Figure 1.
Pandemic situation on the day before the trial testing. Dark color characterizes districts with a higher number of confirmed positive cases by RT–PCR tests [18].
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.