Slovakia gradually scaled up their contact restrictions during Oct as cases kept rising. Then introduced mass testing, first in 4 pilot counties, then nation wide and then in 45 high prevalence counties with a week between each.
The average reduction in infection prevalence within a week after the first round was 61%!
After two weeks and two rounds in the pilot counties the reduction was 82%!
This was against an increasing incidence at time of testing, but also with contact restrictions in place
In a microsimulation model the observed effect was best explained by a combination of a moderately effective lockdown and the effects of mass testing with strong adherence to quarantine of test-positive and their household contacts