Severe acute respiratory syndrome coronavirus 2 prevalence in saliva and gastric and intestinal fluid in patients undergoing gastrointestinal endoscopy in coronavirus disease 2019 endemic areas: Prospective cross-sectional study in Japan

Development of a new gastrointestinal endoscope forceps plug that can minimize gas leakage

Background and aims

In our previous study, we visualized and systematically evaluated gas leakage from the forceps plug of the gastrointestinal endoscope system using the Schlieren system. In order to minimize the potential risk of infection from gas leakage from the gastrointestinal endoscope, the development of a new forceps plug was considered urgent. In this study, we analyzed the structure of commercially available forceps plugs and attempted to develop new forceps plugs with improvements.

Methods

Microfocus computed tomography was used to nondestructively analyze the structural changes that occur when forceps are inserted into a commercially available forceps plug. Based on the findings, the basic structure of the newly developed forceps plug was set. We examined the airtightness of these newly developed plugs using the Schlieren system and also compared their fractional resistance with those of commercially available plugs.

Results

As a result of the nondestructive analysis, all of the commercially available plugs had a single valve, and the cleavage created in the valve during forceps, insertion was large in the case of plugs with slit-type entrances. In the newly developed forceps plugs, all four types of plugs showed less gas leakage and similar or better usability compared to the commercially available plugs.

Conclusions

The structural weaknesses of the existing gastrointestinal endoscopic forceps plugs were identified. Based on the findings, we froze the design of a prototype of a new forceps plug that was airtight and not inferior in usability compared to commercially available plugs.

Use of current automatic smoke evacuation system in flexible gastrointestinal endoscopy: Its feasibility and potential usefulness

Objectives

Flexible endoscopy does not have a system that can automatically evacuate surgical smoke generated in the gastrointestinal lumen. We aimed to investigate the feasibility and potential usefulness of automatic smoke evacuation systems in flexible endoscopy.

Methods

[Bench] After surgical smoke generated in the stomach was evacuated by the evacuator, the degree of residual smoke and gastric luminal collapse were evaluated to optimize the evacuator settings. [Animal] Insufflation, suction, and total operation time to complete the protocol of 10 cauterizations of the gastric mucosa were measured in three groups: "manual suction only," "manual suction with automatic evacuation (50% force)," and "manual suction with automatic evacuation (70% force)." The stability of endoscopic visualization and operability was evaluated by 10 endoscopists blinded to those suction settings, and the number of manual suctions, insufflations, and total operation time were measured.

Results

[Bench] The degree of residual smoke and gastric luminal collapse were inversely correlated. [Animal] When the automatic evacuator was partially used, there was no difference in the insufflation time, but the suction time (vs 50%; p = 0.011, vs. 70%; p = 0.011) and total operation time (vs. 50%; p = 0.012, vs. 70%; p = 0.036) were significantly reduced compared to manual operation only. Furthermore, manual suction with automatic evacuation (50% force) significantly improved the stability of endoscopic visualization and operability compared to manual operation only (p = 0.041, p = 0.0085).

Conclusions

The automatic smoke evacuation in flexible gastrointestinal endoscopy was potentially feasible and useful by improving the device setting.

Effect of COVID-19 infection on the gastrointestinal tract considering preventive methods during endoscopic procedures

Objectives

This study aimed to prevent the infection risk of environmental contamination by feces during endoscopic procedures. We evaluated the effect of coronavirus disease 2019 (COVID-19) on the gastrointestinal tract using fecal polymerase chain reaction (PCR) and examined risk factors affecting endoscopic procedures, to develop infection prevention strategies.

Methods

This single-center prospective observational study enrolled 32 patients diagnosed with COVID-19 at Tokyo Medical University Hospital between January and December 2022. We performed reverse transcriptase-PCR to detect severe acute respiratory syndrome coronavirus 2 in human stool specimens and evaluated the COVID-19 positivity rate in stool, the effect of vaccination on infection detection, and differences in positivity rates considering different patient backgrounds.

Results

Among the 32 nasal PCR-positive patients who underwent fecal PCR testing, the fecal PCR positivity rate was 21.8%. Compared to the negative cases, 71.4% vs. 32% were older than 65 years (p < 0.016), 71.4% vs. 0.8% (p < 0.001) had malignant tumors, the rate during BA.5 variant outbreaks was significantly higher (100% vs. 60% [p = 0.044]), and the rate of diarrheal symptoms was also higher (42.9% vs. 24%). The median collection period for fecal PCR-positive cases was 2 days after sampling.

Conclusions

The severe acute respiratory syndrome coronavirus 2 affects not only the upper respiratory tract but also the gastrointestinal tract. These findings may indicate the risk of digestive fluid infection in older patients with gastrointestinal symptoms and immunocompromised patients with malignant tumor comorbidities, especially during the early stages of viral infection. Therefore, it is advisable to establish a system to prevent infection by using personal protective equipment, including eye guards, in future endoscopic procedures.

Protective Effect of Food Against Inactivation of Human Coronavirus OC43 by Gastrointestinal Fluids

The involvement of the gastrointestinal (GI) tract in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has been reported in multiple studies. Since it has been demonstrated that human intestinal epithelial cells support productive viral replication and that a substantial portion of infected individuals shed the virus in feces, the possibility of fecal-oral and fecal-respiratory modes of transmission have been proposed for SARS-CoV-2. In order to establish viral replication in the intestine, enteric viruses need to retain their infectivity in often low pH gastric fluids, and in intestinal fluids, which contain digestive enzymes and bile salts. In this study, we examined whether human coronaviruses OC43 (HCoV-OC43) can remain infectious in simulated GI fluids that models human fasting-state and fed-state, in the presence or absence of food. We demonstrated that except for fasting-state gastric fluid (pH 1.6), the virus can remain infectious in all other gastrointestinal fluids for 1 h. Furthermore, we demonstrated that presence of food could significantly improve viral survival in gastric fluids. Therefore, this study provides evidence that ingestion with food could protect the virus against inactivation by the GI fluids.

COVID-19 in the endoscopy unit: How likely is transmission of infection? Results from an international, multicenter study

BACKGROUND

Coronavirus disease 2019 (COVID-19) significantly affected endoscopy practice, as gastrointestinal endoscopy is considered a risky procedure for transmission of infection to patients and personnel of endoscopy units (PEU).

AIM

To assess the impact of COVID-19 on endoscopy during the first European lockdown (March-May 2020).

METHODS

Patients undergoing endoscopy in nine endoscopy units across six European countries during the period of the first European lockdown for COVID-19 (March-May 2020) were included. Prior to the endoscopy procedure, participants were stratified as low- or high- risk for potential COVID-19 infection according to the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA) joint statement, and contacted 7-14 d later to assess COVID-19 infection status. PEU were questioned regarding COVID-19 symptoms and/or infection via questionnaire, while information regarding hospitalizations, intensive care unit-admissions and COVID-19-related deaths were collected. The number of weekly endoscopies at each center during the lockdown period was also recorded.

RESULTS

A total of 1267 endoscopies were performed in 1222 individuals across nine European endoscopy departments in six countries. Eighty-seven (7%) were excluded because of initial positive testing. Of the 1135 pre-endoscopy low risk or polymerase chain reaction negative for COVID-19, 254 (22.4%) were tested post endoscopy and 8 were eventually found positive, resulting in an infection rate of 0.7% [(95%CI: 0.2-0.12]. The majority (6 of the 8 patients, 75%) had undergone esophagogastroduodenoscopy. Of the 163 PEU, 5 [3%; (95%CI: 0.4-5.7)] tested positive during the study period. A decrease of 68.7% (95%CI: 64.8-72.7) in the number of weekly endoscopies was recorded in all centers after March 2020. All centers implemented appropriate personal protective measures (PPM) from the initial phases of the lockdown.

CONCLUSION

COVID-19 transmission in endoscopy units is highly unlikely in a lockdown setting, provided endoscopies are restricted to emergency cases and PPM are implemented.

Gastrointestinal Cancer Stage at Diagnosis Before and During the COVID-19 Pandemic in Japan

IMPORTANCE

The COVID-19 pandemic has delayed medical consultations, possibly leading to the diagnosis of gastrointestinal cancer at advanced stages.

OBJECTIVE

To evaluate stage at diagnosis among patients with gastrointestinal cancer in Japan before and during the COVID-19 pandemic.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included patients in a hospital-based cancer registry who were diagnosed with gastrointestinal cancer (ie, esophageal, gastric, colorectal, pancreatic, liver, and biliary tract cancers) between January 2016 and December 2020 at 2 tertiary Japanese hospitals.

EXPOSURES

The pre-COVID-19 period was defined as January 2017 to February 2020, and the COVID-19 period was defined as March 2020 to December 2020.

MAIN OUTCOME AND MEASURE

Monthly numbers of patients with newly diagnosed cancer were aggregated, classified by stage, and compared.

RESULTS

The study evaluated 5167 patients, including 4218 patients (2825 [67.0%] men; mean [SD] age, 71.3 [10.9] years) in the pre-COVID-19 period and 949 patients (607 [64.0%] men; mean [SD] age, 71.8 [10.7] years) in the COVID-19 period. Comparing the pre-COVID-19 period with the COVID-19 period, significant decreases were observed in the mean (SD) number of patients with newly diagnosed gastric cancer (30.63 [6.62] patients/month vs 22.40 [5.85] patients/month; -26.87% change; P < .001) and colorectal cancer (41.61 [6.81] patients/month vs 36.00 [6.72] patients/month; -13.47% change; P = .03). Significant decreases were also observed in the mean (SD) number of cases of stage I gastric cancer (21.55 [5.66] cases/month vs 13.90 [5.99] cases/month; -35.51% change; P < .001), stage 0 colorectal cancer (10.58 [3.36] cases/month vs 7.10 [4.10] cases/month; -32.89% change; P = .008), and stage I colorectal cancer (10.16 [3.14] cases/month vs 6.70 [2.91] cases/month; -34.04% change; P = .003). No significant increases were observed for esophageal, gastric, pancreatic, liver, or biliary tract cancers. A significant decrease was observed in the mean (SD) number of cases per month of stage II colorectal cancer (7.42 [3.06] cases/month vs 4.80 [1.75] cases/month; -35.32% change; P = .01); a significant increase was observed for the mean (SD) number of cases per month of stage III colorectal cancer (7.18 [2.85] cases/month vs 12.10 [2.42] cases/month; 68.42% change; P < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study of patients in a hospital-based cancer registry form Japan, significantly fewer patients were diagnosed with stage I gastric and colorectal cancers during the COVID-19 pandemic. Thus, the number of screening-detected cancers might have decreased, and colorectal cancer may have been diagnosed at more advanced stages.

Perspective: the nose and the stomach play a critical role in the NZACE2-Pātari* (modified ACE2) drug treatment project of SARS-CoV-2 infection

Background: COVID-19 has caused calamitous health, economic and societal consequences globally. Currently, there is no effective treatment for the infection. Areas covered: We have recently described the NZACE2-Pātari project, which seeks to administer modified Angiotensin Converting Enzyme 2 (ACE2) molecules early in the infection to intercept and block SARS-CoV-2 binding to the pulmonary epithelium. Expert opinion: Since the nasopharyngeal mucosa is infected in the first asymptomatic phase of the infection, treatment of the nose is likely to be safe and potentially effective. The intercepted virus will be swallowed and destroyed in the stomach. There is however a limited window of opportunity to alter the trajectory of the infection in an individual patient, which requires access to rapid testing for SARS-CoV-2. The proposed strategy is analogous to passive immunization of viral infections such as measles and may be of particular benefit to immunodeficient and unvaccinated individuals.