How serious is the H7N9 bird flu?

Health authorities worldwide are closely monitoring a deadly new strain of the avian influenza A virus called H7N9. Within a few months, this new avian flu strain has infected well over a hundred people, killing about a fifth of victims. All but one of the cases occurred in China. How serious is the H7N9 bird flu?

“The avian influenza A (H7N9) is potentially deadly. Producing a vaccine to combat this new bird flu strain may, however, take several months. The good news is that bird flu does not spread easily from person to person,” says Dr Jenny L​​ow​, Senior Consultant, Department of Infectious Diseases, Singapore General Hospital (SGH), a member of the SingHealth​ group.

To date, a majority of those infected with H7N9 have contracted it from infected birds and poultry. For the H7N9 bird flu to start spreading from person to person, it has to undergo five mutations. Two mutations have been identified. While there is no immediate threat of human-to-human spread of H7N9, Dr Low cautions against complacency.

“This is the first time the H7N9 virus is in the human population so we have no immunity to it. Practise good personal hygiene and see a doctor immediately if you suffer from persistent flu symptoms such as a high fever, breathing difficulty and cough, especially after an overseas trip. H7N9 can quickly progress to potentially fatal resp​iratory illness,” adds Dr Low.

What is avian influenza A (H7N9)?

H7N9 is a type A influenza virus that affects birds and poultry and does not normally infect humans. This new avian flu strain is potentially deadly because this is the first time it has infected humans. So far, the transmission happens through direct contact with infected birds, poultry and their droppings.

Symptoms of bird flu

H7N9 bird flu symptoms are similar to those of normal flu. These include cough, high fever (38°C or higher) and shortness of breath. Worsening symptoms can lead to pneumonia, acute respiratory distress syndrome (ARDS)​, septic shock, multiple organ failure and death.

The majority of H7N9 bird flu patients fell seriously ill and developed severe respiratory illnesses that required hospitalisation and intensive care.

Read on to find out who is at most risk and tips to prevent it.​​

Ref: S13