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Impact of Variants, Epidemiological Trends, and Comorbidities on Hospitalization Rates of Unvaccinated Children in Brazil: A Retrospective Study (2020-2022)
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  • Rai Watanabe Silva,
  • Ana Cunha Chaves,
  • Felipe Lei,
  • Ana Perosa,
  • Gabriela Barbosa,
  • Nancy Cristina Bellei
Universidade Federal de Sao Paulo

Corresponding Author:[email protected]

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Rai Watanabe Silva
Universidade Federal de Sao Paulo
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Ana Cunha Chaves
Universidade Federal de Sao Paulo
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Felipe Lei
Universidade Federal de Sao Paulo
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Ana Perosa
Sao Paulo Federal University
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Gabriela Barbosa
Universidade Federal de São Paulo
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Nancy Cristina Bellei
Federal University of São Paulo
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This retrospective study aimed to investigate the impact of the emergence of new variants and the epidemiological scenario on hospitalization rates of unvaccinated children (0-12 years) in Brazil. The study included 1,614 children admitted to a hospital between March 2020 and December 2022, with only 101 (6.3%) of them testing positive for COVID-19 via RT-PCR. The frequency of COVID-19 cases increased from 7.5% in 2020 to 9.3% in 2022 with the emergence of the Omicron variant. Children over five years old with comorbidities accounted for the majority of cases (69% [70/101]). Sickle cell anemia was the most frequent comorbidity (20%), and flu disease (36% [36/101]) and decompensation of underlying disease (33% [33/101]) were the main reasons for hospitalization. Co-infection was detected in 11% of cases, with RSV being the most common viral pathogen (71%). Hospital readmission occurred in 26% of cases, with a higher frequency in children over five years old. The death rate was 2.2%, with comorbidities such as cystic fibrosis and congenital heart disease as risk factors. These findings emphasize the need to prioritize vaccination with monovalent Omicron XBB for high-risk groups, including children over five years old with comorbidities, to mitigate the impact of new variants and reduce severe disease outcomes.
29 Sep 2023Submitted to Influenza and other respiratory viruses
30 Sep 2023Assigned to Editor
30 Sep 2023Submission Checks Completed
20 Nov 2023Reviewer(s) Assigned