An unprecedented spike in a rare phenomenon called "thunderstorm asthma" was reported in Melbourne, Australia on November 21, 2016 after wild storms swept through the region, abruptly ending one of the city's hottest days of the year. By the day's end, two people have died, but the number might still rise.
Victoria State Emergency Service received more than 350 calls for assistance after severe storms swept through the region around 18:00 local time, ripping off roofs of houses and damaging cars. The event, however, has also churned up pollen, dust and other irritants in the air, causing a big spike in calls to Ambulance Victoria.
Within 5 hours, between 18:00 and 23:00 local time, the ambulance received nearly 2 000 calls, compared with an average of 345 calls for that period. Most of the calls came from Melbourne's west.
The demand was so great that Ambulance Victoria ran out of ambulances and had to call in police officers, firefighters, non-emergency patient vehicles and field doctors trained for disasters to help with transporting acutely ill patients to the hospital, The Age reported.
"I think a spike in calls would be the understatement of a century," said Ambulance Victoria's State Health Commander Paul Holman. "Every ambulance and ambulance manager was recalled."
"It was an unprecedented night. I have never seen the computer dispatch of Melbourne look like it. It was what we call a sea of red," Holman said.
On a normal night, Holman added, there would be 10 - 20 cases waiting mostly with low or middle priority levels, but these were all quite sick patients, most of them code ones or top-priority emergencies.
"We essentially had a day's workload within five hours," said Ambulance Victoria's Executive Director Emergency Operations Mick Stephenson.
"We were seeing asthma in people who had not experienced breathing issues before," Stephenson added.
Stephenson confirmed that two patients in the west of the city had died, including a 20-year-old. It is believed that ambulances were not able to reach them in time. (Update: On November 23, ABC reported 4 deaths have been attributed to the event.)
A number of hospitals came very close to running out of asthma spray Ventolin.
The last major case of thunderstorm asthma in Melbourne was in 2011, but it was not nearly as bad as this one. Before that, major thunderstorm asthma incident was reported in 1989.
Holman said the cases always occurred in November.
Jill Hennessy, Victoria's health minister, said there would be a full review of what occurred on Monday night and what the clinical outcomes were.
The phenomenon has occurred in other parts of Australia since it was first described in 1987, with south-eastern Australia particularly vulnerable, and in other parts of the world, including England and Italy.
The Guardian talked with a botanist and pollen expert from the University of Melbourne, Ed Newbigin, who said that thunderstorm asthma was a rare and little-understood phenomenon.
“One of the reasons we know about thunderstorm asthma in Melbourne is we have a pollen count here, so we can make associations between pollen and these events,” he said.
“We have had a high pollen count in Melbourne causing hayfever, but grass pollen is usually too big to get into the lungs to cause asthma,” Newbigin said.
“What we think happens is with a thunderstorm you have particularly strong winds causing all that pollen which settled during the day to get back into the air and the moisture in those winds is causing the pollen to rupture into smaller pieces and those small fragments are then small enough to get into lungs.”
But Newbigin said thunderstorms and high pollen counts coincided most years, but did not always trigger a mass asthma event. “So something else is happening here that we don’t understand,” he said. “But they’re such infrequent events they’re hard to research.”
In an article written for The Conversation in 2011, Megan Howden, who is an advanced trainee in respiratory medicine at Austin Health, said that that thunderstorm asthma commonly affects young adults with a history of hay fever but not necessarily of asthma. And of those with a previous diagnosis of asthma, many claimed it wasn’t severe enough to warrant preventer medication.
After the Wagga Wagga thunderstorm asthma epidemic in October 1997, researchers compared the data of those who experienced a thunderstorm asthma attack with those who had an asthma attack on other days of the year (the control group). They found that 95% of those affected by thunderstorm asthma had a history of hay fever and 96% tested positive to grass pollen allergies.
Of those with a history of asthma, only one in four (27%) of affected cases were taking regular preventer inhalers compared with more than half (56%) of the control group.
This suggests that regular use of asthma preventer medication, at least during spring, may protect those with asthma and grass allergies from thunderstorm asthma attacks.
Residents told media that yesterday's winds were similar to a tornado. "It ripped through and it was very quick. There was a lot of air pressure," one resident said.
The maximum recorded temperature in Melbourne on November 21 was 35 °C (95 °F), but the city is expected to cool down to a maximum of 17 °C (62.6 °F) on the 22nd and 18 °C (64.4 °F) on the 23rd.
Featured image: Lightning storm over Melbourne, Australia on January 15, 2014. Credit: Chris Phutully