Follow Up Written Evidence Submitted by Professor Andrew Curran






Thank you for the opportunity to speak at the Committee on 26 October. You requested further details on the process by which HSE would update its guidance on mitigating Covid Transmission, specifically in relation to the potential for transmission to occur through exposure to fomites.


As I mentioned at the hearing, I am co-Chair of the SAGE Environmental and Modelling Subgroup, and as such, I receive both SAGE papers and attend SAGE meetings. These papers, and discussions, form part of my input to the HSE weekly Covid update meetings, and any changes in emphasis from SAGE are noted and reflected upon to ensure that HSE guidance retains its practical and proportionate approach. Additionally, a wide range of emerging results from unpublished research are considered, with a position formed by the balancing of the impact of single papers with the accumulating body of evidence.


With regard to fomite transmission, the most recent SAGE paper of relevance is EMG-Nervtag Update on Transmission and Environmental and Behavioural Mitigation Strategies, including in the context of Delta1. This paper was presented to SAGE on 14 October 2021 and was published on the SAGE pages of GOV.UK on 22 October 2021. The paper states:


Transmission can happen through close range exposure to aerosols and droplets, exposure to aerosols in air, and/or via contaminated surfaces (fomites). Inhalation at close range or in shared indoor air is a more likely route of transmission than via fomites, however all routes of transmission are possible and should be mitigated. A risk assessment approach that considers all activities and modes of transmission remains an important step in managing transmission for all variants (high confidence).


On the basis of this expert position from two of the groups that feed into SAGE, it was considered that there was not enough of a significant change to amend the advice given by HSE on the mitigation of Covid by fomite, or other routes.

1 e mg-and-nervtag-update -13-october-2021

It is the duty holder’s responsibility to assess the risks in the context of their specific environment, and to develop a package of mitigations measures to reduce the risk to as low as reasonably practicable which are pragmatic and proportionate. This is at the core of the general risk-based approach to regulation, and has given us the world class, proportionate, system of workplace health and safety system we have today.


An example of this from a medical setting view, is the recently announced changes to Infection Prevention and Control in Hospitals (UKHSA publishes new recommendations for COVID-19

i nfection prevention and control - GOV.UK ( This change is being reflected in HSE sector specific guidance and discussions with the devolved administrations.


In addition to this published information, researchers from the National Core Study on transmission (known as PROTECT) have been involved in the collection and analysis of data from the human challenge study (delivered by a partnership between the government’s Vaccines Taskforce, Imperial College London, the Royal Free London NHS Foundation Trust and hVIVO). PROTECT researchers have shown that:


The virus was emitted by the participants even though their symptoms were mild;

PROTECT researchers could detect viral RNA released in the air, in breath and on surfaces in the rooms of volunteers who became infected, some of which was infectious;

There is significant variability in the amount of virus emitted and the timeframe when this occurs.


After considering all of this information, I have advised HSE colleagues that the data still supports the possibility of transmission occurring through fomites and contaminated surfaces, and that this route of transmission should still be considered a possibility in guidance and regulatory approaches.


I hope this provides you with the additional information you requested and thank you for your interest in HSE, and our work.



(November 2021)