Question Period Note: Invasive group A streptococcus

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• The United Kingdom Health Security Agency (UKHSA) has reported an increase in invasive group A streptococcus (iGAS) in 2022, particularly in children under age 10, compared to pre-pandemic years. Over the period September 12 to December 12, 2022, 15 deaths have been reported among children diagnosed with iGAS. Of the reported deaths, 14 children were under 15 years old.
• Canada is aware of the cluster of invasive group A streptococcus in the United Kingdom. We are also aware that this is of particular concern for children, with the UK reporting 15 deaths of children with invasive group A strep since mid-September of this year.
• While this is obviously concerning, there is no evidence that a new strain is circulating or that cases of group A strep are more severe overall than in previous years.
• We are not currently recommending any special travel health precautions for visiting the UK. However, we continue to closely monitor the situation and will update travel advice as necessary.
• Most illnesses from group A strep are mild and treatable by common antibiotics, such as penicillin.
• In Canada, the incidence of invasive group A strep dropped from 8.1 cases per 100,000 people in 2019 to 6.7 per 100,000 in 2020. Preliminary data suggest that this decrease may continue through the 2021 and 2022 seasons.
• Individuals experiencing symptoms that they think may be group A strep infection, or caregivers of children with such symptoms, should seek medical attention promptly to receive appropriate antibiotic treatment.
• To prevent viral infections that may predispose people to group A strep infections, it is important to stay up-to-date with vaccinations such as those for COVID-19, chickenpox and influenza.

If pressed
• The Public Health Agency of Canada continues to work with clinicians, including pediatricians, and public health experts to support the diagnosis and treatment of group A strep in Canada.
• Many public health measures can reduce the risk of infection and spread of group A strep, such as staying at home when ill, frequent hand cleaning, covering coughs and sneezes with a tissue or bend of the arm, and cleaning and disinfecting high-touch surfaces and objects.
• With the co-circulation of many respiratory viruses this season, like COVID-19, RSV and influenza, it is recommended that people also practice other personal protective practices to reduce the risk of getting infections or spreading them to others, such as:
o Wearing a well-constructed, well-fitting mask in indoor public settings, especially if the setting is crowded or poorly ventilated, and
o Improving indoor ventilation, such as opening a window or door.

Group A streptococcal (GAS) infections are caused by a bacterium. Most illnesses from GAS are mild and can include strep throat, sinus infections, skin or wound infections, fever, or a rash. While the UK identified cases of GAS-related scarlet fever in their recent public statements, scarlet fever cases are generally mild, and often present as a distinctive pink-red rash. Scarlet fever as a specific GAS-related illness is not considered a higher risk than other associated illnesses.

GAS is spread from person to person through direct contact with nose, throat or wound secretions, or respiratory droplets. Those living in close quarters with one another, such as people living in overcrowded conditions, are at a higher risk for contracting GAS. Studies have observed that invasive bacterial diseases can occur subsequent to viral illnesses such as influenza and respiratory syncytial virus (RSV).
Occasionally, GAS can also cause severe infections. Invasive GAS (iGAS) is an infection where the bacteria are isolated from a normally sterile body site, such as the blood. iGAS can be very serious and can result in lung infections, necrotizing fasciitis (flesh-eating disease), toxic shock syndrome, or even death. Hospitalization and surgery may also be required for more severe invasive disease, depending on the individual course of the infection.

Early antibiotic treatment of group A streptococcus infections is very important to help prevent complications and progression to severe disease. As a bacterial infection, the treatment is generally with antibiotics and is guided by the specific circumstances of the case as well as laboratory culture sensitivity results, etc. In general, penicillin antibiotics are the foundation of treating group A Streptococcus.

The Canadian Pediatric Society provides guidelines for the treatment of GAS and iGAS.

Only iGAS is nationally notifiable in Canada, therefore, PHAC doesn’t collect information on mild cases, such as cases with scarlet fever.

iGAS disease is endemic in Canada with 2000-3000 cases annually in recent years. Since early 2016, several iGAS disease outbreaks have occurred across Canada in various settings, including clusters among persons experiencing homelessness.

Since iGAS became notifiable in 2000, a steady increase in the number of cases and incidence rates have been observed in Canada. Most recently, the rate has doubled from 4.2 cases per 100,000 people in 2010 to 8.1 cases per 100,000 people in 2019. Similar to what has been observed with other communicable diseases, the rate dropped (to 6.7 per 100,000 people) in 2020, likely due to pandemic restrictions. Data for 2021 and 2022 are not yet available.

• Group A streptococcus (GAS) is a bacterial infection that is common among children and adults. Typically, illness due to GAS does not become severe and it is generally treatable with common antibiotics such as penicillin.
• iGAS is the term given to the most serious form of GAS, which occurs when the bacteria get into parts of the body where they are not normally found, such as the lungs or bloodstream.
• The UKHSA has reported an increase in iGAS cases in 2022, particularly in children under the age of 10. In 2022, there were 2.3 cases per 100,000 children aged 1 to 4, compared to 0.5 cases per 100,000 on average over the pre-pandemic years 2017 to 2019. Similarly, there were 1.1 cases per 100,000 children aged 5 to 9 in 2022, compared to 0.3 cases per 100,000 on average over the pre-pandemic years 2017 to 2019.
• Currently, there is no evidence that a new strain is circulating or that cases are more severe than in previous years. According to UKHSA, the increase in iGAS cases may be due to increased susceptibility to these infections in children due to low number of cases in children during the pre-pandemic seasons, along with the current circulation of respiratory viruses.
• UKHSA is conducting investigations to determine the factors that may be contributing to this year’s increase, as well as to better understand the people who are currently most affected.
• Beyond the UK, a number of European countries (including France, Ireland, the Netherlands, Spain, and Sweden) have indicated increases in iGAS in 2022, particularly among children under 10. This was recently reflected in a risk assessment issued by the World Health Organization on December 12.
• Invasive group A strep is nationally notifiable in Canada.