Did the media beat up this year’s flu season and turn it into the Black Death?
Just about, according to a letter published online in the Medical Journal of Australia.
The letter, signed by Dr Vicky Sheppeard, director of the Communicable Diseases Branch at NSW Health, and colleagues, begins: “Mainstream media headlines have raised fears among the community and clinicians about the impact of influenza and likely effectiveness of the 2019 influenza vaccine.
“On Saturday, 6 July 2019, the front page of Sydney’s Daily Telegraph reported ‘Mutant flu crisis’ and ‘Exclusive: Jab fail fears as killer strain takes hold’.”
The World Health Organisation Collaborating Centre for Reference and Research on Influenza was quoted in the article, “explaining that some drift among circulating strains from the vaccine strains is expected every year and that to date in 2019, drifted strains made up just a small portion of circulating virus”.
In other words, there were, as always, some strains of the influenza virus that the 2019 vaccine – vaccines change each year – didn’t protect against. But these strains didn’t affect a high number of people.
“However,” writes Dr Sheppeard and colleagues, “this did not quell the resulting media coverage”.
The authors note that a factor “driving the intense media and community interest in influenza in 2019” has been the record number of notifications.
“But on further analysis, the raw numbers are less worrying.”
Respiratory viral testing has increased considerably in recent years in NSW, “a phenomenon likely to be replicated in much of Australia”.
The authors explain that the shift from influenza diagnosis based mainly on serology to rapid, highly discriminatory polymerase chain-reaction testing widely available in primary and acute services has resulted in annual increases in test numbers – from 29,232 in NSW sentinel laboratories in 2010 to 338,828 in just the first six months of 2019.
“We need to look to other indicators to assess the burden of influenza rather than the raw notification numbers,” they write.
A more reliable indicator is the influenza test-positivity rate.
This was highest in 2017 – “an acknowledged severe season due to ineffectiveness of the vaccine against the predominant influenza A (H3N2) strain and is at a moderate level so far in 2019”.
Other reliable indicators are hospital admissions of people presenting to emergency departments with influenza-like illness, and mortality from influenza and pneumonia, “both of which also show 2019 to be a moderate severity influenza season to date”.
Dr Sheppeard acknowledges that influenza is a serious infection, “with a mortality rate of around 1 per cent in confirmed cases and most of the mortality burden affecting the vulnerable elderly”.
The authors conclude: “We are working to reduce the impact of influenza on the community; hopefully, we can achieve this without generating unfounded community concern.”