Abdulkarim, S., Butt, A., Abdullah, K., Ali, A., Fatima, S., Sattar, S., Hajani, Z., Ali, H. (2023). COVID-19 Infection and Endoscopy–Is Symptom-Based Screening Enough before Proceeding for Endoscopy?. Afro-Egyptian Journal of Infectious and Endemic Diseases, 13(4), 240-248. doi: 10.21608/aeji.2023.239644.1325
Saleem Abdulkarim; Amna Butt; Khadijah Abdullah; Abid Ali; Samar Fatima; Saadia Sattar; Zainish Hajani; Haider Ali. "COVID-19 Infection and Endoscopy–Is Symptom-Based Screening Enough before Proceeding for Endoscopy?". Afro-Egyptian Journal of Infectious and Endemic Diseases, 13, 4, 2023, 240-248. doi: 10.21608/aeji.2023.239644.1325
Abdulkarim, S., Butt, A., Abdullah, K., Ali, A., Fatima, S., Sattar, S., Hajani, Z., Ali, H. (2023). 'COVID-19 Infection and Endoscopy–Is Symptom-Based Screening Enough before Proceeding for Endoscopy?', Afro-Egyptian Journal of Infectious and Endemic Diseases, 13(4), pp. 240-248. doi: 10.21608/aeji.2023.239644.1325
Abdulkarim, S., Butt, A., Abdullah, K., Ali, A., Fatima, S., Sattar, S., Hajani, Z., Ali, H. COVID-19 Infection and Endoscopy–Is Symptom-Based Screening Enough before Proceeding for Endoscopy?. Afro-Egyptian Journal of Infectious and Endemic Diseases, 2023; 13(4): 240-248. doi: 10.21608/aeji.2023.239644.1325
COVID-19 Infection and Endoscopy–Is Symptom-Based Screening Enough before Proceeding for Endoscopy?
1Department of Medicine, Aga Khan University Hospital Karachi, Karachi, Pakistan.
2Department of Pediatrics and Child Health, Aga Khan University Hospital, Karachi, Pakistan.
Abstract
Background and study aim: The coronavirus disease 2019 (COVID-19) substantially affected healthcare systems including endoscopy services worldwide. Besides using PPE, pre-procedure symptom screening was adopted by the majority. The role of polymerase chain reaction (PCR) testing in addition to symptom-based screening over a longer period that includes a post-pandemic environment needed further investigation. This study aimed to evaluate the outcome of COVID-19 screening using PCR testing in low-risk patients narrowed down by a symptom-based pre-procedure screening tool during five waves of COVID-19. Patients and Methods: This cross-sectional study was performed from June 2020 to March 2022. Patients aged ≥ 18 years with no symptoms screened via COVID-19 risk screening questionnaire, who underwent endoscopy procedures at Aga Khan University Hospital, Karachi, were reviewed. Patients who already had positive COVID-19 tests or had COVID-19 in the preceding month were excluded. COVID-19 Reverse Transcriptase PCR on nasopharyngeal swabs was performed within 72 hours pre-procedure. World Health Organization (WHO) timelines were used to define time limits for five COVID-19 waves. Results: Of 7198 patients booked for endoscopic procedures, 4967 (69.0%) patients were tested for COVID-19. The mean age was 47.6 ± 15.9 years and 44.9% were female. Overall COVID-19 positivity rate was 2.7% with the highest rate of 11.9% in the fifth COVID-19 wave followed by the first wave (2.4%). Conclusion: There was a low overall occurrence of COVID-19 infection, apart from the fifth wave in asymptomatic patients undergoing endoscopic procedures. Therefore, increasing compliance with COVID-19 vaccination and conducting thorough symptom-based screening before endoscopic procedures could eliminate the necessity for RT-PCR testing.
Highlights
The overall incidence of COVID-19 infection in low-risk patients screened via the COVID-19 PCR before endoscopic procedures was low except during the fifth COVID-19 wave.
Increasing compliance with a thorough symptom-based screening before endoscopic procedures could eliminate the necessity for RT-PCR testing
Screening strategies for COVID-19 before endoscopy need to take into consideration contextual factors such as local prevalence of disease, compliance with vaccination, and prevalence of mutated virus species.
In December 2019, clusters of cases with severe acute respiratory distress syndrome (ARDS) emerged in Wuhan, China. The pathogen responsible, a novel coronavirus i.e., “severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2),” rapidly spread globally, leading to the declaration of a pandemic. Its highly contagious nature resulted in rapid outbreaks in numerous countries and across all continents [1–5].
The respiratory droplets generated during coughing, sneezing, or talking even at a distance of less than one meter are the primary source of transmission for SARS-CoV-2. The virus could also be transmitted if a person makes direct contact with the mucous membrane of an infected patient, touches an infected surface, and then touches his or her eyes, nose, or mouth. The incubation period for SARS-CoV-2 is within 14 days following the exposure. Moreover, human-to-human transmission can occur from individuals in the pre-incubation period, asymptomatic carriers, or individuals with mild symptoms [6]. Additionally, the virus survives in aerosols (for hours), and on solid surfaces (up to days) adding the risk of aerosol and fomite transmission [7].
The most common signs and symptoms of this disease include fever, cough, sore throat, dyspnea, myalgia, diarrhea, loss of smell or taste, and pneumonia along with a history of travel or contact. The diagnosis of coronavirus disease 2019 (COVID-19) is made by the detection of SARS-CoV-2 ribonucleic acid by nucleic acid amplification tests (NAATs), primarily reverse transcription-polymerase chain reaction (RT-PCR) on specimens collected by nasopharyngeal or oropharyngeal swabs. A positive test for SARS-CoV-2 generally confirms the diagnosis of COVID-19 [8].
While multiple ongoing trials to explore definitive treatment and vaccination have been done, currently, the one major established way to prevent this disease is to avoid cross-transmission. Hence, besides practicing social distancing and hygienic measures to prevent cross-transmission in communities, strategies have been adopted to minimize the risk of bidirectional transmission through healthcare facilities. Therefore, across the world, healthcare systems have prioritized the delivery of care to those requiring hospitalization, emergent, or urgent surgeries, and invasive procedures, while limiting outpatient clinics, and elective procedures [9–11].
Considering almost a three times higher rate of SARS-CoV-2 infection reported among healthcare workers (HCWs) than the general population it became very obvious that healthcare facilities are at a higher risk of nosocomial spread [11–13]. Due to positive insufflation during endoscopic procedures and droplet generation with coughing, upper gastrointestinal (GI) endoscopy procedures are considered high aerosol-generating procedures and a potential source of airborne transmission for SARS-CoV-2 in the hospital setting. Moreover, fecal-oral transmission during lower GI endoscopy procedures emerged as a concern since the virus has been identified in the stools of infected patients [7,9]. Additionally, the droplets from infected patients could reach individuals present two meters or more from the source [14]. Therefore, direct contact with the secretions or aerosols generated during the endoscopy of an infected patient is likely to expose the endoscopist and the assisting staff to an increased risk of acquiring SARS-CoV-2 [15–17].
From the start, the primary focus was to prevent nosocomial transmission of SARS-CoV-2 among HCWs and patients while providing endoscopic services. Besides confirmation of SARS-CoV-2 infection among HCWs after endoscopies of infected patients in a multicenter survey conducted in Italy, endoscopy units also confirmed SARS-CoV-2 among physicians and nurses who required hospitalizations [18]. False-negative results for COVID-19 tests were also observed after testing 4,700 patients who underwent endoscopy [19]. Hence, in addition to the mandatory use of personal protective equipment (PPE), several international gastrointestinal (GI) societies recommended performing time-sensitive endoscopies and delaying elective endoscopies during the COVID-19 pandemic, substantially affecting endoscopy services worldwide [10,20–22].
At our tertiary care center, since June 8, 2020, pretesting for COVID-19 by RT-PCR on a nasopharyngeal swab was made mandatory within seventy-two hours before any endoscopic procedure. Such policies were not being practiced across Pakistan except at very few other institutions mainly due to the huge cost incurred with these tests. Furthermore, at that point, there was a lack of consensus on the utilization of PCR or antibody testing for SARS-CoV-2 before endoscopy to identify asymptomatic carriers [10,23]. Since the resumption of endoscopy services was of major concern, the American College of Gastroenterology and the British Society of Gastroenterology developed guidelines for the resumption phase. Screening by testing for SARS-CoV-2 via RT-PCR on nasopharyngeal swabs or antibody tests before endoscopy in all or selected cases to identify asymptomatic carriers is difficult to implement in all patients, especially in resource-constrained settings [10]. Hence, besides using PPE, triage using a pre-endoscopy COVID-19 clinical screening questionnaire was made mandatory. The American Gastroenterology Association (AGA) conducted a rapid review in 2021 which recommended against routine pre-procedural testing for SARS-CoV-2 in patients scheduled to undergo endoscopy stating that it causes unnecessary delays in patient care that may lead to increased overall morbidity and mortality [24]. Therefore, it is imperative to evaluate the usefulness of symptom-based screening with or without COVID-19 PCR testing to identify asymptomatic patients with COVID-19 infection undergoing endoscopic procedures. This information is especially important in a post-pandemic world where COVID-19 cases are isolated or minimal, and only occur sporadically in a small subset of the population. This would allow us to adopt the best strategies for the early identification of patients asymptomatic for COVID-19 and minimize the risk of nosocomial transmission of SARS-CoV-2 to HCWs. This research would also aid in planning future COVID-19 transmission prevention initiatives cost-effectively and, based on the result of the study, further research can be conducted on a wider level. Hence this study aimed to evaluate the outcome of COVID-19 screening using PCR testing in low-risk patients narrowed down by a symptom-based pre-procedure screening tool during five waves of COVID-19.
PATIENTS/MATERIALS AND METHODS
This cross-sectional study was performed from June 2020 to March 2022. Patients aged ≥ 18 years with no symptoms screened via COVID-19 risk screening questionnaire, who underwent endoscopy procedures as outpatient or inpatient at Aga Khan University Hospital, Karachi, were reviewed. Patients who declined to test COVID-19 PCR had positive COVID-19 tests, or had COVID-19 in the preceding month were excluded. Additionally, patients who were booked for an endoscopic procedure but did not have a COVID-19 PCR done within seventy-two hours of the scheduled procedure were not included in the study. COVID-19 Reverse Transcriptase PCR on nasopharyngeal swabs was performed within 72 hours pre-procedure. World Health Organization (WHO) timelines were used to define time limits for five COVID-19 waves. Patients with a positive PCR or who were asymptomatic were appropriately referred for further clinical assessment and care. Staff involved in the performance of the various endoscopy procedures were required to observe standard precautions as well as the use of PPE during the performance of endoscopy.
Records of these patients undergoing endoscopy were reviewed and data were collected using a standardized data collection tool which included: Age, gender, comorbid conditions, any symptoms of COVID-19, indication for endoscopy, and results of COVID-19 PCR test. The symptom-based screening included a yes/no response to the following items: Fever, difficulty in breathing, cough, shortness of breath, runny nose/sneezing, chest pain, new onset loss of taste or smell, recent onset fatigue, nausea with or without diarrhea, and travel history. The rates of COVID-19 PCR positivity were determined according to the five waves of COVID-19 infection as per WHO timelines to determine any variations in COVID-19 positivity through the various waves of disease.
The data was entered and analyzed by using Statistical Package for Social Science (SPSS). A descriptive analysis was performed, and results were presented as mean with standard deviation for quantitative variables and frequency with percentage for qualitative variables. A comparative analysis was done using an independent t-test and Pearson’s Chi-square test where applicable. All p-values were two-sided and considered statistically significant if < 0.05.
RESULTS
Over the study period, which spanned from June 2020 to March 2022, 7198 patients had been booked for endoscopic procedures in outpatient and inpatient settings. Of these, 4967 patients (69%) had a COVID-19 PCR done within 72 hours before endoscopy and 2231 (31%) did not have a COVID-19 PCR done before endoscopy. Of the 4967 who had a COVID-19 PCR done, 4834 (97.3%) had a negative test and 133 (2.7%) had a positive test. The distribution of positive cases every year is shown below in Figure 1.
There was a progressive rise in the number of positive cases identified from 23 per year to 41 then 69 from 2020 to 2022. The total proportion of positive cases throughout the study period was 133/4967 (2.7%).
The distribution of positive cases was further analyzed and determined as per the waves of COVID-19 infection during the study period to determine whether there was any change in the trend of positive cases in patients who were asymptomatic for COVID-19 infection. The distribution was as follows: 15/616 (2.4%) during the first wave, 21/1313 (1.6%) during the second wave, 16/1197 (1.3%) during the third wave, 12/1263 (1.0%) during the fourth wave and 69/578 (11.9%) during the fifth wave. There was a sequential decline in positive rates from the first to the fourth wave and a spike during the fifth wave of COVID-19 infection. This is summarized in Table 1 and illustrated graphically in Figure 2.
A total of 4967 patients were planned for procedures in the endoscopy unit during the study period. They included various diagnostic and therapeutic procedures and advanced endoscopy procedures such as endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS). An analysis of the procedures was done to determine the relative frequencies of the various procedures. The most common procedures were esophagogastro-duodenoscopy (EGD) (2664/4967;53.6%), colonoscopy (1237/4967; 24.9%), combined EGD and colonoscopy/sigmoidoscopy (398/4967; 8%), ERCP (201/4967; 4%) and flexible sigmoidoscopy (182/4967; 3.7%). Rates of positive cases depending on procedure were also determined and found to be as follows: EGD (81/2664; 3%), colonoscopy (24/1237; 1.9%), combined EGD and colonoscopy/sigmoidoscopy (12/398; 3%), ERCP (8/201; 3.9%) and flexible sigmoidoscopy (5/182; 2.7%). Frequencies of the various procedures and the rates of positive tests are summarized in Table 2.
Table 1. Frequency distribution of positive and negative cases undergoing preprocedural PCR testing in the different waves of COVID-19, n (%)
First
Second
Third
Fourth
Fifth
Total
Negative
601 (97.6)
1292 (98.4)
1181 (98.7)
1251 (99.0)
509 (88.1)
4834 (97.3)
Positive
15 (2.4)
21 (1.6)
16 (1.3)
12 (1.0)
69 (11.9)
133 (2.7)
Total
616
1313
1197
1263
578
4967
Table 2. Frequency distribution of COVID-19 positive and negative cases based on the procedure performed.
The COVID-19 pandemic has not only posed a significant burden of morbidity and mortality globally but has also significantly impacted healthcare delivery [25]. Studies indicate there seems to be a significant impact of the pandemic particularly in developing countries and limited resource settings with effects likely to persist longer due to relatively weaker health infrastructure and slower uptake of vaccines [26]. This effect on disruption of healthcare service delivery has significantly affected the performance of important diagnostic and therapeutic procedures including endoscopy [21, 22].
The pandemic has been associated with a global reduction in the volume of endoscopies performed. A global 2020 survey of 155 endoscopy units distributed over 55 countries revealed up to a greater than 80% reduction in the volume of endoscopies done compared to baseline. Data from Asian endoscopy units reported a 16.3% rate of endoscopy performance after the start of the pandemic compared to the baseline [22].
There has been concern about the possibility of COVID-19 transmission due to the aerosol-generating potential of the procedure and this has been thought to partly contribute to the reduction in endoscopy volume among other factors. In addition, COVID-19 infection appears to be transmitted via both symptomatic and asymptomatic individuals raising the concern about the need for screening asymptomatic patients before aerosol-generating procedures that are associated with a higher risk of infection transmission. For this reason, various pre-procedure testing strategies have also been explored [27].
The AGA issued guidance on the matter of COVID-19 testing in the pre-endoscopy setting [24]. The recommendations made were to implement universal COVID-19 symptom screening and avoid routine pre-procedure testing. This was based on a low prevalence of positive cases in asymptomatic individuals ranging from 0.0% to 1.5% even in the setting of surges of local rates in COVID-19 cases. The data was derived from developed countries with studies mostly from the USA and Europe [28–39].
To our knowledge, there is a lack of locally published data on pre-endoscopy COVID-19 testing strategy from Pakistan. This study was therefore done to evaluate a symptom-based screening approach to gain local data to add to the body of evidence in this area and guide decision-making in a limited-resource setting and a different epidemiological and potentially different clinical context. A study on waves of COVID-19 infection in Pakistan revealed five distinct waves of COVID-19 infection locally and this study also further sought to investigate for variations in positive PCR tests in asymptomatic individuals for the virus during the different waves of COVID-19 disease [40].
This study involved 4967 patients planned for various endoscopic procedures over 22 months with an overall positive rate for COVID-19 of 2.7% in asymptomatic patients. Previous studies on pre-procedure COVID-19 testing had revealed low rates of positive cases in asymptomatic individuals which formed the basis of the AGA recommendation against routine pre-procedure COVID-19 testing [24,28–40]. Subsequent further studies continued to show low rates of positive tests in even larger cohorts [41,42]. However, one study from an Egyptian center revealed a positive COVID-19 PCR rate of 13%, although the sample population, in this case, was relatively smaller at 103 asymptomatic individuals screened before endoscopy [43].
Our study revealed a low overall COVID-19 positivity rate of 2.7% with the highest rate of 11.9% in the 5th COVID-19 wave followed by the 1st wave (2.4%). The positive rate in asymptomatic patients was particularly high in the 5th wave, thus a possible basis to perform PCR testing in addition to symptom-based screening. We hypothesize that the higher positive rate may be due to several reasons including reduced compliance with standard precautions for reducing COVID-19 transmission in the general population, decreased compliance with vaccination, and acceleration of transmission of mutated variants of the virus during 1st and 5th wave. Moreover, considering the low prevalence in asymptomatic patients, symptom-based screening without PCR tests will improve compliance and turnover rate.
PCR-based COVID-19 screening before endoscopy may have to therefore take into consideration a regional burden of infection, vaccination status of HCWs and the general population, availability of PPE, as well as mutated forms of the virus to mitigate the risk of transmission to HCWs, other patients and at the same time, form a basis for rational use of PPE. However, studies do suggest that even in the absence of testing in asymptomatic, transmission risk to HCWs appears to be minimal. In the retrospective study by Hann et al, 15 750 procedures were assigned to either no screening (n=4543), screening using antigen testing (n=682), or screening by PCR resting (n=10 465) [44]. Over the 20-month study period, however, there was no incident case of COVID-19 disease among twenty-nine vaccinated staff involved in the performance of procedures. However, the risk when prevalence is high as was in the case in this study during the fifth wave of infection may need further investigation.
While the study was conducted during the pandemic, it still holds importance in a post-pandemic world for several reasons. Insight into the prevalence and screening of asymptomatic COVID-19 cases during endoscopic procedures is valuable information in helping to prepare for potential future outbreaks or similar infectious diseases, ensuring appropriate screening protocols and infection control measures are in place. Furthermore, it highlights the importance of implementing standardized screening procedures and testing protocols within healthcare settings, enhancing the preparedness of healthcare systems in identifying and managing infectious diseases, even when positivity rates fall below 0.5%. This can help guide risk assessment and decision-making processes, ensuring the safety of both patients and HCWs. Understanding these numbers can assist in optimizing resource allocation which helps healthcare institutions allocate precious resources effectively, especially in resource-constrained settings. Moreover, our findings highlight the need for adaptability according to the state of the pandemic. This flexibility is crucial for adjusting screening and testing strategies as needed, considering the dynamic nature of infectious diseases.
Our study has a large sample size and spans five waves of the pandemic, which increases the generalizability of our results and provides a comprehensive picture of the impact of the disease, capturing all potential variations in data. Standardized data collection and institution-wide policy of preprocedural testing ensure that data is consistent and decrease the likelihood of missing relevant cases. Limitations of our study include reduced generalizability due to a single-center setting, selection bias due to the strict 72-hour PCR testing inclusion criteria, and the retrospective study design. Moreover, our study did not explore the incidence of new COVID-19 infection among endoscopy staff during the period.
CONCLUSION
There was a low overall occurrence of COVID-19 infection, apart from the fifth wave in asymptomatic patients undergoing endoscopic procedures. Therefore, increasing compliance with COVID-19 vaccination and conducting thorough symptom-based screening before endoscopic procedures could eliminate the necessity for RT-PCR testing.
Funding: None. Author funded.
Conflict of Interest: None.
Ethical approval of the study was obtained from the Aga Khan University Ethical Review Committee (ERC) (ERC reference 2021-6504-18861). Patient anonymity was maintained. Patient data was stored on secured files that were accessible by only the primary investigator and coinvestigators.
References
WHO Coronavirus (COVID-19) Dashboard [Internet]. [cited 2023 Jun 28]. Available from: https://covid19.who.int
Wu F, Zhao S, Yu B, Chen YM, Wang W, Song ZG, et al. A new coronavirus associated with human respiratory disease in China. Nature. 2020 Mar; 579(7798):265–9.
Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, et al. A Novel Coronavirus from Patients with Pneumonia in China, 2019. N Engl J Med. 2020 Feb 20;382(8):727–33.
Danese S, Ran ZH, Repici A, Tong J, Omodei P, Aghemo A, et al. Gastroenterology department operational reorganization at the time of COVID-19 outbreak: an Italian and Chinese experience. Gut. 2020 Jun;69(6):981–3.
Deluche E, Salle H, Facchini-Joguet T, Leobon S, Troussel A, Tubiana-Mathieu N, et al. [High fidelity simulation training for medical oncology announcement consultation]. Bull Cancer (Paris). 2020 Apr;107(4):417–27.
Wang W, Xu Y, Gao R, Lu R, Han K, Wu G, et al. Detection of SARS-CoV-2 in Different Types of Clinical Specimens. JAMA. 2020 May 12;323(18):1843–4.
Wang Y, Wang Y, Chen Y, Qin Q. Unique epidemiological and clinical features of the emerging 2019 novel coronavirus pneumonia (COVID-19) implicate special control measures. J Med Virol. 2020 Jun;92(6):568–76.
Repici A, Maselli R, Colombo M, Gabbiadini R, Spadaccini M, Anderloni A, et al. Coronavirus (COVID-19) outbreak: what the Department of Endoscopy should know. Gastrointest Endosc. 2020 Jul;92(1):192–7.
Lui RN, Wong SH, Sánchez-Luna SA, Pellino G, Bollipo S, Wong MY, et al. Overview of guidance for endoscopy during the coronavirus disease 2019 pandemic. J Gastroenterol Hepatol. 2020 May; 35(5):749–59.
Chang D, Xu H, Rebaza A, Sharma L, Dela Cruz CS. Protecting health-care workers from subclinical coronavirus infection. Lancet Respir Med. 2020 Mar;8(3):e13.
Remuzzi A, Remuzzi G. COVID-19 and Italy: What next? The Lancet. 2020 Apr 11; 395(10231):1225–8.
Wong T wai, Lee C kei, Tam W, Lau JT fai, Yu T sun, Lui S fai, et al. Cluster of SARS among Medical Students Exposed to Single Patient, Hong Kong. Emerg Infect Dis. 2004 Feb;10(2):269–76.
Zhang Y, Zhang X, Liu L, Wang H, Zhao Q. Suggestions for infection prevention and control in digestive endoscopy during current 2019-nCoV pneumonia outbreak in Wuhan, Hubei province, China. Endoscopy. 2020 Apr;52(4):312–4.
Li LY, Wu W, Chen S, Gu JW, Li XL, Song HJ, et al. Digestive system involvement of novel coronavirus infection: Prevention and control infection from a gastroenterology perspective. J Dig Dis. 2020 Apr;21(4):199–204.
Chiu PWY, Ng SC, Inoue H, Reddy DN, Ling Hu E, Cho JY, et al. Practice of endoscopy during COVID-19 pandemic: position statements of the Asian Pacific Society for Digestive Endoscopy (APSDE-COVID statements). Gut. 2020 Jun;69(6):991–6.
Repici A, Pace F, Gabbiadini R, Colombo M, Hassan C, Dinelli M, et al. Endoscopy Units and the Coronavirus Disease 2019 Outbreak: A Multicenter Experience From Italy. Gastroenterology. 2020 Jul;159(1):363-366.e3.
Corral JE, Hoogenboom SA, Kröner PT, Vazquez-Roque MI, Picco MF, Farraye FA, et al. COVID-19 polymerase chain reaction testing before endoscopy: an economic analysis. Gastrointest Endosc. 2020 Sep;92(3):524-534.e6.
Castro Filho EC, Castro R, Fernandes FF, Pereira G, Perazzo H. Gastrointestinal endoscopy during the COVID-19 pandemic: an updated review of guidelines and statements from international and national societies. Gastrointest Endosc. 2020 Aug;92(2):440-445.e6.
Parasa S, Reddy N, Faigel DO, Repici A, Emura F, Sharma P. Global Impact of the COVID-19 Pandemic on Endoscopy: An International Survey of 252 Centers From 55 Countries. Gastroenterology. 2020 Oct;159(4):1579-1581.e5.
Alboraie M, Piscoya A, Tran QT, Mendelsohn RB, Butt AS, Lenz L, et al. The global impact of COVID-19 on gastrointestinal endoscopy units: An international survey of endoscopists. Arab J Gastroenterol Off Publ Pan-Arab Assoc Gastroenterol. 2020 Sep;21(3):156–61.
JOINT GI SOCIETY MESSAGE- COVID-19 Clinical Insights for Our Community of Gastroenterologists and Gastroenterology Care Providers [Internet]. www.asge.org. [cited 2023 Jun 28]. Available from: https://www.asge.org/home/joint-gi-society-message-covid-19
Sultan S, Siddique SM, Singh S, Altayar O, Caliendo AM, Davitkov P, et al. AGA Rapid Review and Guideline for SARS-CoV2 Testing and Endoscopy Post-Vaccination: 2021 Update. Gastroenterology. 2021 Sep;161(3):1011-1029.e11.
Roy CM, Bollman EB, Carson LM, Northrop AJ, Jackson EF, Moresky RT. Assessing the indirect effects of COVID-19 on healthcare delivery, utilization, and health outcomes: a scoping review. Eur J Public Health. 2021 Jul 13;31(3):634–40.
Shadmi E, Chen Y, Dourado I, Faran-Perach I, Furler J, Hangoma P, et al. Health equity and COVID-19: global perspectives. Int J Equity Health. 2020 Jun 26;19(1):104.
Muller CP. Do asymptomatic carriers of SARS-COV-2 transmit the virus? Lancet Reg Health Eur. 2021 May;4:100082.
Albendín-Iglesias H, Mira-Bleda E, Roura-Piloto AE, Hernández-Torres A, Moral-Escudero E, Fuente-Mora C, et al. The usefulness of the epidemiological survey and RT-PCR test in pre-surgical patients for assessing the risk of COVID-19. J Hosp Infect. 2020 Aug;105(4):773–5.
Bowyer B, Thukral C, Patel S, Dovalovsky K, Bowyer SG, Ford J, et al. Outcomes of symptom screening and universal COVID-19 reverse transcriptase polymerase chain reaction testing before endoscopy in a community-based ambulatory surgery center. Gastrointest Endosc. 2021 May;93(5):1060-1064.e1.
Casper M, Reichert MC, Rissland J, Smola S, Lammert F, Krawczyk M. Pre-endoscopy SARS-CoV-2 testing strategy during COVID-19 pandemic: the care must go on. Eur J Med Res. 2022 Mar 18;27(1):41.
Dolinger MT, Kumta NA, Greenwald DA, Dubinsky MC. Outcomes of Universal Preprocedure Coronavirus Disease 2019 Testing Before Endoscopy in a Tertiary Care Center in New York City. Gastroenterology. 2020 Nov; 159(5):1962–4.
Forde JJ, Goldberg D, Sussman D, Soriano F, Barkin JA, Amin S. Yield and Implications of Pre-Procedural COVID-19 Polymerase Chain Reaction Testing on Routine Endoscopic Practice. Gastroenterology. 2020 Oct;159(4):1538–40.
Haidar G, Ayres A, King WC, McDonald M, Wells A, Mitchell SL, et al. Preprocedural SARS-CoV-2 Testing to Sustain Medically Needed Health Care Delivery During the COVID-19 Pandemic: A Prospective Observational Study. Open Forum Infect Dis. 2021 Jan 18;8(2):ofab022.
Hayee B, SCOTS II Project group, Bhandari P, Rees CJ, Penman I. COVID-19 transmission following outpatient endoscopy during pandemic acceleration phase involving SARS-CoV-2 VOC 202012/01 variant in the UK. Gut. 2021 Dec;70(12):2227–9.
Hayee B, SCOTS project group, East J, Rees CJ, Penman I. Multicentre prospective study of COVID-19 transmission following outpatient GI endoscopy in the UK. Gut. 2021 May;70(5):825–8.
Hernández Camba A, Marcelino Reyes R, Hernández-Guerra M, Blasco Amato ÓA, Bennemann P, De La Riva N, et al. Pre-procedural antibody testing for SARS-CoV-2 in the routine endoscopic practice. Rev Esp Enferm Dig. 2021 Feb;113(2):116–8.
Lewis SS, Smith BA, Akinboyo IC, Seidelman J, Wolfe C, Kirk AB, et al. Early experience with universal preprocedural testing for SARS-CoV-2 in a relatively low-prevalence area. Infect Control Hosp Epidemiol. 2021 Mar;42(3):341–3.
Mays JA, Greninger AL, Jerome KR, Lynch JB, Mathias PC. Preprocedural Surveillance Testing for SARS-CoV-2 in an Asymptomatic Population in the Seattle Region Shows Low Rates of Positivity. J Clin Microbiol. 2020 Jul 23;58(8):e01193-20.
Tworek JA, Khan F, Sekedat MD, Scheidel C, Malani AN. The Utility of Rapid Nucleic Acid Amplification Testing to Triage Symptomatic Patients and to Screen Asymptomatic Preprocedure Patients for SARS-CoV-2. Open Forum Infect Dis. 2020 Dec 17;8(1):ofaa607.
Ahmad T, Abdullah M, Mueed A, Sultan F, Khan A, Khan AA. COVID-19 in Pakistan: A national analysis of five pandemic waves [Internet]. 2023 [cited 2023 Jun 28]. Available from: https://europepmc.org/article/PPR/PPR608715
Walsh CX, Montagano J, Saliares A, Hawa F, Gunaratnam N. S580 SARS-CoV2 Testing before Endoscopy: Discrepancy Between Estimated and True Asymptomatic Prevalence Rates in a Community-Based Gastroenterology Practice. Off J Am Coll Gastroenterol ACG. 2021 Oct;116:S264.
Gawron AJ, Sultan S, Glorioso TJ, Califano S, Kralovic SM, Jones M, et al. Pre-endoscopy coronavirus disease 2019 screening and severe acute respiratory syndrome coronavirus-2 nucleic acid amplification testing in the Veterans Affairs healthcare system: clinical practice patterns, outcomes, and relationship to procedure volume. Gastrointest Endosc. 2022 Sep;96(3):423-432.e7.
Eliwa A, Osman OM, Helal A, Mohamed AS, ElFayoumie M, Eldamarawy R, et al. COVID-19 screening before gastrointestinal procedures. Egypt Liver J. 2022 Feb 9;12(1):12.
Hann A, Flemming S, Reimer S, Groneberg K, Kudlich T, Germer CT, et al. Impact of pre-procedural testing on SARS-CoV-2 transmission to endoscopy staff. Gut. 2022 Nov;71(11):2167–9.