Information concerning the fundamental properties of a pathogen is essential at the beginning of an outbreak. Often, the fundamental properties of an emerging virus are unknown because the virus is new, as in the recent SARS-CoV-2 pandemic, or because the properties have not been investigated, as was the case during the West African Ebola virus epidemic and the Marburg virus epidemics in Angola and the Democratic Republic of the Congo. The amount of time that a virus can remain viable under various conditions is one of these fundamental properties.
View Article and Find Full Text PDFAccumulating data suggest that some bat species host emerging viruses that are highly pathogenic in humans and agricultural animals. Laboratory-based studies have highlighted important adaptations in bat immune systems that allow them to better tolerate viral infections compared to humans. Simultaneously, ecological studies have discovered critical extrinsic factors, such as nutritional stress, that correlate with virus shedding in wild-caught bats.
View Article and Find Full Text PDFNipah virus (NiV) is a highly pathogenic paramyxovirus capable of causing severe respiratory and neurologic disease in humans. Currently, there are no licensed vaccines or therapeutics against NiV, underscoring the urgent need for the development of countermeasures. The NiV surface-displayed glycoproteins, NiV-G and NiV-F, mediate host cell attachment and fusion, respectively, and are heavily targeted by host antibodies.
View Article and Find Full Text PDFBackground: Although dromedary camels (Camelus dromedarius) are known to be the host reservoir for MERS-CoV, the virus causing Middle East respiratory syndrome (MERS), zoonotic transmission pathways and camel subpopulations posing highest transmission risk are poorly understood. Extensively managed herds, ubiquitous across the Arabian Peninsula, present a major potential source of primary infection. In this study we aimed to address key knowledge gaps regarding MERS epidemiology among high-risk communities associated with such herds, which is essential information for effective control strategies.
View Article and Find Full Text PDFMicrobiol Mol Biol Rev
September 2024
SUMMARYSeveral examples of high-impact cross-species transmission of newly emerging or re-emerging bat-borne viruses, such as Sudan virus, Nipah virus, and severe acute respiratory syndrome coronavirus 2, have occurred in the past decades. Recent advancements in next-generation sequencing have strengthened ongoing efforts to catalog the global virome, in particular from the multitude of different bat species. However, functional characterization of these novel viruses and virus sequences is typically limited with regard to assessment of their cross-species potential.
View Article and Find Full Text PDFThe 2022 mpox virus (MPXV) outbreak was sustained by human-to-human transmission; however, it is currently unclear which factors lead to sustained transmission of MPXV. Here we present Mastomys natalensis as a model for MPXV transmission after intraperitoneal, rectal, vaginal, aerosol and transdermal inoculation with an early 2022 human outbreak isolate (Clade IIb). Virus shedding and tissue replication were route dependent and occurred in the presence of self-resolving localized skin, lung, reproductive tract or rectal lesions.
View Article and Find Full Text PDFThe most recent Sudan virus (SUDV) outbreak in Uganda was first detected in September 2022 and resulted in 164 laboratory-confirmed cases and 77 deaths. There are no approved vaccines against SUDV. Here, we investigated the protective efficacy of ChAdOx1-biEBOV in cynomolgus macaques using a prime or a prime-boost regimen.
View Article and Find Full Text PDFIt remains poorly understood how SARS-CoV-2 infection influences the physiological host factors important for aerosol transmission. We assessed breathing pattern, exhaled droplets, and infectious virus after infection with Alpha and Delta variants of concern (VOC) in the Syrian hamster. Both VOCs displayed a confined window of detectable airborne virus (24-48 hr), shorter than compared to oropharyngeal swabs.
View Article and Find Full Text PDFThe intestinal microbiome plays an important role in mammalian health, disease, and immune function. In light of this function, recent studies have aimed to characterize the microbiomes of various bat species, which are noteworthy for their roles as reservoir hosts for several viruses known to be highly pathogenic in other mammals. Despite ongoing bat microbiome research, its role in immune function and disease, especially the effects of changes in the microbiome on host health, remains nebulous.
View Article and Find Full Text PDFNonhuman primate models are essential for the development of vaccines and antivirals against infectious diseases. Rhesus macaques are a widely utilized infection model for SARS-CoV-2. We compared cellular tropism and virus replication in rhesus macaques inoculated with SARS-CoV-2 via the intranasal route or via exposure to aerosols.
View Article and Find Full Text PDFBackground And Objectives: Timely detection of SARS-CoV-2 infection with subsequent contact tracing and rapid isolation are considered critical to containing the pandemic, which continues with the emergence of new variants. Hence, there is an ongoing need for reliable point-of-care antigen rapid diagnostic tests (Ag-RDT). This report describes the development, evaluation, and analytical sensitivity of the diagnostic performance of the InteliSwab COVID-19 Rapid Test.
View Article and Find Full Text PDFHuman movement drives the transmission and spread of communicable pathogens. It is especially influential for emerging pathogens when population immunity is low and spillover events are rare. We digitized serial printed maps to measure transportation networks (roads and rivers) in Central and West Africa as proxies for population mobility to assess relationships between movement and Ebola transmission.
View Article and Find Full Text PDFLassa fever, caused by Lassa virus (LASV), is endemic to West Africa, where ≈300,000 illnesses and ≈5,000 deaths occur annually. LASV is primarily spread by infected multimammate rats via urine and fomites, highlighting the need to understand the environmental fate of LASV. We evaluated persistence of LASV Josiah and Sauerwald strains on surfaces, in aqueous solutions, and with sodium hypochlorite disinfection.
View Article and Find Full Text PDFBackground: The origins of Ebola disease outbreaks remain enigmatic. Historically outbreaks have been attributed to spillover events from wildlife. However, recent data suggest that some outbreaks may originate from human-to-human transmission of prior outbreak strains instead of spillover.
View Article and Find Full Text PDFOcular complications of Ebola virus disease are well-documented and long-term sequelae in survivors are common and lead to considerable morbidity. However, little is currently known regarding EBOV's tropism and replication kinetics within the eye. To date, limited studies have utilized in vitro infections of ocular cell lines and analyses of archived pathology samples to investigate these issues.
View Article and Find Full Text PDFSARS-CoV-2 transmits principally by air; contact and fomite transmission may also occur. Variants of concern are more transmissible than ancestral SARS-CoV-2. We found indications of possible increased aerosol and surface stability for early variants of concern, but not for the Delta and Omicron variants.
View Article and Find Full Text PDFOphthalmic manifestations and tissue tropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported in association with coronavirus disease 2019 (COVID-19), but the pathology and cellular localization of SARS-CoV-2 are not well characterized. The objective of this study was to evaluate macroscopic and microscopic changes and investigate cellular localization of SARS-CoV-2 across ocular tissues at autopsy. Ocular tissues were obtained from 25 patients with COVID-19 at autopsy.
View Article and Find Full Text PDFNipah virus (NiV) is a highly pathogenic and re-emerging virus, which causes sporadic but severe infections in humans. Currently, no vaccines against NiV have been approved. We previously showed that ChAdOx1 NiV provides full protection against a lethal challenge with NiV Bangladesh (NiV-B) in hamsters.
View Article and Find Full Text PDF