Natural Evolution of Porcine Epidemic Diarrhea Viruses Isolated from Maternally Immunized Piglets

Simple SummaryDuring the long-term co-evolution of the virus and the host, even closely related vaccines may emerge with incomplete protective immunity due to the mutations or deletions of amino acids at specific antigenic sites. The mutation of PEDV was accelerated by the recombination of different strains and the mutation of the strains adapting to the environment. These mutations either cause immune escape from conventional vaccines or affect the virulence of the virus. Therefore, researching and developing new vaccines with cross-protection through continuous monitoring, isolation and sequencing are important to determine whether their genetic characteristics are changed and to evaluate the protective efficacy of current vaccines. The porcine epidemic diarrhea virus (PEDV) can cause severe piglet diarrhea or death in some herds. Genetic recombination and mutation facilitate the continuous evolution of the virus (PEDV), posing a great challenge for the prevention and control of porcine epidemic diarrhea (PED). Disease materials of piglets with PEDV vaccination failure in some areas of Shanxi, Henan and Hebei provinces of China were collected and examined to understand the prevalence and evolutionary characteristics of PEDV in these areas. Forty-seven suspicious disease materials from different litters on different farms were tested by multiplex PCR and screened by hematoxylin-eosin staining and immunohistochemistry. PEDV showed a positivity rate of 42.6%, infecting the small and large intestine and mesenteric lymph node tissues. The isolated strains infected Vero, PK-15 and Marc-145 multihost cells and exhibited low viral titers in all three cell types, as indicated by their growth kinetic curves. Possible putative recombination events in the isolates were identified by RDP4.0 software. Sequencing and phylogenetic analysis showed that compared with the classical vaccine strain, PEDV SX6 contains new insertion and mutations in the S region and belongs to genotype GIIa. Meanwhile, ORF3 has the complete amino acid sequence with aa80 mutated wild strains, compared to vaccine strains CV777, AJ1102, AJ1102-R and LW/L. These results will contribute to the development of new PEDV vaccines based on prevalent wild strains for the prevention and control of PED in China.

General Surgery Resident Case Numbers During the Covid-19 Pandemic

Introduction: The COVID-19 pandemic has had widespread effects on the healthcare system. For trainees, one particular detriment has been the cancellation of elective operations, reducing clinical experience and procedural volumes. Measures instituted to combat the pandemic have resulted in decreased cancellation of elective cases to varying degrees. The aim of this study is to evaluate the ongoing effect of the pandemic on resident operative volume. Method(s): Operative case numbers of general surgical graduates in 2019, 2020, and 2021 were extracted from the Accreditation Council for Graduate Medical Education case logs. Data included mean total cases/graduate and means for individual case types. Data was considered by overall number of cases and cases performed as surgeon chief. Analysis of variance was employed to compare groups with p<0.05 considered significant. Result(s): Mean total major cases differed significantly among groups with reduced volume noted for 2020 graduates but no difference in volume between 2019 and 2021 graduates (1070.5+/-150 vs 1054.8+/-155 vs 1074.1+/-164, p=0.0041). This same pattern was noted for surgeon chief total cases (288.6+/-69 vs 264.4+/-67 vs 286.2+/-73, p<0.0001) as well as several major general surgery subcategories including cases involving the stomach, small intestine, large intestine, biliary system, among others. Conclusion(s): Despite continued reduction in and alteration of elective surgery practice, improved pandemic measures have allowed for increased surgical volume. This has translated to increased operative experience for graduating surgical trainees that are comparable to case numbers that preceded the pandemic. Ramifications for the 2020 graduating cohort as well subsequent cohorts require continued evaluation.

Lactulose Works in the Large Bowel: But How Does It Improve Hepatic Encephalopathy in a Patient Without a Large Bowel?

Introduction: Lactulose is a non-absorbable disaccharide which acts in the large bowel, and is commonly used in the treatment of hepatic encephalopathy. We present an interesting case of altered mental status due to hepatic encephalopathy successfully managed with lactulose in a patient with history of total colectomy. Case Description/Methods: A 67-year-old male with non-alcoholic cirrhosis and inflammatory bowel disease (IBD) post total proctocolectomy with a continent ileostomy known as a Kock-pouch (K-pouch) presented to the hospital with flu like symptoms and altered mental status. He was subsequently found to be positive for COVID-19. At the time of initial evaluation, the patient was obtunded with an elevated ammonia level of 91 umol/L. Colorectal surgery was consulted as the patient was not able to empty his K-pouch. Recently, he complained of inability to catheterize and with bleeding from the stoma. Initial catheterization with a Water's tube yielded 400 cc of effluent. Nasogastric tube was placed through which he was receiving lactulose 30 mg q8 hours. The patient's mental status improved within 24 hours. The patient ultimately underwent flexible pouchoscopy with endoscopic dilation and placement of a 22 French mushroom catheter for decompression of the K-pouch. Discussion(s): Lactulose is a non-absorbable disaccharide composed of galactose and fructose. The small intestine does not have the enzymes required to breakdown lactulose so it reaches the large bowel in its original form. In the large bowel, it is metabolized by colonic bacteria into monosaccharides and then to volatile fatty acids, hydrogen and methane. Lactulose decreases both the production and absorption of ammonia mainly through the presence of gut bacteria. The question arises as to how lactulose decreased ammonia levels in this patient without a large bowel. One proposed mechanism is the translocation of bacteria normally found in the large bowel to the small intestine. Small Intestinal Bacterial Overgrowth (SIBO), is a condition causing an increased number of bacteria in the small intestine. Patients with IBD and structural abnormalities are at increased risk of developing SIBO. Lactulose is commonly used in the diagnosis through the administration of lactulose and subsequent measurements of hydrogen and methane gas in expired air. This condition, in our patient with history of ulcerative colitis and colectomy, is a proposed mechanism of the efficacy of lactulose in the treatment of hepatic encephalopathy.

MORPHOLOGICAL AND FUNCTIONAL FEATURES OF THE MUCOUS MEMBRANE OF SMALL AND LARGE INTESTINE IN PATIENTS WITH COVID-19 AND IN POST-COVID-19 PERIOD.

OBJECTIVE: The aim: To reveal the morphological and functional features of the mucous membrane of small and large intestine in patients with COVID-19 and in post-COVID-19 period. PATIENTS AND METHODS: Materials and methods: In the present study, the authors used biopsy and autopsy material represented by the fragments of the mucous membrane of small and large intestine. All studied material was divided into 10 groups. Group 1 (comparison group) included autopsy material from the deceased who did not have COVID-19 during their lifetime. Groups 2-4 included autopsy material from the deceased who had COVID-19 of varying severity during their lifetime. Groups 5-7 included biopsy material from patients who had recovered from COVID-19 of varying severity, while the duration of the post-COVID period ranged from 1 to 50 days. Groups 8-10 included biopsy material from patients who had in anamnesis COVID-19 of varying severity (the duration of the post-COVID period lasted from 51 to 100 days). Histological, immunohistochemical, morphometric and statistical research methods were used. RESULTS: Results: The comparative analysis showed a more expressed deficiency of ACE2 in the mucous membrane of small and large intestine in patients with moderate and severe COVID-19 compared with patients in post-COVID-19 period of different duration. In patients who had moderate and severe COVID-19 in anamnesis, ACE2 deficiency decreases with increasing duration of post-COVID-19 period. In patients recovered from mild COVID-19, the ACE2 content increases with the duration of post-COVID-19 period from 1 to 50 days and corresponds to the norm with the duration of this period from 51 to 100 days. CONCLUSION: Conclusions: The comprehensive morphological study conducted by the authors made it possible, firstly, to clarify the morphological and functional features of the mucous membrane of small and large intestine in patients with COVID-19 of various degrees of severity; secondly, to obtain new data about the morpho-functional state of the mucous membrane of small and large intestine in patients, taking into account different duration of the post-COVID-19 period and the severity of the infection.

CURRENT BARRIERS TO PATIENTS PROCEEDING WITH DIAGNOSTIC TESTS IN THE ENGLISH BOWEL CANCER SCREENING PROGRAMME

Introduction Uptake rates and pathology detection has increased significantly with integration of faecal immunochemical testing (FIT) in the English Bowel Cancer Screening Programme (BCSP). However a proportion of patients do not uptake diagnostic tests after positive FIT tests. We compared pre and peri-COVID cohorts to identify current barriers to uptake of diagnostic tests within a single, large BCSP centre. Methods Two patient cohorts were analysed from the Wolverhampton BCSP Centre (September 2019-February 2020 (Group A, pre-Covid) and April-July 2021 (Group B, peri- Covid)). Patients with a positive FIT were assessed by either a face-to-face (F2F) consultation (Group A) or a telephone consultation (TC) (Group B) by a specialist screening practitioner (SSP) and offered information and diagnostic tests. Total overall numbers were recorded and cases not proceeding with diagnostic tests reviewed. Statistical analysis utilised Fisher's exact test where appropriate. Results In group A, 26293/42545 (61.8%) patients returned a FIT test compared with, 30214/45538 (66.3%) in group B (p<0.00001) with similar positivity rates (2.1% (A) vs. 2.2% (B), p=NS). The peri-COVID era shows an increase in patients not proceeding with diagnostic tests after positive FIT tests (Group A 90/633 (14.2%) Vs. Group B 144/655 (22%), p=0.0003). Table 1 expands the reasons for this. Conclusion FIT sample return rates have increased in the peri- COVID era but proportions of patients not proceeding with diagnostic investigations following positive FIT testing have risen. Patient choice is a notable barrier to uptake and other barriers which have significantly increased during this current period are patients being assessed as clinically unsuitable due to health reasons, declining initial telephone appointments and DNA tests. Whilst informed patient choice is key in national screening programmes, cancer and polyp detection in FIT positive patients in BCSP are notable. Understanding patient's perspectives on tests, preferences over TC or F2F and SSP education on health assessment for colonoscopy may improve uptake of diagnostic tests within the BCSP.

Autopsy Histopathologic Cardiac Findings in 2 Adolescents Following the Second COVID-19 Vaccine Dose/In Reply

The authors correctly stated that the Centers for Disease Control and Prevention (CDC) performed testing for SARS-CoV-2 and found no evidence of SARS-CoV-2 infection in autopsy tissues from the decedents. Molecular analysis included polymerase chain reaction (PCR) assays on nucleic acid extracted from FFPE heart tissue, including SARS-CoV-2 and enterovirus reverse transcriptase PCR (RT-PCR) assays2,3 and conventional PCR for parvovirus B19. Clostridium septicum produces multiple toxins that cause necrosis of striated muscle cells9,11 and inhibit influx of neutrophils to infected tissues;indeed, paucity of neutrophilic infiltrates in tissues infected with C septicum is considered a hallmark of this disease.9,12 Clostridium septicum is not considered normal flora of the human intestinal tract,13,14 but rather an opportunistic invader of immunologically compromised hosts, particularly persons with colonic adenocarcinoma, leukemia, diabetes, bowel ischemia, or cyclic, congenital, or acquired neutropenia.7,8 Spontaneous infections have been described for a few pediatric patients with no recognized risk factor and for whom microscopic breaches in the mucosa of the large intestine were considered the likely portal of entry.8,15 No representative samples of the small or large intestine were provided to the IDPB for evaluation;however, histologic evidence of bacterial invasion of the external surfaces of the adrenals, kidneys, liver, and spleen support an intraabdominal source of infection. The findings and conclusions in this letter are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. doi: 10.5858/arpa.2022-0084-LE In Reply.-We thank the Centers for Disease Control and Prevention's (CDC's) Infectious Diseases Pathology Branch laboratory for performing these tests and for sharing the full extent of its workup.

Penetrating abdominal trauma: Evaluation in Baghdad during the pandemic Covid-19

Background: Trauma is one of the leading causes of deaths worldwide for all age groups, especially in the younger age group. The purpose of the current study is to assess/analyze the factors for mortality in penetrating abdominal traumas with respect to the total number of intra-abdominal organs injured, related extra-abdominal injuries, gender, type of injury, time of arrival, and amount of blood transfusion needed during the pandemic. Methods: A retrospective study including 523 patients underwent laparotomy in Al-Emamien Al-Kadhimin Medical City from March 2020 to September 2021 for a penetrating abdominal injury due to blast injury, bullet, shrapnel injury, and stab wounds. The study population with penetrating abdominal traumas and indicative abdominal signs was subjected to exploratory laparotomy. Results: In this study, 465 (88.9%) males and 58 (11.1%) females participated;the highest rate was found in small bowel injuries (40.73%) followed by large bowel injuries (21.99%), whereas the lowest rate was found in gallbladder injury (1.34%). Chest injuries represent the highest rate among extra-abdominal injuries (18.36%), whereas head and neck represent the lowest rate (1.34%). Regarding the risk factors affecting the mortality rate, the highest rate of mortality was found in the case of gunshot (13.11%), followed by shrapnel (6.38%) and stab wound injuries (5.26%), which was the lowest. Conclusion: Penetrating abdominal injuries were the most common among males, small bowel injuries are the commonest organs affected by the penetrating abdominal injuries, shrapnel injuries were the commonest causes in our country, and the highest mortality rate was related to gunshot and number of organs affected and delay of arrival to the hospital and number of pints of blood received.