Long/post-COVID in children and adolescents: symptom onset and recovery after one year based on healthcare records in Germany.

PURPOSE: Evidence on the incidence and persistence of post-acute sequelae of COVID-19 (PASC) among children and adolescents is still limited. METHODS: In this retrospective cohort study, 59,339 children and adolescents with laboratory-confirmed COVID-19 in 2020 and 170,940 matched controls were followed until 2021-09-30 using German routine healthcare data. Incidence rate differences (ΔIR) and ratios (IRR) of 96 potential PASC were estimated using Poisson regression. Analyses were stratified according to age (0-11, 12-17 years), and sex. At the individual level, persistence of diagnoses in patients with onset symptoms was tracked starting from the first quarter post-infection. RESULTS: At 0-3 month follow-up, children and adolescents with a previous SARS-CoV-2 infection showed a 34% increased risk of adverse health outcome, and approximately 6% suffered from PASC in association with COVID-19. The attributable risk was higher among adolescents (≥ 12 years) than among children. For most common symptoms, IRRs largely persisted at 9-12 month follow-up. IRR were highest for rare conditions strongly associated with COVID-19, particularly inflammatory conditions among children 0-11 years, and chronic fatigue and respiratory insufficiency among adolescents. Tracking of diagnoses at the individual level revealed similar rates in the decline of symptoms among COVID-19 and control cohorts, generally leaving less than 10% of the patients with persistent diagnoses after 12 months. CONCLUSION: Although very few patients presented symptoms for longer than 12 months, excess morbidity among children and, particularly, adolescents with a history of COVID-19 means a relevant burden for pediatric care.

Post-viral symptoms and conditions are more frequent in COVID-19 than influenza, but not more persistent.

BACKGROUND: Post-viral symptoms have long been known in the medical community but have received more public attention during the COVID-19 pandemic. Many post-viral symptoms were reported as particularly frequent after SARS-CoV-2 infection. However, there is still a lack of evidence regarding the specificity, frequency and persistence of these symptoms in comparison to other viral infectious diseases such as influenza. METHODS: We investigated a large population-based cohort based on German routine healthcare data. We matched 573,791 individuals with a PCR-test confirmed SARS-CoV-2 infection from the year 2020 to contemporary controls without SARS-CoV-2 infection and controls from the last influenza outbreak in 2018 and followed them up to 18 months. RESULTS: We found that post-viral symptoms as defined for COVID-19 by the WHO as well as tissue damage were more frequent among the COVID-19 cohort than the influenza or contemporary control cohort. The persistence of post-viral symptoms was similar between COVID-19 and influenza. CONCLUSION: Post-viral symptoms following SARS-CoV-2 infection constitute a substantial disease burden as they are frequent and often persist for many months. As COVID-19 is becoming endemic, the disease must not be trivialized. Research should focus on the development of effective treatments for post-viral symptoms.

Incident autoimmune diseases in association with SARS-CoV-2 infection: a matched cohort study.

OBJECTIVES: To investigate whether the risk of developing an incident autoimmune disease is increased in patients with prior COVID-19 disease compared to those without COVID-19, a large cohort study was conducted. METHOD: A cohort was selected from German routine health care data. Based on documented diagnoses, we identified individuals with polymerase chain reaction (PCR)-confirmed COVID-19 through December 31, 2020. Patients were matched 1:3 to control patients without COVID-19. Both groups were followed up until June 30, 2021. We used the four quarters preceding the index date until the end of follow-up to analyze the onset of autoimmune diseases during the post-acute period. Incidence rates (IR) per 1000 person-years were calculated for each outcome and patient group. Poisson models were deployed to estimate the incidence rate ratios (IRRs) of developing an autoimmune disease conditional on a preceding diagnosis of COVID-19. RESULTS: In total, 641,704 patients with COVID-19 were included. Comparing the incidence rates in the COVID-19 (IR=15.05, 95% CI: 14.69-15.42) and matched control groups (IR=10.55, 95% CI: 10.25-10.86), we found a 42.63% higher likelihood of acquiring autoimmunity for patients who had suffered from COVID-19. This estimate was similar for common autoimmune diseases, such as Hashimoto thyroiditis, rheumatoid arthritis, or Sjögren syndrome. The highest IRR was observed for autoimmune diseases of the vasculitis group. Patients with a more severe course of COVID-19 were at a greater risk for incident autoimmune disease. CONCLUSIONS: SARS-CoV-2 infection is associated with an increased risk of developing new-onset autoimmune diseases after the acute phase of infection. Key Points • In the 3 to 15 months after acute infection, patients who had suffered from COVID-19 had a 43% (95% CI: 37-48%) higher likelihood of developing a first-onset autoimmune disease, meaning an absolute increase in incidence of 4.50 per 1000 person-years over the control group. • COVID-19 showed the strongest association with vascular autoimmune diseases.