Top 5 Takeaways

1. Significant Outbreak: A total of 158 COVID-19 cases were identified among undergraduate students at an urban university in Chicago following spring break.
2. High Travel and Social Exposure: Among the infected students, 63.6% reported recent travel outside Chicago, and 40.7% reported indoor social exposures.
3. Multiple SARS-CoV-2 Lineages: Whole genome sequencing revealed nine different SARS-CoV-2 lineages, with B.1.1.222 being the most prevalent.
4. Vaccination Status: Only 1.9% of the infected students were fully vaccinated, as undergraduate-aged persons were largely ineligible for vaccination at the time.
5. Prevention Recommendations: Colleges should encourage vaccination, discourage unvaccinated travel, and implement serial COVID-19 screening and masking to prevent outbreaks.

Original Article Author and Citation

Corresponding Author

Richard A. Teran, rteran@cdc.gov

Suggested Citation

Doyle K, Teran RA, Reefhuis J, et al. Multiple Variants of SARS-CoV-2 in a University Outbreak After Spring Break — Chicago, Illinois, March–May 2021. MMWR Morb Mortal Wkly Rep 2021;70:1195–1200. DOI: http://dx.doi.org/10.15585/mmwr.mm7035a3

Summary

In April 2021, the Chicago Department of Public Health (CDPH) was notified of a large COVID-19 outbreak among students at an urban university following spring break. A total of 158 cases were identified, with the majority of infected students living in on-campus dormitories. Whole genome sequencing revealed multiple SARS-CoV-2 lineages, indicating several simultaneous introductions. The outbreak highlighted the potential for COVID-19 spread on university campuses due to student travel and social gatherings.

Methods

The investigation involved interviews with infected students to gather data on demographics, travel history, social activities, and close contacts. Diagnostic testing history and results were extracted from state surveillance and vaccination records. Whole genome sequencing was performed on available specimens to identify SARS-CoV-2 lineages. Social network analyses were conducted to understand transmission patterns.

Discussion

The outbreak demonstrated the challenges of controlling COVID-19 in university settings, especially with unvaccinated students traveling and socializing. The presence of multiple SARS-CoV-2 lineages suggested several introductions, likely driven by student travel. The findings underscored the need for vaccination, serial screening, and other preventive measures to mitigate transmission on campuses.

Conclusion

This outbreak underscores the importance of vaccination and preventive measures in university settings. Colleges should encourage vaccination, discourage unvaccinated travel, and implement serial screening and masking to prevent similar outbreaks. The findings support existing CDC recommendations for COVID-19 control in colleges and universities.

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