Pediatric Infectious Disease and the Fall Respiratory Season

Advisory Alert

September 15, 2023

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To: Local Health System Partners


With the start of a new school year, Public Health Sudbury & Districts would like to highlight important considerations in pediatric infectious disease surveillance as we approach the 2023/2024 respiratory season.

Acute Respiratory Infections

During the respiratory season there can be several respiratory pathogens circulating with similar clinical presentations.

Pertussis is one acute respiratory infection that tends to be underdiagnosed due to the relatively non-specific nature of the clinical presentation. Pertussis should be considered if clients present with clinically compatible signs and symptoms, including:

Given the similarity in clinical presentations, some infectious diseases may be difficult to differentiate. For varicella (chickenpox), the signs and symptoms can appear similar to those for impetigo or scabies. When it comes to varicella in children, the first sign of disease is often a pruritic rash but can also include a fever, fatigue, mild headache, chills, and muscle or joint aches. Within 1-2 days, children will typically develop a maculopapular rash on the scalp and face which can quickly spread down the body to the arms and legs. The generalized rash will then progress to a vesicular rash that later crusts, producing granular scabs in 4-5 days.

Like routine childhood immunizations, such as those for pertussis and varicella, COVID-19 and influenza vaccines are highly effective in reducing the incidence of severe infection. Information regarding the 2023 fall immunization campaign, which will include vaccines for protection against both influenza and COVID-19, is expected to be released by the Ministry over the next few weeks.  For further information related to immunization, visit Public Health Sudbury & Districts’ Vaccines (immunizations) webpage or call the Vaccine Preventable Diseases Team at 705.522.9200 ext 458.

The Ministry of Health COVID-19 self-assessment tool remains an important resource for individuals to assess symptoms of illness and receive recommendations for testing and treatment if eligible, as well as measures to avoid infecting others, including self-isolation as appropriate.

Invasive Group A Streptococcal Disease

Since the COVID-19 pandemic, we have observed several atypical trends in infectious diseases across Ontario. Currently, the Ministry of Health is closely monitoring the increased incidence of invasive Group A Streptococcal disease (iGAS) cases in Ontario. Throughout 2023, an increased incidence of iGAS cases has been observed with the highest rates observed among those aged 0 – 4 years old and 65 years and older. Most northern public health units have a higher rate of iGAS than the non-northern public health units combined. Public Health Sudbury & Districts is among the health units that have a higher rate in the current season compared to the five pre-pandemic seasons.

Group A streptococcus is a common cause of bacterial infections including streptococcal pharyngitis, impetigo, scarlet fever, and cellulitis. Although uncommon, iGAS can occur and quickly progress leading to serious conditions.

The proportion of pediatric iGAS cases with a fatal outcome in Ontario was higher in the 2022-2023 iGAS season (7.5%) than in the five, iGAS pre-pandemic seasons (5.1%). Among recent pediatric iGAS cases with fatal outcomes, most were under the age of 10. Clinical presentations preceding iGAS disease in these cases, in order of most to least common, included vomiting, sore throat, and cough.

It is important to note that clinical presentations preceding iGAS disease vary. Health care providers should be alert to the following symptoms as well:

Among recent pediatric iGAS cases with fatal outcomes, the most common clinical presentations, in order from most to least common, include sepsis, acute respiratory distress syndrome, and hypotension. iGAS can also lead to other serious conditions including streptococcal toxic shock syndrome, soft tissue necrosis, meningitis, and pneumonia.

For pediatric iGAS cases with fatal outcomes occurring in Ontario from October 2022 to July 2023, the time observed between symptom onset and hospitalization (median 2 days), as well as death (median 4 days), has been very short. The most common risk factors reported among these cases were chronic illness/underlying medical condition, and recent streptococcal infection reported. Additional risk factors that health care providers should be alert to include:

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

Note: If an individual meets provincial iGAS case definition, health care providers 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.

Early diagnosis and diligent management of iGAS cases can be critical. For more information on the management of iGAS cases visit Public Health Agency of Canada’s website.

Testing and Reporting

For testing information on group A streptococcus, varicella, and other diseases of public health significance, visit Public Health Ontario’s Test Information Index.

To report a disease of public health significance, complete the communicable disease notification form (PDF, 210 KB) and fax or email the form to 705.677.9618 or Diseases of public health significance must be reported to the local Medical Officer of Health in accordance with Ontario Regulation 135/18 and amendments under the Health Protection and Promotion Act.

For further information regarding acute respiratory infections and diseases of public health significance or how to report, please visit Public Health Sudbury & Districts – Health Professionals (  or contact our Control of Infectious Diseases program at 705.522.9200, ext. 772 (toll-free 1.866.522.9200).


Original Signed By

Dr. Penny Sutcliffe
Medical Officer of Health and Chief Executive Officer

NOTE: All Advisory Alerts are found on our website.

This item was last modified on September 15, 2023