A patient who has symptoms of Covid-19 is four times more likely to spread the virus on to others than someone who stayed asymptomatic.
The major risk of infection may be from sharing a home with an infected individual, according to a statistical review of dozens of contact-tracing reports, which offers new proofs to underscore the need for people to isolate themselves as soon as they shows signs they may be ill.
Imperial College professor Neil Ferguson said, “This analysis provides some of the first evidence that asymptomatic infections are substantially less infectious than symptomatic cases. It also reinforces growing evidence of the importance of household transmission, especially in the context where symptomatic cases are not isolated outside the home.”
The lead author Hayley Thompson said, “The differences we observed in transmissibility by symptom status of index cases and duration of exposure have important implications for outbreak control strategies, highlighting how contact tracing, testing and rapid isolation of cases will be crucial.” Imperial College researcher Andria Mousa said, “Understanding the conditions where transmission is more likely to occur is essential in guiding policy interventions to reduce transmission whilst balancing the economic impact.”