Severe respiratory illness rates are now the highest they’ve been in the last decade, mostly due to very high rates of flu.
This comes as ambulance services struggle to meet demand, and Health NZ urges people to save emergency departments for emergencies.
Professor Michael Plank, School of Mathematics and Statistics, University of Canterbury, comments:
“After an unusually late start to the season, influenza levels have rocketed over the last few weeks and are now close to their highest level in 4 years. The last time influenza indicators were this high was 2022, which was the year of the post-pandemic rebound. This will be putting a lot of pressure on hospitals and GP practices around the country.
“With the very rapid rate of epidemic growth, it is possible we will even exceed the 2022 peak in the next few weeks before levels hopefully begin to come down as spring approaches.
“The good news is that this year’s vaccine formulation appears to be well matched with current strains. It’s definitely not too late to get a flu jab if you haven’t already had one this year and it will provide good protection against sickness.”
Conflict of interest statement: “No conflict of interest to declare.”
Dr Hannah Cooper, Public Health Physician, Health intelligence team at PHF Science, comments:
“Surveillance indicators monitored by PHF Science show that respiratory illness activity was very high in the week ending August 16th, reinforcing what has been reported by many front line health services.
“Severe acute respiratory illness (SARI) rates in the Auckland region were the highest we have seen since this reporting began in 2012.
“Primarily this is being driven by high rates of influenza-SARI, which are close to the high levels seen in 2022. What is different this year is that other respiratory virus activity is higher, particularly RSV and rhinovirus, contributing to the very high overall picture. All indicators suggest COVID-19 activity remains very low.
“Based on the subtyping data available, the predominant circulating strain is influenza A/H3 subclade K – this is the strain that caused a significant flu season in the Northern Hemisphere recently. The influenza A/H3 subclade K strain has evolved to be quite different to other influenza A/H3 strains that have circulated in recent seasons and so there is little natural immunity in the population, contributing to its high transmissibility. In the Northern Hemisphere season, there was no indication influenza A/H3 subclade K caused more severe disease at an individual level, however overall it contributed to a severe season due to the large numbers of cases.
“Importantly, the vaccine was updated ahead of our Southern Hemisphere season to better match influenza A/H3 subclade K, and data from the PHF Science virology lab to date indicate the circulating strains do match the vaccine.
“Even with a well matched vaccine, influenza can spread rapidly through a population as not everyone is vaccinated, and vaccination does not prevent all influenza infections. The primary goal of influenza vaccination is to protect people from becoming very unwell or dying from influenza, which is why they are funded in New Zealand for the groups most at risk of severe outcomes due to age or underlying health conditions. It is not too late to get a flu vaccine this year.”
Conflict of interest statement: “I have no conflicts of interest to report.”