Comparison of clinical, laboratory, and radiological characteristics between SARS-CoV-2 infection and community-acquired pneumonia caused by influenza virus

Abstract

Coronavirus disease 2019 (COVID-19) is the most important global public health issue that we currently face. We aimed to explore the clinical features of patients with COVID-19 and compared them with those of hospitalized community-acquired pneumonia (CAP) patients caused by influenza virus during the same period. From Jan 1, to Mar 4, 2020, patients with COVID-19 or CAP caused by influenza virus who were admitted to the First Affiliated Hospital of Xiamen University were consecutively screened for enrollment. A total of 35 COVID-19 patients and 22 CAP patients caused by influenza virus were included in this study. Most of COVID-19 patients had characteristics of familial clustering (63%), however, in the other group, there was no similar finding. The percentages of patients with a high fever (the highest recorded temperature was ≥39.0°C; 11% vs 45% [COVID-19 vs CAP groups, respectively]), dyspnea (9% vs 59%), leukocytosis (3% vs 32%), elevated C-reactive protein concentrations (>10 mg/L, 48% vs 86%), elevated procalcitonin levels (>0.1 ng/ml, 15% vs 73%), PaO 2 /FiO 2 <200 mm Hg (4% vs 22%), and infiltration on imaging (29% vs 68%) in the COVID-19 group were less than those same indices in the hospitalized CAP patients caused by influenza virus. Ground-glass opacity with reticular pattern (63%) and interlobular septal thickening (71%) in chest CT were commonly observed in the COVID-19 group. COVID-19 and CAP caused by influenza virus appear to share some similarities in clinical manifestaions but they definitely have major distinctions. Influenza infection remains a health problem even during COVID-19 pandemic.

A Comparative Systematic Review of COVID-19 and Influenza

“…In this review, 14 studies of 18 [ 5 , 6 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 18 , 19 , 20 , 21 ] reported a comparison between COVID-19 and influenza patients based on demographic findings, comorbidities, clinical features, and outcome ( Table 2 ). Fever and respiratory symptoms such as cough, expectoration or sputum production and dyspnea were the main symptoms in both groups with COVID-19 and influenza; however, they were significantly more frequent in patients with influenza [ 5 , 9 , 10 , 11 , 13 , 15 , 16 , 19 , 20 ]. Moreover, vomiting, otorhinolaryngological symptoms such as nasal congestion, rhinorrhea, sore throat and ocular symptoms such as tearing and conjunctival hyperhemia were statistically more frequent in patients with influenza than COVID-19 adult patients [ 5 , 10 , 11 , 12 , 15 ].…”

“…A total of 11 studies of 18 [ 7 , 8 , 9 , 10 , 11 , 13 , 14 , 18 , 19 , 20 , 21 ] compared routine laboratory test results between COVID-19 and influenza patients. Both infections caused abnormalities in biological parameters leading to aberrant blood cell counts and sometimes elevated hepatic, renal, and cardiac enzyme activity.…”

“…White blood cells, especially neutrophils (NE) were significantly more elevated in influenza than COVID-19 patients [ 7 , 8 , 10 , 11 , 14 , 18 , 19 , 20 , 21 ]. Lymphocytes proportion in white blood cell count are higher in influenza than COVID-19 patients [ 7 , 8 , 20 ] but without difference between lymphocytes level [ 7 , 8 ], except for one study [ 20 ]. Platelets level was lower [ 11 ] with more often thrombocytopenia [ 18 ] in COVID-19 than influenza patients.…”

“…Platelets level was lower [ 11 ] with more often thrombocytopenia [ 18 ] in COVID-19 than influenza patients. Elevated transaminases were significantly more common in COVID-19 patients [ 7 , 8 , 11 , 18 , 20 ]. In a prospective study by Raija Auvinen et al, it was reported that C-reactive protein (CRP) values were similar at admission but rose significantly higher in COVID-19 patients than influenza patients during hospitalization [ 18 ].…”

“…On PubMed, 331 articles were initially found, out of which 46 articles were selected. In the end, 18 articles were selected [3,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] (8 retrospective studies, 6 cohort studies, 3 casecontrol studies, 1 prospective study, 1 cross-sectional study, 1 review and meta-analysis, and 1 review) ( Figure 1 and Table 1) An outcome-free study population is first identified by the exposure/event of interest and followed in time until the outcome of interest happens. They can be prospective (carried out from the present time into the future) or retrospective (carried out at the present time and look to the past to examine medical events or outcome).…”