Coronavirus Contextualized, 31st edition: Exploring, through data, COVID-19 in Nevada and beyond
Welcome to the 31st 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 stories 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 with only four days left for Nevada to improve its coronavirus numbers or face additional mitigation measures. Last week, Gov. Steve Sisolak urged Nevadans to voluntarily stay home to limit the spread of the virus under what he called “Stay at Home 2.0.”
Cases and test positivity
COVID-19 continues to spread uncontrolled across the state of Nevada, reaching new record case numbers day after day.
An average of 1,833 new COVID-19 cases were reported each day over the last seven days, as of Thursday, setting a new record. The previous record from the summer, the last time coronavirus cases surged, was 1,176.
Thursday’s seven-day average also represents significant growth since last week, when the seven-day average was 1,380. The week before that it was 986. Before cases started rising in mid-September, an average of 267 cases were reported each day.
Since the beginning of the pandemic in March, there have been 128,246 cases reported statewide. That includes 12,829 new cases reported over the last seven days, about 10 percent of the total cases reported during the pandemic.
Julia Peek, deputy administrator of the Division of Public and Behavioral Health, said at a meeting of the COVID-19 Mitigation and Management Task Force on Thursday that about 75 percent of cases are not linked to another positive case, meaning they are acquiring the virus from general community spread.
One in 24 Nevadans has tested positive for the virus since the beginning of the pandemic. Nevada ranks 22nd in the nation for COVID-19 cases per capita, down from 18th last week. Kyra Morgan, state biostatistician, noted at the task force meeting that, regionally, Nevada is outpacing both California and Arizona in cases per 100,000 residents.
“Nevada is now experiencing increases in all three of those — cases, hospitalizations and tests, as well,” Morgan said.
Nevada’s test positivity rate — which looks at the percentage of tests or people coming back positive out of the total tested — also continues to increase. As usual, we’ll look at two different methods of calculating test positivity below, using both individual people and a metric known as testing encounters.
Starting with the number of new reported people who tested positive for COVID-19 out of the total number of new reported people tested each day, the state’s seven-day average test positivity rate was about 35.4 percent as of Thursday, up from a recent low of 9.2 percent on Sept. 17.
However, there are some drawbacks to looking at test positivity using individual people since some people are tested repeatedly. For instance, someone who tested negative four times but tested positive on their fifth time would be counted as a new positive person but not a new person tested. (In other words, they would be counted in the numerator but not the denominator.)
Additionally, someone may receive a rapid antigen test that comes back negative the same day, only to have a positive molecular PCR test, which is more accurate in determining whether someone is negative for COVID-19, come back positive several days later. In that instance, the individual would be counted as a new person tested the day of their first, negative test but a positive several days later.
Another way of looking at test positivity, as we have noted each week, is to examine test encounters, or the number of individual people tested each day. This method of looking at test positivity excludes duplicate samples collected the same day but accounts for people who are tested repeatedly on different days.
It is not possible to independently calculate the test positivity rate based on test encounters because the state only reports the number of positive cases, not the number of positive test encounters. However, the state does provide this number, calculated as an average over a 14-day period with a seven-day lag. As of Wednesday, that number was 15.6 percent, continuing to climb from a recent low of 6.3 percent on Sept. 23.
Whichever calculation you use to look at test positivity, the trend is the same: It continues to increase.
A total of 903,173 people — or about one in 3.4 Nevadans — have been tested for COVID-19 and there have been 1,471,764 individual testing encounters since March.
COVID-19 deaths also continue to increase, though they are not anywhere near the record high from the summer.
As of Thursday, the average number of new deaths each day over the last seven days was 11.1, up from a recent low of 4.1 on Oct. 27. At the high point this summer, on Aug. 20, the seven-day average was 20.7 new deaths each day.
It’s important to note, however, that officials say that trends in deaths typically lag trends in cases by about five weeks, meaning that the significant surge in cases being experienced now wouldn’t be reflected in the death data for several weeks.
Over the last seven days, 78 new COVID-19 deaths have been reported across the state, including 54 in Clark County, 15 in Washoe County, four in Churchill, four in Nye and one in Elko. There were 54 new COVID-19 deaths reported in the seven-day period before that.
A total of 1,958 COVID-19 deaths has been reported statewide since March. Nevada ranks 25th in the nation for deaths per capita, down from 24th last week.
COVID-19 hospitalizations hit a new record on Tuesday and continue to rise.
There were 1,288 people hospitalized with COVID-19 as of Wednesday, the last day for which data is available, up from a recent low of 417 on Sept. 12. At the peak over the summer, 1,165 people were hospitalized with COVID-19 on July 31.
County-level data continue to show how much worse the situation is in Washoe County compared to Clark County. There are currently 284 COVID-19 hospitalizations in Washoe County, more than double the numbers county hospitals were seeing over the summer, while Clark County, at 918 hospitalizations, still has yet to return to its peak.
As of Wednesday, 82 percent of licensed hospital beds and 68 percent of ICU beds statewide were occupied. Those numbers were 88 percent and 70 percent, respectively, in Southern Nevada and 72 percent and 62 percent, respectively, in Northern Nevada.
However, Northern Nevada is only able to staff 1,454 of its 1,725 licensed beds, which makes the percentage of staffed beds occupied actually 85 percent. Southern Nevada, meanwhile, is staffing more than its number of licensed beds — a decision made by hospitals to respond to increased demand — driving its percentage of staffed beds down to 81 percent.
The Nevada Hospital Association, Nevada Rural Hospital Partners and the Nevada State Medical Association, in a joint statement, urged people to remain vigilant against COVID-19.
“During this time of year, hospitals experience an influx of patients including those experiencing heart attack, stroke, diabetes and respiratory infections, to name a few. Add to that COVID-19 patients who are highly contagious and need a different type of care,” they wrote. “Everyone has a duty to act responsibly to limit the spread of infection so we do not overwhelm our health care system.”
They urged people to resist the urge to get “complacent” during the holiday season and take the “necessary steps” to prevent the spread of the virus.
“In recent weeks, we have seen COVID-19 cases and hospitalizations trending upwards nationwide,” they wrote. “If the trend continues in Nevada, it will place a greater strain on hospital team members including doctors, nurses, therapists and custodians, and food service and support staff who have bravely worked to help patients.”
County by county
While Clark County only this week surpassed its previous peak from the summer, other counties, including Washoe County, that weren’t hit quite as hard over the summer have long since surpassed their previous records.
Washoe County’s peak seven-day case average was 98 on July 30. It’s now 390.
Carson City’s previous peak was 6.3 on Aug. 13. It’s now 74.4
Elko County’s summer peak was 14.7 on July 15. It’s now 33.9.
Clark County’s prior peak was 1,073 on July 20. It’s now 1,242.
In total, 14 of the state’s 17 counties currently meet the state’s criteria to be flagged as at risk of elevated spread of COVID-19 as of Thursday, up from 12 last week.
Counties are considered at risk for elevated spread of COVID-19 if they meet two of the following three metrics:
- 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 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.
Carson City continues to have the highest case rate per capita, at 2,234 cases per 100,000 over the last 30 days — driven in large part by an outbreak at Warm Springs Correctional Center, followed by Churchill County at 1,608, Washoe County at 1,542, Elko County at 1,184 and White Pine County at 1,001. The other at-risk counties are Clark, Douglas, Esmeralda, Eureka, Humboldt, Lander, Lincoln, Lyon and Nye.
Nye County has the highest test positivity rate at 24.9 percent, followed by Esmeralda County at 23.1 percent, Lyon County at 20.4 percent and Elko County at 20.3 percent.