Coronavirus cases have more than doubled among students aged 18-22 years after reopening of campuses: CDC
As college and university students in the US returned to campuses in August, coronavirus cases in that age-group have more than doubled, according to the Centers for Disease Control and Prevention (CDC). During August 2-September 5, weekly Covid-19 cases among persons aged 18-22 years increased by 55.1% nationally. Increases were greatest in the Northeast (144%) and Midwest (123%).
The research team says that the rise in cases cannot be solely attributable to increased testing. According to the health experts, the observed increases in coronavirus cases among persons aged 18-22 years could be driven by multiple factors, including changes in behavior or risk profiles resulting from multiple social, economic, and public policy changes during this period. “In August 2020, CDC and case-reporting jurisdictions identified an increase in the percentage of Covid-19 cases among persons aged 18-22 years. The incidence in this age group changed 2.1-fold during August 2-September 5 compared with a 1.5-fold change in testing (possibly related to new screening practices as colleges and universities reopened). Although increased incidence was likely driven in part by an increase in Covid-19 diagnostic testing, this is unlikely to be the sole reason for the observed increases in incidence,” write authors.
The agency suggests that young adults, including those enrolled in colleges and universities, should take precautions, including mask-wearing, social distancing, and hand hygiene, besides following local, state, and federal guidelines for minimizing the spread of Covid-19.
The analysis
Approximately 45% of persons aged 18-22 years were enrolled in colleges and universities in 2019. As these institutions reopen, opportunities for infection increase; therefore, mitigation efforts and monitoring reports of Covid-19 cases among young adults are important, the agency explains. During August 2-September 5, 2020, a total of 999,579 persons with Covid-19 with case report data were reported to CDC, 15.6% of whom were aged 18-22 years.
The analysis reveals that national weekly Covid-19 incidence among persons aged 18-22 years increased 62.7% during a 4-week period (August 2-August 29), from 110 to 180 cases per 100,000 before declining to 171 during August 30-September 5. During August 2-September 5, weekly incidence increased most in the Northeast (144%), from 53 to 130 per 100,000, and in the Midwest (123.4%), from 111 to 247. Notably, in the Northeast, the weekly incidence has remained below 53 cases per 100,000 in all other age groups since July 4. In the South, weekly incidence among persons aged 18-22 years increased 43.8%, from 115 to 166 cases per 100,000. Weekly increases were smallest in the West, where incidence declined initially until August 22 and then increased through September 5, but, overall, declined 1.7% during August. During August 2-September 5, the proportion of all cases per week that occurred among persons aged 18-22 years approximately doubled (2.1-fold), from 10.5% to 22.5%.
During the same period, changes in testing volume for Covid-19 in this age group ranged from a 6.2% decline in the West to a 170.6% increase in the Northeast. Besides, the proportion of cases in this age group among non-Hispanic White persons increased from 33.8% to 77.3% during May 31-September 5.
“When examined by race and ethnicity nationally, during August 2-September 5, the weekly incidence among White persons aged 18-22 years increased 149.7%, from 48 per 100,000 to 120. During May 31-June 20, the proportion of weekly cases that occurred among White persons aged 18-22 years increased from 33.8%% to 50.8%. Then, during August 2-September 5, the proportion was 1.5-fold that during May 31-June 20 (95% CI = 0.2–12.9), having increased from 52.1% to 77.3%. At the same time, incidence among persons of other racial and ethnic minority groups remained stable or declined,” the findings state.
The researchers say that since approximately 45% of persons aged 18-22 years attend colleges and universities and 55% of those attending identified as White persons, it is likely that some of this increase is linked to the resumption of in-person attendance at some colleges and universities. Detailed exposure information from patients in this age group -- such as through targeted epidemiologic studies -- can help identify the specific drivers of the observed trends, they suggest. “Mitigation and preventive measures targeted to young adults can likely reduce Covid-19 transmission among their contacts and communities. As colleges and universities resume operations, taking steps to prevent the spread of Covid-19 among young adults is critical,” emphasize the authors.
Coronavirus clusters on a university campus
A second study reveals that a North Carolina university experienced a rapid increase in Covid-19 cases and clusters within two weeks of opening the campus to students. On August 3, a university in North Carolina broadly opened the campus for the first time since transitioning to primarily remote learning in March.
During August 3-25, 670 laboratory-confirmed cases of Covid-19 were identified, and 96% were among patients aged less than 22 years. Eighteen clusters of five or more epidemiologically linked cases within 14 days of one another were reported, and 30% of cases were linked to a cluster. According to the team, led by researchers from the North Carolina Division of Public Health, CDC, and the University of North Carolina at Chapel Hill, “student gatherings and congregate living settings, both on and off-campus, likely contributed to the rapid spread of coronavirus in this setting.”
On August 19, all university classes transitioned to online, and additional mitigation efforts were implemented. At this point, 334 university-associated coronavirus cases had been reported to the local health department. The rapid increase in cases among college-aged persons at the university suggests that robust measures are needed to reduce transmission at institutes of higher education, including efforts to increase consistent use of masks, reduce the density of on-campus housing, increase testing for Covid-19, and discourage student gatherings, recommend experts.