Symptom-free virus carriers raise fears of new wave of infections

SHANGHAI: The existence of a substantial but unknown number of asymptomatic carriers of coronavirus in China has raised concerns among the public that people could still be spreading Covid-19 without knowing they are sick.

As the virus continues to wreak havoc across the world, China is close to declaring victory and is already easing travel restrictions. The border of Hubei province, epicentre of the virus, opened yesterday after a twomonth shutdown.

But there are concerns that the end of the lockdown will release thousands of infectious people back into circulation.

Asymptomatic cases present a huge challenge in the control of infectious disease, making it harder to detect and stop transmission.

In China, the number of known asymptomatic cases is classified, and it is not included in official data, though the South China Morning Post, citing unpublished official documents, recently said it was more than 40,000.

China had reported 81,218 coronavirus cases, and 3,281 deaths by the end of Tuesday.

Asymptomatic cases are found through “contact tracing”. China identifies people exposed to someone with a confirmed diagnosis, and if they test positive, they are quarantined whether or not they manifest symptoms.

Still, the failure to include them in official data has raised concerns about Beijing’s commitment to transparency, and some experts say it could also create a misleading picture about how the epidemic spreads and whether or not it is under control.

Despite recording

zero new infections from March 18 to March 22, the Covid-19 hotspot city of Wuhan disclosed on March 20 that one newly diagnosed case was not included in official data because the patient, a 62-year old man surnamed Zhang, had shown no symptoms.

Citing hospital sources, the news magazine Caixin also reported that a new case in Wuhan on Tuesday was a doctor who had been infected by an asymptomatic patient. – Reuters