Influenza-induced acute respiratory distress syndrome during the 2010-2016 seasons: bacterial co-infections and outcomes by virus type and subtype

Abstract

Objectives: We aimed to describe bacterial co-infections and acute respiratory distress (ARDS) outcomes according to influenza type and subtype. Methods: A retrospective observational study was conducted from 2012 to 2016 in patients admitted to the respiratory intensive care unit (ICU) of Marseille university hospital for influenza-induced ARDS. Microbiological investigations, including multiplex molecular respiratory panel testing and conventional bacteriological cultures, were performed as part of the routine ICU care on the bronchoalveloar lavage collected at admission. Bacterial co-infections, ICU mortality and respiratory function were investigated according to virus type and subtype. Results: Among the 45 ARDS patients included, A(H1N1)pdm09 was the most frequent influenza virus identified (28/45 A(H1N1)pdm09, eight out of 45 A(H3N2) and nine out of 45 influenza B). Bacterial coinfections involving a total of 23 bacteria were diagnosed in 16/45 patients (36%). A(H1N1)pdm09 patients presented fewer bacterial co-infections (17.9% vs. 50.0% for A(H3N2) patients and 77.8% for B patients; p < 0.01). Overall, mortality at 90 days post admission was 33.3% (15/45), and there was no significant difference between influenza type and subtype. The need for extracorporeal membrane oxygenation was more frequent for A(H1N1)pdm2009 (20/28, 71.4%) and B patients (7/9, 77.8%) than the A(H3N2) subtype (1/8, 12.5%; p < 0.01). A(H1N1)pdm09-ARDS patients were associated with fewer ventilation-free days at day 28 (median (IQR): 0 (0e8) days) compared with other influenzaeARDS patients (15 (0e25) days, p < 0.05). Discussion: In a population of influenza-induced ARDS, A(H1N1)pdm09 was associated with fewer bacterial co-infections but poorer respiratory outcomes. These data underline the major role of A(H1N1) pdm09 subtype on influenza disease severity.

Co-Infection and Ventilator-Associated Pneumonia in Critically Ill COVID-19 Patients Requiring Mechanical Ventilation: A Retrospective Cohort Study

“…We found that bacterial co-infection was an important complication in both critically ill H1N1 and COVID-19 patients. In line with previous reports, bacterial co-infection upon ICU admission was diagnosed in almost one third of H1N1 patients [ 1 , 7 , 8 , 9 , 10 ]. As previously reported [ 11 , 12 , 13 ], co-infection was identified in a lesser proportion of COVID-19 patients at ICU admission.…”

Secondary respiratory early and late infections in mechanically ventilated patients with COVID-19

“…As shown, more than forty percent of our patients developed at least one secondary respiratory infection during their ICU stay. This is higher than previously reported for COVID-19 [9,20,21] but similar to the proportion of secondary infections reported in post influenza ICU patients [22,23]. The incidence of early vs late secondary infection was similar to other studies, where late secondary infections were predominant [5,6,13,24].…”

Corticosteroids Use and Risk of Respiratory Coinfections in Mechanically Ventilated Patients With COVID-19

“…In our cohort, 40.6 % of our patients developed at least one respiratory coinfection during their ICU stay, which is higher than what has been previously reported [9,18,19] but similar to the proportion of coinfections reported in post in uenza ICU patients [20,21]. The proportion of early vs late coinfection shows a similar trend to other studies, where late coinfections were higher than early ones [5,6,13,22].…”