Clinical and Pulmonary CT Characteristics of Patients Infected With the SARS-CoV-2 Omicron Variant Compared With Those of Patients Infected With the Alpha Viral Strain

Abstract

BackgroundOmicron has become the dominant variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) globally. We aimed to compare the clinical and pulmonary computed tomography (CT) characteristics of the patients infected with SARS-CoV-2 Omicron with those of patients infected with the Alpha viral strain.MethodsClinical profiles and pulmonary CT images of 420 patients diagnosed with coronavirus disease-2019 (COVID-19) at Ningbo First Hospital between January 2020 and April 2022 were collected. Demographic characteristics, symptoms, and imaging manifestations of patients infected with the SARS-CoV-2 Omicron variant were compared with those of patients infected with the Alpha strain.ResultsA total of 38 patients were diagnosed to be infected with the Alpha strain of SARS-CoV-2, whereas 382 patients were thought to be infected with the Omicron variant. Compared with patients infected with the Alpha strain, those infected with the Omicron variant were younger, and a higher proportion of men were infected (P < 0.001). Notably, 93 (24.3%) of the patients infected with Omicron were asymptomatic, whereas only two (5.3%) of the patients infected with the Alpha strain were asymptomatic. Fever (65.8%), cough (63.2%), shortness of breath (21.1%), and diarrhea (21.1%) were more common in patients infected with the SARS-CoV-2 Alpha strain, while runny nose (24.1%), sore throat (31.9%), body aches (13.6%), and headache (12.3%) were more common in patients with the Omicron variant. Compared with 33 (86.84%) of 38 patients infected with the Alpha strain, who had viral pneumonia on pulmonary CT images, only 5 (1.3%) of 382 patients infected with the Omicron variant had mild foci. In addition, the distribution of opacities in the five patients was unilateral and centrilobular, whereas most patients infected with the Alpha strain had bilateral involvement and multiple lesions in the peripheral zones of the lung.ConclusionThe SARS-CoV-2 Alpha strain mainly affects the lungs, while Omicron is confined to the upper respiratory tract in patients with COVID-19.

Variants and Vaccination of COVID-19: New Complexities for Chest Imaging Research and Clinical Practice

“…Recent studies have also shown differences in imaging appearance and severity between breakthrough infections in vaccinated individuals and infections in the unvaccinated, even comparing different vaccine types ( 2 ). Differences in radiological severity of pneumonia between SARS-CoV-2 variants have also been documented previously, including comparisons of the Alpha strain to Omicron ( 3 ), and Omicron to Delta ( 4 ).…”

Effect of vitamin D status on adult COVID-19 pneumonia induced by Delta variant: A longitudinal, real-world cohort study

“…Till April 1, 2022, a total of 161 discharged adult patients infected with the Delta variant were included in this study, of which 101 (63%) were male and 46 (29%) presented with pneumonia. The median (IQR) age and baseline 25-hydroxyvitamin D concentration were 37 (28-47) years and 21 (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27) ng/ml, respectively. There were significant differences in age (34 vs. 43 years; p < 0.001), SARS-CoV-2 IgM titer (0.3 vs. 0.1 AU/ml; p = 0.002), SARS-CoV-2 IgG seropositive (84 vs. 44%; p < 0.001), and titer (82.8 vs. 3.3 AU/ml; p < 0.001), lymphocyte (1.36 vs. 0.87 × 10^9/L; p = 0.002) and platelet count (224 vs. 200 × 10^9/L; p = 0.04), fibrinogen (2.9 vs. 3.3 g/L; p < 0.001), and aspartate aminotransferase (27 vs.…”

SARS-CoV-2: The Impact of Co-Infections with Particular Reference to Mycoplasma pneumonia—A Clinical Review

“…In the severe form, the failure of immune response may be linked to insufficient type 1 interferon production or signaling, attenuated or skewed adaptive immune response, which may also be due to viral immune escape properties [ 14 ]. Clinical and pulmonary expression differ in patients affected by different variant strains: Yang et al [ 15 ] showed that SARS-CoV-2 Alpha strain mainly affect the lung, while SARS_CoV-2 Omicron affects mainly the upper respiratory tract.…”

“…The infection may be associated with episodes of skin rush, joint pain, and gastrointestinal symptoms. Hemolytic disorder related to IgM antibodies producing a cold agglutinin reaction has been reported and cardiac involvement with conductive abnormalities on ECG and congestive heart failures may be uncommon but possible complications [ 15 , 16 , 17 ]. Similar to SARS-CoV-2, M. pneumoniae involves mainly the respiratory tract but systemic organs may also be involved [ 15 ].…”

“…Hemolytic disorder related to IgM antibodies producing a cold agglutinin reaction has been reported and cardiac involvement with conductive abnormalities on ECG and congestive heart failures may be uncommon but possible complications [ 15 , 16 , 17 ]. Similar to SARS-CoV-2, M. pneumoniae involves mainly the respiratory tract but systemic organs may also be involved [ 15 ]. Several cases of co-infection of SARS-CoV-2 with other respiratory agents, including M.pneumoniae has been reported in the literature.…”