tetano
Editor, Senior Moderator
J Hosp Infect
. 2023 Jul 5;S0195-6701(23)00210-4.
doi: 10.1016/j.jhin.2023.06.024. Online ahead of print. Influenza A subtype H3N2 is associated with an increased risk of hospital dissemination - an observational study over six influenza seasons
Erik Rothman[SUP] 1 [/SUP], Oskar Olsson[SUP] 2 [/SUP], Claus Bohn Christiansen[SUP] 3 [/SUP], Mattias Rööst[SUP] 4 [/SUP], Malin Inghammar[SUP] 5 [/SUP], Ulf Karlsson[SUP] 6 [/SUP]
Affiliations
Background: Previous studies on hospital-acquired influenza (HAI) have not systematically evaluated the possible impact of different influenza subtypes. HAI has historically been associated with a high mortality, but clinical consequences may be less severe in a modern hospital setting.
Aims: To identify and quantify hospital-acquired influenza (HAI) for each season, investigate possible associations with varying influenza subtypes, and to determine HAI-associated mortality.
Methods: All influenza-PCR positive adult patients (>18 years) hospitalized in Skåne County during 2013 - 2019, were prospectively included in the study. Positive influenza samples were subtyped. Medical records of patients with suspected hospital-acquired influenza (HAI) were examined to confirm a nosocomial origin and to determine 30-day mortality.
Results: Out of 4,110 hospitalized patients with a positive influenza PCR, 430 (10.5%) were HAI. Influenza A(H3N2) infections were more often HAI (15.1%) than influenza A(H1N1)pdm09, and influenza B (6.3% and 6.8% respectively, p<0.001). A majority of HAI caused by H3N2 were clustered (73.3 %) and were the cause of all 20 hospital outbreaks containing ≥ 4 affected patients. In contrast, a majority of HAI caused by influenza A(H1N1)pdm09 and influenza B were solitary cases (60% and 63.2%, respectively, p<0.001). Mortality associated with HAI was 9.3% and similar between subtypes.
Conclusions: HAI caused by influenza A(H3N2) was associated with an increased risk of hospital dissemination. Our study is relevant for future seasonal influenza infection control preparedness and shows that subtyping of influenza may help to define relevant infection control measures. Mortality in hospital-acquired influenza is still substantial in a modern hospital setting.
Keywords: Hospital-acquired influenza; infection control; influenza hospital outbreaks; influenza mortality; influenza subtypes; nosocomial influenza.
. 2023 Jul 5;S0195-6701(23)00210-4.
doi: 10.1016/j.jhin.2023.06.024. Online ahead of print. Influenza A subtype H3N2 is associated with an increased risk of hospital dissemination - an observational study over six influenza seasons
Erik Rothman[SUP] 1 [/SUP], Oskar Olsson[SUP] 2 [/SUP], Claus Bohn Christiansen[SUP] 3 [/SUP], Mattias Rööst[SUP] 4 [/SUP], Malin Inghammar[SUP] 5 [/SUP], Ulf Karlsson[SUP] 6 [/SUP]
Affiliations
- PMID: 37419188
- DOI: 10.1016/j.jhin.2023.06.024
Background: Previous studies on hospital-acquired influenza (HAI) have not systematically evaluated the possible impact of different influenza subtypes. HAI has historically been associated with a high mortality, but clinical consequences may be less severe in a modern hospital setting.
Aims: To identify and quantify hospital-acquired influenza (HAI) for each season, investigate possible associations with varying influenza subtypes, and to determine HAI-associated mortality.
Methods: All influenza-PCR positive adult patients (>18 years) hospitalized in Skåne County during 2013 - 2019, were prospectively included in the study. Positive influenza samples were subtyped. Medical records of patients with suspected hospital-acquired influenza (HAI) were examined to confirm a nosocomial origin and to determine 30-day mortality.
Results: Out of 4,110 hospitalized patients with a positive influenza PCR, 430 (10.5%) were HAI. Influenza A(H3N2) infections were more often HAI (15.1%) than influenza A(H1N1)pdm09, and influenza B (6.3% and 6.8% respectively, p<0.001). A majority of HAI caused by H3N2 were clustered (73.3 %) and were the cause of all 20 hospital outbreaks containing ≥ 4 affected patients. In contrast, a majority of HAI caused by influenza A(H1N1)pdm09 and influenza B were solitary cases (60% and 63.2%, respectively, p<0.001). Mortality associated with HAI was 9.3% and similar between subtypes.
Conclusions: HAI caused by influenza A(H3N2) was associated with an increased risk of hospital dissemination. Our study is relevant for future seasonal influenza infection control preparedness and shows that subtyping of influenza may help to define relevant infection control measures. Mortality in hospital-acquired influenza is still substantial in a modern hospital setting.
Keywords: Hospital-acquired influenza; infection control; influenza hospital outbreaks; influenza mortality; influenza subtypes; nosocomial influenza.