Appropriateness of routine pre-endoscopic SARS-CoV-2 screening with RT-PCR in asymptomatic individuals and its impact on delayed diagnosis

AIMS: Endoscopy units are considered to be at an increased risk of infection by SARS-CoV-2. Our aim is to assess the correlation between pre-endoscopic screening with reverse-transcription-polymerase-chain-reaction (RT-PCR) in asymptomatic individuals scheduled for elective endoscopy and the epidemiological data published by the local Health Administration. PATIENTS AND METHODS: Observational retrospective study collecting the results of our screening strategy spanning June/2020–June/2021, the effective potential growth (EPG), an index measuring the outbreak risk, and the 7 and 14-day cumulative incidence (CI). Indication, delay and the findings of the endoscopic examinations were registered for RT-PCR positive patients. RESULTS: A total of 5808 tests were performed, yielding 125 positive results (2.15%). All positive tests occurred in weeks of high/very high risk (EPG > 100) with the highest monthly rate being 9.36%, recorded in January/2021. A significant correlation (rho = 0.796; p < 0.001) between weekly positive rates and EPG was observed, and a significantly lower weekly number of positive tests was recorded when EPG < 100. Planning the screening strategy one week ahead according to EPG > 100 would have avoided up to 826 tests with only one positive result to account for. One hundred and thirteen individuals tested positive and 89 endoscopies were delayed. The most common findings were colon polyps, colorectal cancer and gastric metaplasia. Oncological diagnosis was delayed 50 ± 3 days. CONCLUSIONS: No positive RT-PCR test were registered out of high-risk periods. Epidemiological administrative data in the preceding two weeks showed a significant correlation with screening results and could be useful to plan pre-endoscopic screening and avoid unnecessary tests.