New strep strain moving east across Canada

A new strain of streptococcal bacteria infection contributed to the deaths of 10 people in northwestern Ontario over the past year, public health experts said Thursday.

About half of the 75 cases of Group A streptococcal infection that have been reported since August 2007 in the Thunder Bay area involved the new strain, called EMM-59, said Lee Sieswerda, an epidemiologist with the Thunder Bay District Health Unit. 

The strain appears to be no more likely to cause highly invasive, potentially lethal cases of strep, compared with established strains of Strep A, Sieswerda said.

The EMM-59 strain has been moving east from British Columbia since 2006 and could migrate farther east by the end of October or November, said Dr. Donald Low, chief microbiologist at Toronto's Mount Sinai Hospital.

"We've seen it in Western Canada, we're seeing it move east," Low said.

"There's a lot of movement of individuals from city to city, so there may well be an opportunity for this thing to hitchhike along with somebody and be introduced into a new community of individuals that are susceptible.

"It's speculation, but it's something that we're going to look out for."

The EMM-59 strain is not a major risk to public health since it is rare, Low told CBC News.

No need to panic 

Since 2000, it has infected 300 people in Canada, including the 75 in Thunder Bay, he added. 

At a news conference Wednesday, public health officials in Thunder Bay stressed the risk to the general public is low. 

The 10 deaths occurred among high-risk individuals, such as intravenous drug users, the homeless, those living in crowded and unhygienic conditions and those with chronic illnesses.

About one-third of those infected have shown severe symptoms of infection including pneumonia, meningitis and flesh-eating disease, Sieswerda said.

There is no need for healthy people to panic but there is reason to be concerned, said Sieswerda,  noting the region normally has six reported cases a year and one death.

"Alarming the general public is not something we really want to get in to," said Sieswerda. "We are doing it now because we haven't been able to follow up on every single contact and we'd like people to identify themselves."

Reaching contacts

Public health officials are trying to contact people who have been in close contact with someone infected, including household members, sexual partners and those who share needles, since the disease spreads through close contact with mucous membranes such as the eyes, nose and mouth.

So far, the outbreak is localized and not part of a national trend, said Ken Allan, director of health protection with the Thunder Bay District Health Unit.

Health officials from Thunder Bay got in touch with the Ontario Ministry of Health and Longterm Care in May to seek help investigating the outbreak.

"In this case, for instance, we helped to deploy a couple of federal field epidemiologists in [the Thunder Bay] area to help with the investigation," said Mark Nesbitt, a spokesperson for the ministry.

"We've also had a lot of teleconferences with [Thunder Bay's] public health unit and provincial and national laboratories, all sorts of other people who are involved in the tracking and care of this situation."

The decision to go public with information about outbreaks is generally made at the local level by public health units and hospitals, Nesbitt said.

Health officials in Thunder Bay did not alert the public earlier since there is no mass vaccination or preventive measures available to combat an outbreak, Sieswerda said.

Public health officials are asking people to take the following steps:

• If you are in close contact with a person who has recently had invasive Group A streptococcal infection, seek out preventive antibiotics from a physician or nurse practitioner.
• Take care of wounds to prevent infection.
• If you are concerned about a wound that becomes increasingly swollen and very painful over a period of hours or days, see a health-care professional right away.
• Make sure all antibiotic treatments are completed as advised by a physician or pharmacist.
• Wash your hands regularly.
• Make sure your immunizations are up to date, including the annual flu shot.

Group A streptococcal bacteria are commonly found in the throat and on the skin.

The infection is caused by the same bacteria responsible for strep throat. In rare cases, the bacteria can invade body tissues.