Investigation of intra-hospital SARS-CoV-2 transmission using nanopore whole-genome sequencing

A H Løvestad; S B Jørgensen; N Handal; O H Ambur; H V Aamot

doi:10.1016/j.jhin.2021.02.022

Investigation of intra-hospital SARS-CoV-2 transmission using nanopore whole-genome sequencing

J Hosp Infect. 2021 May:111:107-116. doi: 10.1016/j.jhin.2021.02.022. Epub 2021 Feb 26.

Authors

A H Løvestad¹, S B Jørgensen², N Handal², O H Ambur³, H V Aamot⁴

Affiliations

¹ Faculty of Health Sciences, Oslo Metropolitan University, Oslo, Norway; Department of Microbiology and Infection Control, Akershus University Hospital, Lørenskog, Norway.
² Department of Microbiology and Infection Control, Akershus University Hospital, Lørenskog, Norway.
³ Faculty of Health Sciences, Oslo Metropolitan University, Oslo, Norway.
⁴ Department of Microbiology and Infection Control, Akershus University Hospital, Lørenskog, Norway; Department of Clinical Molecular Biology (Epigen), Akershus University Hospital and University of Oslo, Lørenskog, Norway. Electronic address: hege.vangstein.aamot@ahus.no.

Abstract

Background: During the SARS-CoV-2 pandemic, healthcare workers (HCWs) are being exposed to infection both at work and in their communities. Determining where HCWs might have been infected is challenging based on epidemiological data alone. At Akershus University Hospital, Norway, several clusters of possible intra-hospital SARS-CoV-2 transmission were identified based on routine contact tracing.

Aim: To determine whether clusters of suspected intra-hospital SARS-CoV-2 transmission could be resolved by combining whole genome sequencing (WGS) of SARS-CoV-2 with contact tracing data.

Methods: Epidemiological data were collected during routine contact tracing of polymerase chain reaction-confirmed SARS-CoV-2-positive HCWs. Possible outbreaks were identified as wards with two or more infected HCWs defined as close contacts who tested positive for SARS-CoV-2 less than three weeks apart. Viral RNA from naso-/oropharyngeal samples underwent nanopore sequencing in direct compliance to the ARTIC Network protocol.

Findings: Five outbreaks were suspected from contact tracing. Viral consensus sequences from 24 HCWs, two patients, and seven anonymous samples were analysed. Two outbreaks were confirmed, one refuted, and two remained undetermined. One new potential outbreak was discovered.

Conclusion: Combined with epidemiological data, nanopore WGS was a useful tool for investigating intra-hospital SARS-CoV-2 transmission. WGS helped to resolve questions about possible outbreaks and to guide local infection prevention and control measures.

Keywords: COVID-19; Healthcare workers; Hospital; SARS-CoV-2; Transmission; Whole-genome sequencing.

MeSH terms

Adult
COVID-19 / epidemiology
COVID-19 / transmission*
Female
Genome, Viral
Health Personnel / statistics & numerical data*
Humans
Infectious Disease Transmission, Patient-to-Professional / statistics & numerical data*
Male
Middle Aged
Nanopores
Norway / epidemiology
Occupational Diseases / genetics*
SARS-CoV-2 / genetics*
SARS-CoV-2 / isolation & purification*
Whole Genome Sequencing*