Coronavirus: asymptomatic patients may shed virus for longer than others, study says
- Team in southwest China finds median duration was 19 days, a third longer than for people with mild symptoms
- But they say releasing the virus into the environment doesn’t necessarily lead to infection of others, and more research is needed
Asymptomatic coronavirus patients could shed the virus for longer than those with symptoms, according to a new study in southwest China.
“The emergence of these silent spreaders … has caused difficulties in the control of the epidemic,” the researchers led by Huang Ailong, from Chongqing Medical University, wrote in a peer-reviewed paper in Nature Medicine on Thursday.
Huang’s team found that the median duration of viral shedding among the 37 asymptomatic patients in the Chongqing study was 19 days – a third longer than the patients with mild symptoms.
In one case, an asymptomatic patient shed the virus for 45 days.
01:57
Coronavirus: Inside a Chinese lab joining global race to find a vaccine
The study also found that asymptomatic patients had lower antibody levels than those with symptoms. All of the patients had antibodies, which are generated by the immune system to stop the virus from infecting cells. But the asymptomatic patients had them at just 15 per cent of the level found in those with symptoms.