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Germs, homes and apps: can we do more to protect people at home when a family member has coronavirus?

Press release issued: 6 May 2020

A paper published in the BMJ today argues that since most people with Covid-19 are cared for at home, it may be important to try to protect the people caring for them by limiting how much virus they come in contact with, the ‘viral load'.

The paper was published by members of a team of health experts at the University of Bristol, University of Southampton, University of Bath, and Public Health England and patient representatives who have been funded by a new UK Research and Innovation and National Institute for Health Research (NIHR) grant to provide online advice and support to people in the community on how to protect themselves and their family from infection. The team are making the ‘Germ Defence’ app freely available.

The BMJ paper looks at evidence from many studies and concludes that exposure to a higher viral load may make people more ill – which is why Personal Protective Equipment is so important in hospitals. It is not practical for people at home to use the same methods that are used to protect hospital workers from infection from patients, but there are many other ways to try to reduce exposure to virus in the home, and they’re explained in GermDefence.org.

Once one member of a household has the virus, other household members may become more ill if they do not reduce their level of exposure to the virus within the house. It’s hard for people to remember to look after themselves when they’re caring for sick family members, but it’s especially important, and could save lives.

Public health advice recommends that people with symptoms of COVID-19 should be isolated from other people in the home, but this can be very difficult. Germ Defence supplements public health advice on infection control in the home by using behaviour change techniques to help people put this advice into practice - for example by pre-planning for how to avoid sharing areas of the home if at all possible, changing the home environment to reduce infection levels, personalised goal setting for increasing a range of infection control behaviours; and problem-solving to overcome barriers.

Germ Defence was developed during the H1N1 pandemic using theory, evidence and extensive feedback from members of the public. Germ Defence was then tested among over 20,000 patients, and shown to reduce the number and severity of infections of users and household members - this trial was published in the Lancet.

Germ Defence is still the only digital behavioural infection control intervention worldwide that has been proven to reduce the transmission of infections in the home and has already been translated into over 20 languages so it can be rolled out internationally.

Paul Little, Professor of Primary Care Research at University of Southampton, who led the BMJ article, said: “We developed and trialled Germ Defence so that it could be widely disseminated both during normal winter months and also during a major pandemic. We showed clear reductions in both transmission of infections to other family members and also in transmission from other family members. It should help reduce both the number of family members who become ill with COVID-19, and also reduce the severity of illness if family members do become ill."

Professor Lucy Yardley, theme lead for the NIHR Health Protection Research Unit in Behavioural Science and Evaluation at the University of Bristol and member of the University of Bristol's Centre for Academic Primary Care, said: “Most people think that if a family member gets ill then it is just a matter of luck whether other people in the household get infected – but our trial of Germ Defence has shown that it is possible to protect the people you live with from also getting ill. We hope the app will save lives by helping people avoid spreading coronavirus to family members.”

Germ Defence is freely available at: germdefence.org

Further information

Germ Defence is one of 21 new studies into the novel coronavirus which have been funded by the UK government, including the first clinical drug trial in primary care, vaccine and therapy development, and studying epidemiology, disease transmission, behavioral interventions and policy approaches to COVID-19.

This second round of projects receive £14.1 million as part of the £24.6 million rapid research response funded by UK Research and Innovation (UKRI), and by the Department of Health and Social Care through the National Institute for Health Research (NIHR).

Paper: Reducing risks from coronavirus transmission in the home—the role of viral load. Paul Little, Robert C Read, Richard Amlôt, Tim Chadborn, Cathy Rice, Jennifer Bostock, Lucy Yardley. Published in BMJ. 6 May 2020.

About the Centre for Academic Primary Care
The Centre for Academic Primary Care (CAPC) at the University of Bristol is a leading centre for primary care research in the UK, one of nine forming the NIHR School for Primary Care Research. It sits within Bristol Medical School, an internationally recognised centre of excellence for population health research and teaching. Follow us on Twitter: @capcbristol. 
Find out more about our COVID-19 research.

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