Evaluation of patients with respiratory infections during the first pandemic wave in Germany: characteristics of COVID-19 versus non-COVID-19 patients

Abstract

Background: Characteristics of COVID-19 patients have mainly been reported within confirmed COVID-19 cohorts. By analyzing patients with respiratory infections in the emergency department during the first pandemic wave, we aim to assess differences in the characteristics of COVID-19 vs. Non-COVID-19 patients. This is particularly important regarding the second COVID-19 wave and the approaching influenza season.

Methods: We prospectively included 219 patients with suspected COVID-19 who received radiological imaging and RT-PCR for SARS-CoV-2. Demographic, clinical and laboratory parameters as well as RT-PCR results were used for subgroup analysis. Imaging data were reassessed using the following scoring system: 0 - not typical, 1 - possible, 2 - highly suspicious for COVID-19.

Results: COVID-19 was diagnosed in 72 (32,9%) patients. In three of them (4,2%) the initial RT-PCR was negative while initial CT scan revealed pneumonic findings. 111 (50,7%) patients, 61 of them (55,0%) COVID-19 positive, had evidence of pneumonia. Patients with COVID-19 pneumonia showed higher body temperature (37,7 ± 0,1 vs. 37,1 ± 0,1 °C; p = 0.0001) and LDH values (386,3 ± 27,1 vs. 310,4 ± 17,5 U/l; p = 0.012) as well as lower leukocytes (7,6 ± 0,5 vs. 10,1 ± 0,6G/l; p = 0.0003) than patients with other pneumonia. Among abnormal CT findings in COVID-19 patients, 57 (93,4%) were evaluated as highly suspicious or possible for COVID-19. In patients with negative RT-PCR and pneumonia, another third was evaluated as highly suspicious or possible for COVID-19 (14 out of 50; 28,0%). The sensitivity in the detection of patients requiring isolation was higher with initial chest CT than with initial RT-PCR (90,4% vs. 79,5%).

Conclusions: COVID-19 patients show typical clinical, laboratory and imaging parameters which enable a sensitive detection of patients who demand isolation measures due to COVID-19.

Keywords: COVID-19; Characteristics; Computed tomography; Laboratory parameters; Pneumonia; Respiratory infection; SARS-CoV2.

Fig. 1

Two COVID-19 patients with initially negative RT-PCR, but highly suspicious findings in initial CT scan. Patient A was tested positive for COVID-19 in the second RT-PCR and patient B in the fourth, while initial CT scan already revealed typical findings

Fig. 2

Flowchart illustrating the composition of our study population and subgroups

Fig. 3

Patients with suspected COVID-19 per week (16 March to 12 April 2020)

Fig. 4

Body temperature and laboratory values compared between ICU and Non-ICU subgroup within confirmed COVID-19 patients. “PCR +” includes COVID-19 patients confirmed by RT-PCR. * p < 0.05; ** p < 0.01; *** p < 0.001; ns = not significant

Fig. 5

Body temperature and laboratory values: 1) COVID-19 positive vs. negative, 2) COVID-19 pneumonia vs. other pneumonia. “PCR +” includes COVID-19 patients confirmed by RT-PCR. “PCR -“ includes patients with a negative result for SARS-CoV-2 in RT-PCR. “CT +” includes patients with pneumonic findings in chest CT. * p < 0.05; ** p < 0.01; *** p < 0.001; ns = not significant