Additional file 7 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 7: Figure S6. Partial dependency plots for (a) I. ricinus and (b) I. persulcatus solely based on host data.

ENDEMIC HANTAVIRUS INFECTION IMPAIRS THE WINTER SURVIVAL OF ITS RODENT HOST

The influence of pathogens on host fitness is one of the key questions in infection ecology. Hantaviruses have coevolved with their hosts and are generally thought to have little or no effect on host survival or reproduction. We examined the effect of Puumala virus (PUUV) infection on the winter survival of bank voles (Myodes glareolus), the host of this virus. The data were collected by monitoring 22 islands over three consecutive winters (a total of 55 island populations) in an endemic area of central Finland. We show that PUUV infected bank voles had a significantly lower overwinter survival probability than antibody negative bank voles. Antibody negative female bank voles from low-densi…

AbstractUnderstanding the dynamics of zoonotic pathogens in their reservoir host populations is a prerequisite for predicting and preventing human disease epidemics. The human infection risk of Puumala hantavirus (PUUV) is highest in northern Europe, where populations of the rodent host (bank vole, Myodes glareolus) undergo cyclic fluctuations. We conducted a 7-year capture-mark-recapture study to monitor seasonal and multiannual patterns of the PUUV infection rate in bank vole populations exhibiting a 3-year density cycle. Infected bank voles were most abundant in mid-winter months during years of increasing or peak host density. Prevalence of PUUV infection in bank voles exhibited a regul…

Hantavirus infections in fluctuating host populations: the role of maternal antibodies.

Infected females may transfer maternal antibodies (MatAbs) to their offspring, which may then be transiently protected against infections the mother has encountered. However, the role of maternal protection in infectious disease dynamics in wildlife has largely been neglected. Here, we investigate the effects of Puumala hantavirus (PUUV)-specific MatAbs on PUUV dynamics, using 7 years' data from a cyclic bank vole population in Finland. For the first time to our knowledge, we partition seropositivity data from a natural population into separate dynamic patterns for MatAbs and infection. The likelihood of young of the year carrying PUUV-specific MatAbs during the breeding season correlated p…

Supporting information for The impact of wildlife and environmental factors on hantavirus infection in host and its translation into human risk

It contains describtive plot for data, supplementary methods and results

Novel activities of safe-in-human broad-spectrum antiviral agents

According to the WHO, there is an urgent need for better control of viral diseases. Re-positioning existing safe-in-human antiviral agents from one viral disease to another could play a pivotal role in this process. Here, we reviewed all approved, investigational and experimental antiviral agents, which are safe in man, and identified 59 compounds that target at least three viral diseases. We tested 55 of these compounds against eight different RNA and DNA viruses. We found novel activities for dalbavancin against echovirus 1, ezetimibe against human immunodeficiency virus 1 and Zika virus, as well as azacitidine, cyclosporine, minocycline, oritavancin and ritonavir against Rift valley feve…

Antiviral Properties of Chemical Inhibitors of Cellular Anti-Apoptotic Bcl-2 Proteins

Viral diseases remain serious threats to public health because of the shortage of effective means of control. To combat the surge of viral diseases, new treatments are urgently needed. Here we show that small-molecules, which inhibit cellular anti-apoptotic Bcl-2 proteins (Bcl-2i), induced the premature death of cells infected with different RNA or DNA viruses, whereas, at the same concentrations, no toxicity was observed in mock-infected cells. Moreover, these compounds limited viral replication and spread. Surprisingly, Bcl-2i also induced the premature apoptosis of cells transfected with viral RNA or plasmid DNA but not of mock-transfected cells. These results suggest that Bcl-2i sensiti…

Cyclic hantavirus epidemics in humans--predicted by rodent host dynamics.

Wildlife-originated zoonotic diseases are a major contributor to emerging infectious diseases. Hantaviruses cause thousands of human disease cases annually worldwide, and understanding and predicting human hantavirus epidemics still poses unsolved challenges. Here we studied the three-level relationships between the human disease nephropathia epidemica (NE), its etiological agent Puumala hantavirus (PUUV) and the rodent host of the virus, the bank vole (Myodes glareolus). A large and long-term data set (14 years, 2583 human NE cases and 4751 trapped bank voles) indicates that the number of human infections shows both seasonal and multi-annual fluctuations, is influenced by the phase of vole…

Additional file 3 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 3: Figure S3. The range (lines) and mean (dots) of model performances over 50 model runs in each model algorithm estimating habitat suitabilities for I. persulcatus in different variable compositions: (a) environmental only, (b) host only, (c) environmental and host, and (d) environmental, host, and suitability for I. ricinus.

Additional file 4 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 4: Figure S4. The relative contributions of the explanatory variables in the data set of (a) host only, (b) environment only based on the mean ensemble model.

Experimental investigation of a hantavirus host-switch between arvicoline rodents Lemmus lemmus and Myodes glareolus

Additional file 8 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 8: Figure S7. Partial dependency plots for (a) I. ricinus and (b) I. persulcatus based on combined host and environmental data, and habitat suitability data for the other tick species.

Prolonged survival of Puumala hantavirus outside the host: evidence for indirect transmission via the environment

The capability of rodent-borne viruses to survive outside the host is critical for the transmission dynamics within rodent populations and to humans. The transmission of Puumala virus (PUUV) in colonized bank voles (Clethrionomys glareolus) was investigated and additional longevity studies in cell culture with PUUV and Tula (TULV) hantaviruses were performed. Wild-type PUUV excreted by experimentally infected donor bank voles was shown to be transmitted indirectly between rodents through contaminated beddings, and maintained its infectivity to recipient voles at room temperature for 12–15 days. In cell culture supernatants, PUUV and TULV remained infectious for 5–11 days at room temperature…

Additional file 3 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 3: Figure S3. The range (lines) and mean (dots) of model performances over 50 model runs in each model algorithm estimating habitat suitabilities for I. persulcatus in different variable compositions: (a) environmental only, (b) host only, (c) environmental and host, and (d) environmental, host, and suitability for I. ricinus.

Additional file 6 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 6: Figure S5. Partial dependency plots for (a) I. ricinus and (b) I. persulcatus solely based on environmental data.

Intracerebral Borna Disease Virus Infection of Bank Voles Leading to Peripheral Spread and Reverse Transcription of Viral RNA

Bornaviruses, which chronically infect many species, can cause severe neurological diseases in some animal species; their association with human neuropsychiatric disorders is, however, debatable. The epidemiology of Borna disease virus (BDV), as for other members of the family Bornaviridae, is largely unknown, although evidence exists for a reservoir in small mammals, for example bank voles (Myodes glareolus). In addition to the current exogenous infections and despite the fact that bornaviruses have an RNA genome, bornavirus sequences integrated into the genomes of several vertebrates millions of years ago. Our hypothesis is that the bank vole, a common wild rodent species in traditional B…

Additional file 5 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 5: Table S1. The number of times each model contributed to the final ensemble in different data sets.

Description of research methods and results tables from Food limitation constrains host immune responses to nematode infections

Trade-offs in the allocation of finite-energy resources among immunological defences and other physiological processes are believed to influence infection risk and disease severity in food-limited wildlife populations. However, this prediction has received little experimental investigation. Here we test the hypothesis that food limitation impairs the ability of wild field voles (Microtus agrestis) to mount an immune response against parasite infections. We conducted a replicated experiment on vole populations maintained in large outdoor enclosures during boreal winter, using food supplementation and anthelmintic treatment of intestinal nematodes. Innate immune responses against intestinal p…

Erratum: Temporal dynamics of Puumala hantavirus infection in cyclic populations of bank voles.

Understanding the dynamics of zoonotic pathogens in their reservoir host populations is a prerequisite for predicting and preventing human disease epidemics. The human infection risk of Puumala hantavirus (PUUV) is highest in northern Europe, where populations of the rodent host (bank vole, Myodes glareolus) undergo cyclic fluctuations. We conducted a 7-year capture-mark-recapture study to monitor seasonal and multiannual patterns of the PUUV infection rate in bank vole populations exhibiting a 3-year density cycle. Infected bank voles were most abundant in mid-winter months during years of increasing or peak host density. Prevalence of PUUV infection in bank voles exhibited a regular, seas…

Additional file 2 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 2: Figure S2. The range (lines) and mean (dots) of model performances over 50 model runs in each model algorithm estimating habitat suitabilities for I. ricinus in different variable compositions: (a) environmental only, (b) host only, (c) environmental and host, and (d) environmental, host, and suitability for I. ricinus.

Experimental Infection of Voles with Francisella tularensis Indicates Their Amplification Role in Tularemia Outbreaks

Tularemia outbreaks in humans have been linked to fluctuations in rodent population density, but the mode of bacterial maintenance in nature is unclear. Here we report on an experiment to investigate the pathogenesis of Francisella tularensis infection in wild rodents, and thereby assess their potential to spread the bacterium. We infected 20 field voles (Microtus agrestis) and 12 bank voles (Myodes glareolus) with a strain of F. tularensis ssp. holarctica isolated from a human patient. Upon euthanasia or death, voles were necropsied and specimens collected for histological assessment and identification of bacteria by immunohistology and PCR. Bacterial excretion and a rapid lethal clinical …

Age-related effects of chronic hantavirus infection on female host fecundity.

1. Pathogens often cause detrimental effects to their hosts and, consequently, may influence host population dynamics that may, in turn, feed back to pathogen transmission dynamics. Understanding fitness effects of pathogens upon animal host populations can help to predict the risks that zoonotic pathogens pose to humans. 2. Here we determine whether chronic infection by Puumala hantavirus (PUUV) affects important fitness-related traits, namely the probability of breeding, reproductive effort and mother and offspring condition, in the bank vole (Myodes glareolus). Using 9 years empirical data in a PUUV endemic area in Central Finland, we found differences between reproductive characteristic…

Serological Survey of Rodent-Borne Viruses in Finnish Field Voles

In northern Europe, rodent populations display cyclic density fluctuations, which can be correlated with the human incidence of zoonotic diseases they spread. During density peaks, field voles (Microtus agrestis) become one of the most abundant rodent species in northern Europe, yet little is known of the viruses they host. We screened 709 field voles, trapped from 14 sites over three years, for antibodies against four rodent-borne, potentially zoonotic viruses or virus groups: hantaviruses, lymphocytic choriomeningitis virus (LCMV), Ljungan virus (LV) and orthopoxviruses (OPV). Antibodies against all four viruses were detected. However, seroprevalence of hantaviruses, LV and LCMV was low. …

Additional file 7 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 7: Figure S6. Partial dependency plots for (a) I. ricinus and (b) I. persulcatus solely based on host data.

The impact of wildlife and environmental factors on hantavirus infection in the host and its translation into human risk

Identifying factors that drive infection dynamics in reservoir host populations is essential in understanding human risk from wildlife-originated zoonoses. We studied zoonotic Puumala orthohantavirus (PUUV) in the host, the bank vole ( Myodes glareolus ), populations in relation to the host population, rodent and predator community and environment-related factors and whether these processes are translated into human infection incidence. We used 5-year rodent trapping and bank vole PUUV serology data collected from 30 sites located in 24 municipalities in Finland. We found that PUUV seroprevalence in the host was negatively associated with the abundance of red foxes, but this process did no…

Environmental change and disease dynamics: effects of intensive forest management on Puumala hantavirus infection in boreal bank vole populations.

Intensive management of Fennoscandian forests has led to a mosaic of woodlands in different stages of maturity. The main rodent host of the zoonotic Puumala hantavirus (PUUV) is the bank vole (Myodes glareolus), a species that can be found in all woodlands and especially mature forests. We investigated the influence of forest age structure on PUUV infection dynamics in bank voles. Over four years, we trapped small mammals twice a year in a forest network of different succession stages in Northern Finland. Our study sites represented four forest age classes from young (4 to 30 years) to mature (over 100 years) forests. We show that PUUV-infected bank voles occurred commonly in all forest age…

Food limitation constrains host immune responses to nematode infections.

Trade-offs in the allocation of finite-energy resources among immunological defences and other physiological processes are believed to influence infection risk and disease severity in food-limited wildlife populations. However, this prediction has received little experimental investigation. Here we test the hypothesis that food limitation impairs the ability of wild field voles ( Microtus agrestis ) to mount an immune response against parasite infections. We conducted a replicated experiment on vole populations maintained in large outdoor enclosures during boreal winter, using food supplementation and anthelmintic treatment of intestinal nematodes. Innate immune responses against intestina…

Additional file 1 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 1: Figure S1. (a) The sampling strategy for new collections in 2021 was created based on the following criteria. Subdivisions of landscape areas (Area1–Area4), CORINE land cover 2018, a 5-km buffer around existing I. persulcatus occurrences (grey circles), and a 500-m buffer around roads were used to delimit the four sampling areas (light grey lines). For each sampling area, a random sample of 25 collection locations was created depending on the relative shares of forest and meadow categories in each area. (b) The map showing the 2021 results indicates the locations where I. ricinus was found with B. burgdorferi (s.l.)-positive locations.

Molecular detection of Bartonella spp. in deer ked pupae, adult keds and moose blood in Finland

SUMMARYThe deer ked (Lipoptena cervi) is a haematophagous ectoparasite of cervids that harbours haemotrophic Bartonella. A prerequisite for the vector competence of the deer ked is the vertical transmission of the pathogen from the mother to its progeny and transstadial transmission from pupa to winged adult. We screened 1154 pupae and 59 pools of winged adult deer keds from different areas in Finland for Bartonella DNA using PCR. Altogether 13 pupa samples and one winged adult deer ked were positive for the presence of Bartonella DNA. The amplified sequences were closely related to either B. schoenbuchensis or B. bovis. The same lineages were identified in eight blood samples collected fro…

Serological evidence for Borna disease virus infection in humans, wild rodents and other vertebrates in Finland

Abstract Background Borna disease virus (BDV) can infect many vertebrate species, including humans. BDV infection may lead to meningoencephalomyelitis in animals. An association with human neuropsychiatric diseases has been reported, but the causal relationship between BDV and human disease remains unclear. Objectives and study design To find out whether BDV is present in Finland and to look for a potential reservoir, we examined a large panel of blood samples from different vertebrate species with immunofluorescence assay. Samples from horses, cats, dogs, sheep, cattle, large predators, grouse, wild rodents and humans were included. Most positive results were confirmed by other specific me…

Additional file 4 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 4: Figure S4. The relative contributions of the explanatory variables in the data set of (a) host only, (b) environment only based on the mean ensemble model.

Additional file 5 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 5: Table S1. The number of times each model contributed to the final ensemble in different data sets.

Maternal antibodies contribute to sex-based difference in hantavirus transmission dynamics

Individuals often differ in their ability to transmit disease and identifying key individuals for transmission is a major issue in epidemiology. Male hosts are often thought to be more important than females for parasite transmission and persistence. However, the role of infectious females, particularly the transient immunity provided to offspring through maternal antibodies (MatAbs), has been neglected in discussions about sex-biased infection transmission. We examined the effect of host sex upon infection dynamics of zoonotic Puumala hantavirus (PUUV) in semi-natural, experimental populations of bank vole ( Myodes glareolus ). Populations were founded with either females or males that we…

Additional file 8 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 8: Figure S7. Partial dependency plots for (a) I. ricinus and (b) I. persulcatus based on combined host and environmental data, and habitat suitability data for the other tick species.

Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

AbstractBackgroundTicks are responsible for transmitting several notable pathogens worldwide. Finland lies in a zone where two human-biting tick species co-occur:IxodesricinusandIxodespersulcatus. Tick densities have increased in boreal regions worldwide during past decades, and tick-borne pathogens have been identified as one of the major threats to public health in the face of climate change.MethodsWe used species distribution modelling techniques to predict the distributions ofI.ricinusandI.persulcatus,using aggregated historical data from 2014 to 2020 and new tick occurrence data from 2021. By aiming to fill the gaps in tick occurrence data, we created a new sampling strategy across Fin…

Additional file 6 of Predicting habitat suitability for Ixodes ricinus and Ixodes persulcatus ticks in Finland

Additional file 6: Figure S5. Partial dependency plots for (a) I. ricinus and (b) I. persulcatus solely based on environmental data.

Data from: Age-related effects of chronic hantavirus infection on female host fecundity

1. Pathogens often cause detrimental effects to their hosts and, consequently, may influence host population dynamics that may, in turn, feed back to pathogen transmission dynamics. Understanding fitness effects of pathogens upon animal host populations can help to predict the risks that zoonotic pathogens pose to humans. 2. Here we determine whether chronic infection by Puumala hantavirus (PUUV) affects important fitness-related traits, namely the probability of breeding, reproductive effort and mother and offspring condition, in the bank vole (Myodes glareolus). Using 9 years empirical data in a PUUV endemic area in Central Finland, we found differences between reproductive characteristic…

Data from: Food limitation constrains host immune responses to nematode infections

Trade-offs in the allocation of finite-energy resources among immunological defences and other physiological processes are believed to influence infection risk and disease severity in food-limited wildlife populations. However, this prediction has received little experimental investigation. Here we test the hypothesis that food limitation impairs the ability of wild field voles (Microtus agrestis) to mount an immune response against parasite infections. We conducted a replicated experiment on vole populations maintained in large outdoor enclosures during boreal winter, using food supplementation and anthelmintic treatment of intestinal nematodes. Innate immune responses against intestinal p…

Data from: Temporal dynamics of Puumala hantavirus infection in cyclic populations of bank voles

Understanding the dynamics of zoonotic pathogens in their reservoir host populations is a prerequisite for predicting and preventing human disease epidemics. The human infection risk of Puumala hantavirus (PUUV) is highest in northern Europe, where populations of the rodent host (bank vole, Myodes glareolus) undergo cyclic fluctuations. We conducted a 7-year capture-mark-recapture study to monitor seasonal and multiannual patterns of the PUUV infection rate in bank vole populations exhibiting a 3-year density cycle. Infected bank voles were most abundant in mid-winter months during years of increasing or peak host density. Prevalence of PUUV infection in bank voles exhibited a regular, seas…

Data from: Maternal antibodies contribute to sex based difference in hantavirus transmission dynamics

Individuals often differ in their ability to transmit disease and identifying key individuals for transmission is a major issue in epidemiology. Male hosts are often thought to be more important than females for parasite transmission and persistence. However, the role of infectious females, particularly the transient immunity provided to offspring through maternal antibodies (MatAbs), has been neglected in discussions about sex-biased infection transmission. We examined the effect of host sex upon infection dynamics of zoonotic Puumala hantavirus (PUUV) in semi-natural, experimental populations of bank vole (Myodes glareolus). Populations were founded with either females or males that were …

Intracerebral Borna disease virus infection of bank voles leading to peripheral spread and reverse transcription of viral RNA

Bornaviruses, which chronically infect many species, can cause severe neurological diseases in some animal species; their association with human neuropsychiatric disorders is, however, debatable. The epidemiology of Borna disease virus (BDV), as for other members of the family Bornaviridae, is largely unknown, although evidence exists for a reservoir in small mammals, for example bank voles (Myodes glareolus). In addition to the current exogenous infections and despite the fact that bornaviruses have an RNA genome, bornavirus sequences integrated into the genomes of several vertebrates millions of years ago. Our hypothesis is that the bank vole, a common wild rodent species in traditional B…