Health authorities are taking new steps to stop an outbreak of strep A from spreading in northern Ontario, where it has killed three people this year.

A strain of invasive Group A streptococcus called EMM-59 has been moving east across the country since it was first reported in British Columbia in 2006.

In the past six months, 15 new cases have been reported in Thunder Bay, bringing the total number of cases there to 90 since August 2007, according to the Thunder Bay District Health unit.

In the past few weeks, two more people have died, bringing the number of fatalities since August 2007 to 13. Normally, there would be one or two deaths in that time, said Lee Sieswerda, an epidemiologist with the health unit. 

The majority of cases are among aboriginal people, the homeless, injection-drug users and people whose immune systems may already be compromised. Reaching out to these groups is often a challenge, said health unit outreach nurse Becky Opyc.

"They're not trusting of the health care system," said Opyc. "What we are trying to do really is break down some of those barriers and bring the care to them."

Twice a week, public health nurses roam the streets in the target areas where the need is greatest. They may take someone's blood pressure, draw blood to test for infectious diseases, and warn people who are showing symptoms of strep A to seek help. 

"It's spread in the same way as strep throat or flu or those other kinds of respiratory type illnesses, but the reason why it goes on to invasive Group A strep is not always easy to identify," Sieswerda said.

The district health unit has implemented a tracing program to identify those who came in contact with those infected, which has helped up somewhat, he added.

There is no vaccine for Group A strep. The only way to treat it is with antibiotics that provide some short-term protection.