Vietnam faces challenge of asymptomatic Covid-19 cases

About 1,000 Covid-19 patients are being treated in 50 medical facilities across the country, with Hanoi's National Hospital for Tropical Diseases, already been locked down as a major hotspot, handling 300 cases on its own, according to the Ministry of Health.

Around half of these active cases are asymptomatic, the ministry says.

Nguyen Van Kinh, part of a team of experts responsible for the diagnosis of Covid-19 patients, said Thursday that the lack of symptoms was a challenge for screening processes in hospitals.

"There are many cases where even X-ray scans of the lungs don't expose their infection status. And when they do, it's already too late," he said.

Nguyen Hong Ha, deputy chairman of the Vietnam Society of Infectious Diseases, said the asymptomatic cases make detection difficult, especially because even Covid-19 tests fail to identify positive cases during the first few tries, making contact tracing "exceedingly difficult."

"If we only wait for people to show symptoms like fever, coughing or difficulty breathing, we will surely miss infections," he said, stressing that Covid-19 screening and contact tracing remain of vital importance in the fight against the pandemic.

Long incubation

Research has revealed that the virus's incubation period could last up to 21 days, with symptoms typically showing up on days 5-12. From day 15-21, very few symptoms are seen, if any.

In most patients, the symptoms are mild and would typically clear up after about a week. But severe cases mean trips to the ICUs, ventilators and increased risk of death.

The disease's trajectory is difficult to anticipate, especially so in elderly patients with underlying conditions, where an asymptomatic case may very quickly turn into a life-threatening one.

Scientists have yet to ascertain exactly how contagious an infected person could be during their asymptomatic period. Some experts are saying, therefore, that the best way to prevent infection is to isolate every close contact of a confirmed infection, besides the usual measures of wearing masks and washing hands.

In response to challenges facing Vietnam during its latest outbreak, the government has increased the mandatory quarantine duration from 14 days to 21 days. It took this action after several Covid-19 cases detected after completing the mandated quarantine.

Luong Ngoc Khue, a senior official with the Ministry of Health, said coronavirus patients should be treated where they are, and only truly severe cases should be transferred to facilities like the National Hospital for Tropical Diseases for treatment because the doctors and nurses there are already overloaded.

Vietnam's latest Covid-19 wave has recorded 665 community transmissions in 26 localities since late last month.