Central Virginians are successfully slowing the spread of COVID-19 even as the number of cases increases, according to statistics from the Virginia Department of Health and the Thomas Jefferson Health District.
Although the number of cases increased in the district this week from 1,894 on Aug. 7 to 2,067 on Friday, the percentage of positive results on virus tests given during the week, known as the positivity rate, remained at 5.6%, according to health department figures.
The rate of positive test results is the key number used by public health officials and local governments when considering stricter social guidelines to stem the pandemic’s spread.
“We’re going to see more cases in the area because transmission is continuing and we’re doing more testing,” said Ryan L. McKay, senior policy analyst at the health district. “As long as that positivity rate stays low, it means that the caseload is unlikely to overwhelm medical services.”
The Thomas Jefferson Health District includes Charlottesville and Albemarle, Greene, Louisa, Fluvanna and Nelson counties. The local rate is below the statewide rate of 7.2% positive for the virus. By comparison, Richmond’s rate is 8.6%, Virginia Beach’s rate is 8.5%, Hampton’s is 9.3% and Portsmouth is 12.7%.
According to the Centers for Disease Control, the country’s positivity rate as of Friday was 9%. The World Health Organization recommends communities take steps to limit social interaction when positivity rates exceed 5%.
“In comparison to the Eastern region, we feel we’re in a better position,” said McKay. “There’s always a potential for an uptick in the rate as things open up and the schools go back into session. As the public schools, private schools and colleges come back, we’ll see the opportunity for an increase in cases and possibly rates. It will take a couple of weeks to see where we’re headed.”
As of Friday, there have been a total of 44 deaths in the region, including 16 in Albemarle County and 15 in Charlottesville, the figures show. Fluvanna County has had nine deaths since the pandemic struck the region in March. Louisa and Greene counties have had two deaths each and Nelson County has yet to have a COVID-19-related death.
No deaths were reported between Aug. 7 and Friday in the region, statistics show.
“If we look at the day-to-day data, it gives us a snapshot of the virus’ impact in time. The data is looking backward to tell us where we were,” McKay said. “We can see trends in hindsight and we use that data to make decisions now. If we see an uptick, we can use it to decide what we need to do to address the issue from a public health standpoint.”
McKay said the percentage of positive tests is important to determine whether there is significant spread of the disease in the general population outside of contained outbreaks and one-time exposure events.
“We can go behind the data to see what’s behind an increase. Is a case increase related to a particular event?” McKay said. “If we see an increase in cases and in the positivity rate, then we really get concerned. That means there could be spread in the general community.”
The positivity rate figure was used by Charlottesville and Albemarle County elected officials last month when they passed ordinances requiring masks, social distancing and other restrictions. Both localities passed their ordinances in late July when the positivity rate in the district was 7.5%.
“In July, we were seeing more cases and a higher positivity rate. We were doing more testing in the community in advance of the schools coming back, so that rate was concerning,” McKay said. “The rate has since dropped back down so we may have been getting a little lax in wearing face coverings or social distancing and created more community spread for a while.”
Keeping the rate low allows easier tracing of people who may have come in contact with a positive person. It also helps prevent swamping medical care givers and hospitals with seriously and critically ill patients, McKay said.
McKay said anyone reading the statistics, which are available on the health district and state health department websites, should pay attention to those figures that show trends over time.
“We’ll see a lot of variation in the figures from day-to-day but if you look at where we’ve been and where we’re at, you can get a sense of where we’re going,” he said. “There are decisions being made on this data all the time, like the face covering requirements. Studies consistently show they work by reducing the amount of [aerosol particulates] when someone talks. A vaccine is still a ways off and until it’s developed, we need to do things we know will have impact.”