Arizona's cases of Covid-19, the disease caused by the novel coronavirus, increased 151% after the state's stay-at-home order expired—and then declined 75% after local jurisdictions were permitted to impose mask requirements and the state paused it's reopening plan, according to a CDC Morbidity and Mortality Weekly Report (MMWR).
Report details and case count metrics
The report, which CDC released last week, was written by staff at the Arizona Department of Health Services, including Cara Christ, the department's director.
According to the report, between June 1 and June 15—two weeks after Arizona's stay-at-home order expired—the daily average number of Covid-19 cases increased by 151%. (If someone exposed to the novel coronavirus develops Covid-19, it generally takes between two and 14 days for those symptoms to present, USA Today reports.)
The surge in Covid-19 cases ultimately ended up overwhelming hospitals in the state, according to USA Today. On June 6, Christ issued a letter to Arizona hospitals recommending they "fully activate" their emergency plans. Then on June 29, as cases began to peak, Christ said hospitals could activate "crisis care standards," which permit the allocation of resources to patients based on factors such as odds of survival.
Overall, the case count peaked between June 29 and July 2, before stabilizing between July 3 and July 12. Then, between July 13 and August 13, the case count dropped precipitously, by 75%.
According to USA Today, the state's Covid-19 metrics have continued to stabilize and decline during September. As of Sept. 27, the White House Coronavirus Task Force put Arizona in the "green" zone for its positive test rate, which is -4.9% or below, and in the "yellow" zone for Covid-19 case counts, which means in the prior week, the state had between 10 and 50 new cases per 100,000 population.
What contributed to the large decline?
According to the report authors, the latest findings demonstrate that Covid-19 case counts "stabilized and then decreased after sustained implementation and enforcement of statewide and locally enhanced mitigation measures." According to the report, on June 17, local public health officials began enforcing mask mandates and "enhanced sanitation practices." About two weeks later, cases began to decline, decreasing further "during July 13–August 7, after statewide limitations and closures of certain services and businesses." Arizona Gov. Doug Ducey (R), who has refrained so far from imposing a statewide mask mandate, issued an executive order that required bars, gyms, theaters, water parks, and inner-tubing facilities to close; limited swimming pool attendance to 10 people; and capped public gatherings at 50 people. The order officially paused the state's reopening through July 27, although individual business were allowed to apply to reopen, as long as they met various requirements.
The report credited mask-wearing specifically, noting, "Mitigation measures mandated through public policy can effectively increase social distancing, and wearing masks has prevented transmission of [the novel coronavirus]."
That said, the report authors wrote that mask-wearing, business closures, and other mitigation efforts many not be the only factors that helped lower the state's case count. For instance, according to the authors, restrictions on travel, measures in nearby states, and people's individual choices—including how well they adhered to state and local guidance—may have also influenced the overall numbers.
Experts push back on response efforts
According to USA Today, the report didn't delve into the background on when and how the mask mandates were instituted—an omission that some public health experts in the state voiced concerns about.
Will Humble, executive director of the Arizona Public Health Association, in a blog post said the report was "wordsmithed" to omit key details about the mask mandates. For instance, Ducey did not permit local jurisdictions to implement local mask mandates until June 17. "[C]ourageous elected officials in county and local government across the state" had asked Ducey for authority to require mask-wearing, Humble wrote, and many of them later "faced backlash from elements of their electorate" when the mask mandates were put in place.
Separately, Bob England, former Maricopa County health director and former interim director of the Pima County Health Department, said, "If they'd been allowed to do so earlier, a number of those jurisdictions, if not all of them, would have had those mandates in place earlier and our peak of infection would have been lower."
England added, "But that's all hindsight. What matters now as we head into the winter months and we all anticipate another surge of this infection coming, the locals need to have the continued ability to impose mitigating measures like masks" (Innes, USA Today/Arizona Republic, 10/11; CDC, Morbidity and Mortality Weekly Report, 10/9).