Scarlet fever — also called scarletina — was known as a fatal illness in the 19th century.
The sickness caused thousands of deaths in the Victorian Era among North Americans and the British until antibiotics were created in the early 20th century.
But Public Health England (PHE) is warning that the disease is once again spiking in the country. There have been 6,225 cases reported since September 2017, compared to 3,764 during the same time last year, the organization said in a press release.
“This increasing trend is in line with usual patterns although cases are currently higher than those reported at this point in the last 4 seasons,” the PHE statement read.
Here’s what the increase in cases across the Atlantic Ocean means for Canadians:
What is scarlet fever?
Scarlet fever is caused by group A streptococcus (GAS), which is a bacteria found in the throat and skin.
The symptoms include a red, sore throat, red and dry rashes, swollen glands, and a swollen tongue. Health Canada notes these symptoms usually begin one to four days after exposure to the bacteria.
WATCH: 8-year-old Texas boy battling brain infection doctors say was caused by flu
The illness, which most commonly occurs in children, also involves a fever of at least 38.3 C, or 101 F.
Dr. Isaac Bogoch, an infectious disease specialist at University Health Network in Toronto, explained that there are two signs that really differentiate the illness from others.
“Fever and sore throat are common, but sandpaper-like rashes and strawberry tongue are really the hallmarks of scarlet fever. That’s where scarlet fever gets its name from.”
Some less common signs of the illness include headaches, nausea, vomiting, and body aches. Untreated, extreme cases may result in some forms of heart disease and kidney damage.
Spike in cases unexplained
Bogoch explained that the illness has actually been rising for years in several countries including the U.K., U.S. and Canada. But it’s still drastically less common than it was in previous centuries.
While cases are spiking in the U.K., there was a rise in scarlet fever in Hong Kong about seven years ago.
Bogoch explained that research hasn’t been conclusive on what’s causing these spikes.
“There’s really no information on why it’s spiking,” he said, explaining there are theories such as immunity changing as a society, particular strains that may be difficult to catch.
WATCH: Emotional meeting between strep infection survivors
Researchers quoted in a 2016 article from The Guardian were also perplexed by the illness’s recent spike.
“That was a bit of a surprise for us,” Dr. Theresa Lamagni from PHE, said of the increase. “It doesn’t seem that the bugs themselves are giving us any clues as to what is happening.”
History of scarlet fever in Canada
The Public Health Agency of Canada stopped tracking the number of scarlet fever cases in 1978 because the disease was not considered to be invasive. That means it’s difficult to say how much of a spike there has been in the country.
WATCH: 8-year-old Alberta girl suffers debilitating reaction to strep infection
Data from the final year of tracking shows that there were 23,408 reported cases in the country. A closer look at the rates of the illness shows that while there were periods of spikes in Canada’s history, it became gradually less common beginning in the mid-1930s.
Other, more invasive forms of GAS illness (referred to as iGAS), are still closely tracked because they can be deadly, Bogoch explains.
An invasive form of GAS has killed nine people in the London, Ont., area since an outbreak was declared in April 2016.
As of November 2017, the Middlesex-London Health Unit said more than 132 cases of iGAS infection had been reported. Of the more than 132 cases, 22 per cent required intensive care treatment, while 15 per cent had streptococcal toxic shock syndrome. About 15 per cent of cases had necrotizing fasciitis — or “flesh-eating” disease.
How to minimize the risk, and feel better faster
Bogoch explained that scarlet fever is spread by direct contact with an infected person.
“It is spread through direct contact, so if you are living with someone, touching the same surfaces as them,” he said.
WATCH: Why you shouldn’t be concerned about streptococcal infection
He added that the best way to avoid catching the illness is by simply practising good hand hygiene.
But if the disease is caught, the treatment is antibiotics prescribed by a doctor. And after 24 hours of starting the medication, Health Canada says the patient will no longer be infectious.
Like any illness, scarlet fever is uncomfortable, but Bogoch says it’s not the deadly disease it used to be.
“It’s completely curable.”
— With files from 980 CFPL Radio