Pre-endoscopy viral testing may not be necessary to prevent coronavirus transmission from patients to endoscopy staff members, according to a new study published in Gut.
Instead, using personal protective equipment (PPE) and ensuring up-to-date COVID-19 vaccination among the medical team was found to be enough to substantially reduce the risk of spreading SARS-CoV-2, wrote Alexander Hann, Dr.med., gastroenterologist at University Hospital Würzburg in Germany, and colleagues.
“We suggest that pre-selection of patients using respective questionnaires, vaccination, and particularly PPE appears to be sufficient for the prevention of SARS-CoV-2 transmission in GI endoscopy,” they wrote.
Dr. Hann and colleagues analyzed 15,750 endoscopies performed by 29 staff members during the period between May 2020 and December 2021. The researchers looked at three test approaches: No testing (4,543 patients), rapid antigen testing (682 patients), and real-time PCR testing (10,465 patients). In addition, 60 endoscopies were performed in patients with known COVID-19. Overall, no staff members became infected with SARS-CoV-2 during the study period. In all three scenarios, staff used PPE, and the vaccination rate of the team was 97%.
University Hospital Würzburg, with a tertiary endoscopy unit, is located in an area that had medium COVID-19 incidence during the study period. The hospital, which is spatially divided into a center for operative medicine and a center for internal medicine, required a negative PCR test for all endoscopies in the operative medicine center. In the internal medicine center, a PCR test was required only for in-patient procedures. Starting in January 2021 a negative rapid antigen test was required for patients scheduled for complex procedures with overnight surveillance; outpatient endoscopy procedures did not require a test.
All patients were interviewed before admission for COVID-19 symptoms, close contact with infected people, and recent travel to high-risk countries. Moreover, some endoscopies were performed even if a patient had positive markers for COVID-19.
The clinical team wore recommended PPE, including a high-filter FFP2 mask, one pair of gloves, protective eyewear, and disposable gowns. For patients with known COVID-19, staff wore two pairs of gloves, a disposable hairnet, and a water-resistant disposable gown. In addition, endoscopies were performed in negative pressure intervention rooms.
Among the 29 staff members involved, 16 physicians and 13 assistants worked in the endoscopy unit for at least 2 days per week for at least 6 months. The hospital’s internal policy required medical staff to undergo PCR testing if a rapid antigen test was positive or symptoms developed. Staff were vaccinated with two doses of the Pfizer-BioNTech vaccine in January and February 2021. A single booster dose of the Pfizer or Moderna vaccine was administered in November and December 2021.
The clinical team was not tested routinely, so asymptomatic infections may have existed. Moreover, the relatively low COVID-19 incidence in the local area might have influenced the risk of transmission. “However, even at the end of 2021, when the incidence was increasing, we did not see any higher risk of transmission,” the researchers explained.
“An important limitation of our study relates to the new variant Omicron that was dominant in our local area after the analyzed time frame.” Additional studies may be needed to understand the risk of transmission with the latest Omicron variants, and given the additional costs and implications on routine activity, current testing guidelines may need to be reconsidered.
“Although our data were not part of a randomized prospective study, we were able to demonstrate on a fairly high number of patients that PPE measures in addition to a short interview for assessment of a patient’s individual risks appear to be highly effective to control transmission of SARS-CoV-2 during an endoscopy. ... Pre-procedural RT-PCR testing or RA testing did not show any additional benefit,” Dr. Hann and colleagues concluded.
The authors reported no conflicts of interest.