Volume 27, Number 2—February 2021
Research Letter
Severe Acute Respiratory Syndrome Coronavirus 2 Outbreak Related to a Nightclub, Germany, 2020
, Mareike Kunze1, Fabienne Steitz, Neil J. Saad, Barbara Mühlemann, Jörn I. Beheim-Schwarzbach, Julia Schneider, Christian Drosten, Lukas Murajda, Sandra Kochs, Claudia Ruscher, Jan Walter, Nadine Zeitlmann2, and Victor M. Corman2
Table
Calculated attack rates for identified coronavirus disease outbreak cases among staff members and guests attending events in a nightclub, Berlin, Germany, March 2020*
| Characteristics | Cases, no. (%) | No. attending |
||
|---|---|---|---|---|
| Event 1 | Event 2 | Event 3 | ||
| Estimated guests† | – | 300 | 150 | 200 |
| Staff members, n = 16‡ |
– |
11 |
6 |
11 |
| Total cases |
74 (100) |
|||
| Cases by generation§ | ||||
| First-generation, n = 55 | 55 (74.3) | |||
| Guests¶ | 46 (83.6) | 39 | 0 | 3 |
| Staff | 9 (16.4) | – | – | – |
| Second-generation, n = 10 | 10 (13.5) | – | – | – |
| Generation unknown, n = 9 |
9 (12.2) |
– |
– |
– |
| Cases by case definition# | ||||
| Confirmed cases, n = 72 | 72 (97.3) | – | – | – |
| PCR-confirmed | 70 (97.2) | – | – | – |
| Antibody testing-confirmed | 2 (2.8) | – | – | – |
| Probable cases |
2 (2.7) |
– |
– |
– |
| Attack rate, %** | Pooled over all events | Event 1 | Event 2 | Event 3 |
| Guests | – | 13 | – | 2 |
| Staff | 56 | – | – | – |
*Event-related case numbers are shown only for first-generation guest cases as all of them confirmed to only have attended 1 of the 3 events. –, value not calculated. †The exact number of guests attending the events is unknown. For event 1, an estimate of attending guests was based on the maximum capacity of the club; staff and contacted guests confirmed that the club was running at full capacity. For events 2 and 3, the club owner provided estimates listed here. ‡Most staff members attended >2 of the events. §First-generation cases were defined as cases exposed during event 1, 2, or 3. Second-generation cases were defined as cases without exposure at club X but with exposure to first-generation cases. Cases of unknown generation were confirmed cases of the outbreak but without contact information to reveal whether they were first- or second-generation cases. ¶All guests contacted confirmed they attended only 1 of the 3 events. Information on the event of exposure was available for 42 first-generation cases among guests. No guest case reported visiting club X for event 2. #The outbreak case definition is described in the Appendix. All cases confirmed by antibody testing were otherwise probable cases. **Calculation of primary attack rates for guests was based on approximations for the denominator, the number of guests attending. Because most staff members were exposed repeatedly while working at >1 event we separately calculated attack rates for staff pooled over all events.
1These first authors contributed equally to this article.
2These senior authors contributed equally to this article.