Influenza B viral load analysis in patients with acute respiratory infection from a tertiary hospital in Brazil. Issue 8 (9th December 2019)

• Record Type: Journal Article
• Authors: Rodrigues Guimarães Alves, Vitória; Kleber de Souza Luna, Luciano; Santiago Cruz, Jessica; Helena Perosa, Ana; Bellei, Nancy
• Is Part Of: Journal of medical virology. Volume 92:Issue 8(2020)
• Page Start: 1350
• Page End: 1354
• Publication Date: 2019-12-09
• Subjects: Influenza B virus -- Victoria -- viral Load -- Yamagata; Virology -- Periodicals; 616
• DOI: 10.1002/jmv.25648
• Languages: English
• ISSNs: 0146-6615

Abstract

Abstract: Currently, 2 genotypes of Influenza B viruses (IFB) are cocirculating in humans: Victoria (VIC) and Yamagata (YAM). Infection and viral load (VL) were analyzed in 105 genotyped IFB (59 VIC and 46 YAM) out of 3452 respiratory samples from immunodepressed (ID), immunocompetent (IC) including outpatients (OP) and hospitalized patients (HP) attended during 2001‐2013 at São Paulo Hospital. VL (Log10 RNA copies/mL) calculation was possible in 78 samples (47 VIC, 31 YAM). The age group of 12 to 18 years presented the highest detection (14.13%). Rates of infection among groups were of 3.67% (IC), 1.68% (ID), 3.50% (OP), 0.6% (HP), and VLs varied from 2.8 to 10.13 with no difference regarding age, immune status, and disease severity. From 10 OP vaccinated against influenza, 8 (7 children, 1 ID) received a matching strain shot (VIC), and 2 a monovalent influenza A H1N1pdm09. Those patients presented a VL of 6.31 ± 1.62 (mean ± SD). IFB infection rates follow an age pattern, but VL seems not to be related to frequency or clinical outcome. IFB patients with previous immunization could point to some protection for VIC infections since there was no HP. Other immunological aspects, such as lineage infection immune priming, previous infections, and vaccinations, should be further investigated. Research Highlights: The age group of 12–18 years old presented the highest IFB detection. IFB YAM infections occurred more frequently among those with <5 years and ≥59 years old. IFB VIC infections were predominantly among younger age groups. Patients vaccinated with a season matching vaccine strain (VIC) were infected.