Negative = Total - Positive.
Positives occasionally update before totals do; we do not revise negatives down, keep the last calculated negative.
As of May 24, Connecticut is reporting PCR specimens tested. Because some people may be tested more than once, this number is probably higher than the number of people tested.
On May 27, Connecticut reported they had "removed 356 cases and 808 tests...which were identified as duplicates in the system." When combined with actual new cases, these removals resulted in a net reduction of 15 positives on May 27.
As of May 29, CHA changed to only reporting the number of patients with laboratory-confirmed COVID-19; data for previous dates include patients with laboratory-confirmed or suspected COVID-19. This impacts the numbers for cumulative hospitalizations and recoveries.
On June 18, Connecticut reported that "Please note that 81 new cases were reported in the past 24-hours; 70 previously reported cases were removed from the total counts due to correction of data errors."
On June 24, Connecticut removed 2770 previously reported tests due to correction of a data error. Negatives decreased as a result. Starting July 11, Connecticut is longer reporting data on weekends.