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JBC and Defra: A qualitative risk assessment to estimate the likelihood of SARS-CoV-2 infection of rodents from contact with the environment and onward exposure to humans, 8 April 2021
Paper prepared by the Department for Environment, Food and Rural Affairs (Defra) and the Joint Biosecurity Centre (JBC).
From:Scientific Advisory Group for Emergencies
Published:23 April 2021
Documents
JBC and Defra: A qualitative risk assessment to estimate the likelihood of SARS-CoV-2 infection of rodents from contact with the environment and onward exposure to humans, 8 April 2021
PDF, 325KB, 18 pages
This file may not be suitable for users of assistive technology.
Request an accessible format.Details
Paper by Defra and JBC. This paper looks at SARS-CoV-2 exposure and infection in animals and potential onward exposure. It was presented at SAGE 86 on 8 April 2021.
The paper is the assessment of the evidence at the time of writing. As new evidence or data emerges, SAGE updates its advice accordingly.
These documents are released as pre-print publications that have provided the government with rapid evidence during an emergency. These documents have not been peer-reviewed and there is no restriction on authors submitting and publishing this evidence in peer-reviewed journals.
Published 23 April 2021
https://www.gov.uk/government/publi...s-from-contact-with-the-environment-and-onwar
--------------------------------------
...
Risk being assessed:
1. viable virus in sewage
2. contact with rodents
and level of infectious
dose for variants of
concern and ?wild type?
virus
3. transmission rate in
wild rodents
4. exposure to humans ?
general population and
occupational exposure
Outcome of risk assessment:
P1: What is the likelihood of SARS-CoV-2 to remain
viable in the environment and waste water (pretreatment) such that a rodent could receive an
infectious dose? VERY LOW but HIGH uncertainty
(unsatisfactory confidence).
P2: What is the likelihood that a variant of concern
(VOC) of SARS-CoV-2 which has arisen in the human
population could infect a rodent and produce sustained
population level transmission? HIGH but MEDIUM
uncertainty (satisfactory confidence).
P3: What is the likelihood that a human is exposed to
an infectious dose of virus (VOC or otherwise) ? either
the general public or someone who has regular contact
with rodents through pest control, waste management
or waste water management? VERY LOW for general
public; MEDIUM for occupational exposure; HIGH
uncertainty (unsatisfactory confidence).
Key uncertainties:
? Whether mucus or faeces would have a protective
effect on the virus. Whether pathogen overdispersal
is protective in certain heterogenic environments and
rates of decay of virus in different media (faeces,
mucus).
? What viral dose is required to infect a wild rodent.
Infectious dose to a rodent from different media. With
over 8 million rats in the UK, the aggregated risk for
one rat to become infected (based on 1-(1-p)
n
)
increases when more rats are exposed.
? Transmission rates for the common viral transmission
pathways between rats are unknown ? faecal oral
route, respiratory, mutual grooming. This will also
include uncertainty around the magnitude of viral
shedding by an infected rodent.
? Movement of pest rodents from overseas does occur
and would most likely occur at the ports and border
control posts.
? Endogenous coronaviruses in rodents and risk of
recombination with SARS-CoV-2 or selection
pressure for SARS-CoV-2 evolution to infect and
transmit among rodents.
...
https://assets.publishing.service.g...79445/S1191_Risk_Assessment_COVID_Rodents.pdf
JBC and Defra: A qualitative risk assessment to estimate the likelihood of SARS-CoV-2 infection of rodents from contact with the environment and onward exposure to humans, 8 April 2021
Paper prepared by the Department for Environment, Food and Rural Affairs (Defra) and the Joint Biosecurity Centre (JBC).
From:Scientific Advisory Group for Emergencies
Published:23 April 2021
Documents
JBC and Defra: A qualitative risk assessment to estimate the likelihood of SARS-CoV-2 infection of rodents from contact with the environment and onward exposure to humans, 8 April 2021PDF, 325KB, 18 pages
This file may not be suitable for users of assistive technology.
Request an accessible format.Details
Paper by Defra and JBC. This paper looks at SARS-CoV-2 exposure and infection in animals and potential onward exposure. It was presented at SAGE 86 on 8 April 2021.
The paper is the assessment of the evidence at the time of writing. As new evidence or data emerges, SAGE updates its advice accordingly.
These documents are released as pre-print publications that have provided the government with rapid evidence during an emergency. These documents have not been peer-reviewed and there is no restriction on authors submitting and publishing this evidence in peer-reviewed journals.
Published 23 April 2021
https://www.gov.uk/government/publi...s-from-contact-with-the-environment-and-onwar
--------------------------------------
...
Risk being assessed:
1. viable virus in sewage
2. contact with rodents
and level of infectious
dose for variants of
concern and ?wild type?
virus
3. transmission rate in
wild rodents
4. exposure to humans ?
general population and
occupational exposure
Outcome of risk assessment:
P1: What is the likelihood of SARS-CoV-2 to remain
viable in the environment and waste water (pretreatment) such that a rodent could receive an
infectious dose? VERY LOW but HIGH uncertainty
(unsatisfactory confidence).
P2: What is the likelihood that a variant of concern
(VOC) of SARS-CoV-2 which has arisen in the human
population could infect a rodent and produce sustained
population level transmission? HIGH but MEDIUM
uncertainty (satisfactory confidence).
P3: What is the likelihood that a human is exposed to
an infectious dose of virus (VOC or otherwise) ? either
the general public or someone who has regular contact
with rodents through pest control, waste management
or waste water management? VERY LOW for general
public; MEDIUM for occupational exposure; HIGH
uncertainty (unsatisfactory confidence).
Key uncertainties:
? Whether mucus or faeces would have a protective
effect on the virus. Whether pathogen overdispersal
is protective in certain heterogenic environments and
rates of decay of virus in different media (faeces,
mucus).
? What viral dose is required to infect a wild rodent.
Infectious dose to a rodent from different media. With
over 8 million rats in the UK, the aggregated risk for
one rat to become infected (based on 1-(1-p)
n
)
increases when more rats are exposed.
? Transmission rates for the common viral transmission
pathways between rats are unknown ? faecal oral
route, respiratory, mutual grooming. This will also
include uncertainty around the magnitude of viral
shedding by an infected rodent.
? Movement of pest rodents from overseas does occur
and would most likely occur at the ports and border
control posts.
? Endogenous coronaviruses in rodents and risk of
recombination with SARS-CoV-2 or selection
pressure for SARS-CoV-2 evolution to infect and
transmit among rodents.
...
https://assets.publishing.service.g...79445/S1191_Risk_Assessment_COVID_Rodents.pdf
