Multiple variants of SARS-CoV-2 in a post-spring break college outbreak - Chicago, IL, March-May 2021.
Doyle K, Teran RA, Reefhuis J, etal. Multiple variants of SARS-CoV-2 in a post-spring break college outbreak-Chicago, Illinois, March-May 2021. mwRMorbMortal Wkly Rep 2021; 70: 1195 -1200. doi: http: //dx.doi.org/10.15585/mmwr.mm7035a3
Commentary
To prevent the transmission of SARS-CoV-2, universities are employing multiple strategies including testing, isolation, quarantine, contact tracing, masking, and vaccination.
In April 2021, the Chicago Department of Public Health (CDPH) was notified of a large population of students infected with COVID-19 at an urban university after spring break.
This resulted in a total of 158 cases of COVID-19 diagnosed among undergraduates between March 15 and May 3, 2021.
The majority of these (114; 72.2%) lived in on-campus dorms, and CDPH assessed the role of travel and social connections, and the potential impact of the SARS-CoV-2 variant on transmission.
Of the 140 infected students surveyed, 89 (63.6%) left Chicago during spring break, and 57 (40.7%) reported indoor social exposure.
At the time of the outbreak, students were not eligible for vaccination in Chicago, and only 3 (1.9%) of the students with confirmed infection were fully vaccinated.
Whole genome sequencing (WGS) of 104 specimens revealed several different SARS-CoV-2 lineages, suggesting several nearly simultaneous introductions.
Most specimens (66; 63.5%) were found to be B.1.1.222, a strain that was not widely detected in Chicago before or after this outbreak.
These results indicate the potential for an outbreak of COVID-19 on college campuses after students are shown to have attended indoor get-togethers or traveled extensively, such as during vacations and at the start of a new semester.
Therefore, in order to prevent SARS-CoV-2 transmission, universities need to encourage COVID-19 vaccination, and it is recommended that unvaccinated students be discouraged from traveling, including during university breaks, and that serial screening for COVID-19 be conducted in unvaccinated individuals to encourage masking.
