Thank you, Mr. Chair.
I'd like to thank the members of the Standing Committee on Health for having invited me to appear in connection with its study on public health and the prevention of childhood illnesses.
I'm a pediatrician, infectious diseases microbiologist, and clinician investigator at the Centre hospitalier universitaire Sainte-Justine, and a full professor of microbiology and pediatrics at the Université de Montréal. I also hold the Canada Research Chair in Infection Prevention and Control: from Hospital to Community, a tier 1 chair.
I'm the director of the POPCORN network, which the Canadian Institutes of Health Research funded in 2022 for a two-year period. The purpose of the network is to make it possible to monitor the progress of a child's care in Canada's 16 pediatric hospitals with a view to strengthening national infrastructure, expertise and human capital in pediatric research, and studying the repercussions of interventions or events on the mental health and development of children in Canada.
The Canadian Institutes of Health Research had asked the network to study the impact of COVID‑19 on children, and an initial national conference is scheduled in May 2023 to communicate preliminary results and plan the next steps.
I acquired my expertise as a clinician and researcher in the field of infection prevention and vaccination. I will therefore focus on these areas, to avoid hearing my children say, “Stay in your lane, mom.”
Although we all take vaccination for granted and have the impression that vaccine-preventable diseases are a thing of the past, it's important to realize the extent to which today's world is still experiencing a resurgence of illnesses that we thought had disappeared.
One example is poliomyelitis. Until last year, no one would have thought that a case might occur in the state of New York. But wastewater surveillance, here and elsewhere, has shown that the virus is being shed and that in the absence of vaccination, people are still exposed to the risk of infection. Most of us are too young to remember the harm caused by polio, and the deaths and paralysis suffered by children who had otherwise been in perfect health.
Similarly, measles is still affecting people, even in developed countries, when the vaccination rate falls below 95%. Almost 20,000 people were recently exposed to a case of measles in Kentucky. There is a risk that a case could enter the country, and young children are most at risk of experiencing a serious illness as a result.
Why is immunization coverage so low? In 2019, a survey of immunization coverage by the Institut national de santé publique du Québec showed that by the age of 15 months, approximately 95% of children had received all their vaccinations against poliomyelitis, measles and pneumococcal diseases. However, the vaccination records show that immunization coverage for measles is closer to 85%. The actual figure is likely somewhere between the two, but the assessment of how the pandemic affected immunization coverage remains to be carried out.
It would appear that concerns about the efficacy and safety of COVID‑19 vaccines probably eroded the confidence of some parents in other vaccines that have been used for decades. This trust needs to be restored or we risk seeing a resurgence of these vaccine-preventable diseases and all the complications that come with them: meningitis, encephalitis, deafness, long-term side effects and deaths. Infectious diseases are also democratic: they will affect everyone, but will have more of an impact on those who are medically and socio-demographically most vulnerable. Health inequities are also reflected in infectious diseases.
A child who goes to a day care is expected to catch 8 to 12 colds a year. The pandemic led to the reappearance of many different respiratory viruses, the end result of which was a significant increase in secondary bacterial infections, such as orbital cellulitis, mastoiditis, pulmonary abscess, meningitis and intracranial abscess.
To date, the antibiotic resistance of these bacteria has remained relatively stable in Canada, but inappropriate use of antibiotics, the difficulty of diagnosing and differentiating a viral infection from a bacterial infection, combined with globalization, could be a threat to treatments that we now take for granted.
Antibiotic resistance is potentially the next pandemic we will have to face. Not only that, but more and more studies are beginning to reveal a link between exposure to various environmental contaminants and lowered immune response. This research needs to be continued from the standpoint of a concept based on a “one health” approach that promotes an integrated, systemic and unified approach to human, animal and environmental health.
Efforts are currently being made to determine whether the recent increase in viral infections is due simply to a cohort effect, with serious bacterial infections simply the outcome of the larger number of viral infections in circulation, or rather due to the emergence of more virulent bacterial clones.
It's therefore critical to establish surveillance programs, including genomic surveillance, for infectious diseases across Canada.
One of the cornerstones of infection prevention is ensuring that measures introduced do not cause any serious collateral damage. The subtleties involved are often difficult to communicate to the public. Research and evaluation are therefore essential in support of public health decisions. The POPCORN platform could answer these questions, but the best option would have been to factor in and assess child health earlier on during the pandemic.
I'll conclude by saying that it's impossible to overstate the importance of infection prevention, as well as the data and research required to maintain the current health status of children. More investment in this key sector would save lives and public funds.
It's important for us to understand and measure the impact of the pandemic on immunization coverage and to restore parental confidence, where needed, by using open and valid data.
It will be important to ensure that effective surveillance programs, including genomic surveillance programs, can measure the burden of infectious diseases and vaccine-preventable diseases, and to make the results available to everyone.
It's essential to make sure that children's health is factored into research priorities and that there is more than just short-term funding for networks.
The resources and measures required to prevent the emergence of antibiotic resistance must be allocated.
The “One Health” concept needs to be promoted in health decision-making and research with respect to children.
Thank you for your attention.
I'd be happy to answer your questions.