Multi-household social gatherings contribute to the second SARS-CoV-2 wave in Rhineland-Palatinate, Germany, August to November 2020. Issue 4 (April 2022)

• Record Type: Journal Article
• Authors: Schepers, Markus; Zanger, Philipp; Jahn, Klaus; König, Jochem; Strauch, Konstantin; Gianicolo, Emilio
• Is Part Of: Journal of infection. Volume 84:Issue 4(2022)
• Page Start: 551
• Page End: 557
• Publication Date: 2022-04
• Subjects: Public health -- COVID-19 -- SARS-CoV-2 -- descriptive statistics -- epidemiology -- private households -- social gatherings -- Germany; Infection -- Periodicals; Bacterial Infections -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.905
• DOI: 10.1016/j.jinf.2022.01.028
• Languages: English
• ISSNs: 0163-4453

Abstract

Highlights: 68% of SARS-CoV-2 cases in private clusters emerge from multi-household outbreaks. among private activities, social gatherings lead to largest no. contacts / clusters. hygiene breaches followed by superspreading drive transmission at social gatherings. Abstract: Background: Although the private household setting is considered a major driver of viral spread, only little is known about the contextual details of SARS-CoV-2 household transmission, thus hampering political decision-making. Materials and methods: We analyzed individual case and cluster data from statutory notifications from August to November 2020 in Rhineland-Palatinate - the period preceding the second SARS-CoV-2 wave. We also conducted an into-depth survey on contextual details of household transmission in a representative sample of 149 private household clusters that had occurred during this period. Results: During the study period, 18, 695 PCR-confirmed SARS-CoV-2 cases were notified, 3, 642 of which occurred in 911 clusters (private households (67.3%), the workplace (7.8%), elderly homes (1.8%), others (23.2%). Demographically, clustered cases were representative of all notified cases. Two-thirds (77/113, 68%) of sample response clusters involved more than one private household. These caused on average more close contact persons (mean 13.5, ±SD 15.8) and secondary cases (3.9, ±SD 0.4) than clusters involving one household only (5.1 ± 13.8 and 2.9 ± 0.2). About one in six multi-household clusters in the private setting (13/77) followed a social gathering (e.g. birthday party). Breaches of one or more of the three major barrier concepts (mask, ventilation, and distance) were identified in most (10/13) of these social gatherings. SARS-CoV-2 clusters following social gatherings were overrepresented during the second half of the study period. Conclusion: In times of increasing infectious pressure in a given population, multi-household social gatherings appear to be an important target for reducing SARS-CoV-2 transmission.