2024 Volume 39 Issue 6 Pages 228-232
An individual with COVID-19 is infectious during the pre-symptomatic period and even when they are asymptomatic. Consequently, many hospitals have introduced screening tests for individuals who are asymptomatic amid the COVID-19 pandemic. This study retrospectively investigates the impact of pre-admission screening tests on infection control measures.
We conducted a retrospective cohort study at Tokyo Medical and Dental University Hospital; pre-admission screening tests were conducted on patients scheduled for admission from April 1, 2020, to March 13, 2023. Samples were collected from the nasopharynx using a swab, and RT-PCR tests for SARS-CoV-2 were performed. The test results were retrospectively collected, and the positivity and false positivity rates were calculated by verifying the presence or absence of symptoms from the test results and medical records.
During the period, 45,979 tests were conducted. In total, 400 positive cases and 189 cases with pending results were recorded. However, the number of cases identified as new infections was 182, and the number of cases deemed as previous infections was 239. In total, 46 cases that tested negative in the pre-admission screening but were diagnosed after developing symptoms during hospitalization were recorded.
In the early stages of the pandemic, screening tests for individuals who were asymptomatic might have been beneficial for infection control; however, the number of positive cases per patient remained low. Following the emergence of the Omicron variant, the number of positive cases per patient increased with the onset of the epidemic. However, the number of pending results and the false positivity rate increased after the peak. Although a contribution to hospital infection control was observed from the pre-admission screening tests, it may have been possible to review and revise the operation at an earlier stage.
