University of Sydney researchers have established a link between influenza and devastating brain diseases in children.

Published in the journal Clinical Infectious Diseases, the paper reported 54 cases of potentially fatal Influenza–Associated Neurological Disease (IAND) among children hospitalized with influenza at two Australian hospitals over three flu seasons.

The 54 cases represent 7.6 per cent of children up to 16 years of age hospitalised for influenza over this period.

“This is the first Southern Hemisphere research conducted into IAND,” says paediatric infectious disease expert, Dr Philip Britton, who co–authored the paper with colleagues from around Australia, including the Marie Bashir Institute of Infectious Diseases and Biosecurity Institute, The Children's Hospital at Westmead, and the National Centre for Immunisation Research and Surveillance.

“We’re hoping this research begins a discussion that influences policy decision making surrounding the influenza vaccine and children.”

The rare Influenza–Associated Neurological Disease (IAND) cases often presented as Influenza Associated Encephalitis (IAE), which can result in brain inflammation and in severe cases, brain damage or death.

Overall, there were 10 cases of Influenza Associated Encephalitis (1.4 per cent) among children hospitalised for influenza.

Of these 10 cases, eight survived, with six being admitted to an Intensive Care Unit and three suffering neurological impairment due to IAE.

Dr Britton says the study revealed two groups of children at heightened risk of neurological diseases from the flu.

“One group at risk are children with pre–existing neurological conditions, such as epilepsy. The other group at heightened risk were previously healthy children with no known risk factor.

“We believe the susceptibility to neurological complications in previously healthy children likely stems from a genetic predisposition, however we’re yet to prove that. If that is the case then it’s very difficult for us to know in advance who is at risk and who isn’t,” says Dr Britton.

Dr Britton says that while the conditions are rare, they can be avoided through the influenza vaccine.

“In this case, prevention is better than treatment. The influenza vaccine is effective in preventing the flu and therefore, IAND. The vaccine is already funded for children with a pre–existing condition but, we are asking the question, “should we be providing funding for all young children to access the flu vaccine?” knowing that this could potentially save lives.”

The study began in 2013 at the Westmead Children’s Hospital in New South Wales and Princess Margaret Hospital in Western Australia before expanding in 2014 to retrospectively collate cases of influenza from hospitals across Queensland, Victoria and South Australia. Research was also completed by members of the Marie Bashir Institute.