The Healthcare Infection Society has put out a rather innovative interactive webinar on some challenges and solutions related to IPC for COVID-19. The webinar was an expert panel Q&A format, and worked really well.
The panel was chaired by Prof Hilary Humphreys (a consultant microbiologist) and included Cariad Evans (consultant virologist), Peter Hoffman (consultant clinical scientist), Martin Kiernan (infection control nurse – and fellow blogger!), and Chris Settle (consultant microbiologist).
Here’s the webinar, with some of my notes below.
The questions and answers went something like this:
- Should AGPs be performed at negative pressure? If negative pressure is available, it should be used, but if not, there is no requirement to use negative pressure.
- If supply was constrained, would you advocate a UV or HPV decontaminated FFP2/3 respirator mask? The idea of moving towards “fighter pilot” style FFP3 masks that can be safely decontaminated by hand was advocated. Along with rationalising the use of FFP2/3 masks. The helpful IPS/CSC guidance was referenced. Some unease among the panel about the idea of using UV or HPV to decontaminate FFP2/3 masks.
- Do AGPs on tissues other than the respiratory tract pose a risk for transmission? The virus needs the ACE2 receptor to replicate; these receptors are mainly in the respiratory tract but are found elsewhere. SARS-CoV-2 found in faeces, but rarely in other body fluids (including blood and CSF). So, the conclusion seems to be that risk posed by AGPs outside of the respiratory tract (+/- the GI tract) would be low.
- What’s the rationale for gown use for AGPs and aprons for non-AGPs? When you do an AGP, you don’t just get aerosols – you also get a range of droplets and splashes (hence the need for gowns). When there are no risks of splashes, aprons provide adequate coverage. The message from PHE and the national advisory group is that coughing does not produce sufficient droplets that would require a gown.
- Is testing of asymptomatic staff a realistic way forward? The emerging evidence suggests that asymptomatic COVID-19 infection in staff is pre-symptomatic. Mathematical modelling suggests that detecting asymptomatic staff should be a major part of the IPC approach to COVID-19.
- How often should asymptomatic staff be tested? The frequency of testing will need to be determined by local epidemiology and patient mix.
- Is there evidence that higher viral inoculation leads to more severe illness? This question is essentially unanswerable based on current evidence – there are so many factors that drive the severity of disease and clinical outcomes.
- Why are different infectivity durations recommended for patients (7 days) vs. patients (14 days)? This is because of the presumed severity of disease in admitted patients vs. non-admitted staff (who have less severe disease).
- How long can the SAR-CoV-2 virus survive on difficult-to-decontaminate items (such as bank notes)? Lab experiments can be difficult to translate into real-world settings – although suggest survival on environmental surfaces for around 5 days (or more), albeit with diminishing concentration. The role of this contamination in transmission is uncertain.
- Are portable air conditioners safe to use in wards with COVID-19 patients? Since these device recycle air and don’t disrupt air pressures, there shouldn’t be an issue.
- Will there be PHE guidance on creating and protecting “green” elective pathways? Pre-admission testing and PPE use will help to protect these pathways. But the logistics are tricky!
- How will the risk of AGPs be managed when dentistry begins again? Lots of AGPs produced in dentistry and it may not be feasible to wait for an hour between patients!
- Is sessional use of gowns introducing the risk of transmission organisms between patients? The panel accepted this risk was real, and made worse by gowns with poor fitting cuffs (which make hand hygiene between patients even more difficult).