Lethal Swine Acute Diarrhea Syndrome Coronavirus Infection in Suckling Mice.

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a recently emerging bat-borne coronavirus responsible for high mortality rates in piglets. In vitro studies have indicated that SADS-CoV has a wide tissue tropism in different hosts, including humans. However, whether this virus potentially threatens other animals remains unclear. Here, we report the experimental infection of wild-type BALB/c and C57BL/6J suckling mice with SADS-CoV. We found that mice less than 7 days old are susceptible to the virus, which caused notable multitissue infections and damage. The mortality rate was the highest in 2-day-old mice and decreased in older mice. Moreover, a preliminary neuroinflammatory response was observed in 7-day-old SADS-CoV-infected mice. Thus, our results indicate that SADS-CoV has potential pathogenicity in young hosts. IMPORTANCE SADS-CoV, which likely has originated from bat coronaviruses, is highly pathogenic to piglets and poses a threat to the swine industry. Little is known about its potential to disseminate to other animals. No efficient treatment is available, and the quarantine strategy is the only preventive measure. In this study, we demonstrated that SADS-CoV can efficiently replicate in suckling mice younger than 7 days. In contrast to infected piglets, in which intestinal tropism is shown, SADS-CoV caused infection and damage in all murine tissues evaluated in this study. In addition, neuroinflammatory responses were detected in some of the infected mice. Our work provides a preliminary cost-effective model for the screening of antiviral drugs against SADS-CoV infection.

Mutations in Porcine Epidemic Diarrhea Virus nsp1 Cause Increased Viral Sensitivity to Host Interferon Responses and Attenuation In Vivo.

Coronavirus (CoV) nonstructural protein 1 (nsp1) inhibits cellular gene expression and antagonizes interferon (IFN) response. Porcine epidemic diarrhea virus (PEDV) infects pigs and causes high mortality in neonatal piglets. We hypothesized that a recombinant PEDV carrying mutations at the conserved residues N93 and N95 of nsp1 induces higher IFN responses and is more sensitive to IFN responses, leading to virus attenuation. We mutated PEDV nsp1 N93 and N95 to A93 and A95 to generate the recombinant N93/95A virus using the infectious clone of a highly virulent PEDV strain, PC22A (icPC22A), and evaluated N93/95A virus in vitro and in vivo. Compared with icPC22A, the N93/95A mutant replicated to significantly lower infectious titers, triggered stronger type I and III IFN responses, and was more sensitive to IFN treatment in vitro. To evaluate the pathogenicity and immunogenicity, 5-day-old gnotobiotic piglets were orally inoculated with the N93/95A or icPC22A strain or mock inoculated and then challenged at 22 days postinoculation (dpi) with icPC22A. icPC22A in all pigs (100% [5/5]) caused severe diarrhea and death within 6 dpi. Only one pig (25% [1/4]) died in the N93/95A group. Compared with the icPC22A group, significantly delayed and diminished fecal PEDV shedding was detected in the N93/95A group. Postchallenge, all piglets in N93/95A group were protected from severe diarrhea and death, whereas all pigs in the mock-challenged group developed severe diarrhea, and 25% (1/4) of them died. In summary, nsp1 N93A and N95A mutations attenuated PEDV but retained viral immunogenicity and can be targets for the development of live attenuated vaccines for PEDV. IMPORTANCE PEDV causes porcine epidemic diarrhea (PED) and remains a great threat to the swine industry worldwide because no effective vaccines are available yet. Safe and effective live attenuated vaccines can be designed using reverse genetics to induce lactogenic immunity in pregnant sows to protect piglets from the deadly PED. We found that an engineered PEDV mutant carrying N93A and N95A mutations of nsp1 was partially attenuated and remained immunogenic in neonatal pigs. Our study suggested that nsp1 N93 and N95 can be good targets for the rational design of live attenuated vaccines for PEDV using reverse genetics. Because CoV nsp1 is conserved among alphacoronaviruses (α-CoVs) and betacoronaviruses (ß-CoVs), it may be a good target for vaccine development for other α-CoVs or ß-CoVs.

Evaluation of Diarrhea in Patients with COVID-19.

BACKGROUND/AIMS: The COVID-19 disease, which was declared epidemic by the WHO, is a global emergency public health problem. Patients with extrapulmonary symptoms are the group of patients who should be considered for person-to-person transmission in the community. In our study, it was aimed to investigate the characteristics of patients with COVID-19-related diarrhea symptoms. MATERIALS AND METHODS: The study was conducted retrospectively in CO-VID-19 rtRT-PCR-positive patients in 5 medical centers. Three or more loose/liquid stools per day or increased number of defecations compared to normal defecation were defined as diarrhea. The patients were analyzed in 2 groups as those with and without diarrhea. RESULTS: One thousand eighty-six patients were included in the study. Seventy-eight (7.2%) of the patients had diarrhea. Diarrhea was watery in 54 (69.2%) patients while with blood and mucus in 18 (23.1%) patients. Diarrhea continued for an average of 5.2 ± 1.6 (2-11) days. The clinical and laboratory findings of patients with diarrhea were more serious than those without diarrhea. Diarrhea is more common in the elderly and people with comorbid disease, and patients with diarrhea had higher CMI score and CRP and higher complaints of fever, cough, shortness of breath, myalgia, and fatigue. CONCLUSIONS: The presence of diarrhea should indicate a suspected COVID-19 infection and suggest testing for early diagnosis of the disease. It should be kept in mind that the course of the disease may be more severe in these patients, and precautions should also be taken in terms of fecal transmission during discharge.

Serial Screening for SARS-CoV-2 in Rectal Swabs of Symptomatic COVID-19 Patients.

We used serial rectal swabs to investigate the amount and duration of virus secretion through the gastrointestinal tract and assessed the association between fecal shedding and gastrointestinal symptoms and to clarify the clinical usefulness testing rectal swabs. We enrolled ten adult patients hospitalized with symptomatic coronavirus disease 2019 (COVID-19). Respiratory and stool specimens were collected by physicians. The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was confirmed using real-time reverse-transcription polymerase chain reaction. All ten patients had respiratory symptoms, six had diarrhea, and seven were positive for SARS-CoV-2 on rectal swabs. The viral loads in the respiratory specimens was higher than those in the rectal specimens, and no rectal specimens were positive after the respiratory specimens became negative. There was no association between gastrointestinal symptoms, pneumonia, severity, and rectal viral load. Rectal swabs may play a role in detecting SARS-CoV-2 in individuals with suspected COVID-19, regardless of gastrointestinal symptoms.

Early viral versus late antibiotic-associated diarrhea in novel coronavirus infection.

ABSTRACT: Diarrhea is one of the manifestations of the novel coronavirus disease (COVID-19), but it also develops as a complication of massive antibiotic therapy in this disease. This study aimed to compare these types of diarrhea.We included patients with COVID-19 in a cohort study and excluded patients with chronic diarrhea, laxative use, and those who died during the first day of hospitalization.There were 89 (9.3%), 161 (16.7%), and 731 (75.7%) patients with early viral, late antibiotic-associated, and without diarrhea, respectively. Late diarrhea lasted longer (6 [4-10] vs 5 [3-7] days, P < .001) and was more severe. Clostridioides difficile was found in 70.5% of tested patients with late diarrhea and in none with early diarrhea. Presence of late diarrhea was associated with an increased risk of death after 20 days of disease (P = .009; hazard ratio = 4.7). Patients with late diarrhea had a longer hospital stay and total disease duration, and a higher proportion of these patients required intensive care unit admission. Oral amoxicillin/clavulanate (odds ratio [OR] = 2.23), oral clarithromycin (OR = 3.79), and glucocorticoids (OR = 4.41) use was a risk factor for the development of late diarrhea, while ceftriaxone use (OR = 0.35) had a protective effect. Before the development of late diarrhea, decrease in C-reactive protein levels and increase in lymphocyte count stopped but the white blood cell and neutrophil count increased. An increase in neutrophils by >0.6 × 109 cells/L predicted the development of late diarrhea in the coming days (sensitivity 82.0%, specificity 70.8%, area under the curve = 0.791 [0.710-0.872]).Diarrhea in COVID-19 is heterogeneous, and different types of diarrhea require different management.

Gastrointestinal symptoms in patients with COVID-19: Is there a relationship with mortality and new variations of SARS-CoV-2?

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although, respiratory symptoms are typical the digestive system is also a susceptible target with gastrointestinal symptoms present even in the absence of respiratory symptoms. The gastrointestinal symptoms of COVID-19 include diarrhea, abdominal pain, anorexia, and nausea among other symptoms. Some questions that remain to be answered include: Do patients with gastrointestinal symptoms have a higher mortality? SARS-CoV-2 variants are already a global reality: Do these variants present with a greater prevalence of gastrointestinal symptoms? Do patients with these symptoms warrant more intensive care unit care?

Bovine coronavirus infections in Turkey: molecular analysis of the full-length spike gene sequences of viruses from digestive and respiratory infections.

Bovine coronavirus (BCoV) can be spread by animal activity. Although cattle farming is widespread in Turkey, there are few studies of BCoV. The aim of this study was to evaluate the current situation regarding BCoV in Turkey. This is the first study reporting the full-length nucleotide sequences of BCoV spike (S) genes in Turkey. Samples were collected from 119 cattle with clinical signs of respiratory (n = 78) or digestive tract (n = 41) infection on different farms located across widely separated provinces in Turkey. The samples were screened for BCoV using RT-nested PCR targeting the N gene, which identified BCoV in 35 samples (9 faeces and 26 nasal discharge). RT-PCR analysis of the S gene produced partial/full-length S gene sequences from 11 samples (8 faeces and 3 nasal discharge samples). A phylogenetic tree of the S gene sequences was made to analyze the genetic relationships among BCoVs from Turkey and other countries. The results showed that the local strains present in faeces and nasal discharge samples had many different amino acid changes. Some of these changes were shown in previous studies to be critical for tropism. This study provides new data on BCoV in Turkey that will be valuable in designing effective vaccine approaches and control strategies.

SARS-CoV-2 Related Ischemic Colitis in an Adolescent With Trisomy 21: Diagnostic Pitfalls and Considerations.

Millions of patients seek medical attention for diarrhea, vomiting, nausea, and abdominal pain. In the current environment, it is important to recognize that these symptoms may be the only manifestation or may precede more serious systemic complications of COVID-19. Herein, we describe the first case of ischemic colitis (IC) in a young adult who presented with diarrhea and highlight the laboratory pitfalls for patients with COVID-19 presenting with gastrointestinal (GI) symptoms.

Clinical Characteristics of 195 Cases of COVID-19 with Gastrointestinal Symptoms COVID-19 with Gastrointestinal Symptoms.

BACKGROUND: Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), have fever, dry cough, dyspnea, and fatigue. The disease has now become a global pandemic. The purpose of this study was to explore the relationship between COVID-19 and gastrointestinal (GI) symptoms. METHODS: We collected and analyzed data on patients with laboratory-confirmed COVID-19 by high-throughput sequencing or reverse transcription-polymerase chain reaction. We reviewed electronic medical records of 405 hospitalized COVID-19 patients in the Third Hospital of Wuhan. RESULTS: Among the 405 confirmed patients, 210 had no GI symptoms, 195 had GI symptoms, and the first symptom of 155 patients was GI. The prevalence of vascular and digestive diseases in the group with GI symptoms was significantly higher than in the group without GI symptoms. In patients with GI symptoms, the proportion with fever, cough, dysphoria, chest tightness, poor appetite, chest pain, and pharyngeal pain was significantly higher than in those without GI symptoms. There was no significant difference in imaging between the 2 groups. In patients with GI symptoms, the proportion with increased procalcitonin (PCT) level and decreased lymphocyte count was significantly higher than in those without GI symptoms. CONCLUSION: COVID-19 patients with GI symptoms had significantly more vascular and digestive system diseases and were more likely to have clinical manifestations of fever, cough, poor appetite, chest tightness, chest pain, insomnia, and pharyngeal pain. There were more patients with diarrhea, nausea, and vomiting. Patients with GI symptoms were more likely to have increased PCT and decreased lymphocyte count.

Prevalence and Persistent Shedding of Fecal SARS-CoV-2 RNA in Patients With COVID-19 Infection: A Systematic Review and Meta-analysis.

INTRODUCTION: The prevalence and shedding of fecal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA indicate coronavirus disease 2019 (COVID-19) infection in the gastrointestinal (GI) tract and likely infectivity. We performed a systemic review and meta-analysis to evaluate the prevalence and the duration of shedding of fecal RNA in patients with COVID-19 infection. METHODS: PubMed, Embase, Web of Science, and Chinese databases Chinese National Knowledge Infrastructure and Wanfang Data up to June 2020 were searched for studies evaluating fecal SARS-CoV-2 RNA, including anal and rectal samples, in patients with confirmed COVID-19 infection. The pooled prevalence of fecal RNA in patients with detectable respiratory RNA was estimated. The days of shedding and days to loss of fecal and respiratory RNA from presentation were compared. RESULTS: Thirty-five studies (N = 1,636) met criteria. The pooled prevalence of fecal RNA in COVID-19 patients was 43% (95% confidence interval [CI] 34%-52%). Higher proportion of patients with GI symptoms (52.4% vs 25.9%, odds ratio = 2.4, 95% CI 1.2-4.7) compared with no GI symptoms, specifically diarrhea (51.6% vs 24.0%, odds ratio = 3.0, 95% CI 1.9-4.8), had detectable fecal RNA. After loss of respiratory RNA, 27% (95% CI 15%-44%) of the patients had persistent shedding of fecal RNA. Days of RNA shedding in the feces were longer than respiratory samples (21.8 vs 14.7 days, mean difference = 7.1 days, 95% CI 1.2-13.0). Furthermore, days to loss of fecal RNA lagged respiratory RNA by a mean of 4.8 days (95% CI 2.2-7.5). DISCUSSION: Fecal SARS-CoV-2 RNA is commonly detected in COVID-19 patients with a 3-fold increased risk with diarrhea. Shedding of fecal RNA lasted more than 3 weeks after presentation and a week after last detectable respiratory RNA.

The characteristics of gastrointestinal symptoms in patients with severe COVID-19: a systematic review and meta-analysis.

Although primarily a respiratory illness, several studies have shown that COVID-19 causes elevation of liver enzymes and various gastrointestinal (GI) symptoms. The aim of this study was to undertake a systematic review and meta-analysis to determine whether the presence of gastrointestinal (GI) symptoms contributed toward COVID-19 severity, and identify the GI symptoms characteristic of severe COVID-19. We conducted a literature search of PubMed from December 1, 2019, to June 30, 2020, and identified all reports with GI symptoms reported. A meta-analysis comparing the severity of COVID-19 with the presence of liver enzyme elevation and GI symptoms was performed using RevMan version 5.4. Pooled data from 15,305 unique reverse transcriptase-polymerase chain reaction positive COVID-19 patients from 44 studies were analyzed. We found that the severe COVID-19 patients significantly had abdominal pain compared to the non-severe COVID-19 patients (OR = 2.70, 95% CI 1.17-6.27, Z = 2.32, p = 0.02, I2 = 0%) by analyzed 609 patients of 4 studies who reported both abdominal pain and COVID-19 severity. However, there was no significant difference in the incidence of diarrhea, nausea, or vomiting between the two groups. Thus, this systematic review and meta-analysis demonstrated that abdominal pain could be characteristic of severe COVID-19 infections. Compared with other viral infections that primarily infect the respiratory system, patients with COVID-19 have a slightly lower frequency of diarrheal symptoms with abdominal pain. However, to confirm this, further studies with COVID-19 patients across various countries and ethnicities are required.

The effect of Chinese herbal medicine on digestive system and liver functions should not be neglected in COVID-19: An updated systematic review and meta-analysis.

Gastrointestinal symptoms and liver injury are common in patients with coronavirus disease 2019 (COVID-19). However, profiles of different pharmaceutical interventions used are relatively underexplored. Chinese herbal medicine (CHM) has been increasingly used for patients with COVID-19, but the efficacy of CHM used in COVID-19 on gastrointestinal symptoms and liver functions has not been well studied with definitive results based on the updated studies. The present study aimed at testing the efficacy of CHM on digestive symptoms and liver function (primary outcomes), the aggravation of COVID-19, and the time to viral assay conversion (secondary outcomes), among patients with COVID-19, compared with standard pharmacotherapy. The literature search was undertaken in 11 electronic databases from December 1, 2019 up to November 8, 2020. Appraisal of the evidence was conducted with Cochrane risk of bias tool or Newcastle Ottawa Scale. A random-effects model or subgroup analysis was conducted when significant heterogeneity was identified in the meta-analysis. The certainty of the evidence was assessed with the grading of recommendations assessment, development, and evaluation approach. Forty-eight included trials involving 4,704 participants were included. Meta-analyses favored CHM plus standard pharmacotherapy for COVID-19 on reducing the aggravation of COVID-19 and the time to viral assay conversion compared with standard pharmacotherapy. However, the present CHM as a complementary therapy for treating COVID-19 may not be beneficial for improving most gastrointestinal symptoms and liver function based on the current evidence. More well-conducted trials are warranted to confirm the potential efficacy of CHM furtherly.

Coinfection of porcine deltacoronavirus and porcine epidemic diarrhea virus increases disease severity, cell trophism and earlier upregulation of IFN-α and IL12.

Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) cause an enteric disease characterized by diarrhea clinically indistinguishable. Both viruses are simultaneously detected in clinical cases, but a study involving the co-infection has not been reported. The study was therefore conducted to investigate the disease severity following a co-infection with PEDV and PDCoV. In the study, 4-day-old pigs were orally inoculated with PEDV and PDCoV, either alone or in combination. Following challenge, fecal score was monitored on a daily basis. Fecal swabs were collected and assayed for the presence of viruses. Three pigs per group were necropsied at 3 and 5 days post inoculation (dpi). Microscopic lesions and villous height to crypt depth (VH:CD) ratio, together with the presence of PEDV and PDCoV antigens, were evaluated in small intestinal tissues. Expressions of interferon alpha (IFN-α) and interleukin 12 (IL12) were investigated in small intestinal mucosa. The findings indicated that coinoculation increased the disease severity, demonstrated by significantly prolonged fecal score and virus shedding and decreasing VH:CD ratio in the jejunum compared with pigs inoculated with either PEDV or PDCoV alone. Notably, in single-inoculated groups, PEDV and PDCoV antigens were detected only in villous enterocytes wile in the coinoculated group, PDCoV antigen was detected in both villous enterocytes and crypts. IFN-α and IL12 were significantly up-regulated in coinoculated groups in comparison with single-inoculated groups. In conclusion, co-infection with PEDV and PDCoV exacerbate clinical signs and have a synergetic on the regulatory effect inflammatory cytokines compared to a single infection with either virus.

Implications of SARS-CoV-2 infection for neurogastroenterology.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is associated with gastrointestinal and hepatic manifestation in up to one fifth of patients. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of COVID-19, infects gastrointestinal epithelial cells expressing angiotensin-converting enzyme 2 (ACE2) receptors triggering a cascade of events leading to mucosal and systemic inflammation. Symptomatic patients display changes in gut microbiota composition and function which may contribute to intestinal barrier dysfunction and immune activation. Evidence suggests that SARS-CoV-2 infection and related mucosal inflammation impact on the function of the enteric nervous system and the activation of sensory fibers conveying information to the central nervous system, which, may at least in part, contribute symptom generation such as vomiting and diarrhea described in COVID-19. Liver and pancreas dysfunctions have also been described as non-respiratory complications of COVID-19 and add further emphasis to the common view of SARS-CoV-2 infection as a systemic disease with multiorgan involvement. PURPOSE: The aim of this review was to highlight the current knowledge on the pathophysiology of gastrointestinal SARS-CoV-2 infection, including the crosstalk with the gut microbiota, the fecal-oral route of virus transmission, and the potential interaction of the virus with the enteric nervous system. We also review the current available data on gastrointestinal and liver manifestations, management, and outcomes of patients with COVID-19.

Self-Reported Symptoms of COVID-19, Including Symptoms Most Predictive of SARS-CoV-2 Infection, Are Heritable.

Susceptibility to infection such as SARS-CoV-2 may be influenced by host genotype. TwinsUK volunteers (n = 3261) completing the C-19 COVID-19 symptom tracker app allowed classical twin studies of COVID-19 symptoms, including predicted COVID-19, a symptom-based algorithm to predict true infection, derived from app users tested for SARS-CoV-2. We found heritability of 49% (32-64%) for delirium; 34% (20-47%) for diarrhea; 31% (8-52%) for fatigue; 19% (0-38%) for anosmia; 46% (31-60%) for skipped meals and 31% (11-48%) for predicted COVID-19. Heritability estimates were not affected by cohabiting or by social deprivation. The results suggest the importance of host genetics in the risk of clinical manifestations of COVID-19 and provide grounds for planning genome-wide association studies to establish specific genes involved in viral infectivity and the host immune response.

Features of Intestinal Disease Associated With COVID-Related Multisystem Inflammatory Syndrome in Children.

ABSTRACT: Multisystem inflammatory syndrome in children (MIS-C) is a recently identified syndrome that appears to be temporally associated with novel coronavirus 2019 infection. MIS-C presents with fever and evidence of systemic inflammation, which can manifest as cardiovascular, pulmonary, neurologic, and gastrointestinal (GI) system dysfunction. Presenting GI symptoms are seen in the majority, including abdominal pain, diarrhea, and vomiting. Any segment of the GI tract may be affected; however, inflammation in the ileum and colon predominates. Progressive bowel wall thickening can lead to luminal narrowing and obstruction. Most will have resolution of intestinal inflammation with medical therapies; however, in rare instances, surgical resection may be required.

Clinical characteristics of coronavirus disease 2019 patients with diarrhea in Daegu.

BACKGROUND/AIMS: Coronavirus disease 2019 (COVID-19) can reportedly cause gastrointestinal symptoms. Therefore, we investigated the clinical characteristics of COVID-19 patients with diarrhea. METHODS: We included 118 COVID-19 patients admitted to a single hospital from February 20 to March 31, 2020. Medical records with clinical characteristics, laboratory data, treatment course, and clinical outcomes were compared based on the presence or absence of diarrhea. Prognostic factors for disease severity and mortality in COVID-19 were also assessed. RESULTS: Among patients, 54 (45.8%) had diarrhea, whereas seven (5.9%) had only diarrhea. The median age of patients with diarrhea was 59 years (44 to 64), and 22 (40.7%) were male. Systemic steroid use, intensive care unit admission, septic shock, and acute respiratory distress syndrome were less frequent in the diarrhea group than in the non-diarrhea group. No significant differences were observed in total hospital stay and mortality between groups. On multivariate analysis, age (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.01 to 1.12; p = 0.044), diabetes (OR, 3.00; 95% CI, 1.25 to 20.47; p = 0.042), and dyspnea (OR, 41.19; 95% CI, 6.60 to 823.16; p < 0.001) were independent risk factors for septic shock. On Cox regression analysis, diabetes (hazard ratio [HR], 4.82; 95% CI, 0.89 to 26.03; p = 0.043) and chronic obstructive pulmonary disease (HR, 16.58; 95% CI, 3.10 to 88.70; p = 0.044) were risk factors for mortality. CONCLUSION: Diarrhea was present in 45.8% of patients and was a common symptom of COVID-19. Although patients with diarrhea showed less severe clinical features, diarrhea was not associated with disease severity or mortality.

Surveillance of COVID-19-Associated Multisystem Inflammatory Syndrome in Children, South Korea.

A concerning development during the coronavirus disease pandemic has been multisystem inflammatory syndrome in children. Reports of this condition in East Asia have been limited. In South Korea, 3 cases were reported to the national surveillance system for multisystem inflammatory syndrome in children. All case-patients were hospitalized and survived with no major disease sequelae.