It's a common bacteria, one you may have in or on your body right now: Streptococcus Group A.

It usually causes strep throat or skin infections, but in extreme cases, the bacteria can become invasive and lead to serious illness like necrotizing fasciitis, or 'flesh-eating disease'.

That's what happened to Lindsey Hubley. The 33-year-old Halifax woman became ill just days after giving birth to her first child in early March. Her family says the infection set in quickly.

"They went into surgery and Mike was advised that this was very serious. After surgery she was put into an induced coma," says Lindsey's sister-in-law Susan Hubley.

Lindsey Hubley has been through seven surgeries. She's now out of the coma but facing many months in hospital, and more surgery and rehabilitation to come.

"I think that's going to be her biggest struggle going forward, is dealing with the resulting damage. It's a severe septic shock and what that's done to her body," says Susan Hubley.

In Winnipeg, 28-year-old Cari Kirkness thought her sore throat was just a cold. But the Strep A infection spiralled out of control, forcing doctors to amputate both her legs and one of her arms to save her life. It's a frightening, but rare outcome.

Doctors don't know for sure why Strep A affects different patients in different ways. It may have to do with the strain of bacteria, according to the Nova Scotia Health Authority's Chief of Microbiology.

"But then there's also the person, so are there features of the person that make them more at risk for severe infections," says Dr. Todd Hatchett.

So far in 2017 there have been seven cases of invasive Strep A in Nova Scotia. Three of those are considered severe.

In New Brunswick there have been five cases, with three considered severe.

The most recent numbers for a full year in Nova Scotia are for 2015, when there were 25 cases, 10 of which were severe. New Brunswick saw a spike in 2015: 41 cases, 19 considered severe.

Dr. Hatchett says these severe cases aren't a cause for panic, but anyone with signs of an infection should see a doctor.

"We do see more strep throat in the wintertime, and severe strep infections are a rare, but well-known complication of influenza,” says Dr. Hatchett.

Lindsey Hubley is not in the clear yet. As she continues to recover in hospital, a GoFundMe page in her name has raised nearly $50,000 for her young family.

With files from CTV Atlantic's Sarah Ritchie.