The utility of chest computed tomography (CT) and RT-PCR screening of asymptomatic patients for SARS-CoV-2 prior to semiurgent or urgent hospital procedures

Abstract

Objective: At present, there is a paucity of evidence guiding clinicians on the optimal approach to safely screen patients for SARS-CoV-2 (COVID-19) infection prior to a non-emergent hospital procedure. In this report we describe our experience in screening for SARS-CoV-2 (COVID-19) prior to semi-urgent and urgent hospital procedures. Design: Retrospective case series. Setting: Single tertiary medical center. Participants: Patients ≥ 18 years of age who had semi-urgent or urgent hospital procedures or surgeries. Methods: 625 patients were screened for SARS-CoV-2 (COVID-19) using a combination of phone questionnaire (7 days prior to the anticipated procedure), RT-PCR and chest CT, between 3/1/2020 and 4/30/2020. Results: Of the 625 patients, 520 scans (83.2%) were interpreted as normal, 1 (0.16%) as having typical features, 18 scans (2.88%) as having indeterminate features, and 86 (13.76%) as having atypical features of SARS-CoV-2 (COVID-19). A total of 640 RT-PCRs were performed, with 1 positive result (0.15%) in a patient with CT scan read as atypical. Out of 18 patients with chest CTs categorized as indeterminate, 5 underwent repeat negative RT-PCR nasopharyngeal swab one week after their initial swab. 1 patient with chest CT categorized as typical had a follow up repeat negative RT-PCR, indicating that the chest CT was likely a false positive. None of the patients, after surgery, developed signs or symptoms suspicious of COVID-19, needing repeat RT-PCR or CT scan. Conclusion: In our experience, chest CT scanning did not prove provide valuable information in detecting asymptomatic cases of SARS-CoV-2 (COVID-19) in our low prevalence population.

Global Percentage of Asymptomatic SARS-CoV-2 Infections Among the Tested Population and Individuals With Confirmed COVID-19 Diagnosis

“…Among 95 studies, 18 were excluded because that the percentage of asymptomatic infections among the confirmed population was 100%. 22 , 30 , 31 , 36 , 39 , 43 , 49 , 56 , 58 , 71 , 77 , 79 , 80 , 81 , 87 , 96 , 101 , 108 The remaining 77 studies were included in the meta-analysis for the percentage of asymptomatic infections among the confirmed population, 12 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 32 , 33 , 34 , 35 , 37 , 38 , 40 , 41 , 42 , 44 , 45 , 46 , 47 , 48 , 50 , 51 , 52 , 53 , 54 , 55 , 57 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 <...>…”

“…Among 95 studies, 18 were excluded because that the percentage of asymptomatic infections among the confirmed population was 100%. 22,30,31,36,39,43,49,56,58,71,77,[79][80][81]87,96,101,108 The remaining 77 studies were included in the meta-analysis for the percentage of asymptomatic infections among the confirmed population, 3).…”

Asymptomatic COVID-19 infection: diagnosis, transmission, population characteristics

“…In lowprevalence populations, CT chest scans may be more effective in detecting asymptomatic cases. 14 It has also been found to be more reliable for early diagnosis in the elderly, but less reliable in young children. 15 16 We suggest adopting the method of joint testing.…”

Pre-operative prevalence of asymptomatic carriers of COVID-19 in hospitals in Catalonia during the first wave after the resumption of surgical activity

“…The incubation period ranges from 2 to 14 days after exposure to the virus, and the first symptoms appear within the first 5 days of exposure in 50% of cases 3 . Transmission from asymptomatic or presymptomatic subjects has been clearly documented, and the proportion of asymptomatic infections is between 0.13% and 41%, according to different studies 4 , 5 , 6 , 7 , 8 , 9 .…”