positive.
Jay Varma, senior adviser for public health in the New York City mayor’s office, said 10% of the city’s infections are due to travel, 5% from gatherings, and another 5% from institutional settings such as nursing homes.
“The vast majority of the remainder—somewhere probably around 50% or more—we don’t have a way to directly attribute their source of infection,” Mr. Varma said. “And that’s a concern.”
https://www.wsj.com/articles/as-covid-19-surges-the-big-unknown-is-where-people-are-getting-infected-11605474874?mod=hp_lead_pos7
