Robot companion animals used in a study led by Hannah Bradwell

Research from the University of Plymouth suggests that robot pets, widely used in care homes in the UK and globally, could pose an infection risk if passed between staff and service users without cleaning.

A study published today in the open-access journal PLOS ONE found that the devices, used to reduce depression, isolation and loneliness in older adults and people with dementia, became unacceptably dirty after use as bacteria built up on their surface and ‘fur’. 

However, the study, led by Hannah Bradwell from the University of Plymouth’s Centre for Health Technology with colleagues from the Centre, Auckland University of Technology in New Zealand, Radboud University in the Netherlands and Royal Cornwall Hospitals NHS Trust (RCHT), concluded that a simple cleaning procedure was effective in reducing that bacterial load to safe levels.

Following the advent of COVID-19, further work was carried out by Miss Bradwell and colleagues from the Centre for Health Technology and RCHT, looking specifically at whether the same cleaning procedure might be effective against COVID-19 virus SARS-CoV-2. The team concluded that urgent further research was needed into the possibility of the virus being transmitted via the robot pets, and until such research was carried out, shared use of the devices ‘appeared unsafe’.

However, researchers recognised the important role that companion robots continue to play in mitigating some of the ways the pandemic has affected older people’s lives – an increase in loneliness and isolation and a dramatic decrease in social contact.

Miss Bradwell said:

"The care homes that we work with have told us these robot pets have been really important to residents during the pandemic and lockdown. However, our work has shown the urgent need to consider infection control in relation to these devices.

“On balance, their shared use appears unsafe, until further research can be undertaken. However, it is important to say that the danger arises from shared use, where the animals are passed between people, and the risk is removed if the robots are used by just one person.”

Even before the pandemic, there was a wealth of research on the use of the robots in care and long-term nursing homes. Paro the robot seal and other robotic animals have been linked to reductions in depression, agitation, loneliness, nursing staff stress, and medication use.

In the PLOS One study, researchers measured the microbial load found on the surface of eight different robot animals (Paro, Miro, Pleo rb, Joy for All dog, Joy for All cat, Furby Connect, Perfect Petzzz dog, and Handmade Hedgehog) after interaction with four care home residents, and again after cleaning by a researcher or care home staff member. The animals ranged in material from fur to soft plastic to solid plastic. The cleaning process involved spraying with anti-bacterial product, brushing any fur, and vigorous cleaning with anti-bacterial wipes.

Most of the devices gathered enough harmful microbes during 20 minutes of standard use to have a microbial load above the acceptable threshold of 2.5 CFU/cm2 (colony forming units per square centimetre). Only the Joy for All cat and the MiRo robot remained below this level when microbes were measured after a 48 hour incubation period; microbial loads on the other 6 robots ranged from 2.56 to 17.28 CFU/cm2. The post-cleaning microbial load, however, demonstrated that regardless of material type, previous microbial load, or who carried out the cleaning procedure, all robots could be brought to well below acceptable levels. 5 of the 8 robots had undetectable levels of microbes after cleaning and 48 hours of incubation, and the remaining 3 robots had only 0.04 to 0.08 CFU/cm2 after this protocol.

In the follow up work, the team reviewed the cleaning products used against the USA Environment Protection Agency List N - Disinfectants for Use Against SARS-CoV-2, to assess whether the same procedure would be effective against the virus. Although one of the products used does meet criteria for use against SARS-CoV-2, on balance, they concluded shared use appeared unsafe at present.

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