This analysis found increased incidence rates of several symptoms and conditions during the 31–365 days after a diagnosis of COVID-19 among children and adolescents aged 0–17 years. The highest aHRs were associated with potentially serious conditions, such as acute pulmonary embolism, myocarditis and cardiomyopathy, venous thromboembolic event, acute and unspecified renal failure, and type 1 diabetes. These conditions with the highest aHRs were rare or uncommon among children and adolescents in this analysis. Some of the study's findings are consistent with previous evidence of elevated risk for new onset of diabetes, myocarditis, and certain symptoms, whereas other conditions (acute pulmonary embolism, venous thromboembolic event, acute renal failure, coagulation and hemorrhagic disorders, and cardiac dysrhythmias) have not been previously reported as post-COVID conditions among children and adolescents.
Several symptoms and conditions (respiratory signs and symptoms, mental health symptoms and conditions, neurological conditions, muscle disorders, and sleeping disorders) were less likely to occur among patients with COVID-19 than among patients without COVID-19. Reasons for these observed associations are likely multifactorial, and might be, in part, because patients without COVID-19 were selected from a cohort of patients with a health care encounter possibly related to COVID-19 and were less healthy than were patients with COVID-19 at baseline. Although most of the symptoms and conditions selected for the analysis were based on those observed in previous post-COVID studies, they are not unique to patients with a history of COVID-19, and many are common among children and adolescents. A United Kingdom study found a high prevalence of poor mental health and wellbeing among all children and adolescents aged 11–17 years during the pandemic, but no difference among those with positive and negative SARS-CoV-2 test results. Respiratory signs and symptoms were less likely to occur among patients with COVID-19 than among those without in the main cohort. The opposite result was found in a subset of children aged 2–4 years and in a cohort of children and adolescents with no previous symptoms or conditions of interest; new respiratory signs and symptoms were more likely to occur among children and adolescents who had COVID-19, compared with those without a history of COVID-19.
The findings in this report are subject to at least seven limitations. First, the definitions of potential post-COVID symptoms and conditions are subject to misclassification bias because the symptoms and conditions were defined by a single ICD-10-CM code and no information on laboratory assessments or degree of severity was available. Second, because the incidence date of a symptom or a condition was based on the first occurrence of the ICD-10-CM code, the actual incidence date of that symptom or condition might have occurred prior to COVID-19. Third, patients infected with SARS-CoV-2 without a documented COVID-19 diagnosis or positive test result might have been misclassified as not having had COVID-19, potentially reducing the magnitude of observed associations. Fourth, the aHR estimates might be reduced because patients without COVID-19 were patients with a health care encounter possibly related to COVID-19. Fifth, because patients' vaccination status was likely underreported in this dataset, this analysis was not adjusted for previous receipt of COVID-19 vaccines. Sixth, although this study relied on statistical significance for interpreting the increased rates of symptoms and conditions, further understanding of the clinical significance of the observed associations, including whether these symptoms and conditions are transient or chronic, is necessary. Finally, generalizability might be limited because the analysis was restricted to children and adolescents aged 0–17 years included in a medical claims database, approximately 70% of whom were enrolled in Medicaid managed care; therefore, findings are not necessarily representative of all children and adolescents with COVID-19 or of those who do not seek health care.
These findings can be used to apprise health care professionals and caregivers about new symptoms and conditions that occur among children and adolescents in the months after SARS-CoV-2 infection. COVID-19 prevention strategies, including vaccination for all eligible persons aged ≥6 months, are critical for preventing SARS-CoV-2 infection and subsequent illness and for reducing the public health impact of post-COVID symptoms and conditions.
Members of the Data, Analytics, and Visualization Task Force, CDC COVID-19 Emergency Response Team; Matthew Oster, Center on Birth Defects and Developmental Disabilities, CDC; John R. Pleis, Division of Research and Methodology, National Center for Health Statistics, CDC.
Morbidity and Mortality Weekly Report. 2022;71(31):993-999. © 2022 Centers for Disease Control and Prevention (CDC)