Daily coronavirus cases in Arizona fell by 75% by late August, possibly in correlation with stricter mitigation measures, per a new report from the Centers for Disease Control and Prevention (CDC).
The agency looked at Arizona’s daily virus cases and seven-day moving averages from Jan. 22 to Aug. 7 in the context of mitigation measures to assess the efficacy of these strategies. This relationship carries a “temporal correlation” and not causality, the authors noted.
Arizona ordered a public state of emergency on March 11 and closed schools statewide several days later. Daily virus cases ranged from 154 to 443 until mid-May but a phased approach for reopenings and the end of the stay-at-home order coincided with a drastic jump in cases.
Average daily cases increased by about 151% from June 1 to June 15, from 808 cases to 2,026 cases. Up until this point, masks were not mandated, however, updated guidance from the state then allowed local officials to implement mask mandates; on June 17 those local policies affected about 85% of Arizona’s population, the CDC wrote.
Further efforts to tamp down virus cases included closures of bars, gyms, water parks and movie theaters in late June, reducing dine-in restaurant capacity thereafter.
While cases continued to climb, they peaked in early July, began to stabilize until July 12 and then dropped off by 75% by Aug. 7, per the report.
“Widespread implementation and enforcement of sustained community mitigation measures informed by state and local officials’ continual data monitoring and collaboration can help prevent transmission of SARS-CoV-2 and decrease the numbers of COVID-19 cases,” the CDC wrote.
Other factors may have attributed to the dropoff in case counts, such as travel restrictions or mitigation steps taken in neighboring states, the agency noted. The CDC did not assess individuals’ adherence to the measures, adding, “these findings are not necessarily generalizable to other settings,” given other states’ higher population densities.