Factors associated with poor outcomes among adults hospitalised for influenza in France: A three-year prospective multicenter study

Paul Loubet (1, 2) , Nezha Samih-Lenzi (3) , Florence Galtier (4, 5) , Philippe Vanhems (6, 7) , Pierre Loulergue (2, 1, 3) , Xavier Duval (8) , Stéphane Jouneau (9) , Déborah Postil (10) , Sylvie Rogez (10) , Martine Valette (11, 12) , Corinne Merle (5) , Corinne Régis (13) , Yolande Costa (8) , Zineb Lesieur (3) , Pierre Tattevin (14, 15, 16) , Bruno Lina (11, 12) , Fabrice Carrat (17, 18) , Odile Launay (2, 1, 19, 3)

1 Service des Maladies Infectieuses
2 CIC 1417 - CIC Cochin Pasteur
3 F-CRIN, Innovative clinical research network in vaccinology (I-REIVAC)
4 CIC Montpellier
5 CHRU Montpellier - Hôpital Saint Eloi
6 Service d'Hygiène, Epidémiologie et Prévention [Hôpital Edouard Herriot - HCL]
7 LPE-Fondation Mérieux - Laboratoire des pathogènes émergents -- Emerging Pathogens Laboratory
8 CIC Hôpital Bichat
9 Service de pneumologie [Rennes] = Pneumology [Rennes]
10 Service de Bactériologie, Virologie, Hygiène [CHU Limoges]
11 Centre National de Référence Virus Influenza (Région Sud)
12 Virpath - Virpath-Grippe, de l'émergence au contrôle -- Virpath-Influenza, from emergence to control
13 LBBE - Laboratoire de Biométrie et Biologie Evolutive - UMR 5558
14 CIC - Centre d'Investigation Clinique [Rennes]
15 Service des maladies infectieuses et réanimation médicale [Rennes] = Infectious Disease and Intensive Care [Rennes]
16 Fonction, structure et inactivation d'ARN bactériens
17 iPLESP - Institut Pierre Louis d'Epidémiologie et de Santé Publique
18 CHU Saint-Antoine [AP-HP]
19 CRESS (U1153 / UMR_A_1125 / UMR_S_1153) - Centre de Recherche Épidémiologie et Statistique Sorbonne Paris Cité

Background: Influenza is an important cause of serious illness and death, particularly in elderly and high-risk groups. Objectives Aim of this study was to identify factors associated with poor outcomes among adults hospitalized in France for laboratory-confirmed seasonal influenza. Study design Patients hospitalized for influenza were identified in a prospective, multicenter study carried out in French hospitals during three consecutive influenza seasons (2012–2015). Influenza virus infection was confirmed by reverse transcription polymerase chain reaction. Sociodemographic and clinical variables were compared according to the virus type and subtype. Risk factors for complications, intensive care unit (ICU) admission and death were analyzed by backward stepwise logistic regression. Results The study population consisted of 566 patients, of whom 56% were older than 65 years and 82% had underlying chronic illnesses. Type A influenza viruses infected 422 patients (75%), including subtype H3N2 in 239 patients (57%). The prior vaccine coverage rate was 38%. Complications occurred in 255 patients (45%), consisting mainly of pneumonia (n = 143, 30%) and respiratory failure (n = 116, 20%). Eighty-three patients (15%) were admitted to an ICU, and the in-hospital mortality rate was 4% (n = 21). Sixty-six patients (12%) received oseltamivir. Age over 65 years was the only identified risk factor for complications. Risk factors for ICU admission were an absence of vaccination, no oseltamivir administration before admission, pre-existing chronic respiratory disease, and current smoking. Age over 65 years and ICU admission were risk factors for death. Conclusions Older individuals and patients with underlying conditions are most at risk of influenza complications. Vaccination and early oseltamivir administration, both of which are recommended for these patients, appear to reduce ICU admissions

Keywords: Hospitalisation; Influenza; Antiviral; Adults; Vaccination; Severe

Domains: Life Sciences [q-bio]; Life Sciences [q-bio]; Microbiology and Parasitology; Virology

Paul Loubet, Nezha Samih-Lenzi, Florence Galtier, Philippe Vanhems, Pierre Loulergue, et al.. Factors associated with poor outcomes among adults hospitalised for influenza in France: A three-year prospective multicenter study. Journal of Clinical Virology, 2016, 79, pp.68-73. ⟨10.1016/j.jcv.2016.04.005⟩. ⟨hal-01302409⟩