The importance of viral load in the severity of acute bronchiolitis in infants

Author(s)

De Paulis, Milena ^{[1, 2]} ; Leal Oliveira, Danielle Bruna ^{[3, 4]} ; Thomazelli, Luciano Matsumiya ^[3] ; Ferraro, Alexandre Archanjo ^[5] ; Durigon, Edison Luiz ^{[3, 6]} ; Vieira, Sandra E. ^[5]

Affiliation

^[1] Univ Sao Paulo, Hosp Univ, Div Pediat, Unidade Urgencia & Emergencia Referenciada Infant, Sao Paulo, SP - Brazil

^[2] Hosp Israelita Albert Einstein, Unidade Pronto Atendimento, Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, Inst Ciencias Biomed, Dept Microbiol, Lab Virol Clin & Mol, Sao Paulo, SP - Brazil

^[4] Inst Israelita Ensino & Pesquisa Albert Einstein, Sao Paulo, SP - Brazil

^[5] Univ Sao Paulo, Fac Med FMUSP, Dept Pediat, Sao Paulo, SP - Brazil

^[6] Univ Sao Paulo, Plataforma Cient Pasteur, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Clinics; v. 76, 2021.
• Web of Science Citations: 0

Abstract

OBJECTIVE: The relationship between viral load and the clinical evolution of bronchiolitis is controversial. Therefore, we aimed to analyze viral loads in infants hospitalized for bronchiolitis. METHODS: We tested for the presence of human respiratory syncytial virus (HRSV) or human rhinovirus (HRV) using quantitative molecular tests of nasopharyngeal secretions and recorded severity outcomes. RESULTS: We included 70 infants {[}49 (70%) HRSV, 9 (13%) HRV and 12 (17%) HRSV+HRV]. There were no differences among the groups according to the outcomes analyzed individually. Clinical scores showed greater severity in the isolated HRSV infection group. A higher isolated HRSV viral load was associated with more prolonged ventilatory support, oxygen therapy, and hospitalization days, even after adjustment for the age and period of nasopharyngeal secretion collection. In the co-infection groups, there was a longer duration of oxygen therapy when the HRSV viral load was predominant. Isolated HRV infection and co-infection with a predominance of HRV were not associated with severity. CONCLUSION: Higher HRSV viral load in isolated infections and the predominance of HRSV in co-infections, independent of viral load, were associated with greater severity. These results contribute to the development of therapeutic and prophylactic approaches and a greater understanding of the pathophysiology of bronchiolitis. (AU)

• FAPESP's process: 12/22854-9 - Analysis of the gene expression patterns in peripherical mononuclear cells of infants with respiratory syncytial virus infection
• Grantee: Sandra Elisabete Vieira
• Support Opportunities: Regular Research Grants