Differences between COVID-19 infected patients and influenza infected patients
In the near future, it is conceivable that co-circulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza virus A/B may occur, but from a clinical perspective, the distinction between the two disease entities will be important for patient management. This study was designed to detect clinical differences between coronavirus disease 2019 (COVID-19) and seasonal influenza patients upon admission.
In a single-center, observational study, the
All consecutive patients hospitalized with COVID-19 and influenza between November 2019 and May 2020 will be included, and data will be extracted from national surveillance programs and electronic health records.COVID-19 and influenza patients will be compared in terms of baseline characteristics, clinical symptoms, and outcomes. COVID-19 and influenza patients were compared in terms of baseline characteristics, clinical symptoms, and outcomes, and recursive partitioning was used to generate a classification tree to distinguish between COVID-19 and influenza patients.
Results.
96 COVID-19 and 96 influenza patients were included. In COVID-19, the median age was 68 vs. 70 years (p = 0.90), 72% vs. 56% (p = 0.024) were male, and the median Charlson Comorbidity Index (CCI) was 1 vs. 2 (p = 0.027).
The time from symptom onset to hospitalization was longer for COVID-19 (median 7 days) than for influenza patients (median 3 days), and other variables favoring the diagnosis of COVID-19 in the classification tree were elevated systolic blood pressure, absence of sputum, and absence of headache.
The tree classified 86/192 patients (45%) into two subsets, with more than 80% of patients infected with influenza or COVID-19, respectively. In-hospital mortality was higher in patients with COVID-19.
In conclusion, it is difficult to distinguish between the clinical manifestations of COVID-19 and influenza, which have similar routes of transmission, and one conclusion is that COVID-19 patients had significantly longer hospital stays and significantly higher mortality.
Sieber, P., Flury, D., Güsewell, S. et al. Characteristics of patients with Coronavirus Disease 2019 (COVID-19) and seasonal influenza at time of hospital admission: a single center comparative study. BMC Infect Dis 21, 271 (2021). Available at: https://doi.org/10.1186/s12879-021-05957-4
Summary
Although it was considered difficult to distinguish clinical symptoms, we found that the length of hospital stay was comparable. This was due to the fact that COVID-19 infection is considered to have a longer period of time from onset to symptom onset, and some cases were reported to worsen within 5 to 8 days after onset.
In terms of gender, males are considered to be a risk factor for more severe cases, and oxygen saturation is slightly lower during COVID-19 infection. Headache seems to occur at a higher rate with influenza infection, and olfactory symptoms seem to be a characteristic of COVID-19.
There is also data that COVID-19 patients have higher systolic blood pressure, and there are some categories of laboratory values that are significantly higher, but there seems to be no difference between influenza and COVID-19 when variables are adjusted in the classification tree.
Since this is the first classification tree published and there is a possibility of bias in the reported cases, it may be easier to classify in the future, but at present, judgments based on clinical symptoms are still an issue.
