Increased Invasive Group A Streptococcal Disease in Ontario

Advisory Alert

May 25, 2023

*Cette information est seulement disponible en anglais.

To: Local Health System Partners


The Ministry of Health is closely monitoring invasive Group A Streptococcal Disease (iGAS) trends in Ontario and is requesting that health care providers be alert for the signs and symptoms of iGAS in patients. Please see the attached memo from Dr. Barbara Yaffe, Associate Chief Medical Officer of Health.

Group A Streptococcus is a common cause of bacterial infections including strep pharyngitis, impetigo, scarlet fever, and cellulitis. Although uncommon, iGAS can occur and quickly progress leading to serious conditions such as streptococcal toxic shock syndrome, sepsis, soft tissue necrosis, meningitis, and pneumonia. Manifestations preceeding the onset of iGAS vary, however, symptoms may include the the following.

Recently, Ontario identified an increase in iGAS cases among all age groups, where rates of illness are highest among children aged 0 – 4 years old as well as 65 years of age and older. Individuals at increased risk of iGAS include those age 0 – 4 years old, older adults, pregnant and postpartum individuals, people who are immunocompromised, individuals experiencing homelessness, people who use injection drugs, and those with chickenpox.


If iGAS is suspected, the health care provider must obtain appropriate specimens for routine bacterial culture or DNA detection by nucleic acid amplification testing. See further testing guidance on Public Health Ontario’s website.

Note: If an individual meets provincial iGAS case definition, the health care provider must immediately report the case to their local Public Health Unit, for case and contact management purposes. See the Diseases of Public Health Significance reporting process on Public Health Sudbury & Districts’ website

Case Management

In addition to implementing routine infection prevention and control practices, contact and droplet precautions should be in effect for iGAS cases until 24 hours after beginning and complying with appropriate antimicrobial therapy. For severe cases of iGAS, clinical management involves supportive treatment, antimicrobials, and measures to minimize or neutralize the effects of toxin production when indicated. Early diagnosis and aggressive management can be critical. For more information on the management of iGAS cases visit Public Health Agency of Canada’s website.

Contact Management

The following individuals are considered close contacts of iGAS cases as per the Infectious Disease Protocol Appendix 1.

  1. Household contacts of a case who have spent at least 4 hour/day on average with the case in the previous 7 days.
  2. Non-household persons who share the same bed with the case or had sexual relations with the case.
  3. Persons who have had direct mucous membrane contact with the oral or nasal secretions of a case, such as mouth to mouth resuscitation, open mouth kissing, or unprotected direct contact with an open skin lesion of the case.
  4. Individuals who use injection drugs and have shared needles with a case.

Public Health follows-up directly with all close contacts to provide direction to monitor for signs and symptoms of iGAS and to seek medical attention immediately if any develop within 30 days after their exposure to a case. Public Health notifies close contacts and their health care providers directly when chemoprophylaxis is recommended. Chemoprophylaxis, when indicated, should be administered as soon as possible and up to 7 days after the last contact with an infectious case. For more information on the management of iGAS contacts visit Public Health Agency of Canada’s website.

Information about Group A Streptococcal disease is also available on Public Health Sudbury & Districts’ website or by contacting our Control of Infectious Diseases program via 705.522.9200, ext. 772 or toll-free at 1.866.522.9200.


Original Signed By

Dr. Marlene Spruyt

Acting Medical Officer of Health
On behalf of Dr. Penny Sutcliffe Medical Officer of Health and Chief Executive Officer

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This item was last modified on May 25, 2023