The study, led by Imperial College London, sheds new light on the spread of the coronavirus in homes – and is the first to link virus particles on hands and commonly touched surfaces in the home and the risk of infection for those in contact.
The results show that the presence of SARS-CoV-2 on hands and surfaces is a major contributor to the spread of Covid-19, the lead author said Ajit Lalvani from Imperial College in a broadcast: In households in which the corona virus was found on surfaces and on the hands of the study participants, the infection of contact persons and thus the transmission was significantly higher.
Taps, kettles, fridge handles
The study was conducted at the height of the pandemic – before and during Alpha-Wave – carried out in 279 London households. 279 newly infected people and 414 contacts between the ages of six and 79 took part. Because the study took place early in the pandemic, between August 2020 and March 2021, very few of the participants were vaccinated or previously infected, leaving the majority vulnerable to infection.
All contact persons were regularly tested for SARS-CoV-2 infection using a PCR test. Swabs were also taken from the hands of all participants, as well as from the most commonly touched surfaces in common areas: faucets, kettles and refrigerator door handles.
After factors such as gender, vaccination status, underlying diseases and the relationship of the contact persons to the infected person were taken into account, the research team found that contacts in the same household were 1.7 times more likely to be infected if the virus was on the hands of the infected person has been proven. The likelihood of infection was just as high if the virus was on frequently touched surfaces in the household.
“Easy-to-use measures”
Because this is an observational study, no causality can be proven, the research team said. However, the research results, which have now been published in the journal The Lancet Microbe, strongly suggest that washing hands and disinfecting surfaces can prevent infections. Given that new variants are likely to continue to spread despite booster shots, these are easy-to-apply measures to disrupt the spread of the virus, Lalvani said.