Hospitals have been forced to leave patients to wait in ambulances due to a lack of space as emergency services and departments are overwhelmed by a surge in winter illnesses, an ED director says.
St John had its busiest June on record, responding to as many as an extra 300 emergency callouts a day compared to this time last year.
Calls to the ambulance service jumped from 74,000 in June 2016 to 80,000 last month, up 7 percent nationally, and as much as 14 percent in Waikato and 16 percent in Northland.
But a health ministry official said influenza rates were about average for this time of year, but spikes in certain parts of the country were skewing the statistics.
St John director of clinical operations Norma Lane said the spike in calls put enormous pressure on workers.
"It's been really hard for all of our people, our call handlers and front line staff."
Stewart Jessamine from the Ministry of Health told Morning Report the rate of influenza was about average this year and "significantly" lower than three of the last five years, but spikes in certain parts of the country were skewing the statistics.
Waikato and the Hutt Valley had between twice and three times the rate of influenza than other areas.
"In other parts of the country [there are] very very low rates. So what you will see are these kinds of ... hots spots of influenza that stress the system in different cities whilst the rest of the country is running along.
Dr John Bonning from Waikato Hospital's emergency department said it does not have enough beds to cope with the influx of patients.
"The amount of pressure on the health system, the number of people needing beds, has gone up steadily.
"It's had quite a significant blip this year," he said.