Arizona has now surpassed the threshold marking high levels of transmission. Unfortunately, the potential size and/or duration of this outbreak remains uncertain. At 108 cases per 100K residents, Arizona ranks 12^th among the 50 states. Louisiana, Florida, Arkansas, and Missouri are currently leading the pack with rates more than double ours: 302, 291, 272, and 252 cases per 100K residents per week, respectively. Fortunately, these rates remain well below the peaks seen during January 2021 outbreak.

According to the CDC, 55% of Arizona adults have received 2-doses of vaccine while another 9% have received 1-dose. For a bit of perspective, only 43% of adults were vaccinated against influenza in the 2019-2020 season so we are doing better than usual, but still not good enough. While Arizona passed peak vaccination rates in early April, about 60 thousand doses were administered last week. Even though we are months away from achieving >70% fully vaccinated, our efforts are still making progress. As slow and frustrating as it may seem, it is important to continue vaccine outreach.

Note: Data for this report was updated Thursday, July 22.

Many K – 12 schools are resuming in-person instruction. Trends in childhood case rates are shown in Figure 2b. As discussed in prior reports, children 15 – 19 years of age have case rates that approximate those of adults while prepubertal children have lower rates likely owing to physiologic and behavior differences. Even though mask wearing in classrooms is recommended by the CDC (unvaccinated) and the American Academy of Pediatrics (everyone), out state isn’t going to follow suit. Yet another reason to keep supporting vaccination efforts.

Figure 2c left shows that the proportion of cases attributable to children and older adults has been relatively stable over time, <15% of all cases for both age groups, despite the availability of vaccines. These data help dispel undue angst that children are responsible for COVID-19 outbreaks in the post-vaccine era. Like in the past, particularly in Arizona, adults are letting children down, not the other way around.

The state is also attempting to prohibit schools from instituting differential quarantine strategies where the unvaccinated would be required to quarantine following an exposure while the vaccinated and asymptomatic could carry on as normal (CDC recs).

A report of a summer camp outbreak indicates that the secondary attack rate within households of infected campers was 45%, meaning about one-half of all contacts within the household became infected. It difficult to think that schools and summer camps are all that different with regard to transmission risk. The good news is that wearing a facemask and maintaining physical distancing both reduced transmission by half.

Test positivity among those undergoing traditional nasopharyngeal PCR testing rose to 20% this week, another meaningful week-to-week increase (Figure 3). This level indicates testing is inadequate for optimal public health practice and means many cases are likely going undiagnosed.

As of July 21st, 868 (11%) of Arizona’s 8675 general ward beds were occupied by Covid-19 patients, a 26% increase from the previous week’s 689 occupied beds (Figure 4 and Figure 5 Panel A). Another 861 (10%) beds remained available for use. The number of available beds is lower than the previous week’s 926 beds. The last time this many ward beds were occupied by COVID- 19 was March 10, 2021 (n=879).

As of July 21st, 217 (16%) of Arizona’s 1731 ICU beds were occupied with Covid-19 patients, an 18% increase from the prior week’s count of 184 patients (Figure 4 and Figure 5 Panel B). An additional 217 (13%) ICU beds remained available for use, about the same as last week’s 218 beds. The last time this many ICU beds was occupied by COVID-19 was March 13, 2021 (n=215).

Arizona hospital occupancy remains above seasonal levels. Improvements in ward and ICU occupancy remain stalled at ≥85% occupancy (Figure 6). Undoubtedly, some medically necessary procedures that were previously postponed are still being rescheduled to address the backlog of care. Occupancy will need to fall <70-75% before conditions will be back to “normal.” However, hospitals should be prepared for >10% COVID-19 occupancy for the foreseeable future as viral transmission transitions from substantial to high levels.

The week ending January 17, 2021 remains Arizona’s deadliest with 1093 deaths (Figure 7). The number of deaths will begin to rise in the coming weeks as increased case rates will ultimately translate into more deaths. The case fatality rate remains about 1.5% meaning that in 3 – 4 weeks Arizona could be seeing >100 deaths per week (e.g., 1.5% x 7836 = 118).

For the week ending July 4th, 577 Pima County residents were diagnosed with Covid-19 (Figure 8). This is a 36% increase from the 423 cases initially reported last week.

New cases are being diagnosed at a rate of 55 cases per 100K residents per week. This rate is increasing by 13 cases per 100K residents per week. Pima County’s rates remain lower than the state average. Trends across the various age groups appear in Figure 9.