Evaluation of two inoculation routes of an adenovirus-mediated viral protein inhibitor in a Crimean-Congo hemorrhagic fever mouse model.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne nairovirus with a wide geographic spread that can cause severe and lethal disease. No specific medical countermeasures are approved to combat this illness. The CCHFV L protein contains an ovarian tumor (OTU) domain with a cysteine protease thought to modulate cellular immune responses by removing ubiquitin and ISG15 post-translational modifications from host and viral proteins. Viral deubiquitinases like CCHFV OTU are attractive drug targets, as blocking their activity may enhance cellular immune responses to infection, and potentially inhibit viral replication itself. We previously demonstrated that the engineered ubiquitin variant CC4 is a potent inhibitor of CCHFV replication in vitro. A major challenge of the therapeutic use of small protein inhibitors such as CC4 is their requirement for intracellular delivery, e.g., by viral vectors. In this study, we examined the feasibility of in vivo CC4 delivery by a replication-deficient recombinant adenovirus (Ad-CC4) in a lethal CCHFV mouse model. Since the liver is a primary target of CCHFV infection, we aimed to optimize delivery to this organ by comparing intravenous (tail vein) and intraperitoneal injection of Ad-CC4. While tail vein injection is a traditional route for adenovirus delivery, in our hands intraperitoneal injection resulted in higher and more widespread levels of adenovirus genome in tissues, including, as intended, the liver. However, despite promising in vitro results, neither route of in vivo CC4 treatment resulted in protection from a lethal CCHFV infection.

ICTV Virus Taxonomy Profile: Nairoviridae 2024.

Nairoviridae is a family for negative-sense RNA viruses with genomes of about 17.2-21.1 kb. These viruses are maintained in and/or transmitted by arthropods among birds, reptiles and mammals. Norwaviruses and orthonairoviruses can cause febrile illness in humans. Several orthonairoviruses can infect mammals, causing mild, severe and sometimes, fatal diseases. Nairovirids produce enveloped virions containing two or three single-stranded RNA segments with open reading frames that encode a nucleoprotein (N), sometimes a glycoprotein precursor (GPC), and a large (L) protein containing an RNA-directed RNA polymerase (RdRP) domain. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) report on the family Nairoviridae, which is available at www.ictv.global/report/nairoviridae.

Nucleocapsid protein-specific monoclonal antibodies protect mice against Crimean-Congo hemorrhagic fever virus.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a WHO priority pathogen. Antibody-based medical countermeasures offer an important strategy to mitigate severe disease caused by CCHFV. Most efforts have focused on targeting the viral glycoproteins. However, glycoproteins are poorly conserved among viral strains. The CCHFV nucleocapsid protein (NP) is highly conserved between CCHFV strains. Here, we investigate the protective efficacy of a CCHFV monoclonal antibody targeting the NP. We find that an anti-NP monoclonal antibody (mAb-9D5) protected female mice against lethal CCHFV infection or resulted in a significant delay in mean time-to-death in mice that succumbed to disease compared to isotype control animals. Antibody protection is independent of Fc-receptor functionality and complement activity. The antibody bound NP from several CCHFV strains and exhibited robust cross-protection against the heterologous CCHFV strain Afg09-2990. Our work demonstrates that the NP is a viable target for antibody-based therapeutics, providing another direction for developing immunotherapeutics against CCHFV.

Characterization of humoral responses to Nipah virus infection in the Syrian Hamster model of disease.

Nipah virus (NiV) is a highly pathogenic paramyxovirus. The Syrian hamster model recapitulates key features of human NiV disease and is a critical tool for evaluating antivirals and vaccines. Here we describe longitudinal humoral immune responses in NiV-infected Syrian hamsters. Samples were obtained 1-28 days after infection and analyzed by ELISA, neutralization, and Fc-mediated effector function assays. NiV infection elicited robust antibody responses against the nucleoprotein and attachment glycoprotein. Levels of neutralizing antibodies were modest and only detectable in surviving animals. Fc-mediated effector functions were mostly observed in nucleoprotein-targeting antibodies. Antibody levels and activities positively correlated with challenge dose.

Recombinant Sudan virus and evaluation of humoral cross-reactivity between Ebola and Sudan virus glycoproteins after infection or rVSV-ΔG-ZEBOV-GP vaccination.

Ebola disease outbreaks are major public health events because of human-to-human transmission and high mortality. These outbreaks are most often caused by Ebola virus, but at least three related viruses can also cause the disease. In 2022, Sudan virus re-emerged causing more than 160 confirmed and probable cases. This report describes generation of a recombinant Sudan virus and demonstrates its utility by quantifying antibody cross-reactivity between Ebola and Sudan virus glycoproteins after human infection or vaccination with a licensed Ebola virus vaccine.

Cholecystectomy following endoscopic clearance of common bile duct during the same admission.

BACKGROUND: The recurrence of common bile duct stones and other biliary events after endoscopic retrograde cholangiopancreatography (ERCP) is frequent. Despite recommendations for early cholecystectomy, intervention during the same admission is carried out inconsistently. METHODS: We reviewed the records of patients who underwent ERCP for gallstone disease and common bile duct clearance followed by cholecystectomy between July 2012 and June 2022. Patients were divided into 2 groups: the index group underwent cholecystectomy during the same admission and the delayed group was discharged and had their cholecystectomy postponed. Data on demographics and prognosis factors were collected and analyzed. RESULTS: The study population was composed of 268 patients, with 71 (26.6%) having undergone cholecystectomy during the same admission after common bile duct clearance with ERCP. A greater proportion of patients aged 80 years and older were in the index group than in the delayed group. The American Society of Anesthesiologists score was significantly higher in the index group. There was no significant difference between groups regarding surgical complications, open cholecystectomy and death. The operative time was significantly longer in the delayed group. Among patients with delayed cholecystectomy, 18.3% had at least 1 recurrence of common bile duct stones (CBDS) and 38.6% had recurrence of any gallstone-related events before cholecystectomy. None of these events occurred in the the index group. There was no difference in the recurrence of CBDS and other biliary events after initial diagnosis associated with stone disease. CONCLUSION: Cholecystectomy during the same admission after common bile duct clearance is safe, even in older adults with comorbidities. Compared with delayed cholecystectomy, it was not associated with adverse outcomes and may have prevented recurrence of biliary events.

Delay for cholecystectomy after common bile duct clearance with ERCP is just running after recurrent biliary event.

BACKGROUND: Gallstone disease will affect 15% of the adult population with concomitant common bile duct stone (CBDS) occurring in up to 30%. Endoscopic retrograde cholangiopancreatography (ERCP) is the mainstay of management for removal of CBDS, as cholecystectomy for the prevention of recurrent biliary event (RBE). RBE occurs in up to 47% if cholecystectomy is not done. The goal of this study was to evaluate the timing of occurrence of RBE after common bile duct clearance with ERCP and associated outcomes. METHODS: The records of all patients who underwent ERCP for gallstone disease followed by cholecystectomy, in a single center from 2010 to 2022, were reviewed. All RBE were identified. Actuarial incidence of RBE was built. Patients with and without RBE were compared. RESULTS: The study population is composed of 529 patients. Mean age was 58.0 (18-95). There were 221 RBE in 151 patients (28.5%), 39/151 (25.8%) having more than one episode. The most frequent RBE was acute cholecystitis (n = 104) followed by recurrent CBDS (n = 95). Median time for first RBE was 34 days. Actuarial incidence of RBE started from 2.5% at 7 days to reach 53.3% at 1 year. Incidence-rate of RBE was 2.9 per 100 person-months. Patients with RBE had significant longer hospitalisation time (11.7 vs 6.4 days; P < 0.0001), longer operative time (66 vs 48 min; P < 0.0001), longer postoperative stay (2.9 vs 0.9 days; P < 0.0001), higher open surgery rate (7.9% vs 1.3%; P < 0.0001), and more complicated pathology (23.8% vs 5.8%; P < 0.0001) and cholecystitis (64.2% vs 25.9%; P < 0.0001) as final diagnoses. CONCLUSIONS: RBE occurred in 28.5% of the subjects at a median time of 34 days, with an incidence of 2.5% as early as 1 week. Cholecystectomy should be done preferably within 7 days after common bile duct clearance in order to prevent RBE and adverse outcomes.

Single-dose mucosal replicon-particle vaccine protects against lethal Nipah virus infection up to 3 days after vaccination.

Nipah virus (NiV) causes a highly lethal disease in humans who present with acute respiratory or neurological signs. No vaccines against NiV have been approved to date. Here, we report on the clinical impact of a novel NiV-derived nonspreading replicon particle lacking the fusion (F) protein gene (NiVΔF) as a vaccine in three small animal models of disease. A broad antibody response was detected that included immunoglobulin G (IgG) and IgA subtypes with demonstrable Fc-mediated effector function targeting multiple viral antigens. Single-dose intranasal vaccination up to 3 days before challenge prevented clinical signs and reduced virus levels in hamsters and immunocompromised mice; decreases were seen in tissues and mucosal secretions, critically decreasing potential for virus transmission. This virus replicon particle system provides a vital tool to the field and demonstrates utility as a highly efficacious and safe vaccine candidate that can be administered parenterally or mucosally to protect against lethal Nipah disease.

Corrigendum: Editorial: Emerging SARS-CoV-2 variants: genomic variations, transmission, pathogenesis, clinical impact and interventions.

[This corrects the article DOI: 10.3389/fmed.2023.1178696.].

Annual (2023) taxonomic update of RNA-directed RNA polymerase-encoding negative-sense RNA viruses (realm Riboviria: kingdom Orthornavirae: phylum Negarnaviricota).

In April 2023, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by one new family, 14 new genera, and 140 new species. Two genera and 538 species were renamed. One species was moved, and four were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

Development of a neutralization assay using a vesicular stomatitis virus expressing Nipah virus glycoprotein and a fluorescent protein.

Nipah virus (NiV) is a highly pathogenic paramyxovirus with a high case fatality rate. Due to its high pathogenicity, pandemic potential, and lack of therapeutics or approved vaccines, its study requires biosafety level 4 (BSL4) containment. In this report, we developed a novel neutralization assay for use in biosafety level 2 laboratories. The assay uses a recombinant vesicular stomatitis virus expressing NiV glycoprotein and a fluorescent protein. The recombinant virus propagates as a replication-competent virus in a cell line constitutively expressing NiV fusion protein, but it is restricted to a single round of replication in wild-type cells. We used this system to evaluate the neutralization activity of monoclonal and polyclonal antibodies, plasma from NiV-infected hamsters, and serum from human patients. Therefore, this recombinant virus could be used as a surrogate for using pathogenic NiV and may constitute a powerful tool to develop therapeutics in low containment laboratories.

Two Sites of Obstruction with Gallstones: A Case Report of Bouveret Syndrome with a Concurrent Biliary Ileus.

Bouveret syndrome is a gastric outlet obstruction, and biliary ileus is an obstruction of the small bowel, and both are caused by a gallstone that escaped the gallbladder through a bilio-enteric fistula. The concurrent occurrence of obstruction at both sites is encountered very rarely, and only two such cases associated with Bouveret syndrome were reported before. We now present a case involving a 78-year-old female with simultaneous obstruction at both the duodenum and jejunum. The literature is reviewed to evaluate the incidence of such a situation and to discuss the management of the case.

Structural characterization of protective non-neutralizing antibodies targeting Crimean-Congo hemorrhagic fever virus.

Crimean-Congo Hemorrhagic Fever Virus (CCHFV) causes a life-threatening disease with up to a 40% mortality rate. With no approved medical countermeasures, CCHFV is considered a public health priority agent. The non-neutralizing mouse monoclonal antibody (mAb) 13G8 targets CCHFV glycoprotein GP38 and protects mice from lethal CCHFV challenge when administered prophylactically or therapeutically. Here, we reveal the structures of GP38 bound with a human chimeric 13G8 mAb and a newly isolated CC5-17 mAb from a human survivor. These mAbs bind overlapping epitopes with a shifted angle. The broad-spectrum potential of c13G8 and CC5-17 and the practicality of using them against Aigai virus, a closely related nairovirus were examined. Binding studies demonstrate that the presence of non-conserved amino acids in Aigai virus corresponding region prevent CCHFV mAbs from binding Aigai virus GP38. This information, coupled with in vivo efficacy, paves the way for future mAb therapeutics effective against a wide swath of CCHFV strains.

2022 taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.

In March 2022, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by two new families (bunyaviral Discoviridae and Tulasviridae), 41 new genera, and 98 new species. Three hundred forty-nine species were renamed and/or moved. The accidentally misspelled names of seven species were corrected. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

Intussusception Caused by Cecal Duplication in an Adult: A Case Report.

Cecal duplication is a rare congenital malformation and majority of the cases are discovered in the first years of life. Ileocolic intussusception is also a rare situation encountered in adults. A 19-year-old female presented with acute abdominal pain and bowel occlusion in relation with an ileocecal intussusception. She underwent an emergent laparotomy and ileocecal resection. A cecal duplication cyst was found to be the cause of the intussusception. While duplications and intussusception are very rare situations encountered in the adult life, the presence of both at the same time remains frankly anecdotal. The present case demonstrates that intussusception may likely be involved with any cecal lesion, like duplication.

Lessons from the pandemic: Responding to emerging zoonotic viral diseases-a Keystone Symposia report.

The COVID-19 pandemic caught the world largely unprepared, including scientific and policy communities. On April 10-13, 2022, researchers across academia, industry, government, and nonprofit organizations met at the Keystone symposium "Lessons from the Pandemic: Responding to Emerging Zoonotic Viral Diseases" to discuss the successes and challenges of the COVID-19 pandemic and what lessons can be applied moving forward. Speakers focused on experiences not only from the COVID-19 pandemic but also from outbreaks of other pathogens, including the Ebola virus, Lassa virus, and Nipah virus. A general consensus was that investments made during the COVID-19 pandemic in infrastructure, collaborations, laboratory and manufacturing capacity, diagnostics, clinical trial networks, and regulatory enhancements-notably, in low-to-middle income countries-must be maintained and strengthened to enable quick, concerted responses to future threats, especially to zoonotic pathogens.