Severe influenza A in a Tunisian ICU sentinel SARI centre: Epidemiological and clinical features

Abstract

Introduction Influenza A virus infection is a contagious acute respiratory infection which mostly evolves in an epidemic form, less frequently as pandemic outbreaks. It can take a severe clinical form that needs to be managed in intensive care unit (ICU). The aim of this study was to describe the epidemiological and clinical aspects of influenza A, then to determine independent predictive factors of ICU mortality in Abderrahmen Mami hospital, Ariana, Tunisia. Methods It was a single-center study, including all hospitalized patients in intensive care, between November 1st, 2009 and October 31st, 2019, with influenza A virus infection. We recorded demographic, clinical and biological data, evolving features; then multivariate analysis of the predictive factors of ICU mortality was realized. Results During the study period (10 consecutive seasons), 120 patients having severe Influenza A were admitted (Proportion = 2.5%) from all hospitalized patients, with a median age of 48 years and a gender-ratio of 1.14. Among women, 14 were pregnant. Only 7 patients (5.8%) have had seasonal flu vaccine during the year before ICU admission. The median values of the Simplified Acute Physiology Score II, Acute Physiologic and Chronic Health Evaluation II and Sepsis-related Organ Failure Assessment were respectively 26, 10 and 3. Virus strains identified with polymerase chain reaction were H1N1 pdm09 (84.2%) and H3N2 (15.8%). Antiviral therapy was prescribed in 88 (73.3%) patients. A co-infection was recorded in 19 cases: bacterial (n = 17) and aspergillaire (n = 2). An acute respiratory distress syndrome (ARDS) was diagnosed in 82 patients. Non-invasive ventilation (NIV) was conducted for 72 (60%) patients with success in 34 cases. Endotracheal intubation was performed in 59 patients with median duration of invasive mechanical ventilation 8 [3.25–13] days. The most frequent complications were acute kidney injury (n = 50, 41.7%), shock (n = 48, 40%), hospital-acquired infections (n = 46, 38.8%) and thromboembolic events (n = 19, 15.8%). The overall ICU mortality rate was of 31.7% (deceased n = 38). Independent predictive factors of ICU mortality identified were: age above 56 years (OR = 7.417; IC95% [1.474–37.317]; p = 0.015), PaO2/FiO2 ≤ 95 mmHg (OR = 9.078; IC95% [1.636–50.363]; p = 0.012) and lymphocytes count ≤ 1.325 109/L (OR = 10.199; IC95% [1.550–67.101]; p = 0.016). Conclusion Influenza A in ICU is not uncommon, even in A(H1N1) dominant seasons; its management is highly demanding. It is responsible for considerable morbi-mortality especially in elderly patients.

Changes in Epidemiology and Antibiotic Prescription of Influenza: Before and after the Emergence of COVID-19

“…Differences we found were that patients hospitalized after 2022 were younger (63-year-old median age Before-2020 vs. 59.5-year-old median age After-2022), and asthma and obesity were more prevalent in this population, but asthma was still less frequent than in the 2009 flu pandemic caused by the AH1N2pdm09 strain [ 19 ]. The prevalence of obesity increased to 25% of hospitalized patients After-2022 in this database, which is more than other studies which addressed this [ 20 , 21 ]. The study groups were also very similar in the rates of severe cases (64.7% cases Before-2022, 62.69% After-2022).…”

“…The prevalence of pneumonia with infiltrates of this study is lower than in other studies in the literature. Amira Jamoussi et al found that pneumonia with infiltrates was present in 85% of their subjects [ 20 ], but their study was focused only on patients with severe acute respiratory infection. Kelsey M Sumner et al [ 22 ] also identified a higher percentage of pneumonia in their group, but the definition of pneumonia was not provided.…”

Influenza A virus replicates productively in primary human kidney cells and induces factors and mechanisms related to regulated cell death and renal pathology observed in virus-infected patients

“…A recent meta-analysis showed that the rate of positive urine tests for IAV was 58% in patients infected with IAV ( Lowry et al., 2023 ). Importantly, the 2009 pandemic was associated with significant extrapulmonary complications ( Lee et al., 2011 ), among which IAV-induced acute kidney injury (IAV-AKI) was related to increased mortality ( Abdulkader et al., 2010 ; Martin-Loeches et al., 2011 ; Nin et al., 2011a ; Thakkar and Golestaneh, 2021 ), and this trend is continuing in IAV-AKI ( Ersoy et al., 2021 ; Hsu et al., 2022 ; Jamoussi et al., 2022 ). Yet, the pathophysiology of IAV-AKI is incompletely understood ( Joannidis and Forni, 2011 ; Watanabe, 2013 ).…”