Analysis of the effectiveness of hygiene measures and COVID-19 vaccination at a tertiary-care university hospital during the first two years of the SARS-CoV-2 pandemic

Valentin Niekrens; Bernd Kunz; Markus Werner; Giuseppe Valenza; Christof Seggewies; Christian Bogdan; Jan Esse

doi:10.1016/j.heliyon.2024.e30311

Analysis of the effectiveness of hygiene measures and COVID-19 vaccination at a tertiary-care university hospital during the first two years of the SARS-CoV-2 pandemic

Heliyon. 2024 Apr 26;10(9):e30311. doi: 10.1016/j.heliyon.2024.e30311. eCollection 2024 May 15.

Authors

Valentin Niekrens¹, Bernd Kunz¹, Markus Werner¹, Giuseppe Valenza¹, Christof Seggewies², Christian Bogdan^{1

3}, Jan Esse¹

Affiliations

¹ Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Wasserturmstraße 3/5, D-91054, Erlangen, Germany.
² Medical Informatics and Communication Center, Universitätsklinikum Erlangen, Glückstraße 11, D-91054, Erlangen, Germany.
³ FAU Profile Center Immunomedicine, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Schlossplatz 1, D-91054, Erlangen, Germany.

Abstract

Objective: Assessment of the effectiveness of protective measures at a tertiary-care hospital during the SARS-CoV-2 infection waves to provide advice for future pandemics.

Design: Retrospective cohort study among hospital staff using in-house surveillance data.

Setting: University Hospital Erlangen (UKER), a tertiary-care provider in Bavaria, Germany.

Methods: We outline the preventive measures introduced at UKER and retrospectively assess their effectiveness using anonymized monitoring data that were collected during the SARS-CoV-2 pandemic from February 2020 to the end of January 2022. Analysed data includes the incidence of SARS-CoV-2 infections among employees, the frequency of high-risk contacts with infected patients or staff members and breakthrough infections considering the context of exposure.

Results: The cumulative incidence of SARS-CoV-2 infections among UKER employees was higher before, but lower after the vaccination campaign when compared to the general population. Healthcare workers (HCW), notably physicians and nurses, were especially at risk of infection compared to other UKER employees with less direct patient contact (OR 1.36 [95% CI 1.18-1.57 p < 0.001]). Breakthrough infections mostly occurred after exposure during private life, i.e. in situations without protective equipment. The frequency of high-risk contacts during direct patient care remained stable after SARS-CoV-2 vaccination. Prior to vaccination, 5.2% of HCW with direct patient care tested positive for SARS-CoV-2 within 14 days. After vaccination until the onset of the Omicron wave, conversion rate dropped to 0%.

Conclusions: This study provides real-world data on the effectiveness of vaccination, contact tracing, personal protective equipment and general hygiene measures during the SARS-CoV-2 pandemic. Based on our findings, we recommend a protective approach combining all these preventive measures.

Keywords: BNT162b2; Breakthrough infection; Hospital hygiene; Infection prevention; Personal protective equipment; Surveillance.