Potential intestinal infection and faecal-oral transmission of human coronaviruses

Enhancing enteric pathogen detection: implementation and impact of multiplex PCR for improved diagnosis and surveillance

BACKGROUND

Syndromic surveillance of acute gastroenteritis plays a significant role in the diagnosis and management of gastrointestinal infections that are responsible for a substantial number of deaths globally, especially in developing countries. In Lebanon, there is a lack of national surveillance for acute gastroenteritis, and limited data exists regarding the prevalence of pathogens causing diarrhea. The one-year study aims to investigate the epidemiology of common gastrointestinal pathogens and compare our findings with causative agents of diarrhea reported by our study collaborative centers.

METHODS

A multicenter, cross-sectional study was conducted over a one-year period. A total of 271 samples were obtained from outpatients and inpatients presenting with symptoms of acute gastroenteritis at various healthcare facilities. The samples were then analyzed using Allplex gastrointestinal assay that identifies a panel of enteric pathogens.

RESULTS

Overall, enteropathogens were detected in 71% of the enrolled cases, 46% of those were identified in patients as single and 54% as mixed infections. Bacteria were observed in 48%, parasites in 12% and viruses in 11%. Bacterial infections were the most prevalent in all age groups. Enteroaggregative E. coli (26.5%), Enterotoxigenic E. coli (23.2%) and Enteropathogenic E. coli (20.3%) were the most frequently identified followed by Blastocystis hominis (15.5%) and Rotavirus (7.7%). Highest hospitalization rate occurred with rotavirus (63%), Enterotoxigenic E. coli (50%), Blastocystis hominis (45%) and Enteropathogenic E. coli (43%). Enteric pathogens were prevalent during summer, fall and winter seasons.

CONCLUSIONS

The adoption of multiplex real-time PCR assays in the diagnosis of gastrointestinal infections has identified gaps and improved the rates of detection for multiple pathogens. Our findings highlight the importance of conducting comprehensive surveillance to monitor enteric infections. The implementation of a syndromic testing panel can therefore provide healthcare professionals with timely and accurate information for more effective treatment and public health interventions.

Gastrointestinal Manifestations of SARS-CoV-2: Transmission, Pathogenesis, Immunomodulation, Microflora Dysbiosis, and Clinical Implications

The clinical manifestation of COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in the respiratory system of humans is widely recognized. There is increasing evidence suggesting that SARS-CoV-2 possesses the capability to invade the gastrointestinal (GI) system, leading to the manifestation of symptoms such as vomiting, diarrhea, abdominal pain, and GI lesions. These symptoms subsequently contribute to the development of gastroenteritis and inflammatory bowel disease (IBD). Nevertheless, the pathophysiological mechanisms linking these GI symptoms to SARS-CoV-2 infection remain unelucidated. During infection, SARS-CoV-2 binds to angiotensin-converting enzyme 2 and other host proteases in the GI tract during the infection, possibly causing GI symptoms by damaging the intestinal barrier and stimulating inflammatory factor production, respectively. The symptoms of COVID-19-induced GI infection and IBD include intestinal inflammation, mucosal hyperpermeability, bacterial overgrowth, dysbiosis, and changes in blood and fecal metabolomics. Deciphering the pathogenesis of COVID-19 and understanding its exacerbation may provide insights into disease prognosis and pave the way for the discovery of potential novel targets for disease prevention or treatment. Besides the usual transmission routes, SARS-CoV-2 can also be transmitted via the feces of an infected person. Hence, it is crucial to implement preventive and control measures in order to mitigate the fecal-to-oral transmission of SARS-CoV-2. Within this context, the identification and diagnosis of GI tract symptoms during these infections assume significance as they facilitate early detection of the disease and the development of targeted therapeutics. The present review discusses the receptors, pathogenesis, and transmission of SARS-CoV-2, with a particular focus on the induction of gut immune responses, the influence of gut microbes, and potential therapeutic targets against COVID-19-induced GI infection and IBD.

Molecular mechanisms implicated in SARS-CoV-2 liver tropism

The coronavirus disease 2019 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hepatic involvement is common in SARS-CoV-2-infected individuals. It is currently accepted that the direct and indirect hepatic effects of SARS-CoV-2 infection play a significant role in COVID-19. In individuals with pre-existing infectious and non-infectious liver disease, who are at a remarkably higher risk of developing severe COVID-19 and death, this pathology is most medically relevant. This review emphasizes the current pathways regarded as contributing to the gastrointestinal and hepatic ailments linked to COVID-19-infected patients due to an imbalanced interaction among the liver, systemic inflammation, disrupted coagulation, and the lung.