COVID-19 spreads easily among people who live together and other family members, even before an infected person shows any symptoms, according to a modelling study that is the first-of-its-kind to quantify symptomless transmission.
The research, published in The Lancet Infectious Diseases journal on Wednesday, also suggests the SARS-CoV-2 that causes COVID-19 may spread more easily in households than severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS).
The analysis, based on contact tracing data from 349 people with COVID-19 and 1,964 of their close contacts in Guangzhou, China, found that people with COVID-19 were at least as infectious before they developed symptoms as during their actual illness.
The researchers, including those from the University of Florida in the US, also found that people aged 60 years or more were most susceptible to household infection with SARS-CoV-2.