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Int J Infect Dis
. 2024 Mar 30:107034.
doi: 10.1016/j.ijid.2024.107034. Online ahead of print. Association of viral loads of influenza A(H3N2) with age and care setting on presentation - a prospective study during the 2022/23 influenza season in Spain
Iván Sanz-Muñoz 1 , Javier Sánchez-Martínez 2 , Carla Rodríguez-Crespo 2 , Irene Arroyo-Hernantes 3 , Marta Domínguez-Gil 4 , Silvia Rojo-Rello 5 , Marta Hernández 6 , José M Eiros 7
Affiliations
Background: The aim of this study was to analyze viral load (VL) using Cycle threshold (Ct) in patients infected with influenza A(H3N2).
Methods: This prospective study was conducted during the 2022-2023 influenza season in sentinel, non-sentinel and hospitalized patients of Castilla y León (Spain). Respiratory samples were obtained from nasopharyngeal swabs and analyzed by qRT-PCR specific for influenza A(H3N2) to obtain the Ct value.
Results: A total of 1,047 individuals were enrolled (174[16.6%] sentinel; 200[19.1%] non-sentinel; 673[64.3%] hospitalized). The mean Ct value was lower in infants, young-children and in the elderly, with a sharp increase in the last from 65 years old ill 90 years. Additionally, the lower Ct values were observed in non-sentinel patients and then in hospitalized, probably because non-sentinel are outpatients in the acute phase of the influenza infection.
Conclusions: A higher viral load (lower Ct value) is related with the extreme ages of life, children and the elderly. Also, the higher viral load is related with the care setting, being probably higher in the out-patients because they are on the acute phase of the disease, and slightly lower in hospitalized because they are attended during the post-acute phase.
Keywords: Cycle threshold; Influenza; Viral load; hospitalized; primary care; sentinel.
. 2024 Mar 30:107034.
doi: 10.1016/j.ijid.2024.107034. Online ahead of print. Association of viral loads of influenza A(H3N2) with age and care setting on presentation - a prospective study during the 2022/23 influenza season in Spain
Iván Sanz-Muñoz 1 , Javier Sánchez-Martínez 2 , Carla Rodríguez-Crespo 2 , Irene Arroyo-Hernantes 3 , Marta Domínguez-Gil 4 , Silvia Rojo-Rello 5 , Marta Hernández 6 , José M Eiros 7
Affiliations
- PMID: 38561041
- DOI: 10.1016/j.ijid.2024.107034
Background: The aim of this study was to analyze viral load (VL) using Cycle threshold (Ct) in patients infected with influenza A(H3N2).
Methods: This prospective study was conducted during the 2022-2023 influenza season in sentinel, non-sentinel and hospitalized patients of Castilla y León (Spain). Respiratory samples were obtained from nasopharyngeal swabs and analyzed by qRT-PCR specific for influenza A(H3N2) to obtain the Ct value.
Results: A total of 1,047 individuals were enrolled (174[16.6%] sentinel; 200[19.1%] non-sentinel; 673[64.3%] hospitalized). The mean Ct value was lower in infants, young-children and in the elderly, with a sharp increase in the last from 65 years old ill 90 years. Additionally, the lower Ct values were observed in non-sentinel patients and then in hospitalized, probably because non-sentinel are outpatients in the acute phase of the influenza infection.
Conclusions: A higher viral load (lower Ct value) is related with the extreme ages of life, children and the elderly. Also, the higher viral load is related with the care setting, being probably higher in the out-patients because they are on the acute phase of the disease, and slightly lower in hospitalized because they are attended during the post-acute phase.
Keywords: Cycle threshold; Influenza; Viral load; hospitalized; primary care; sentinel.