Search

Orthohantaviruses are globally distributed. Until now, they have been detected in rodents, insectivores, and bats. Rodentborne orthohantaviruses, which are associated with human diseases, are divided into 3 major groups, murid-borne, [...]

Parapoxviruses (PPVs) usually cause contagious skin infections in ruminants and occasionally infect other species such as humans (1). The genus Parapoxvirus encompasses the following recognized species: Orf virus, bovine papular [...]

Orthohantaviruses (family Hantaviridae, genus Orthohantavirus) are a group of zoonotic viruses primarily found in muroid rodents; many of the viruses are pathogenic in humans (1). Pathogenic orthohantaviruses in the Americas [...]

Despite extensive research since the first documented human Ebola virus (EBOV) disease outbreak in 1976, animal species involved and mechanisms by which ebolaviruses spillover to humans remains enigmatic. Bats have [...]

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused millions of infections and fatalities globally since its emergence in late 2019. The virus was first detected in Finland in January 2020, after which it rapidly spread among the populace in spring. However, compared to other European nations, Finland has had a low incidence of SARS-CoV-2. To gain insight into the origins and turnover of SARS-CoV-2 lineages circulating in Finland in 2020, we investigated the phylogeographic and -dynamic history of the virus.MethodsThe origins of SARS-CoV-2 introductions were inferred via Travel-aware Bayesian time-measured phylogeographic analyses. Sequences for the analyses included virus genomes belonging to the B.1 lineage and with the D614G mutation from countries of likely origin, which were determined utilizing Google mobility data. We collected all available sequences from spring and fall peaks to study lineage dynamics.ResultsWe observed rapid turnover among Finnish lineages during this period. Clade 20C became the most prevalent among sequenced cases and was replaced by other strains in fall 2020. Bayesian phylogeographic reconstructions suggested 42 independent introductions into Finland during spring 2020, mainly from Italy, Austria, and Spain.ConclusionsA single introduction from Spain might have seeded one-third of cases in Finland during spring in 2020. The investigations of the original introductions of SARS-CoV-2 to Finland during the early stages of the pandemic and of the subsequent lineage dynamics could be utilized to assess the role of transboundary movements and the effects of early intervention and public health measures.

During 2022, an unprecedented multicountry outbreak of monkeypox virus (MPXV) infection among humans was detected. The first verified mpox cases in Europe were reported in mid-May 2022 with no apparent [...]

Reverse transmission of diverse zoonotic pathogens (bacteria, viruses, eukaryotic parasites, fungi) from humans to animals has been recognized and documented as a global concern for years (1). On July 6, [...]

The most recent SARS-CoV-2 variant of concern, Omicron (Pango lineage B.1.1.529), was first detected in South Africa (1), although it might have emerged elsewhere, and has since spread globally at [...]

The severity of COVID-19 is linked to excessive inflammation. Neutrophils represent a critical arm of the innate immune response and are major mediators of inflammation, but their role in COVID-19 pathophysiology remains poorly understood. We conducted transcriptomic profiling of neutrophils obtained from patients with mild and severe COVID-19, as well as from SARS-CoV-2 infected mice, in comparison to non-infected healthy controls. In addition, we investigated the inflammasome formation potential in neutrophils from patients and mice upon SARS-CoV-2 infection. Transcriptomic analysis of polymorphonuclear cells (PMNs), consisting mainly of mature neutrophils, revealed a striking type I interferon (IFN-I) gene signature in severe COVID-19 patients, contrasting with mild COVID-19 and healthy controls. Notably, low-density granulocytes (LDGs) from severe COVID-19 patients exhibited an immature neutrophil phenotype and lacked this IFN-I signature. Moreover, PMNs from severe COVID-19 patients showed heightened nigericin-induced caspase1 activation, but reduced responsiveness to exogenous inflammasome priming. Furthermore, IFN-I emerged as a priming stimulus for neutrophil inflammasomes. These findings suggest a potential role for neutrophil inflammasomes in driving inflammation during severe COVID-19. Altogether, these findings open promising avenues for targeted therapeutic interventions to mitigate the pathological processes associated with the disease. Author summary: COVID-19, caused by the SARS-CoV-2, ranges from mild "flu"-like symptoms to severe respiratory distress or even death. Neutrophils are important cells of our immune system which are strongly involved in inflammatory responses, including those occurring in COVID-19. However, despite extensive research, the precise contribution of neutrophils to the pathogenesis of COVID-19 remains elusive, and further clarification on their role is still needed. In this study, we isolated neutrophils from COVID-19 patients and healthy controls to analyze changes in their gene expression profile and inflammatory functions. These analyses revealed a distinct type I interferon (IFN-I) gene signature expressed by mature, but not immature, neutrophils from severe COVID-19 patients, which was absent in mild cases and healthy controls. Additionally, neutrophils from severe COVID-19 showed signs of increased inflammasome activation, a protein complex that contributes to inflammation by releasing inflammatory cytokines. Notably, IFN-I alone was able to promote neutrophil inflammasome formation in vitro suggesting a direct link between IFN-I response and inflammasome formation during COVID-19. Furthermore, increased neutrophil inflammasome activity was detected also in a mouse model of COVID-19. These findings suggest a potential role for neutrophils in driving excessive inflammation during severe COVID-19, and a role for IFN-I in priming the assembly of inflammasomes in these cells. [ABSTRACT FROM AUTHOR]

Bats harbor viruses that can cause severe disease and death in humans including filoviruses (e.g., Ebola virus), henipaviruses (e.g., Hendra virus), and coronaviruses (e.g., SARS-CoV). Bats often tolerate these viruses without noticeable adverse immunological effects or succumbing to disease. Previous studies have largely focused on the role of the bat's innate immune response to control viral pathogenesis, but little is known about bat adaptive immunity. A key component of adaptive immunity is the humoral response, comprised of antibodies that can specifically recognize viral antigens with high affinity. The antibody genes within the 1,400 known bat species are highly diverse, and these genetic differences help shape fundamental aspects of the antibody repertoire, including starting diversity and viral antigen recognition. Whether antibodies in bats protect, mediate viral clearance, and prevent transmission within bat populations is poorly defined. Furthermore, it is unclear how neutralizing activity and Fc-mediated effector functions contribute to bat immunity. Although bats have canonical Fc genes (e.g., mu, gamma, alpha, and epsilon), the copy number and sequences of their Fc genes differ from those of humans and mice. The function of bat antibodies targeting viral antigens has been speculated based on sequencing data and polyclonal sera, but functional and biochemical data of monoclonal antibodies are lacking. In this review, we summarize current knowledge of bat humoral immunity, including variation between species, their potential protective role(s) against viral transmission and replication, and address how these antibodies may contribute to population dynamics within bats communities. A deeper understanding of bat adaptive immunity will provide insight into immune control of transmission and replication for emerging viruses with the potential for zoonotic spillover. [ABSTRACT FROM AUTHOR]

Several new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged globally, most notably variants of concern Alpha (B.1.1.7) (1), Beta (B1.351) (2), Gamma (P.1) (3), and most [...]

Identifying possible pathogen hosts and studying transmission dynamics of hosts in their populations are crucial steps in controlling zoonotic diseases. The origin of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [...]

Wildlife viromes harbor potentially threatening zoonoses for humans that require increased effort in identification and surveillance (1). Rodents are considered main reservoirs of emerging zoonoses (2), and the large population [...]

SARS-CoV-2 has been detected in farmed and feral American mink (Neovison vison) in multiple countries, and extensive environmental contamination and human-to-mink and mink-to-human transmission has been documented (1-5). These factors [...]

Synanthropic bats live in close proximity to humans and domestic animals, creating opportunities for potential pathogen spillover. We explored environmental correlates of occurrence for a widely distributed synanthropic African bat, Mops pumilus—a species associated with potential zoonotic viruses—and estimated current and future environmental suitability in the Taita Hills region and surrounding plains in Taita–Taveta County in southeast Kenya. To project future environmental suitability, we used four Coupled Model Intercomparison Project Phase 6 general circulation models that capture temperature and precipitation changes for East Africa. The models were parameterized with empirical capture data of M. pumilus collected from 2016 to 2023, combined with satellite‐based vegetation, topographic, and climatic data to identify responses to environmental factors. The strongest drivers for current environmental suitability for M. pumilus were short distance to rivers, higher precipitation during the driest months, sparse vegetation—often related to urban areas—and low yearly temperature variation. To predict current and future areas suitable for M. pumilus, we created ensemble niche models, which yielded excellent predictive accuracies. Current suitable environments were located southward from the central and southern Taita Hills and surrounding plains, overlapping with urban centers with the highest human population densities in the area. Future projections for 2050 indicated a moderate increase in suitability range in the southern portion of the region and surrounding plains in human‐dominated areas; however, projections for 2090 showed a slight contraction of environmental suitability for M. pumilus, potentially due to the negative impact of increased temperatures. These results show how environmental changes are likely to impact the human exposure risk of bat‐borne pathogens and could help public health officials develop strategies to prevent these risks in Taita–Taveta County, Kenya, and other parts of Africa. [ABSTRACT FROM AUTHOR]

Lymphocytic choriomeningitis virus (LCMV) is a rodentborne pathogen that belongs to the genus Mammarenavirus, family Arenaviridae. The house mouse (Mus musculus) is considered the reservoir of LCMV (1). Humans can [...]

Bombali virus (BOMV) is the sixth and most recently identified virus of the genus Ebolavirus (1), first detected in Sierra Leone in oral and rectal swab samples from 2 species [...]

Rodents are the most diversified order of wild mammals and are also the prevailing mammal lineage associated with human-inhabited socioecosystems. In addition to their destructive behaviors, rodents are involved in [...]