Virginia Tech’s COVID-19 numbers suggest a daunting situation.
More students are living in campus quarantine than ever before. The university on Tuesday reported more people testing positive in a single day — 61 individuals — than at any point since early September. President Tim Sands says the community should assume different strains of COVID-19, thought to be more contagious, are circulating locally.
But two opposing factors — old infections and new variants — are complicating this picture.
Is a surge in cases merely a result of sensitive COVID-19 tests that can pick up virus from a person no longer infectious? Or a prelude to a more contagious COVID-19 variant that could become the dominant strain by late March?
Within the last week, 215 students and three employees at Virginia Tech have tested positive for COVID-19, out of 810 students and 32 employees since the beginning of the year.
Case investigators are finding that many of these positive cases are not actually contagious cases, Dr. Noelle Bissell, director of the New River Health District, said last week in a media briefing.
“Our investigations are revealing that a lot of these cases are not necessarily new infections, but these are situations where the test can stay positive for far longer than the 10 days that [a person] can be infectious,” she said.
Students who contracted COVID-19 earlier this semester or in the fall may still get swept up in the university’s mandatory testing regimen. A person can test positive on a sensitive PCR (polymerase chain reaction) test as far as 90 days after first contracting the virus, according to infectious disease experts.“When using a highly sensitive test, in our experience, a substantial number of people continue testing PCR positive for several weeks, if not months after initial infection without a known new exposure or new symptoms,” Jason Deese, an epidemiologist with the New River Health District, said in an email Saturday.
Earlier this month, Tech removed 35 positive PCR tests from its COVID-19 dashboard for January because subsequent antibody testing showed the infections weren’t active at the time, the university has said.
“While the initial testing does not differentiate between the active and inactive virus in a person’s system, medical and public health personnel continue to evaluate each case to determine when individuals are no longer actively shedding the virus, and any lag in reporting case numbers is due to this diligence in assessing disease spread and diagnosis,” Mark Owczarski, a university spokesman, said in an email at the time.
The change was made, he said, “to accurately reflect the known status of the presence of COVID-19 within our community at a particular moment in time.”
Owczarski said Friday that the university continues to place a student in quarantine or isolation if they test positive, unless a health official confirms they’re no longer infectious.
While Tech has limited quarantine stays from 14 days to 10 days in keeping with federal recommendations, a record 193 students were living in quarantine as of Thursday.
The health department said Saturday it didn’t have readily available data on the number of recent positive tests at Tech that were old versus new infections.
Deese, the epidemiogist, said case investigators use multiple tools to determine whether a positive test is just a prior infection. That includes clinical symptoms (is the person currently symptomatic?), epidemiological information (are they known to be recently exposed?) and time since the initial positive test (is it less than 90 days?). Antigen and antibody tests can also add clarity, he said.
At the same time that the health district has downplayed new positive tests on campus, the university’s president has warned the community it should assume more contagious strains of COVID-19 are present.
“Recent studies indicate the U.K. variant is more infectious and causes people to become even sicker than before,” Sands said in a message on Feb. 16. “ We are seeing evidence among our student population that the prevalence of moderate symptoms is increasing.”
(The health department on Saturday confirmed cases of the UK variant in three adults living in the southwest region.)
Two days later, the health department confirmed the presence of the so-called South African variant in the southwest region, an area that spans from Lynchburg to Lee County.
Virginia Tech won’t confirm the presence of any variants on campus, referring such questions to the health department. The local health department declined to elaborate. The state health department has been issuing news releases of confirmed cases of the variants.
“We don’t disclose any more granular [information] than region, so it is the southwest region and, in fact, the people who are diagnosed don’t even know,” Bissell said. “So we have the variant in the southwest region and that’s about as specific as I can get.”
Not every university or local health district appears to treat news about variants the same way.
Two weeks ago, the University of Virginia announced that “there are cases of the B.1.1.7. coronavirus variant in the UVA community,” referring to the U.K. variant.
Brian Coy, a UVa spokesman, said in an email Friday that the university worked with the health department to confirm the case belonged to a member of the university community, “so that we could inform our community of the need for greater adherence to public health measures.”
The emergence of variants could complicate an overall downward trend in cases across the state and country.
“While the news is good in most of the state, several colleges and universities are experiencing outbreaks,” said a report Friday from disease modelers at UVa’s Biocomplexity Institute, which has been tracking the pandemic. “Half of the top ten hot spots are in zip codes associated with colleges and universities, including zip codes in Charlottesville, Richmond, Lexington and Blacksburg.”
The report said the U.K. variant could become the dominant strain by late March.
Dr. Paul Skolnik, chair of Carilion’s department of medicine and an infectious disease expert, said new strains of COVID-19 could crop up in people who have already been exposed to the coronavirus.
“The variants are important because they bring the status quo into question,” Skolnik said. “By that, I mean it’s possible that even after natural infection or even after vaccination that people can be reinfected with the variants in a way or at a time that’s different than the original strains.”
That presents complications with testing, too.
Currently, if someone tests positive for COVID-19 within 90 days of first contracting the disease, it’s unlikely they have a variant, Skolnik said.
But if they test positive more than three months after first contracting COVID-19?
“So if we get a positive test now that’s past 90 days, we not only have to ask, ‘Is this a reinfection?’ but also, ‘Is this a reinfection with one of the variants?’”