Surge in flu this winter

Australia is seeing unusually high levels of a different type of flu this winter (flu type B), with children and the elderly particularly at risk from the virus and outbreaks occurring in schools and nursing homes.

Influenza, commonly known as the flu, is cause by highly contagious virus that is spread by fluids produced during coughing and sneezing, or by direct contact with those fluids on surfaces.

Each year between 1500 and 3000 Australians die from the flu, about 18,000 people are hospitalised, and 300,000 visit a doctor.

Figures from NSW Health indicate the number of outbreaks that have involved "type B" influenza are far higher than last year.

Professor Robert Booy, infectious diseases and immunisation expert at University of Sydney says that flu type B can make children and the elderly very ill, very quickly, with symptoms including severe muscle ache, high fever and respiratory complications.

“Although we all know influenza as ‘the flu’, there are actually many different subtypes of the influenza virus, with flu type A and B the cause of outbreaks of seasonal flu. Flu type B often occurs after a surge of flu type A, but this year flu type B is the first cab off the rank.

"The only prominent symptom with flu type B is severe muscle aches, especially with primary school kids. They can find it really painful to walk - we have been seeing that quite a lot in the emergency department.

“Flu will be peaking by late August in Australia, and people should see their doctor promptly if they experiences symptoms,” said Professor Booy.

Nationally, flu figures to the end of June show flu type B has been responsible for two-thirds of flu notifications this year.  Children appear to be most at risk - more than 16 per cent of children who have presented at hospital with the flu have been admitted to intensive care, compared with 6 per cent of adults.

Professor Booy said the government-subsidised flu vaccine only protects against one type of B flu, not the two that are circulating.

“While it is thought that the vaccine gives some cross protection, it means that even those who have been immunised may still catch the B flu – particularly as the season peaks”.

“Importantly, this virus is actually treatable at the very early stages of illness. If a patient sees their GP within 24-48 hours of developing symptoms, they can be treated with an antiviral medication that can help them to recover much faster.

“Our research on flu in nursing homes shows that using antiviral treatment can lessen the duration of outbreaks. There are nursing homes in Sydney right now that are closed to visitors and new admissions because of influenza outbreaks.

“The earlier you are treated, the better the chance of recovery. Treatment with an antiviral in these cases will prevent hospital admissions and help reduce the burden on busy emergency rooms. It can also reduce mortality in intensive care patients.

Professor Robert Booy is an infectious diseases and vaccine expert at the University of Sydney.