Ada, Kootenai counties account for half of Idaho's new COVID-19 cases Saturday Chadd Cripe, The Idaho Statesman Dec. 20—Ada and Kootenai counties continued to account for a large percentage of Idaho's new COVID-19 cases Saturday. Ada County added 262 new confirmed coronavirus cases (29,593 total), according to the Idaho Department of Health and Welfare's daily data update. Kootenai County added 91 (10,036 total). The homes of Boise and Coeur d'Alene accounted for roughly half of the state's 704 new confirmed cases. Idaho also added 29 new probable cases Saturday for a total of 733 new cases. The state's seven-day moving average of new COVID-19 cases has dropped for nine consecutive days to 1,208.3.