Co‐infection of influenza A virus and SARS‐CoV‐2: A retrospective cohort study

Abstract

The coronavirus 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread across the world and is responsible for over 1,686,267 deaths worldwide. Co-infection with influenza A virus (IFV-A) during the upcoming flu season may complicate diagnosis and treatment of COVID-19. Little is known about epidemiology and outcomes of co-infection. Data for 213 COVID-19 patients treated at Tongji Hospital in Wuhan from January 28, 2020 to March 24, 2020 were retrospectively analyzed. Ninety-seven of the patients (45.5%) tested positive for anti-IFV-A immunoglobulin M antibodies. The clinical characteristics were described and analyzed for patients with SARS-CoV-2 infection only and patients with SARS-CoV-2/IFV-A co-infection. Patients with co-infection showed similar patterns of symptoms and clinical outcomes to patients with SARS-CoV-2 infection only. However, an increased expression of serum cytokines (interleukin-2R [IL-2R], IL-6, IL-8, and tumor necrosis factor-α) and cardiac troponin I, and higher incidence of lymphadenopathy were observed in patients with SARS-CoV-2 infection only. Male patients and patients aged less than 60 years in the SARS-CoV-2 infection group also had significantly higher computed tomography scores than patients in co-infection group, indicating that co-infection with IFV-A had no effect on the disease outcome but alleviated inflammation in certain populations of COVID-19 patients. The study will provide a reference for diagnosing and treating IFV-A and SARS-CoV-2 co-infection cases in the upcoming flu season.

Coinfections with Bacteria, Fungi, and Respiratory Viruses in Patients with SARS-CoV-2: A Systematic Review and Meta-Analysis

“…The current meta-analysis is more comprehensive and included a total of 71 studies [2,80] and one abstract [3], including a total of 31,953 patients. The inclusion of 18 recently published studies [2,3,[5][6][7][8][9][10][12][13][14]22,24,27,41,62,64,65] contributed to the refinement of the estimate of the pooled prevalence of pathogens contributing to coinfections in SARS-CoV-2 patients.…”

“…Of the initial 7317 retrieved publications, there were 4609 duplicate articles, and 2080 articles were found to be irrelevant based on their titles and abstracts and were excluded. An additional 1065 articles were excluded after review, meaning that we included 72 articles in the systematic review [80][81][82], while 68 articles were included in the meta-analysis [2][3][4][5][6][7][8][9][10][11][39][40][41][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][59][60][61][62][63][64][65][66][67][68][69][70][80][81][82] (Figure 1).…”

“…Thus, timely diagnosis is important to initiate appropriate therapy and limit the overuse of antimicrobial agents. Previous studies, including case series [2,5,8,11,[14][15][16]19,20,, cohort studies [3,4,6,7,9,10,12,13,17,18,21,22,[51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70], and meta-analyses [71][72][73], have shown variable results. In light of recent studies evaluating coinfections in SARS-CoV-2 patients, we aimed to re-evaluate the prevalence of bacterial, fungal, and respiratory viral coinfections in a comprehensive meta-analysis.…”

“…Globally, as of 15 April 2021, there have been 137,866,311 confirmed cases of COVID-19, including 2,965,707 deaths, as reported by the World Health Organization [ 1 ]. Coinfection with SARS-CoV-2 and other bacterial, fungal, and respiratory viral pathogens [ 2 , 3 , 4 ], Gram-positive and Gram-negative bacteria [ 5 , 6 , 7 ], Middle East respiratory syndrome coronavirus (MERS-CoV) [ 8 ], and influenza [ 9 , 10 , 11 , 12 , 13 ] has been described. However, the reported frequency is variable.…”

The Complexity of Co-Infections in the Era of COVID-19

“…Several reports of co-infection with influenza were obtained after the first wave of COVID-19 in early 2020 [19,[40][41][42][43][44][45][46]. Four reports from China detailed a high frequency of influenza co-infection, especially for influenza A variants [19,42,43,46]. The finding of nearly one-half of their patients having dual infection raises some concern for diagnostic specificity.…”