The 28-year-old man, who was working in China's Guangxi Province, had returned home to Kon Tum to celebrate the Lunar New Year holiday on January 23. A few days later, he and his 26-year-old wife developed high fever and had coughing fits.

On February 3, the couple were quarantined at the provincial general hospital. Tests showed them positive for the A/H1N1 influenza virus.

After two days of treatment, their health is in stable condition, doctors said Thursday.

Influenza A/H1N1 is a regular seasonal flu. Chronic patients, people with compromised immune systems, pregnant women and other vulnerable people contracting the influenza A virus are susceptible to multiple organ damage and severe complications that can even prove fatal.

The contagious virus spreads when an infected person coughs, sneezes, laughs, or talks. The disease can also be spread by touching the surface of an infected item and sharing utensils and toothbrushes with sick persons.

A global epidemic of this strain of the swine flu killed more than 17,000 people in 2009.

In 2018, eight people died of the flu in Vietnam.

Taiwan has been severely affected by the seasonal swine flu that has claimed 61 deaths in the past three months, the Taiwan Center for Disease Control has reported.