Tran Dac Phu, head of the Preventive Medicine Department (PMD), made the confirmation on January 22 following news that more than 30 students of Hanoi’s Tri Duc secondary school had been hospitalilsed for the past three days, showing flu-like symtoms of fever, coughing and chest infections.

After medical-checkups, most of the students were discharged from the Central Hospital for Tropical Diseases.

Phu said two out of the first 13 students tested positive for a flu virulent strain (type A), and their blood samples were sent to the National Institute of Hygiene and Epidemiology for further testing. 

He confirmed the students were infected with the normal seasonal influenza and so far no one has displayed serious life threatening symptoms.

Veterinarians fanned out to disinfect the affected area in Tu Liem district.

Since the first case of A/H1N1 flu was detected in Vietnam in 2009, there have been repeat incidences of the same strain.

The PMD warned that the weather in winter-spring is particularly conducive to the development and spread of the flu virus in general and bird flu in particular.

It urged citizens to take precautionary measures such as washing hands thoroughly with soap, maintaining good personal hygiene and eating nutritious food to prevent flu. They are encouraged to limit or avoid contact with those who are suspected of infection.