Coronavirus (COVID-19) Nosocomial Review Group minutes: January 2022

Items and actions

1. CNRG were presented with the latest situation COVID-19 sitrep for w/e 26 December 2021. NI cases had risen over December, however around half were asymptomatic. Coronavirus (COVID-19) Nosocomial Review Group (CNRG) noted that this may be reflective of the changing symptom presentation or vaccine effect in Omicron variant infection cases. Nosocomial cases account for 0.1 percent of total COVID-19 cases during this time.
2. It was noted that the majority of clusters in non- respiratory pathways in recent weeks are reported in care of elderly, mental health and general medicine wards. It was noted that almost half of the NI cases during December had not had a third booster dose at time of positive test and most were in eligible groups. Ensuring vaccine uptake of hospital in patients remains important. Testing at admission remains vital and CNRG noted that multiplex testing on admission for the range of respiratory viruses is very important for IPC - flu levels are low so far this year however, patient placement depends on testing and is critical to manage NI risks.
3. A whole genome sequencing (WGS) Omicron sitrep update was given. CNRG were informed that three sub linages of the Omicron variant have been identified – BA.1, BA.2 and BA.3, and that BA.1 is the most dominant linage circulating within the UK. Whole genome (WGS) sequencing showed the rapid switch from circulating Delta variant to the Omicron. It was highlighted that within five weeks of the first WGS Omicron case on 23 November 2021, approximately 95 percent of all WGS samples in Scotland were Omicron. The Outbreak and incident identification and investigation work package was overviewed, noting this would include a genomic clusters pipeline to identify identical genomic groups and summarise the linked metadata in interactive NHS Board specific reports, which include data of clusters associated within particular age group, localised cluster data, hospital associated clusters and those spanning NHS boards, and prison associated clusters.
4. Omicron nosocomial infection risk modelling on vaccination protection against the Omicron variant was presented. Data assessing the effectiveness of any combination of first, second and third dose of vaccination against the Omicron variant in Scotland using data from 1 November 2021 to 4 January 2022 were presented. From the data the preliminary results showed that vaccination results in a reduction in the hazard of admission, and vaccine effects associated with the prevention of hospital admission among those with infections, are similar for Omicron and Delta.
5. CNRG noted the UK IPC Cell position on the updated  World Health Organisation (WHO) guidance from 23 December 2021 remains unchanged and the current Scottish Winter guidance is in line with this. Given the importance in the current context of Omicron, CNRG endorsed that the risk assessment sections would be moved to a more prominent position in the Scottish guidance and emphasised in all health and care settings.
6. CNRG noted the continuing evidence emerging re aerosols inclusive of a recent novel study of the Dynamics of Infectivity with Aerosol Microenvironment by Oswin et al investigating the viability of COVID-19 suspended in droplet aerosols over time. The study points to the importance of survival as a key step in the transmission of such pathogens. Understanding the impact that airborne transport has on pathogens and the influence of environmental conditions on pathogen survival can inform the implementation of strategies to mitigate the spread of diseases such as COVID-19. CNRG noted the limitations but importance of this study in terms of building the evidence base on transmissibility, it was noted that the study was not designed to investigate viral activity according to differences in viral load.
7. An update on HCW testing figures was provided. Members were made aware that daily LFD testing commenced from 17 December 2021. This has led to a doubling of numbers of LFD test been recorded week on week. Highlighted to CNRG that PCR testing path figures remain stable between 93 -95 percent a week uptake by eligible staff.
8. CNRG noted that the staff self-isolation guidance was currently being updated to reflect the change in the isolation rules for the general population.