Coronavirus (COVID-19) Nosocomial Review Group minutes: 20 May 2022

Items and actions

1. CNRG were presented with the latest COVID-19 sitrep for w/e 1 May 2022. Although there had been a slight increase in the number of cases presenting in hospital the previous week (week ending 24 April), this was not considered to reflect any increase in nosocomial cases. The overall decreasing trend is aligned with the situation across all hospital onset categories. 
2. The majority of patients with nosocomial infection were aged 65 year or older. Nosocomial infection accounted for 1.4% of all COVID-19 and 39.5% of COVID-19 diagnosed in hospital. It was noted that this measure is becoming less meaningful given there is little community testing going on at this point in the pandemic. It was noted that approximately 60% of nosocomial cases were asymptomatic at the point of testing, however these data are not complete as not all health boards report whether cases are asymptomatic or symptomatic.
3. CNRG were presented with an analysis of nosocomial COVID-19 mortality. Overall there has been a decreasing trend in 28 day all-cause mortality since September 2021. Modelling of 28 day all-cause mortality indicated mortality was higher in men, increased risk with increasing age, an increased risk with increasing Charlson score and a decreased risk in vaccinated versus unvaccinated. There was a continued decrease in 28 day all-cause mortality in the latest quarter of reporting and across variant waves.
4. CNRG were updated on the future monitoring of COVID-19 and the epidemic intelligence that will inform the nosocomial agenda. Hospital onset surveillance is under review due to the scaling back of population testing and possible changes to asymptomatic patient testing. Cluster reporting will align in future with other routine outbreak reporting. Whole genome sequencing, genomic cluster and outbreak analysis will continue. It was noted that ARHAI will continue to consider Public Health Scotland reporting of COVID-19 intelligence and available data from the Office for National Statistics COVID-19 Infection Survey.
5. CNRG were updated by PHS on whole genome sequencing (WGS) analysis of hospital onset COVID-19 cases reported in February 2022. There was approximately 41% sequencing coverage of hospital onset cases for this period. More than half of the sequenced hospital onset cases (57%) had unique sequences and were therefore not part of a wider hospital genomic clusters. It was noted this may indicate that introductions to hospitals, for the data examined in this report, did not result in onward transmission chains (based on available sequencing data). There were epidemiologically linked clusters reported to ARHAI that had at least two sequenced cases - these were clusters with either identical phylotypes or highly related phylotypes (difference of one single nucleotide polymorphism (SNP) only and further clusters with more than phylotype.
6. These results provide evidence for epidemiologically linked clusters with confirmed nosocomial transmission but also evidence of epidemiologically linked clusters that are in fact multiple introductions onto the ward. This has important implications for the interpretation of ARHAI cluster reporting and the understanding complexity in chains of transmission particularly during periods of high community prevalence.
7. The majority of genomic clusters of hospital cases were part of wider clusters with associated community cases. The span of genomic clusters across community and hospital settings demonstrates how connected transmission chains are and highlights the increased nosocomial risk when there is a high prevalence in the community. CNRG noted that the pandemic context has meant multiple community importations happen concurrently in hospital settings, inclusive of those from HCWs which the WGS will under report.
8. PHS and ARHAI are continuing to develop WGS requirements for nosocomial transmission inclusive of beyond COVID-19. It was highlighted that cluster identification is an important tool to better understand complex chains of transmission and provide additional granularity to epidemiological data that can be used to support decision making about testing and IPC measures. CNRG noted that WGS data available to date was useful, however if available in real time would be more helpful in managing cases/ defining outbreaks. It was agreed that the turnaround of WGS has improved over the course of the pandemic but is not real time yet. This would require further investment. 
9. CNRG were provided with the current figures for HCW testing uptake. This was 1000 less than the previous week, which could be due to non-patient facing healthcare workers no longer asymptomatically testing. Testing strategy was noted as important at this point in the pandemic. A meeting of all four nations CMOs are w/b 23 May to discuss moving to a lower threat level for SARS-CoV-2. Members were made aware that if the threat level was lowered this would trigger an automatic response in NHS England for all asymptomatic HCW testing to cease. Additionally, the UK Government have drafted a list of patient testing pathways which would also cease. It was noted that although Scotland may have a different list of patient testing pathways, there is a plan for a four nation communications approach to strengthen the messaging, however implementation is likely to be staggered across the nations. CNRG endorsed for asymptomatic HCW testing to cease in line with four nation CMOs lowering the threat level.
10. CNRG discussed future preparedness and the importance of reviewing the national HAI response to COVID-19 by CNRG in the light of the terms of reference for the group. Policy advice will be given in this regard. The future governance for decision making areas as CNRG is stood down was also given consideration and will be subject to future advice. ARHAI noted that transmission-based precaution were being reviewed more broadly as part of the refresh of the NIPCM work and an international oversight group is currently being established to oversee this review.
11. CNRG agreed that meeting 39 would be the last before a summer recess. Members agreed that any additional group asks will be co-ordinated via email. Members were thanked for the commitment and expert advice to date.