"The 18-24 age group as a percent of cases doubled in about three weeks so clearly that was the driving factor. We can't specifically say X amount of cases were from UNC but that age group being the one that exploded as the number of positives is kind of an indicator," said Orange County Community Relations Director Todd McGee.
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In the weeks following Memorial Day weekend and as North Carolina entered Phase 2, Orange County kept cases rising at a slower rate than the rest of the state.
However, in mid-August, as the rest of the state started to stabilize, Orange County saw a sharp spike in cases--in the week of August 19, cases rose 15%. The following week, that rate of increase more than doubled to 34%.
To date, there are more than 1,160 cases connected to the university. McGee said it's hard to say what percentage of Orange County's cases are associated with UNC, because many professors live in surrounding counties and students may use their home address instead of their address while at school.
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However, several weeks after both UNC made the decision to transition classes online and move students out of residence halls, the county's case increase rate has decreased to a level more in-line with the rest of the state--just a 5% increase between September 2 and September 9.
McGee said the county is still in contact with UNC officials and is hosting a weekly testing event in Chapel Hill. Furthermore, the university began voluntary daily testing for students without COVID-19 symptoms this week at the Campus Health to preemptively identify cases in residence halls. In a statement, UNC Provost Robert A. Blouin said a similar program will be set up of students who live off-campus in the next few weeks.
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"We just want to keep those numbers driving down," McGee said.
Wake County and Pitt County, home to North Carolina State University and East Carolina University respectively, also saw similar spikes in cases in August. For comparison, Johnston County, which has no major universities, did not have a spike in cases in August.
In Wake County, the number of new cases added each week had been decreasing in early August. However, by August 26--two weeks after NC State students started classes, the county reported more than 1,200 new cases, compared to 744 the week before.
"As we saw the spike, we began to identify cases and follow our proper procedures and doing the assessments on them and monitoring and isolating for those cases," said Dr. Nicole Mushonga, a representative for the Wake County Health Department.
Though the spike in cases at NC State didn't have the same magnitude of an effect on Wake County's numbers as UNC had on Orange County, McGee said the difference in county population could explain why Orange County's cases increased at a much higher rate than Wake County's.
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"You look at Wake County and the population is about a million, so you know NC State's 30,000 students is 3% of the population," McGee said. "When you look at Orange County, our population is around 150,000 or so and 30,000 UNC students, that's 20% of the population. I think it was just a matter of numbers."
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This week--two weeks after NC State Chancellor Randy Woodson moved courses online, Wake County only reported 624 new COVID-19 cases. But Mushonga warned that decrease isn't an excuse to become complacent.
"We really just have to continue to be vigilant in those preventative measures and to not let our guards down and just to continue with the three W's," Mushonga said.
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However, Durham County did not see an increase in cases in August--in fact, cases declined throughout the month, even though the county is home to both Duke University and North Carolina Central University.
Duke University is still operating in-person classes, however, the school was one of just a few that required students and faculty to be tested for COVID-19 before returning to campus, and is still conducting ongoing testing. To date, the university has reported 52 cases since the start of the school year.