Findings from a nationwide, retrospective cohort study from France, which compared hospitalizations and deaths from Covid-19 in the spring of 2020 to those from influenza during a seasonal outbreak the previous year, confirmed that Covid-19 is a far more serious and deadly disease.
Nearly twice as many Covid-19 hospitalizations were reported in March and April than influenza hospitalizations between Dec. 2018 and Feb. 2019, and deaths from Covid-19 were triple those reported for influenza during the respective periods.
Surprisingly, the researchers found that even though children and adolescents with Covid-19 had a lower risk for hospitalization than those with influenza, they had a higher risk for ICU admission and death.
Among adolescents between the ages of 11 and 17 years, in-hospital mortality was 10-times higher among those hospitalized with Covid-19 than those hospitalized with influenza, although the overall numbers were very small.
The analysis, published online in the journal Lancet Respiratory Medicine, highlighted significant differences between patients with Covid-19 and influenza who require hospitalization, wrote researcher Lionel Piroth, MD, of Dijon University Hospital, Dijon, France, and colleagues.
“SARS-CoV-2 appears to have a higher potential for respiratory pathogenicity, leading to more respiratory complications in patients with fewer comorbidities, and is associated with a higher risk of mortality, particularly in adolescents, although any conclusions from this age group must be treated with caution considering the small number of deaths,” they wrote.
The analysis included data on all patients hospitalized for Covid-19 from March 1 to April 30, 2020 (n=89,530) and those hospitalized during an influenza outbreak between Dec. 1, 2018 and Feb. 28, 2019 (n=45,819).
Comparisons of risk factors, clinical characteristics and outcomes between the two groups were conducted and data was also stratified by age.
The median age of patients was 68 years (IQR 52–82) for Covid-19 and 71 years (34–84) for influenza. Patients with Covid-19 were more likely to be obese or overweight, and they had a higher prevalence diabetes, hypertension, and dyslipidemia than patients with influenza.
Patients with influenza were more likely to have heart failure, chronic respiratory disease, cirrhosis, and deficiency anemia.
Covid-19 hospitalization was associated with a higher prevalence of acute respiratory failure, pulmonary embolism, septic shock, and hemorrhagic stroke, but Covid-19 patients were less likely to have myocardial infarction or atrial fibrillation, compared to patients hospitalized for influenza.
Among the other main findings:
- In-hospital mortality was higher in patients with Covid-19 than in patients with influenza (15,104 [16.9%] of 89,530 versus 2,640 [5.8%] of 45,819), with a relative risk of death of 2.9 (95% CI, 2.8-3.0) and an age-standardized mortality ratio of 2.82.
- The proportion of pediatric patients (<18 years) was smaller for Covid-19 than for influenza (1,227 [1.4%] versus 8,942 [19.5%]), but a larger proportion of patients younger than 5 years needed intensive care support for Covid-19 than for influenza (14 [2.3%] of 613 versus 65 [0.9%] of 6,973).
- Among adolescents (11-17 years), in-hospital mortality was ten-times higher for Covid-19 than for influenza (5 [1.1%] of 458 versus 1 [0.1%] of 804). Adolescents hospitalized for Covid-19 were more likely to be obese (12 [2.6%] of 458 cases versus 4 [0.5%] of 804 cases, P<0.0001) or overweight (16 [3.5%] versus 9 [1.1%]; P=0.0036).
In an accompanying commentary, infectious disease specialist Eskild Petersen, DSc, of Denmark’s University of Aarhus, wrote that it is likely that the influenza cohort differed from the Covid-19 cohort in one important respect.
“It must be assumed that there was some residual immunity against influenza in the influenza cohort,” Petersen wrote. “By contrast, severe acute respiratory syndrome coronavirus 2 is a new virus for which no one had any previous immunity.” Petersen added that the study findings highlight the importance of receiving annual vaccination against influenza.
The study also has important implications with the roll-out of vaccination against Covid-19, Petersen noted.
“Clearly people with obesity, diabetes, and hypertension must be considered high-risk group, but the results also show that children and adolescents must be offered immunization, given that young people can also become severely ill,” he wrote. “Even if health-care workers and people older than 65 years are prioritized for the first rounds of immunizations, children and adolescents should also be offered the vaccine when it becomes available.”
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Nearly twice as many Covid-19 hospitalizations were reported in March and April in France than influenza hospitalizations from Dec. 2018 through Feb. 2019.
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Among adolescents between the ages of 11 and 17 years, in-hospital mortality was ten-times higher among those hospitalized with Covid-19 than those hospitalized with influenza, although the overall numbers were very small.
Salynn Boyles, Contributing Writer, BreakingMED™
This research was funded by the French National Research Agency.
Researcher Lionel Piroth reported receiving travel grants from Janssen-Cilag, Merck Sharp & Dohme, Pfizer and Gilead. Researcher Pascale Tubert-Bitter reported receiving personal fees and other fees from Roche and Boehringer Inelheim. Editorial writer Eskild Petersen reported no relevant disclosures.
Cat ID: 30
Topic ID: 79,30,254,930,730,933,30,926,653,927,151,928,924,934
