Welcome to the 25th installment of “Coronavirus Contextualized,” a recurring feature in which we explore some of the numbers swirling around in the time of coronavirus.
Through these stories, we hope to parse the numbers, including confirmed cases of COVID-19, people tested, number of hospitalizations and deaths, and provide some context to them. You can view the prior editions of “Coronavirus Contextualized” here on our coronavirus page.
These accounts serve as a written roundup of the COVID-19 trends we kept our eyes on this week, with all graphs and charts living permanently on our COVID-19 data page, where they are updated multiple times a day with the latest numbers.
We’re continuing to take suggestions for what kind of data, graphs and trends you would like to see analyzed in future versions of this story or included in a future update of our data page. Reach out to [email protected] with any feedback.
Below, we take a look at some of the latest COVID-19 trends in Nevada, as the COVID-19 Mitigation and Management Task Force met this week for the first time in several weeks and voted to slightly relax some of the criteria used to determine which counties are at risk of elevated spread of COVID-19.
Cases and tests
The number of new COVID-19 cases reported each day has been fluctuating over the last week after a rise in mid- to late September.
An average of 493 new COVID-19 cases were reported each day over the last seven days as of Thursday, slightly up from 452 last week and 364 the week before that. But that seven-day average has been fluctuating in the 450 to 500 range since Sept. 28. Those numbers are up from the recent low of 267 on Sept. 14 but still significantly less than the high point of 1,176 average new cases reported each day on July 20.
Since the beginning of the pandemic, there have been 83,963 confirmed cases of COVID-19 across the state, meaning that one in 37 Nevadans has tested positive for the virus. The Silver State ranks 13th in the nation for COVID-19 cases per capita, down from 12th last week.
Still, more cases were reported over the last seven days, 3,454, than in the seven days before that, 3,165, or the seven days before that, 2,547. At the peak in mid-July, 1,451 new cases were reported in a single day.
Kyra Morgan, the state’s biostatistician, noted at a meeting of the state’s COVID-19 Mitigation and Management Task Force on Thursday that the increase in cases is “not nearly as steep as what we had seen at the end of June, beginning of July” but that the state is “seeing a slow but steady increase in the cases being diagnosed on a daily basis.”
The daily test positivity rate, calculated as the number of new people testing positive each day as a percentage of the number of new people tested, has been slightly increasing over the last week. The seven-day average positivity rate was 17.2 percent on Thursday, up from 12.9 percent a week before. (Those numbers are calculated using the number of new cases reported back each day, not the day people were actually tested.)
The state, which calculates its average positivity rate slightly differently, has also seen a bit of a rise on its data dashboard over the last two weeks, though it has started to plateau in recent days. As of Tuesday, the most recent day for which the data is available, the average daily positivity rate was 8.1 percent, unchanged from the prior Tuesday but up from 6.9 percent the Tuesday before that. (The state calculates its positivity rate on a lag and uses the number of positive tests as a percent of total tests, instead of positive people as a percent of total people.)
Morgan noted that the test positivity rate is “still staying quite a bit lower than what we saw at the end of July, beginning of August” but that there is “definitely a little bit of an increasing trend there.”
The number of COVID-19 tests collected each day has been fluctuating but is down over the last week. The average number of new tests reported each day over the last seven days was 6,132 as of Thursday, down from 7,718 the week before. At the high point in late July, the seven-day average of new tests reported each day was 12,260.
Caleb Cage, Nevada’s COVID-19 response director, attributed the decreases — and the fact that only 1,066 new tests were reported back on Wednesday — to the end of a weeks-long mass testing event in conjunction with the federal government.
“We’ve identified an unusually low number of new labs in the last 24 hours,” Cage said during a press call on Wednesday. “As a result, the state has talked to different labs and identified that part of the issue of the decrease in testing was due to the end of surge testing in Clark County.”
A total of 722,508 people — or about one in four Nevadans — have been tested for COVID-19 since March. Fewer people have been tested than the total number of individual tests because some people are tested more than once. In other instances, multiple specimens will be collected to be tested from one person.
COVID-19 deaths continue to generally be on the decline, though the trends in the number of new deaths each day generally lag trends in the number of new cases reported each day by about five weeks.
The average number of new deaths reported each day over the last seven days was 6.6 on Thursday, slightly up from a recent low 5.1 on Tuesday but down from a high of 20.7 on Aug. 20. The previous low point before cases started to increase this summer was 1.9 deaths per day, reported on June 28. A total of 1,649 COVID-19 deaths have been reported statewide since March. Nevada ranks 21st in the nation for deaths per capita.
The number of people hospitalized with confirmed or suspected COVID-19 continued to generally plateau this week, though the numbers have been higher in recent days.
Hospitalizations have generally fluctuated between 410 and 490 for the last four weeks, though they climbed to 495 on Tuesday and 498 on Wednesday, the last day for which data is available. Those numbers are higher than the previous low of 316 the state hit on May 30 before hospitalizations surged this summer but lower than the high point of 1,165 on July 31.
The Nevada Hospital Association, in its daily reports this week, noted that the state “remains within the plateau range” but “is experiencing a climb” in hospitalizations “driven primarily by suspected cases” of COVID-19. Cases are considered suspected until they are confirmed by a lab result.
However, the hospital association also noted that “hospitals throughout the state continue to have available capacity to treat all patients and all causes requiring care.”
As of Wednesday, 72 percent of licensed hospital beds and 58 percent of ICU beds statewide were occupied. Those numbers were 78 percent and 62 percent, respectively, in Clark County and 63 percent and 47 percent, respectively, in Washoe County.
County by county
Washoe County remains at elevated risk for the spread of COVID-19 this week for the second week in a row after two weeks of being off the state’s list of at-risk counties while Humboldt County was newly added back to the list after six weeks of being off of it. Lyon County was removed from the list this week after three weeks of being on it.
The COVID-19 Mitigation and Management Task Force, however, voted Thursday to amend the county criteria moving forward. Counties will be considered at elevated risk of the spread of COVID-19 if they meet two of the three following criteria:
- The average number of tests per day per 100,000, calculated over a 14-day period. If this number is less than 100, a county could be considered at risk. (The previous threshold was 150.)
- The case rate per 100,000, calculated by taking the number of cases diagnosed and reported over a 30-day period. If this number is greater than 200, a county could be considered at risk.
- The case rate per 100,000 and the test positivity rate, calculated over a 14-day period with a seven-day lag. If the case rate is greater than 50 and the test positivity rate is greater than 8.0 percent, a county could be considered at risk. (The previous limit was 7.0 percent.)
Morgan, the state’s biostatistician, said during the task force’s meeting on Thursday that the new criteria would better reflect standards set at the national level and by other states without compromising Nevada’s standards.
“The impact is fairly minimal, but I think it makes a lot of sense,” she said.
According to the task force’s analysis, which was released on Monday, Washoe County continues to have the highest case rate in the state, 412.2 cases per 100,000 over the last 30 days, coupled with a 8.4 percent test positivity rate. Humboldt County has a case rate of only 99.6 but has a low test rate, 74.5 average tests per day per 100,000, and a high test positivity rate, 8.4 percent.
Even if the new criteria had been in effect this week, Washoe and Humbodlt counties would still have made the list of at-risk counties.