Arizona case rates remain “stuck” just above the threshold differentiating substantial and moderate risk. As predicted in the March 26 Update, our 3-month streak of sustained improvements has stalled owing to more transmissible variants (e.g., B.1.1.7) and/or normalization of business and social activities (e.g., EO 2021-06). Nevertheless, hospital capacity remains adequate to meet Arizona’s needs even though the backlog of non- Covid care has yet to be fully addressed.

While residents and businesses should continue to follow public health recommendations, normalization of low-risk activities remains reasonable. New cases are now being diagnosed at a rate of 59 per 100K residents per week; this rate is neither increasing nor decreasing. For reference, September 8^th marked the fall nadir between the summer and winter outbreaks at 38 cases per 100K residents per week. Post-holiday case rates reached a low of 53 cases per 100K residents on March 23, 2021.

Unvaccinated Arizonans who are at risk of developing severe disease (e.g., age or comorbid conditions) or who simply wish to remain uninfected should continue to shelter as much as feasible because viral activity remains widespread.

Note: Data for this report was updated Friday, April 9 allowing 4 full days to adjudicate cases and keep week-over-week backfill <10%. This allows more interpretable comparisons and graphics. All comparisons are week-over-week changes.

Test positivity among those undergoing traditional nasopharyngeal PCR testing is continuing to hold steady at 8% (Figure 3). Positivity remains within the recommended 5 – 10% window for optimal public health practice.

As of April 9th, 576 (7%) of Arizona’s 8571 general ward beds were occupied by Covid-19 patients, a 6% increase from the previous week’s 541 occupied beds (Figure 4 and Figure 5 Panel A). This represents the first increase in 3 months. Another 985 (11%) beds remained available for use. The number of available beds is higher than the previous week’s 931 beds.

Covid-19 occupancy has dropped by 89% from its January 11^th peak of 5082 ward patients. The summer-fall nadir was 468 occupied beds on September 27th.

As of April 4th, 147 (9%) of Arizona’s 1734 ICU beds were occupied with Covid-19 patients, a 4% decrease from the prior week’s count of 153 patients (Figure 4 and Figure 5 Panel B). An additional 256 (15%)

ICU beds remained available for use. This is similar to the prior week’s 264 available beds. ICU occupancy has fallen 88% from its January 11^th peak of 1183 occupied beds. The summer-fall nadir was 114 occupied beds on September 22^nd.

Arizona hospital occupancy remains above seasonal trends. Improvements in ward and ICU occupancy remain stalled at ≥85% occupancy (Figure 6, following page). This indicates that medically necessary procedures that were previously postponed are being scheduled at higher than seasonal amounts to address the backlog of care. It will still take several more months to resolve. Occupancy will need to fall <70-75% before conditions will be back to “normal.” As capacity constraints are lessened, care practices should return to those prior to the outbreak ensuring all patients will receive optimal care. Hospitals will remain crowded through April - May before returning to pre-outbreak levels especially since reductions in viral transmission have stalled.

The week ending January 17th remains Arizona’s deadliest with 1084 deaths (Figure 7). Covid-19 deaths are expected to fall below 200 per week by the week ending March 14^th.

For the week ending April 4th, 571 Pima County residents were diagnosed with Covid-19, essentially unchanged from the 568 cases initially reported last week (Figure 8). Last week’s initial tally was upwardly revised by 1% (7 cases) to 575 cases.

New cases are being diagnosed at a rate of 55 cases per 100K residents per week and are stable. For reference, October 9^th marked a nadir between the summer and winter outbreak at 46 cases per 100K residents per week. Case rates reached their lowest post-holiday level at 43 cases per 100K residents per week on March 20^th. Trends across the various age groups appear in Figure 9.