Pre-Procedural COVID Testing: The “New Normal”

Dear Editors:

We read with great interest “Yield and Implications of Pre-Procedural COVID-19 PCR Testing on Routine Endoscopic Practice” by Forde et al,¹ describing the early experience of resuming endoscopic procedures at an academic university hospital with universal pre-procedural coronavirus disease 2019 (COVID-19) testing after a negative symptom screen. This important study comes as endoscopy units throughout the country and across varied practice settings consider ways to reopen to serve their patients, while balancing the risk of COVID-19 exposure and transmission to patients and the health care team, in light of the fact that endoscopic procedures are aerosol-generating.² The authors describe their pre-procedure process for symptom assessment involving a screening phone call and temperature and symptom assessment on the day of the procedure, in addition to polymerase chain reaction (PCR)–based COVID-19 testing 72 hours before the procedure, which can serve as a model for endoscopy practices developing their own operating protocols. It is important to note that full personal protective equipment was used, including N95 respirators, irrespective of all patients testing negative for COVID-19. Their key findings were that of the 396 COVID-19 swabs performed on asymptomatic patients, only 1 patient tested positive; none of the endoscopy staff developed symptoms of, or tested positive for, COVID-19; and the rate of COVID-19 in their patients was lower than that of the surrounding general population.

We practice at a large comprehensive cancer center within Los Angeles County and, as such, our patients have required endoscopic procedures as part of their time-sensitive cancer care as it relates to diagnosis, staging, and management of complications of cancer therapy. Due to their immunosuppressed states, they are also at the highest risk for morbidity and mortality if infected with COVID-19. On March 19, 2020, a stay at home order was issued across our state, the first such order in the country. We implemented symptom screening and temperature checks before entry into our medical center and cancelled all outpatient and nonemergent inpatient endoscopy beginning March 16, 2020. Institutional endoscopy guidelines for case selection, universal pre-procedure COVID-19 testing (Diasorin Simplexa COVID-19 Direct real-time reverse transcription PCR assay) 24 hours before the procedure (through an on-site, walk-in febrile respiratory clinic for outpatients) and within 24 hours for inpatients, and universal use of personal protective equipment, including N95 respirators, were adopted on March 24, 2020 based on the available data at the time.^{3 , 4} On April 13, 2020, a drive-through clinic was implemented for pre-procedural COVID-19 testing, which was universally required 24 hours before the procedure, with up to 72 hours being allowed for patients with procedures on Mondays. Between March 24 and May 31, 2020, a total of 290 PCR nasopharyngeal swabs for COVID-19 were performed on our endoscopy patients before procedures and none were positive. To date, none of our endoscopy staff have displayed symptoms of, or tested positive for, COVID-19. In this same time period in Los Angeles County, of the 582,931 citizens tested, 49,179 (8.5%) have tested positive, with no publicly available data on the rates in asymptomatic patients in our county.

Taken together, the data on universal pre-procedure COVID-19 testing of asymptomatic patients suggests a very low positive rate of 0.14% (1 of 686), as well as no instances of suspected or documented transmission to the endoscopy staff in the setting of negative-tested patients. However, our interpretation of the data differs from that of the authors. Given that asymptomatic spread of COVID-19 is well established^{5 , 6} and has likely contributed to the development of the pandemic,⁷ we believe that reliance on symptom-based screening has proven to be inadequate and has the real potential to cause an outbreak.^{6 , 7} Until further data are available from other endoscopy units using universal pre-procedural COVID-19 testing, we believe it is premature to suggest any alternative mode of screening. In fact, the current data simply support the recommendation for universal pre-procedure COVID-19 testing. We do agree that despite a negative COVID-19 test, full personal protective equipment should be used, given the possibility of a false negative and new infection between the time of test and endoscopy procedure.

We laud the authors for publishing their initial experience and hope that others from various practice settings will soon share their experience as well. Despite relaxing of social distancing regulations nationwide, we believe that ongoing vigilance is required to prevent the unintended spread in our endoscopy units and that the currently implemented strategies may be the “new normal.”