Features of enteric disease from human coronaviruses: Implications for COVID-19

Differing Susceptibilities to Certain Microbicidal Chemistries among Three Representative Enveloped Viruses

Three lipid-enveloped viruses (bovine viral diarrhea virus [BVDV], vaccinia virus, and severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) were evaluated in side-by-side liquid inactivation efficacy studies of low pH (3.0 to 3.1) treatment and of the non-formulated microbicidal actives sodium hypochlorite (100 ppm), ethanol (70%), quaternary ammonium compound BTC® 835 (100 ppm), and peracetic acid (100 ppm). Low pH was evaluated at 10 and 60 min contact times, and the microbicides were evaluated at 1 min contact time at room temperature per the ASTM E1052 standard. In each case, 5% animal serum was included in the viral inoculum as a challenge soil load. The three viruses displayed similar susceptibility to sodium hypochlorite and ethanol, with complete inactivation resulting. Significant differences in susceptibility to BTC® 835 and peracetic acid were identified, with the ordering of the three viruses for susceptibility to BTC® 835 being SARS-CoV-2 > vaccinia virus = BVDV, and the ordering for peracetic acid being vaccinia virus > SARS-CoV-2 > BVDV. The ordering for susceptibility to low pH treatment (60 min contact time) was vaccinia virus > SARS-CoV-2 > BVDV. Not all enveloped viruses display equivalent susceptibilities to inactivation approaches. For the chemistries evaluated here, BVDV appears to represent a worst-case enveloped virus.

COVID-19 among infants: key clinical features and remaining controversies

Infants aged <1 year represent a seemingly more susceptible pediatric subset for infections. Despite this, coronavirus disease 2019 (COVID-19) infection has not been proven as more serious in this age group (outside the very early neonatal period) than in others. Indeed, a considerable number of asymptomatic infections have been recorded, and the symptoms and morbidity associated with COVID- 19 differ minimally from those of other respiratory viral infections. Whether due to an abundance of caution or truly reduced susceptibility, infections in infants have not raised the same profile as those in other age groups. In addition to direct severe acute respiratory syndrome coronavirus 2 diagnostic tests, laboratory markers that differentiate COVID-19 from other viral infections lack specificity in infants. Gastrointestinal presentations are common, and the neurological complications of infection mirror those of other respiratory viral infections. There have been relatively few reports of infant deaths. Under appropriate precautions, breastfeeding in the context of maternal infections has been associated with tangible but infrequent complications. Vaccination during pregnancy provides protection against infection in infants, at least in the early months of life. Multi-inflammatory syndrome in children and multi-inflammatory syndrome in neonates are commonly cited as variants of COVID-19; however, their clinical definitions remain controversial. Similarly, reliable definitions of long COVID in the infant group are controversial. This narrative review examines the key clinical and laboratory features of COVID-19 in infants and identifies several areas of science awaiting further clarification.

A narrative review of alternative transmission routes of COVID 19: what we know so far

The Coronavirus disease 19 (COVID-19) pandemics, caused by severe acute respiratory syndrome coronaviruses, SARS-CoV-2, represent an unprecedented public health challenge. Beside person-to-person contagion via airborne droplets and aerosol, which is the main SARS-CoV-2's route of transmission, alternative modes, including transmission via fomites, food and food packaging, have been investigated for their potential impact on SARS-CoV-2 diffusion. In this context, several studies have demonstrated the persistence of SARS-CoV-2 RNA and, in some cases, of infectious particles on exposed fomites, food and water samples, confirming their possible role as sources of contamination and transmission. Indeed, fomite-to-human transmission has been demonstrated in a few cases where person-to-person transmission had been excluded. In addition, recent studies supported the possibility of acquiring COVID-19 through the fecal-oro route; the occurrence of COVID-19 gastrointestinal infections, in the absence of respiratory symptoms, also opens the intriguing possibility that these cases could be directly related to the ingestion of contaminated food and water. Overall, most of the studies considered these alternative routes of transmission of low epidemiological relevance; however, it should be considered that they could play an important role, or even be prevalent, in settings characterized by different environmental and socio-economic conditions. In this review, we discuss the most recent findings regarding SARS-CoV-2 alternative transmission routes, with the aim to disclose what is known about their impact on COVID-19 spread and to stimulate research in this field, which could potentially have a great impact, especially in low-resource contexts.

Identification, Isolation, and Molecular Characterization of Betacoronavirus in Oryx leucoryx

Coronaviruses (CoVs) are enveloped viruses with a large RNA genome (26 to 32 kb) and are classified into four genera: Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus. CoV infections cause respiratory, enteric, and neurologic disorders in mammalian and avian species. In 2019, Oryx leucoryx animals suffered from severe hemorrhagic diarrhea and high morbidity rates. Upon initial diagnosis, we found that the infected animals were positive for coronavirus by pancoronavirus reverse transcriptase RT-PCR. Next, we detected the presence of CoV particles in these samples by electron microscopy and immunohistochemistry. CoV was isolated and propagated on the HRT-18G cell line, and its full genome was sequenced. Full-genome characterization and amino acid comparisons of this viral agent demonstrated that this virus is an evolutionarily distinct Betacoronavirus belonging to the subgenus Embecovirus and the Betacoronavirus 1 species. Furthermore, we found that it is most similar to the subspecies dromedary camel coronavirus HKU23 by phylogenetic analysis. Here, we present the first report of isolation and characterization of Betacoronavirus associated with enteric disease in Oryx leucoryx. IMPORTANCE CoVs cause enteric and respiratory infections in humans and animal hosts. The ability of CoVs to cross interspecies barriers is well recognized, as emphasized by the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The identification of novel CoV strains and surveillance of CoVs in both humans and animals are relevant and important to global health. In this study, we isolated and characterized a newly identified Betacoronavirus that causes enteric disease in a wild animal, Oryx leucoryx (the Arabian oryx). This work is the first report describing CoV infection in Oryx leucoryx and provides insights into its origin.

Three birds, one stone: Disinfecting and turning waste medical masks into valuable carbon dots for sodium hydrosulfite and Fe3+ detection enabled by a simple hydrothermal treatment

Disposable medical masks are widely used to prevent respiratory infections due to their ability to block virus particles from entering the human body. The coronavirus disease 2019 (COVID-19) pandemic highlighted the importance of medical masks, leading to their widespread use around the world. However, a large number of disposable medical masks have been discarded, some carrying viruses, which have posed a grave threat to the environment and people's health, as well as wasting resources. In this study, a simple hydrothermal method was used for the disinfection of waste medical masks under high-temperature conditions as well as for their transformation into high-value-added carbon dots (CDs, a new type of carbon nanomaterial) with blue-emissive fluorescence, without high energy consumption or environmental pollution. Moreover, the mask-derived CDs (m-CDs) could not only be used as fluorescent probes for sensing sodium hydrosulfite (Na₂S₂O₄), which is widely used in the food and textile industries but is seriously harmful to human health, but also be used for detecting Fe³⁺ which is harmful to the environment and human health due to its wide use in industries.

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.

Wastewater-based epidemiology: a new frontier for tracking environmental persistence and community transmission of COVID-19

Recent research in many parts of the world has pointed towards evidence of SARS-CoV-2 RNA in both treated and raw municipal wastewater discharged by communities. Therefore, concerns regarding it being a possible enteric virus are abundant. Past history of SARS-CoV-1 outbreaks and viral survival information helps in establishing information regarding possible viral infectivity and survival of SARS-CoV-2. The paper examines the existing strategies and techniques including the efficacy of laboratory-based RT-qPCR technique for tracking environmental persistence and community transmission of COVID-19. Analysis of studies targeting untreated and treated wastewater as source of samples is carried out. The analysis shows that untreated samples were mostly positive for SARS-CoV-2 RNA in the target studies. Infectivity estimation from viral load data was found to be about two orders of magnitude higher than actual case data in one of the studies. Additionally, relevant research on environmental survivability of SARS-CoV-2 and possible gaps are examined. Biosensors and excretion metabolite tracking in viral detection are also examined, which hold tremendous importance for future research. Wastewater-based epidemiology (WBE) shows incredible promise in the near future for tracking environmental persistence and community transmission of highly infectious diseases such as SARS-CoV-2. With limited research available on SARS-CoV-2 with regard to WBE, it is imperative that focus be established on the evidence-based targeted studies.

Survival of human coronavirus 229E at different temperatures on various food-contact surfaces and food and under simulated digestive conditions

The COVID-19 pandemic caused by SARS-CoV-2 has had a major impact on human health and the global economy. Various transmission possibilities of SARS-CoV-2 have been proposed, such as the surface of food in the cold chain and food packaging, as well as the fecal-oral route, although person-to-person contact via droplets and aerosols has been confirmed as the main route of transmission. This study evaluated the survivability of HCoV-229E, a SARS-CoV-2 surrogate, in suspension, on food-contact surfaces and on food at various temperatures, and in simulated digestive fluids by TCID₅₀ assay. In suspension, HCoV-229E survived after 5 days at 20 °C with a 3.69 log reduction, after 28 days at 4 °C with a 3.07 log reduction, and after 12 weeks at -20 °C with a 1.18 log reduction. On food-contact surfaces, HCoV-229E was not detected on day 3 on stainless steel (SS), plastic (LDPE), and silicone rubber (SR) at 20 °C with a 3.28, 3.24 and 3.28 log reduction, respectively, and survived after 28 days on SS and LDPE at 4 °C with a 3.13 and 2.88 log reduction, respectively, and survived after 12 weeks on SS, LDPE, and SR at -20 °C with a 1.92, 1.32 and 1.99 log reduction, respectively. On food, HCoV-229E was not detected on day 3 on lettuce and day 4 on chicken breast and salmon at 20 °C with a 3.61, 3.26 and 3.08 log reduction, respectively, and on day 14 on lettuce and day 21 on chicken breast and salmon at 4 °C with a 3.88, 3.44 and 3.56 log reduction, respectively. The virus remained viable for 12 weeks in all foods at -20 °C with 2-2.47 log reduction. In addition, in simulated digestive fluid experiments, HCoV-229E was relatively resistant in simulated salivary fluid (SSF; pH 7, 5), fed state simulated gastric fluid (FeSSGF; pH 3, 5, 7), and fasted state simulated intestinal fluid (FaSSIF; pH 7). However, the virus was less tolerant in fasted state simulated gastric fluid (FaSSGF; pH 1.6) and fed state simulated intestinal fluid (FeSSIF; pH 5). Therefore, this study suggested that HCoV-229E remained infectious on various food-contact surfaces and foods; in particular, it survived longer at lower temperatures and survived depending on the pH of the simulated digestive fluid.

Disinfection and decontamination in the context of SARS-CoV-2-specific data

Given the high transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as witnessed early in the coronavirus disease 2019 (COVID-19) pandemic, concerns arose with the existing methods for virus disinfection and decontamination. The need for SARS-CoV-2-specific data stimulated considerable research in this regard. Overall, SARS-CoV-2 is practically and equally susceptible to approaches for disinfection and decontamination that have been previously found for other human or animal coronaviruses. The latter have included techniques utilizing temperature modulation, pH extremes, irradiation, and chemical treatments. These physicochemical methods are a necessary adjunct to other prevention strategies, given the environmental and patient surface ubiquity of the virus. Classic studies of disinfection have also allowed for extrapolation to the eradication of the virus on human mucosal surfaces by some chemical means. Despite considerable laboratory study, practical field assessments are generally lacking and need to be encouraged to confirm the correlation of interventions with viral eradication and infection prevention. Transparency in the constitution and use of any method or chemical is also essential to furthering practical applications.

Split T7 promoter-based isothermal transcription amplification for one-step fluorescence detection of SARS-CoV-2 and emerging variants

The negative global impact of the coronavirus disease pandemic has highlighted the crucial need for a rapid and convenient method of viral RNA detection. In this study, we report a novel method, termed as the split T7 promoter-based isothermal transcription amplification with light-up RNA aptamer (STAR), for one-pot detection of viral RNA. STAR uses a split T7 promoter that is applied to a three-way junction to mediate the selective transcription by the T7 RNA polymerase in the presence of target RNA. In addition, a light-up RNA aptamer is used for signal amplification. STAR can detect viral RNA in less than 30 min with high specificity and sensitivity. By testing of 60 nasopharyngeal SARS-CoV-2 samples, the STAR assay demonstrates an excellent sensitivity and specificity of 96.7% and 100%, respectively. Moreover, we provide experimental evidence of the broad applicability of this assay through the multiplex detection of SARS-CoV-2 variants (D614G mutation) and direct detection of bacterial 16S rRNA.

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.

Gastrointestinal Manifestations of COVID-19 Infection: Clinicopathologic Findings in Intestinal Resections Performed at Single Institution

It is now known that COVID-19 not only involves the lungs, but other organs as well including the gastrointestinal tract. Although clinic-pathological features are well-described in lungs, the histopathologic features of gastrointestinal involvement in resection specimens are not well characterized. Herein, we describe in detail the clinicopathologic features of intestinal resection specimens in four patients with COVID-19 infection. COVID-19 viral particles by in situ hybridization and immunofluorescence studies are also demonstrated. All four patients were males, aged 28–46 years, with comorbidities. They initially presented with a severe form of pulmonary COVID-19 and showed gastrointestinal symptoms, requiring surgical intervention. Histopathologic examination of resected GI specimens, mostly right colectomies, revealed a spectrum of disease, from superficial mucosal ischemic colitis to frank transmural ischemic colitis and associated changes consistent with pneumatosis cystoides intestinalis. Three patients were African American (75%), and one was Caucasian (25%); three patients died due to complications of their COVID-19 infection (75%), while one ultimately recovered from their GI complications (25%), but experienced prolonged sequela of COVID-19 infection including erectile dysfunction. In conclusion, COVID-19 infection, directly or indirectly, can cause ischemic gastrointestinal complications, with predilection for the right colon.

Favorable postoperative outcomes for children with COVID-19 infection undergoing surgical intervention: Experience at a free-standing children's hospital

BACKGROUND

Current literature has shown that adult patients with perioperative Coronavirus Disease-2019 (COVID-19) have increased rates of postoperative morbidity and mortality. We hypothesized that children with COVID-19 have favorable postoperative outcomes compared to the reported adult experience.

METHODS

We performed a retrospective cohort study for children with a confirmed preoperative COVID-19 diagnosis from April 1st, 2020 to August 15th, 2020 at a free-standing children's hospital. Primary outcomes evaluated were postoperative complications, readmissions, reoperations, and mortality within 30 days of operation. Secondary outcomes included hospital resource utilization, hospital length of stay, and postoperative oxygen support.

RESULTS

A total of 66 children with preoperative confirmed COVID-19 were evaluated with median age of 9.5 years (interquartile range (IQR) 5-14) with 65% male and 70% Hispanic White. Sixty-five percent of patients had no comorbidities, with abdominal pain identified as the most common preoperative symptom (65%). Twenty-three percent of patients presented with no COVID-19 related symptoms. Eighty-two percent of patients had no preoperative chest imaging and 98% of patients did not receive preoperative oxygen support. General pediatric surgeons performed the majority of procedures (68%) with the most common diagnosis appendicitis (47%). Forty-one percent of patients were discharged the same day as surgery with 9% of patients utilizing postoperative intensive care unit resources and only 5% receiving postoperative invasive mechanical ventilation. Postoperative complications (7%), readmission (6%), and reoperation (6%) were infrequent, with no mortality.

CONCLUSION

COVID-19+ children requiring surgery have a favorable postoperative course and short-term outcomes compared to the reported adult experience.

TYPE OF STUDY

Prognosis Study.

LEVEL OF EVIDENCE

Level IV.

In pursuit of the right tail for the COVID-19 incubation period

Definition of the incubation period for COVID-19 is critical for implementing quarantine and thus infection control. Whereas the classical definition relies on the time from exposure to time of first symptoms, a more practical working definition is the time from exposure to time of first live virus excretion. For COVID-19, average incubation period times commonly span 5-7 days which are generally longer than for most typical other respiratory viruses. There is considerable variability reported however for the late right-hand statistical distribution. A small but yet epidemiologically important subset of patients may have the late end of the incubation period extend beyond the 14 days that is frequently assumed. Conservative assumptions of the right tail end distribution favor safety, but pragmatic working modifications may be required to accommodate high rates of infection and/or healthcare worker exposures. Despite the advent of effective vaccines, further attention and study in these regards are warranted. It is predictable that vaccine application will be associated with continued confusion over protection and its longevity. Measures for the application of infectivity will continue to be extremely relevant.

Exploring the potential of foodborne transmission of respiratory viruses

The ongoing pandemic involving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised the question whether this virus, which is known to be spread primarily though respiratory droplets, could be spread through the fecal-oral route or via contaminated food. In this article, we present a critical review of the literature exploring the potential foodborne transmission of several respiratory viruses including human coronaviruses, avian influenza virus (AVI), parainfluenza viruses, human respiratory syncytial virus, adenoviruses, rhinoviruses, and Nipah virus. Multiple lines of evidence, including documented expression of receptor proteins on gastrointestinal epithelial cells, in vivo viral replication in gastrointestinal epithelial cell lines, extended fecal shedding of respiratory viruses, and the ability to remain infectious in food environments for extended periods of time raises the theoretical ability of some human respiratory viruses, particularly human coronaviruses and AVI, to spread via food. However, to date, neither epidemiological data nor case reports of clear foodborne transmission of either viruses exist. Thus, foodborne transmission of human respiratory viruses remains only a theoretical possibility.

The Complexity of Co-Infections in the Era of COVID-19

The current frequency of COVID-19 in a pandemic era ensures that co-infections with a variety of co-pathogens will occur. Generally, there is a low rate of bonafide co-infections in early COVID-19 pulmonary infection as currently appreciated. Reports of high co-infection rates must be tempered by limitations in current diagnostic methods since amplification technologies do not necessarily confirm live pathogen and may be subject to considerable laboratory variation. Some laboratory methods may not exclude commensal microbes. Concurrent serodiagnoses have long been of concern for accuracy in these contexts. Presumed virus co-infections are not specific to COVID-19. The association of influenza viruses and SARS-CoV-2 in co-infection has been considerably variable during influenza season. Other respiratory virus co-infections have generally occurred in less than 10% of COVID-19 patients. Early COVID-19 disease is more commonly associated with bacterial co-pathogens that typically represent usual respiratory micro-organisms. Late infections, especially among severe clinical presentations, are more likely to be associated with nosocomial or opportunistic pathogens given the influence of treatments that can include antibiotics, antivirals, immunomodulating agents, blood products, immunotherapy, steroids, and invasive procedures. As anticipated, hospital care carries risk for multi-resistant bacteria. Overall, co-pathogen identification is linked with longer hospital stay, greater patient complexity, and adverse outcomes. As for other viral infections, a general reduction in the use of empiric antibiotic treatment is warranted. Further insight into co-infections with COVID-19 will contribute overall to effective antimicrobial therapies and disease control.

Temperature effect on the SARS-CoV-2: A molecular dynamics study of the spike homotrimeric glycoprotein

Rapid spread of SARS-CoV-2 virus have boosted the need of knowledge about inactivation mechanisms to minimize the impact of COVID-19 pandemic. Recent studies have shown that SARS-CoV-2 virus can be disabled by heating, the exposure time for total inactivation depending on the reached temperature (e.g. more than 45 min at 329 K or less than 5 min at 373 K. In spite of recent crystallographic structures, little is known about the molecular changes induced by the temperature. Here, we unravel the molecular basis of the effect of the temperature over the SARS-CoV-2 spike glycoprotein, which is a homotrimer with three identical monomers, by executing atomistic molecular dynamics (MD) simulations at 298, 310, 324, 338, 358 and 373 K. Furthermore, both the closed down and open up conformational states, which affect the accessibility of receptor binding domain, have been considered. Our results suggest that the spike homotrimer undergoes drastic changes in the topology of the hydrogen bonding interactions and important changes on the secondary structure of the receptor binding domain (RBD), while electrostatic interactions (i.e. salt bridges) are mainly preserved. The proposed inactivation mechanism has important implications for engineering new approaches to fight the SARS-CoV-2 coronavirus, as for example, cleaving or reorganizing the hydrogen bonds through chaotropic agents or nanoparticles with local surface resonant plasmon effect.

A Comprehensive Analysis of Maternal and Newborn Disease and Related Control for COVID-19

The maternal-fetal/newborn unit is established at risk for COVID-19 infection. This narrative review summarizes the contemporary and cumulative publications which detail maternal infection, antenatal and newborn infections, and maternal/fetal/newborn management and prevention. There is a wide spectrum of maternal disease, but the potential for severe disease albeit in a minority is confirmed. COVID-19 carries risk for preterm delivery. Pregnant females can suffer multisystem disease, and co-morbidities play a significant role in risk. Congenital infection has been supported by several anecdotal reports, but strong confirmatory data are few. No typical congenital dysmorphisms are evident. Nevertheless, placental vascular compromise must be considered a risk for the fetus during advanced maternal infections. Clinical manifestations of newborn infection have been mild to moderate and relatively uncommon. Proven antiviral therapy is of yet lacking. The mode of delivery is a medical decision that must include patient risk assessment and patient directives. Both presymptomatic and asymptomatic mothers and offspring can complicate infection control management with the potential for spread to others in several regards. In the interim, infections of the maternal-fetal-newborn unit must be taken seriously both for the disease so caused and the potential for further dissemination of disease.

Human Intestinal Organoids Recapitulate Enteric Infections of Enterovirus and Coronavirus

Enteroviruses, such as EV-A71 and CVA16, mainly infect the human gastrointestinal tract. Human coronaviruses, including SARS-CoV and SARS-CoV-2, have been variably associated with gastrointestinal symptoms. We aimed to optimize the human intestinal organoids and hypothesize that these optimized intestinal organoids can recapitulate enteric infections of enterovirus and coronavirus. We demonstrate that the optimized human intestinal organoids enable better simulation of the native human intestinal epithelium, and that they are significantly more susceptible to EV-A71 than CVA16. Higher replication of EV-A71 than CVA16 in the intestinal organoids triggers a more vigorous cellular response. However, SARS-CoV and SARS-CoV-2 exhibit distinct dynamics of virus-host interaction; more robust propagation of SARS-CoV triggers minimal cellular response, whereas, SARS-CoV-2 exhibits lower replication capacity but elicits a moderate cellular response. Taken together, the disparate profile of the virus-host interaction of enteroviruses and coronaviruses in human intestinal organoids may unravel the cellular basis of the distinct pathogenicity of these viral pathogens.

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An optimized differentiation protocol improves maturation of intestinal organoids

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SARS-CoV-2 and SARS-CoV infection triggers less robust response than enteroviruses

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Coronaviruses show lower sensitivity to type III IFNs than enteroviruses

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Intestinal organoids recapitulate disparate pathogenicity of CoVs and enteroviruses

Dysentery as the only presentation of COVID-19 in a child: a case report

Introduction

The coronavirus disease 2019 (COVID-19) pandemic has caused irreparable damage to society, and the damage continues. Pediatricians are confronted with COVID-19 in a variety of presentations, which may lead to delayed diagnosis and treatment. Early diagnosis of the disease plays an important role in preventing transmission of the virus in the community.

Case presentation

Here we report a 27-month-old previously healthy Iranian female child who presented with fever and bloody diarrhea, diagnosed with COVID-19 based on contact history, exclusion of enteric bacterial pathogens and parasites, and positive stool and nasopharyngeal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcriptase polymerase chain reaction (RT-PCR) tests. The patient had viral shedding for more than a month.

Conclusions

The pediatric population usually does not present with typical clinical features of COVID-19, which are respiratory involvement. Dysentery may be the only presentation of this disease, and long-term isolation should be considered, as the viral shedding may last for more than a month.

The role of wastewater treatment plants as tools for SARS-CoV-2 early detection and removal

The world is facing the third coronavirus caused pandemic in less than twenty years. The SARS-CoV-2 virus not only affects the human respiratory system, but also the gastrointestinal tract. The virus has been found in human feces, in sewage and in wastewater treatment plants. It has the potential to become a panzootic disease, as it is now proven that several mammalian species become infected. Since it has been shown that the virus can be detected in sewage even before the onset of symptoms in the local population, Wastewater Based Epidemiology should be developed not only to localize infection clusters of the primary wave but also to detect a potential second, or subsequent, wave. To prevent a panzootic, virus removal techniques from wastewater need to be implemented to prevent the virus dissemination into the environment. In that context, this review presents recent improvements in all the fields of wastewater treatment from treatment ponds to the use of algae or nanomaterials with a particular emphasis on membrane-based techniques.

Complicating Infections Associated with Common Endemic Human Respiratory Coronaviruses

Coronaviruses OC43, 229E, NL63, and HKU1 are endemic human respiratory coronaviruses that typically cause mild to moderate upper respiratory infections, similar to the common cold. They also may cause simple and complicated lower respiratory infections, otitis media, asthma exacerbations, gastroenteritis, and a few systemic complications. These viruses are usually seasonal (with winter dominance) and affect nearly all age groups. The seasonal and annual variation in virus prevalence has implications for understanding the concept of acquired immunity and its persistence or diminution. Coronaviruses generally have outbreak potential in susceptible populations of any age, particularly in patients with comorbidities, who tend to have increased clinical disease. These 4 coronaviruses are often found in the context of what appears to be coinfection with other pathogens, but especially other viruses. If coronaviruses are not specifically tested for, the sole detection of a viral copathogen would suggest the pathogen is the causative agent, when a coronavirus may be culpable, or both. The detection of these viruses in circumstances where respiratory viruses are generally sought in clinical samples is, therefore, justified. These pathogens can be chronically shed from the respiratory tract, which is more likely to occur among immunocompromised and complicated patients. These viruses share the potential for genetic drift. The genome is among the largest of RNA viruses, and the capability of these viruses to further change is likely underestimated. Given the potential disease among humans, it is justified to search for effective antiviral chemotherapy for these viruses and to consider uses in niche situations should effective therapy be defined. Whereas SARS-CoV-2 may follow the epidemiological pattern of SARS-CoV and extinguish slowly over time, there is yet concern that SARS-CoV-2 may establish itself as an endemic human respiratory coronavirus similar to OC43, 2299E, NL63, and HKU1. Until sufficient data are acquired to better understand the potential of SARS-CoV-2, continued work on antiviral therapy and vaccination is imperative.

Environmental and decontamination issues for human coronaviruses and their potential surrogates

Pandemic coronavirus disease‐2019 (COVID‐19) gives ample reason to generally review coronavirus (CoV) containment. For establishing some preliminary views on decontamination and disinfection, surrogate CoVs have commonly been assessed. This review serves to examine the existing science in regard to CoV containment generically and then to translate these findings into timely applications for COVID‐19. There is widespread dissemination of CoVs in the immediate patient environment, and CoVs can potentially be spread via respiratory secretions, urine, and stool. Interpretations of the spread however must consider whether studies examine for viral RNA, virus viability by culture, or both. Presymptomatic, asymptomatic, and post‐14 day virus excretion from patients may complicate the epidemiology. Whereas droplet spread is accepted, there continues to be controversy over the extent of possible airborne spread and especially now for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). CoVs are stable in body secretions and sewage at reduced temperatures. In addition to temperature, dryness or relative humidity, initial viral burden, concomitant presence of bioburden, and the type of surface can all affect stability. Generalizing, CoVs can be susceptible to radiation, temperature extremes, pH extremes, peroxides, halogens, aldehydes, many solvents, and several alcohols. Whereas detergent surfactants can have some direct activity, these agents are better used as complements to a complex disinfectant solution. Disinfectants with multiple agents and adverse pH are more likely to be best active at higher water temperatures. Real‐life assessments should be encouraged with working dilutions. The use of decontamination and disinfection should be balanced with considerations of patient and caregiver safety. Processes should also be balanced with considerations for other potential pathogens that must be targeted. Given some CoV differences and given that surrogate testing provides experimental correlates at best, direct assessments with SARS‐CoV, Middle East respiratory syndrome‐related coronavirus (MERS‐CoV), and SARS‐CoV‐2 are required.

Environmental spread in the immediate context of infected hosts is common for coronaviruses.

The epidemiology of coronavirus infections is complicated by presymptomatic, asymptomatic, and post‐fourteen day infection spread.

Mechanical removal of associated organic debris is vital to effective coronavirus decontamination.

Proper exposure times for disinfection are vital to effective coronavirus inactivation.

Temperature of disinfectant working dilutions and pH can have impact on antiviral activity.

The immediate patient environment should be simplified for necessary and reusable items.

Coronavirus inactivation should be considered in the context of other pathogens that need to be inactivated simultaneously.

Features of enteric disease from human coronaviruses: Implications for COVID-19

Coronaviruses have long been studied in both human and veterinary fields. Whereas the initial detection of endemic human respiratory coronaviruses was problematic, detection of these and newly discovered human coronaviruses has been greatly facilitated with major advances in the laboratory. Nevertheless, technological factors can affect the accuracy and timeliness of virus detection. Many human coronaviruses can be variably found in stool samples. All human coronaviruses have been variably associated with symptoms of gastroenteritis. Coronaviruses can occasionally be cultured from enteric specimens, but most detection is accomplished with genetic amplification technologies. Excretion of viral RNA in stool can extend for a prolonged period. Culture‐positive stool samples have been found to exceed a fourteen day period after onset of infection for some coronaviruses. Virus can also sometimes be cultured from patients' respiratory samples during the late incubation period. Relatively asymptomatic patients may excrete virus. Both viable and nonviable virus can be found in the immediate environment of the patient, the health care worker, and less often the public. These lessons from the past study of animal and human coronaviruses can be extended to presumptions for severe acute respiratory syndrome coronavirus 2. Already, the early reports from the coronavirus disease‐2019 pandemic are confirming some concerns. These data have the cumulative potential to cause us to rethink some current and common public health and infection control strategies.

coronaviruses are variably found in human enteric samples during the course of infection.

abdominal and intestinal illnesses are associated with coronavirus infections.

enteric excretion of live virus and viral RNA have been confirmed.

occasionally, live virus can be found in stool samples to exceed a fourteen day period after disease onset, and virus can also be cultured from these samples during the late incubation period or from asymptomatic individuals.