Corrigendum: Second malignant neoplasms within 5 years from first primary diagnosis in pediatric oncology patients in Canada: a population-based retrospective cohort study.

[This corrects the article DOI: 10.3389/fonc.2024.1376652.].

Second malignant neoplasms within 5 years from first primary diagnosis in pediatric oncology patients in Canada: a population-based retrospective cohort study.

Introduction: From the advancement of treatment of pediatric cancer diagnosis, the five-year survival rate has increased significantly. However, the adverse consequence of improved survival rate is the second malignant neoplasm. Although previous studies provided information on the incidence and risk of SMN in long term survivors of childhood cancer, there is still scarce information known for short term (< 5 years) prognosis. This study aims to assess the incidence, characteristics, management, and outcome of children who develop SMN malignancies within 5 years of diagnosis of their initial cancer. Method: This is a retrospective cohort study of early Second Malignant Neoplasms (SMN) in pediatric oncology patients. The Cancer in Young People - Canada (CYP-C) national pediatric cancer registry was used and reviewed pediatric patients diagnosed with their first cancer from 2000-2015. Results: A total of 20,272 pediatric patients with a diagnosis of a first malignancy were analyzed. Of them, 0.7% were diagnosed with a SMN within the first 5 years following their first cancer diagnosis. Development of a SMN impacted survival, shown by an inferior survival rate in the SMN cohort (79.1%) after three years compared to that of the non-SMN cohort (89.7%). Several possible risk factors have been identified in the study including the use of epipodophyllotoxins, exposure to radiation, and hematopoietic stem cell 169 transplant. Discussion: This is the first national study assessing the incidence, 170 characteristics, risk factors and outcome of early SMN in Canadian children 171 from age 0-15 from 2000-2015.

Mumps resurgence in a highly vaccinated population: Insights gained from surveillance in Canada, 2002-2020.

Although mumps vaccination has been routine in Canada for decades, mumps cases and outbreaks continue to occur periodically. Mumps surveillance, including monitoring of the mumps virus genotype associated with disease activity, is important to document baseline activity and to advance further research into vaccine effectiveness. Here we describe a detailed analysis of mumps cases that have been detected in Canada from 2002 to 2020, with a focus on the mumps molecular epidemiology. In total, 7395 cases of mumps were reported to the surveillance system, with outbreaks occurring in the years 2007, 2010 and 2016 to 2018. Adolescents and young adults aged 15 to 29 years had the highest risk of being a case (rate ratios ranging from 1.50 to 2.29), compared to adults aged 30 to 39. Genotypes of mumps viruses were determined in 3225 specimens. Genotype G was predominantly detected (96% of genotyped specimens) and was first reported in 2005. Other genotypes were more likely to be detected in cases that also reported travel (or were linked to imported cases) than the cases with genotype G detected (p < 0.0001). The genotype G viruses had little sequence diversity in the 316 nucleotide window used for genotyping (the small hydrophobic protein gene) and mainly belonged to a single phylogenetic lineage that included the MuVi/Sheffield.GBR/1.05 reference sequence. The analysis of over ten years of data has demonstrated that mumps genotype G, specifically belonging to a single lineage, the Sheffield lineage, is the endemically circulating virus in Canada. This lineage is seen also in other countries using the genotype A vaccine. Mumps remains endemic despite high MMR vaccination coverage which has been sufficient to eliminate circulation of measles and rubella in Canada, raising the hypothesis of the evolution towards a vaccine escape mumps virus.

Accuracy of administrative database algorithms for autism spectrum disorder, attention-deficit/hyperactivity disorder and fetal alcohol spectrum disorder case ascertainment: a systematic review. / Exactitude des algorithmes des bases de données administratives pour la détermination des cas de trouble du spectre de l'autisme, de trouble du déficit de l'attention/hyperactivité et de trouble du spectre de l'alcoolisation fœtale : revue systématique.

INTRODUCTION: The purpose of this study was to perform a systematic review to assess the validity of administrative database algorithms used to identify cases of autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD) and fetal alcohol spectrum disorder (FASD). METHODS: MEDLINE, Embase, Global Health and PsycInfo were searched for studies that validated algorithms for the identification of ASD, ADHD and FASD in administrative databases published between 1995 and 2021 in English or French. The grey literature and reference lists of included studies were also searched. Two reviewers independently screened the literature, extracted relevant information, conducted reporting quality, risk of bias and applicability assessments, and synthesized the evidence qualitatively. PROSPERO CRD42019146941. RESULTS: Out of 48 articles assessed at full-text level, 14 were included in the review. No studies were found for FASD. Despite potential sources of bias and significant between-study heterogeneity, results suggested that increasing the number of ASD diagnostic codes required from a single data source increased specificity and positive predictive value at the expense of sensitivity. The best-performing algorithms for the identification of ASD were based on a combination of data sources, with physician claims database being the single best source. One study found that education data might improve the identification of ASD (i.e. higher sensitivity) in school-aged children when combined with physician claims data; however, additional studies including cases without ASD are required to fully evaluate the diagnostic accuracy of such algorithms. For ADHD, there was not enough information to assess the impact of number of diagnostic codes or additional data sources on algorithm accuracy. CONCLUSION: There is some evidence to suggest that cases of ASD and ADHD can be identified using administrative data; however, studies that assessed the ability of algorithms to discriminate reliably between cases with and without the condition of interest were lacking. No evidence exists for FASD. Methodologically higher-quality studies are needed to understand the full potential of using administrative data for the identification of these conditions.

Obstetric and perinatal health outcomes after pertussis vaccination during pregnancy in Ontario, Canada: a retrospective cohort study.

BACKGROUND: In February 2018, Canada's National Advisory Committee on Immunization recommended maternal vaccination with tetanus-diphtheria-acellular pertussis (Tdap) vaccine during pregnancy to prevent severe pertussis infection in young infants. This study assessed the relation between maternal Tdap vaccination and obstetric and perinatal outcomes in Ontario. METHODS: We performed a population-based cohort study of all births from April 2012 to March 2017 using multiple linked health administrative databases. We used Cox regression with a time-dependent exposure variable to estimate adjusted hazard ratios (HRs) for preterm birth (< 37 wk), very preterm birth (< 32 wk) and stillbirth. We assessed remaining outcomes (gestational hypertension, chorioamnionitis, postpartum hemorrhage, severe postpartum hemorrhage, being small for gestational age, neonatal intensive care unit stay > 24 h, composite neonatal morbidity) using log-binomial regression to generate adjusted risk ratios (RRs). We adjusted estimates for potential confounding using propensity score weighting. RESULTS: Of 615 213 infants (live births and stillbirths), 11 519 were exposed to Tdap vaccination in utero. There was no increased risk for preterm birth (adjusted HR 0.98, 95% confidence interval [CI] 0.91-1.06), very preterm birth (adjusted HR 1.10, 95% CI 0.86-1.41), stillbirth (adjusted HR 1.15, 95% CI 0.82-1.60) or being small for gestational age (adjusted RR 0.96, 95% CI 0.90-1.02). The risks of a neonatal intensive care unit stay exceeding 24 hours (adjusted RR 0.82, 95% CI 0.76-0.88) and neonatal morbidity (adjusted RR 0.81, 95% CI 0.75-0.87) were decreased. There was no association with chorioamnionitis (adjusted RR 1.17, 95% CI 0.99-1.39), postpartum hemorrhage (adjusted RR 1.01, 95% CI 0.91-1.13) or severe postpartum hemorrhage (adjusted RR 0.79, 95% CI 0.55-1.13), but we observed a reduced risk of gestational hypertension (adjusted RR 0.87, 95% CI 0.78-0.96). INTERPRETATION: Our results complement evidence that maternal Tdap vaccination is not associated with adverse outcomes in mothers or infants. Ongoing evaluation in Canada is needed as maternal Tdap vaccination coverage increases in coming years.

Health Outcomes in Young Children Following Pertussis Vaccination During Pregnancy.

BACKGROUND AND OBJECTIVES: Maternal immunization with tetanus, diphtheria, and acellular pertussis vaccine (Tdap) is routinely recommended in many countries as a strategy to protect young infants against severe pertussis infection; few studies have assessed whether prenatal exposure to the vaccine is associated with any longer-term adverse health effects in children. We evaluated the long-term safety of exposure to Tdap vaccination during pregnancy. METHODS: Population-based retrospective cohort study conducted in Ontario, Canada using multiple linked province-wide health administrative databases. All live births between April 2012 and March 2017 were included, and children were followed for up to 6 years to ascertain study outcomes. Children exposed to prenatal Tdap were propensity score matched to unexposed children at a 1:5 ratio. Tdap vaccination during pregnancy was ascertained by using vaccine-specific fee codes. Immune-related (infectious diseases, asthma) and nonimmune-related (neoplasm, sensory disorders) outcomes and a nonspecific morbidity outcome (urgent or inpatient health service use) were evaluated from birth to end of follow-up. RESULTS: Of 625 643 live births, 12 045 (1.9%) were exposed to Tdap in utero. There were no significant increased risks of adverse childhood outcomes and prenatal Tdap exposure; however, we observed inverse associations (adjusted incidence rate ratio [95% confidence interval]) with upper respiratory infections (0.94 [0.90-0.99]), gastrointestinal infections (0.85 [0.79-0.91]), and urgent and inpatient health service use (0.93 [0.91-0.96]). CONCLUSIONS: Exposure to Tdap vaccination in pregnancy was not associated with any increased risk of adverse health outcomes in early childhood, supporting the long-term safety of Tdap administration in pregnancy.

Multisystem inflammatory syndrome in children in Canada.

This article provides a summary of the epidemiology of multisystem inflammatory syndrome in children (MIS-C) cases reported nationally in Canada by provincial and territorial health authorities. Multisystem inflammatory syndrome in children is a post-viral inflammatory syndrome that temporally follows coronavirus disease 2019 (COVID-19). Symptoms may include fever, abdominal pain, vomiting, diarrhea, skin rash and other signs of inflammation. In Canada, MIS-C is rare, with 269 cases reported to the Public Health Agency of Canada between March 11, 2020 and October 2, 2021. One hundred forty-two (53%) of these cases were lab-confirmed COVID-19 cases or epidemiologically-linked with COVID-19 cases. Cases have been reported in infants as young as one week to youth as old as 18 years, with a median age of six years. Cases were more likely to occur in males than females (58% vs 42%, respectively; p=0.006). Almost all MIS-C cases (99%) required hospitalization and 36% required intensive care unit admission. No deaths have been reported to date. The time trend of MIS-C aligns with the incidence rate time trend of COVID-19 reported in children, with a two to six-week lag.