CBC News has learned the Thunder Bay District and northwestern Ontario suffer a much higher rate of necrotizing fasciitis — also known as flesh-eating disease — than the rest of Ontario.

Last year, there were close to 30 cases per 100,000 people in the northwest — more than six times the average Ontario rate.

Medical officer of health Dr. David Williams said the general public is not at risk, but health officials are trying to find out why the rate is so much higher in this area.

david williams

Thunder Bay's medical officer of health Dr. David Williams said the general public is not at risk for contracting flesh-eating disease. (Nicole Ireland/CBC)

The bacterial infection tends to strike vulnerable populations like the homeless, IV drug users, and those with poor nutrition.

"We found it mostly among our homeless population. There's risk factors related to alcoholism, intravenous drug usage, [and] poor nutrition,” he said.

"Some people have some co-morbidity related with ... poorly-controlled diabetes, or with issues of post-cancer ... a number of things that seemed related to lower immune competency.”

Living in crowded conditions can also be a risk factor.

Williams said the tissue-destroying disease leads to long hospital stays, amputations, and sometimes death.

"It's nothing to be taken lightly and, even though it's a hard population group to reach, it challenged us to say, 'well, we need to be doing something about this.'"

Williams said the rate has been higher in northwestern Ontario for a few years now.

The health unit wants to study if there are ways to intervene in vulnerable populations so the infection doesn't progress, he added, and wants to work with partners like Thunder Bay Regional Health Sciences Centre, as well as Shelter House.  

How it starts

Necrotizing fasciitis is most often caused by Group A Streptococcus bacteria. The bacteria itself is common on skin and tissue and infections are usually mild or moderate, and can include infections like strep throat.

Sometimes necrotizing fasciitis progresses to an invasive state, and gets into the blood, deeper tissue, muscle or central nervous system. That's when the infection turns into the condition known as necrotizing fasciitis, and causes severe injury, damage or death.

Thunder Bay’s medical officer of health, Dr. David Williams, said the science behind the progression to necrotizing fasciitis is not fully understood, but the hypothesis is that it can start with a superficial cut that gets infected when someone doesn't have the immune system to fight it off.  To treat it, the dead tissue needs to be removed and patients are given antibiotics, Williams said.

Long hospital stays, multiple surgeries, intensive care, large amounts of drugs and medications and follow-up are often required.

Williams said the estimated hospitalization cost for one case of necrotizing fasciitis can be st $250,000 or more, so it makes financial sense to invest in prevention.

The impact on the individual is often devastating, Wlliams added. "[It] could leave them disabled, sometimes with amputations and sometimes, unfortunately ... death."