Contact Settings and Risk for Transmission in 3410 Close Contacts of Patients With COVID-19 in Guangzhou, China https://www.acpjournals.org/doi/full/10.7326/M20-2671?fbclid=IwAR3LGvjoZeXD5fz0SNpjSc8lrdPN5L92DTWLQuTXM-anB9cLW-fP4i8NNLY&jour…