COVID-19 in Egypt after a year: the first and second pandemic waves from the radiological point of view; multi-center comparative study on 2000 patients

Abstract

Background One year has passed since the announcement of COVID-19 as a pandemic and two waves had already stricken Egypt. The authors witnessed several atypical radiological features through the second pandemic wave, either early at the active infective stage or delayed at the post-infectious convalescent period. They believed every radiologist should be familiar with these features. Therefore, they performed this comparative study on 2000 Egyptian patients using multi-slice computed tomography (MSCT) to highlight the radiological differences between the first and second pandemic waves and correlate them to the clinical status. Results This random multi-center comparative study was retrospectively conducted on 2000 COVID-19 Egyptian patients; 1000 patients were registered at the first pandemic wave from April 2020 till September 2020, while the other 1000 patients were registered at the second pandemic wave from October 2020 till March 2020. Follow up CT examinations were performed for 49 and 122 patients through the first and second pandemic waves respectively. MSCT examinations were carefully evaluated by four expert consulting radiologists who came to a consensus. Meanwhile, the correlation with the clinical outcome was performed by two consulting pulmonologists. During the second pandemic wave, the prevalence rate of the “crazy-paving” pattern had significantly increased by 1.3 times (P value = 0.002). Additionally, the prevalence rate of the “air-bubble” sign had significantly increased by 1.9 times (P value = 0.02). Similarly, the presence of enlarged mediastinal lymph nodes (> 1 cm in short-axis diameter) had significantly increased by 1.7 times (P value = 0.036). Furthermore, the prevalence rate of pericardial effusion had significantly increased by 2.5 times (P value = 0.003). The above-mentioned signs were correlated to increased clinical severity and higher rates of hospitalization. Unexpectedly, other atypical radiological signs were only encountered through the second pandemic wave, including bronchiectatic changes (2.5%), “head-cheese” pattern (0.8%), cavitation (0.5%), and “bulls-eye” sign (0.2%). The prevalence rate of post-COVID fibrosis had doubled through the second wave but not in a significant way (P value = 0.234). Secondary fungal infection was only encountered throughout the second pandemic wave in four patients. COVID-19 reinfection was encountered in a single patient only during the second pandemic wave. Conclusion After 1 year from the announcement of COVID-19 as a pandemic, the radiological presentation of COVID-19 patients showed some significant differences between its first and second waves.

Correlation between chest CT scores and clinical impact in patients re-infected with COVID-19 during the two attacks: an observational study

“…We found two studies that compared CT findings of different patients between the first and second pandemic waves, one done in Ghana [ 31 ] and the other in Egypt [ 18 ]. In our study, we compared CT findings in the same patients that infected twice.…”

“…In the study done in Egypt [ 18 ], they reported some atypical CT findings which were only encountered during the second pandemic wave. They included the bronchiectatic changes, the “head-cheese” pattern, the “bulls-eye” sign and the cavitation.…”

“…In the Egyptian study [ 18 ], they reported 10% rise in the clinical and CT severity-score as well as the hospitalization rates in the second pandemic wave reported through the fourth and fifth decades of life.…”

“… Atoll sign represents an area of GGO surrounded by near complete ring of consolidation [ 17 ]. “Bull’s-eye sign” or “Target sign” or “Double-halo” Central nodule or consolidation and peripheral organization rim with ground glass in between [ 18 ]. “Crazy-paving pattern” represent thickened interlobular septa superimposed on GGO [ 17 ].…”

“…“Bull’s-eye sign” or “Target sign” or “Double-halo” Central nodule or consolidation and peripheral organization rim with ground glass in between [ 18 ].…”