The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Michael Begon - One of the best experts on this subject based on the ideXlab platform.
-
host condition and individual risk of Cowpox virus infection in natural animal populations cause or effect
Epidemiology and Infection, 2009Co-Authors: Pablo Martin Beldomenico, Malcolm J. Bennett, Sandra Telfer, Lukasz Lukomski, Stephanie Gebert, Michael BegonAbstract:Recent studies have provided evidence that endemic pathogens may affect dynamics in animals. However, such studies have not typically considered that infected individuals might have a preceding underlying poor condition. We examined whether individuals in poor condition are more likely to become infected by an endemic pathogen, using as a system the dynamics of Cowpox virus in field voles. With data from monthly sampled vole populations, a nested case-control study evaluated whether susceptible individuals with poorer condition had higher probabilities of contracting Cowpox. The influence of condition was found to be considerable, especially for males. At times when a susceptible male with good body condition had a relatively low probability of becoming infected, a susceptible male with poor body condition was twice as likely to contract Cowpox; if this male was also anaemic, the chances were almost quadrupled. We discuss the care needed when interpreting the findings of wildlife disease studies.
-
Cowpox virus infection in natural field vole Microtus agrestispopulations: significant negative impacts on survival
2008Co-Authors: Sarah J. Burthe, Malcolm J. Bennett, Michael Begon, Sandra Telfer, A. Smith, Xavier LambinAbstract:1. Cowpox virus is an endemic virus circulating in populations of wild rodents. It has been implicated as a potential cause of population cycles in field voles Microtus agrestis L., in Britain, owing to a delayed density-dependent pattern in prevalence, but its impact on field vole demographic parameters is unknown. This study tests the hypothesis that wild field voles infected with Cowpox virus have a lower probability of survival than uninfected individuals. 2. The effect of Cowpox virus infection on the probability of an individual surviving to the next month was investigated using longitudinal data collected over 2 years from four grassland sites in Kielder Forest, UK. This effect was also investigated at the population level, by examining whether infection prevalence explained temporal variation in survival rates, once other factors influencing survival had been controlled for. 3. Individuals with a probability of infection, P(I), of 1 at a time when base survival rate was at median levels had a 22.4% lower estimated probability of survival than uninfected individuals, whereas those with a P(I) of 0.5 had a 10.4% lower survival. 4. At the population level, survival rates also decreased with increasing Cowpox prevalence, with lower survival rates in months of higher Cowpox prevalence. 5. Simple matrix projection models with 28 day time steps and two stages, with 71% of voles experiencing Cowpox infection in their second month of life (the average observed seroprevalence at the end of the breeding season) predict a reduction in 28-day population growth rate during the breeding season from λ = 1.62 to 1.53 for populations with no Cowpox infection compared with infected populations. 6. This negative correlation between Cowpox virus infection and field vole survival, with its potentially significant effect on population growth rate, is the first for an endemic pathogen in a cyclic population of wild rodents.
-
Cowpox virus infection in natural field vole Microtus agrestis populations: significant negative impacts on survival
The Journal of animal ecology, 2008Co-Authors: Sarah J. Burthe, Malcolm J. Bennett, Michael Begon, Sandra Telfer, A. Smith, Xavier LambinAbstract:1. Cowpox virus is an endemic virus circulating in populations of wild rodents. It has been implicated as a potential cause of population cycles in field voles Microtus agrestis L., in Britain, owing to a delayed density-dependent pattern in prevalence, but its impact on field vole demographic parameters is unknown. This study tests the hypothesis that wild field voles infected with Cowpox virus have a lower probability of survival than uninfected individuals. 2. The effect of Cowpox virus infection on the probability of an individual surviving to the next month was investigated using longitudinal data collected over 2 years from four grassland sites in Kielder Forest, UK. This effect was also investigated at the population level, by examining whether infection prevalence explained temporal variation in survival rates, once other factors influencing survival had been controlled for. 3. Individuals with a probability of infection, P(I), of 1 at a time when base survival rate was at median levels had a 22.4% lower estimated probability of survival than uninfected individuals, whereas those with a P(I) of 0.5 had a 10.4% lower survival. 4. At the population level, survival rates also decreased with increasing Cowpox prevalence, with lower survival rates in months of higher Cowpox prevalence. 5. Simple matrix projection models with 28 day time steps and two stages, with 71% of voles experiencing Cowpox infection in their second month of life (the average observed seroprevalence at the end of the breeding season) predict a reduction in 28-day population growth rate during the breeding season from lambda = 1.62 to 1.53 for populations with no Cowpox infection compared with infected populations. 6. This negative correlation between Cowpox virus infection and field vole survival, with its potentially significant effect on population growth rate, is the first for an endemic pathogen in a cyclic population of wild rodents.
-
Cowpox virus infection in natural field vole microtus agrestis populations delayed density dependence and individual risk
Journal of Animal Ecology, 2006Co-Authors: Sarah J. Burthe, Malcolm J. Bennett, Sandra Telfer, A. Smith, Xavier Lambin, David Carslake, Michael BegonAbstract:1. Little is known about the dynamics of pathogen (microparasite) infection in wildlife populations, and less still about sources of variation in the risk of infection. Here we present the first detailed analysis of such variation. 2. Cowpox virus is an endemic sublethal pathogen circulating in populations of wild rodents. Cowpox prevalence was monitored longitudinally for 2 years, in populations of field voles exhibiting multiannual cycles of density in Kielder Forest, UK. 3. The probability that available susceptible animals seroconverted in a given trap session was significantly positively related to host density with a 3-month time lag. 4. Males were significantly more likely to seroconvert than females. 5. Despite most infection being found in young animals (because transmission rates were generally high) mature individuals were more likely to seroconvert than immature ones, suggesting that behavioural or physiological changes associated with maturity contribute to variation in infection risk. 6. Hence, these analyses confirm that there is a delayed numerical response of Cowpox infection to vole density, supporting the hypothesis that endemic pathogens may play some part in shaping vole cycles.
-
inference of Cowpox virus transmission rates between wild rodent host classes using space time interaction
Proceedings of The Royal Society B: Biological Sciences, 2006Co-Authors: David Carslake, Malcolm J. Bennett, Sarah M. Hazel, Sandra Telfer, Michael BegonAbstract:There have been virtually no studies of 'who acquires infection from whom' in wildlife populations, but patterns of transmission within and between different classes of host are likely to be reflected in the spatiotemporal distribution of infection among those host classes. Here, we use a modified form of K-function analysis to test for space-time interaction among bank voles and wood mice infectious with Cowpox virus. There was no evidence for transmission between the two host species, supporting previous evidence that they act as separate reservoirs for Cowpox. Among wood mice, results suggested that transmission took place primarily between individuals of the opposite sex, raising the possibility that Cowpox is sexually transmitted in this species. Results for bank voles indicated that infected females might be a more important source of infection to either sex than are males. The suggestion of different modes of transmission in the two species is itself consistent with the apparent absence of transmission between species.
Malcolm J. Bennett - One of the best experts on this subject based on the ideXlab platform.
-
host condition and individual risk of Cowpox virus infection in natural animal populations cause or effect
Epidemiology and Infection, 2009Co-Authors: Pablo Martin Beldomenico, Malcolm J. Bennett, Sandra Telfer, Lukasz Lukomski, Stephanie Gebert, Michael BegonAbstract:Recent studies have provided evidence that endemic pathogens may affect dynamics in animals. However, such studies have not typically considered that infected individuals might have a preceding underlying poor condition. We examined whether individuals in poor condition are more likely to become infected by an endemic pathogen, using as a system the dynamics of Cowpox virus in field voles. With data from monthly sampled vole populations, a nested case-control study evaluated whether susceptible individuals with poorer condition had higher probabilities of contracting Cowpox. The influence of condition was found to be considerable, especially for males. At times when a susceptible male with good body condition had a relatively low probability of becoming infected, a susceptible male with poor body condition was twice as likely to contract Cowpox; if this male was also anaemic, the chances were almost quadrupled. We discuss the care needed when interpreting the findings of wildlife disease studies.
-
Cowpox virus infection in natural field vole Microtus agrestispopulations: significant negative impacts on survival
2008Co-Authors: Sarah J. Burthe, Malcolm J. Bennett, Michael Begon, Sandra Telfer, A. Smith, Xavier LambinAbstract:1. Cowpox virus is an endemic virus circulating in populations of wild rodents. It has been implicated as a potential cause of population cycles in field voles Microtus agrestis L., in Britain, owing to a delayed density-dependent pattern in prevalence, but its impact on field vole demographic parameters is unknown. This study tests the hypothesis that wild field voles infected with Cowpox virus have a lower probability of survival than uninfected individuals. 2. The effect of Cowpox virus infection on the probability of an individual surviving to the next month was investigated using longitudinal data collected over 2 years from four grassland sites in Kielder Forest, UK. This effect was also investigated at the population level, by examining whether infection prevalence explained temporal variation in survival rates, once other factors influencing survival had been controlled for. 3. Individuals with a probability of infection, P(I), of 1 at a time when base survival rate was at median levels had a 22.4% lower estimated probability of survival than uninfected individuals, whereas those with a P(I) of 0.5 had a 10.4% lower survival. 4. At the population level, survival rates also decreased with increasing Cowpox prevalence, with lower survival rates in months of higher Cowpox prevalence. 5. Simple matrix projection models with 28 day time steps and two stages, with 71% of voles experiencing Cowpox infection in their second month of life (the average observed seroprevalence at the end of the breeding season) predict a reduction in 28-day population growth rate during the breeding season from λ = 1.62 to 1.53 for populations with no Cowpox infection compared with infected populations. 6. This negative correlation between Cowpox virus infection and field vole survival, with its potentially significant effect on population growth rate, is the first for an endemic pathogen in a cyclic population of wild rodents.
-
Cowpox virus infection in natural field vole Microtus agrestis populations: significant negative impacts on survival
The Journal of animal ecology, 2008Co-Authors: Sarah J. Burthe, Malcolm J. Bennett, Michael Begon, Sandra Telfer, A. Smith, Xavier LambinAbstract:1. Cowpox virus is an endemic virus circulating in populations of wild rodents. It has been implicated as a potential cause of population cycles in field voles Microtus agrestis L., in Britain, owing to a delayed density-dependent pattern in prevalence, but its impact on field vole demographic parameters is unknown. This study tests the hypothesis that wild field voles infected with Cowpox virus have a lower probability of survival than uninfected individuals. 2. The effect of Cowpox virus infection on the probability of an individual surviving to the next month was investigated using longitudinal data collected over 2 years from four grassland sites in Kielder Forest, UK. This effect was also investigated at the population level, by examining whether infection prevalence explained temporal variation in survival rates, once other factors influencing survival had been controlled for. 3. Individuals with a probability of infection, P(I), of 1 at a time when base survival rate was at median levels had a 22.4% lower estimated probability of survival than uninfected individuals, whereas those with a P(I) of 0.5 had a 10.4% lower survival. 4. At the population level, survival rates also decreased with increasing Cowpox prevalence, with lower survival rates in months of higher Cowpox prevalence. 5. Simple matrix projection models with 28 day time steps and two stages, with 71% of voles experiencing Cowpox infection in their second month of life (the average observed seroprevalence at the end of the breeding season) predict a reduction in 28-day population growth rate during the breeding season from lambda = 1.62 to 1.53 for populations with no Cowpox infection compared with infected populations. 6. This negative correlation between Cowpox virus infection and field vole survival, with its potentially significant effect on population growth rate, is the first for an endemic pathogen in a cyclic population of wild rodents.
-
Cowpox virus infection in natural field vole microtus agrestis populations delayed density dependence and individual risk
Journal of Animal Ecology, 2006Co-Authors: Sarah J. Burthe, Malcolm J. Bennett, Sandra Telfer, A. Smith, Xavier Lambin, David Carslake, Michael BegonAbstract:1. Little is known about the dynamics of pathogen (microparasite) infection in wildlife populations, and less still about sources of variation in the risk of infection. Here we present the first detailed analysis of such variation. 2. Cowpox virus is an endemic sublethal pathogen circulating in populations of wild rodents. Cowpox prevalence was monitored longitudinally for 2 years, in populations of field voles exhibiting multiannual cycles of density in Kielder Forest, UK. 3. The probability that available susceptible animals seroconverted in a given trap session was significantly positively related to host density with a 3-month time lag. 4. Males were significantly more likely to seroconvert than females. 5. Despite most infection being found in young animals (because transmission rates were generally high) mature individuals were more likely to seroconvert than immature ones, suggesting that behavioural or physiological changes associated with maturity contribute to variation in infection risk. 6. Hence, these analyses confirm that there is a delayed numerical response of Cowpox infection to vole density, supporting the hypothesis that endemic pathogens may play some part in shaping vole cycles.
-
inference of Cowpox virus transmission rates between wild rodent host classes using space time interaction
Proceedings of The Royal Society B: Biological Sciences, 2006Co-Authors: David Carslake, Malcolm J. Bennett, Sarah M. Hazel, Sandra Telfer, Michael BegonAbstract:There have been virtually no studies of 'who acquires infection from whom' in wildlife populations, but patterns of transmission within and between different classes of host are likely to be reflected in the spatiotemporal distribution of infection among those host classes. Here, we use a modified form of K-function analysis to test for space-time interaction among bank voles and wood mice infectious with Cowpox virus. There was no evidence for transmission between the two host species, supporting previous evidence that they act as separate reservoirs for Cowpox. Among wood mice, results suggested that transmission took place primarily between individuals of the opposite sex, raising the possibility that Cowpox is sexually transmitted in this species. Results for bank voles indicated that infected females might be a more important source of infection to either sex than are males. The suggestion of different modes of transmission in the two species is itself consistent with the apparent absence of transmission between species.
Sandra Telfer - One of the best experts on this subject based on the ideXlab platform.
-
host condition and individual risk of Cowpox virus infection in natural animal populations cause or effect
Epidemiology and Infection, 2009Co-Authors: Pablo Martin Beldomenico, Malcolm J. Bennett, Sandra Telfer, Lukasz Lukomski, Stephanie Gebert, Michael BegonAbstract:Recent studies have provided evidence that endemic pathogens may affect dynamics in animals. However, such studies have not typically considered that infected individuals might have a preceding underlying poor condition. We examined whether individuals in poor condition are more likely to become infected by an endemic pathogen, using as a system the dynamics of Cowpox virus in field voles. With data from monthly sampled vole populations, a nested case-control study evaluated whether susceptible individuals with poorer condition had higher probabilities of contracting Cowpox. The influence of condition was found to be considerable, especially for males. At times when a susceptible male with good body condition had a relatively low probability of becoming infected, a susceptible male with poor body condition was twice as likely to contract Cowpox; if this male was also anaemic, the chances were almost quadrupled. We discuss the care needed when interpreting the findings of wildlife disease studies.
-
Cowpox virus infection in natural field vole Microtus agrestispopulations: significant negative impacts on survival
2008Co-Authors: Sarah J. Burthe, Malcolm J. Bennett, Michael Begon, Sandra Telfer, A. Smith, Xavier LambinAbstract:1. Cowpox virus is an endemic virus circulating in populations of wild rodents. It has been implicated as a potential cause of population cycles in field voles Microtus agrestis L., in Britain, owing to a delayed density-dependent pattern in prevalence, but its impact on field vole demographic parameters is unknown. This study tests the hypothesis that wild field voles infected with Cowpox virus have a lower probability of survival than uninfected individuals. 2. The effect of Cowpox virus infection on the probability of an individual surviving to the next month was investigated using longitudinal data collected over 2 years from four grassland sites in Kielder Forest, UK. This effect was also investigated at the population level, by examining whether infection prevalence explained temporal variation in survival rates, once other factors influencing survival had been controlled for. 3. Individuals with a probability of infection, P(I), of 1 at a time when base survival rate was at median levels had a 22.4% lower estimated probability of survival than uninfected individuals, whereas those with a P(I) of 0.5 had a 10.4% lower survival. 4. At the population level, survival rates also decreased with increasing Cowpox prevalence, with lower survival rates in months of higher Cowpox prevalence. 5. Simple matrix projection models with 28 day time steps and two stages, with 71% of voles experiencing Cowpox infection in their second month of life (the average observed seroprevalence at the end of the breeding season) predict a reduction in 28-day population growth rate during the breeding season from λ = 1.62 to 1.53 for populations with no Cowpox infection compared with infected populations. 6. This negative correlation between Cowpox virus infection and field vole survival, with its potentially significant effect on population growth rate, is the first for an endemic pathogen in a cyclic population of wild rodents.
-
Cowpox virus infection in natural field vole Microtus agrestis populations: significant negative impacts on survival
The Journal of animal ecology, 2008Co-Authors: Sarah J. Burthe, Malcolm J. Bennett, Michael Begon, Sandra Telfer, A. Smith, Xavier LambinAbstract:1. Cowpox virus is an endemic virus circulating in populations of wild rodents. It has been implicated as a potential cause of population cycles in field voles Microtus agrestis L., in Britain, owing to a delayed density-dependent pattern in prevalence, but its impact on field vole demographic parameters is unknown. This study tests the hypothesis that wild field voles infected with Cowpox virus have a lower probability of survival than uninfected individuals. 2. The effect of Cowpox virus infection on the probability of an individual surviving to the next month was investigated using longitudinal data collected over 2 years from four grassland sites in Kielder Forest, UK. This effect was also investigated at the population level, by examining whether infection prevalence explained temporal variation in survival rates, once other factors influencing survival had been controlled for. 3. Individuals with a probability of infection, P(I), of 1 at a time when base survival rate was at median levels had a 22.4% lower estimated probability of survival than uninfected individuals, whereas those with a P(I) of 0.5 had a 10.4% lower survival. 4. At the population level, survival rates also decreased with increasing Cowpox prevalence, with lower survival rates in months of higher Cowpox prevalence. 5. Simple matrix projection models with 28 day time steps and two stages, with 71% of voles experiencing Cowpox infection in their second month of life (the average observed seroprevalence at the end of the breeding season) predict a reduction in 28-day population growth rate during the breeding season from lambda = 1.62 to 1.53 for populations with no Cowpox infection compared with infected populations. 6. This negative correlation between Cowpox virus infection and field vole survival, with its potentially significant effect on population growth rate, is the first for an endemic pathogen in a cyclic population of wild rodents.
-
Cowpox virus infection in natural field vole microtus agrestis populations delayed density dependence and individual risk
Journal of Animal Ecology, 2006Co-Authors: Sarah J. Burthe, Malcolm J. Bennett, Sandra Telfer, A. Smith, Xavier Lambin, David Carslake, Michael BegonAbstract:1. Little is known about the dynamics of pathogen (microparasite) infection in wildlife populations, and less still about sources of variation in the risk of infection. Here we present the first detailed analysis of such variation. 2. Cowpox virus is an endemic sublethal pathogen circulating in populations of wild rodents. Cowpox prevalence was monitored longitudinally for 2 years, in populations of field voles exhibiting multiannual cycles of density in Kielder Forest, UK. 3. The probability that available susceptible animals seroconverted in a given trap session was significantly positively related to host density with a 3-month time lag. 4. Males were significantly more likely to seroconvert than females. 5. Despite most infection being found in young animals (because transmission rates were generally high) mature individuals were more likely to seroconvert than immature ones, suggesting that behavioural or physiological changes associated with maturity contribute to variation in infection risk. 6. Hence, these analyses confirm that there is a delayed numerical response of Cowpox infection to vole density, supporting the hypothesis that endemic pathogens may play some part in shaping vole cycles.
-
inference of Cowpox virus transmission rates between wild rodent host classes using space time interaction
Proceedings of The Royal Society B: Biological Sciences, 2006Co-Authors: David Carslake, Malcolm J. Bennett, Sarah M. Hazel, Sandra Telfer, Michael BegonAbstract:There have been virtually no studies of 'who acquires infection from whom' in wildlife populations, but patterns of transmission within and between different classes of host are likely to be reflected in the spatiotemporal distribution of infection among those host classes. Here, we use a modified form of K-function analysis to test for space-time interaction among bank voles and wood mice infectious with Cowpox virus. There was no evidence for transmission between the two host species, supporting previous evidence that they act as separate reservoirs for Cowpox. Among wood mice, results suggested that transmission took place primarily between individuals of the opposite sex, raising the possibility that Cowpox is sexually transmitted in this species. Results for bank voles indicated that infected females might be a more important source of infection to either sex than are males. The suggestion of different modes of transmission in the two species is itself consistent with the apparent absence of transmission between species.
Sarah M. Hazel - One of the best experts on this subject based on the ideXlab platform.
-
inference of Cowpox virus transmission rates between wild rodent host classes using space time interaction
Proceedings of The Royal Society B: Biological Sciences, 2006Co-Authors: David Carslake, Malcolm J. Bennett, Sarah M. Hazel, Sandra Telfer, Michael BegonAbstract:There have been virtually no studies of 'who acquires infection from whom' in wildlife populations, but patterns of transmission within and between different classes of host are likely to be reflected in the spatiotemporal distribution of infection among those host classes. Here, we use a modified form of K-function analysis to test for space-time interaction among bank voles and wood mice infectious with Cowpox virus. There was no evidence for transmission between the two host species, supporting previous evidence that they act as separate reservoirs for Cowpox. Among wood mice, results suggested that transmission took place primarily between individuals of the opposite sex, raising the possibility that Cowpox is sexually transmitted in this species. Results for bank voles indicated that infected females might be a more important source of infection to either sex than are males. The suggestion of different modes of transmission in the two species is itself consistent with the apparent absence of transmission between species.
-
space time clustering of Cowpox virus infection in wild rodent populations
Journal of Animal Ecology, 2005Co-Authors: David Carslake, Malcolm J. Bennett, Sarah M. Hazel, Sandra Telfer, Kevin J. Bown, Michael BegonAbstract:Summary 1 The spatial and temporal scale at which infectious animals pose a transmission risk to others may be inferred by a study of space–time interaction in the clustering of cases of infection. 2 We analyse the distribution of bank voles and wood mice infectious with Cowpox virus, using 7 years of monthly live-trapping data from a woodland in north-west England. 3 A published method, K-function analysis, is adapted to measure space–time interaction among infectious animals trapped on a grid system, where the populations at risk may vary in density. 4 We hypothesized that the risk of Cowpox transmission from an infectious animal would be contained within a temporal scale of one infectious period and a spatial scale of one home-range diameter. 5 Cowpox cases among wood mice showed significantly greater spatial clustering than the population at risk at the smallest spatial scale, corresponding to animals caught in the same location. At larger scales, and for bank voles at all scales, Cowpox cases showed no spatial clustering beyond that expected from an association with host distribution. 6 Cowpox cases among wood mice showed strong evidence of temporal clustering beyond that of the host population, indicating short-lived outbreaks. No such effect was apparent among bank voles. 7 Significant space–time interaction among Cowpox cases was detected at the hypothesized spatial and temporal scales in both host species. This suggests that the risk of transmission is concentrated locally. 8 Results are discussed in terms of transmission, including consideration of the appropriateness of distance and nearest-neighbour based clustering tests to infections transmitted by local density and frequency dependent mechanisms.
-
The effects of Cowpox virus on survival in natural rodent populations: increases and decreases
Journal of Animal Ecology, 2002Co-Authors: Sandra Telfer, Malcolm J. Bennett, Sarah M. Hazel, Kevin J. Bown, Rachel Cavanagh, Trevor Jones, Laurent Crespin, Michael BegonAbstract:Summary 1 The effect of Cowpox virus on survival in two rodent hosts was investigated using nearly 4 years of longitudinal data from two sites. 2 We investigated whether an individual's probability of infection influenced the probability of surviving the next month. We also investigated the effect at the population level, examining whether, in addition to seasonal effects, changes in Cowpox prevalence explained further temporal variation in survival rates. 3 In bank voles, but not wood mice, individuals with high probabilities of infection survived better than uninfected animals. 4 At the level of the population, the effect of infection on survival varied through the year in both species. Survival rates in late summer increased with Cowpox prevalence, whilst survival rates in winter decreased with Cowpox prevalence. 5 We discuss why parasites such as Cowpox virus may increase or decrease host survival and why the effect may depend on the time of year.
-
A longitudinal study of an endemic disease in its wildlife reservoir: Cowpox and wild rodents.
Epidemiology and infection, 2000Co-Authors: Sarah M. Hazel, Malcolm J. Bennett, Derrick Baxby, Kevin J. Bown, Rachel Cavanagh, Trevor Jones, Julian Chantrey, Michael BegonAbstract:Cowpox is an orthopoxvirus infection endemic in European wild rodents, but with a wide host range including human beings. In this longitudinal study we examined Cowpox in two wild rodent species, bank voles Clethrionomys glareolus and wood mice Apodemus sylvaticus, to investigate the dynamics of a virus in its wild reservoir host. Trapping was carried out at 4-weekly intervals over 3 years and each animal caught was uniquely identified, blood sampled and tested for antibodies to Cowpox. Antibody prevalence was higher in bank voles than in wood mice and seroconversion varied seasonally, with peaks in autumn. Infection was most common in males of both species but no clear association with age was demonstrated. This study provides a model for studying other zoonotic infections that derive from wild mammals since other approaches, such as one-off samples, will fail to detect the variation in infection and thus, risk to human health, demonstrated here.
Andreas Nitsche - One of the best experts on this subject based on the ideXlab platform.
-
equination inoculation of horsepox an early alternative to vaccination inoculation of Cowpox and the potential role of horsepox virus in the origin of the smallpox vaccine
Vaccine, 2017Co-Authors: José Esparza, Clarissa R. Damaso, Livia Schrick, Andreas NitscheAbstract:For almost 150 years after Edward Jenner had published the “Inquiry” in 1798, it was generally assumed that the Cowpox virus was the vaccine against smallpox. It was not until 1939 when it was shown that vaccinia, the smallpox vaccine virus, was serologically related but different from the Cowpox virus. In the absence of a known natural host, vaccinia has been considered to be a laboratory virus that may have originated from mutational or recombinational events involving Cowpox virus, variola viruses or some unknown ancestral Orthopoxvirus. A favorite candidate for a vaccinia ancestor has been the horsepox virus. Edward Jenner himself suspected that Cowpox derived from horsepox and he also believed that “matter” obtained from either disease could be used as preventative of smallpox. During the 19th century, inoculation with Cowpox (vaccination) was used in Europe alongside with inoculation with horsepox (equination) to prevent smallpox. Vaccine-manufacturing practices during the 19th century may have resulted in the use of virus mixtures, leading to different genetic modifications that resulted in present-day vaccinia strains. Horsepox, a disease previously reported only in Europe, has been disappearing on that continent since the beginning of the 20th century and now seems to have become extinct, although the virus perhaps remains circulating in an unknown reservoir. Genomic sequencing of a horsepox virus isolated in Mongolia in 1976 indicated that, while closely related to vaccinia, this horsepox virus contained additional, potentially ancestral sequences absent in vaccinia. Recent genetic analyses of extant vaccinia viruses have revealed that some strains contain ancestral horsepox virus genes or are phylogenetically related to horsepox virus. We have recently reported that a commercially produced smallpox vaccine, manufactured in the United States in 1902, is genetically highly similar to horsepox virus, providing a missing link in this 200-year-old mystery.
-
Cowpox after a cat scratch – case report from Poland
Annals of agricultural and environmental medicine : AAEM, 2015Co-Authors: Karolina Świtaj, Andreas Kurth, Piotr Kajfasz, Andreas NitscheAbstract:Cowpox in humans is a rare zoonotic disease; its recognition is therefore problematic due to the lack of clinical experience. The differential diagnosis includes other poxvirus infections and also infections with herpesviruses or selected bacteria. The clinical course can be complicated and the improvement may take weeks. Late diagnosis is one of the causes of unnecessary combined antibiotic therapy or surgical intervention. A case of Cowpox after a cat scratch in a 15-year-old girl is presented, with a summary of the available clinical data on Cowpox infections.
-
Cowpox after a cat scratch case report from poland
Annals of Agricultural and Environmental Medicine, 2015Co-Authors: Karolina świtaj, Piotr Kajfasz, Andreas Kurth, Andreas NitscheAbstract:Cowpox in humans is a rare zoonotic disease; its recognition is therefore problematic due to the lack of clinical experience. The differential diagnosis includes other poxvirus infections and also infections with herpesviruses or selected bacteria. The clinical course can be complicated and the improvement may take weeks. Late diagnosis is one of the causes of unnecessary combined antibiotic therapy or surgical intervention. A case of Cowpox after a cat scratch in a 15-year-old girl is presented, with a summary of the available clinical data on Cowpox infections.
-
comparison of host cell gene expression in Cowpox monkeypox or vaccinia virus infected cells reveals virus specific regulation of immune response genes
Virology Journal, 2013Co-Authors: Daniel Bourquain, Piotr Wojtek Dabrowski, Andreas NitscheAbstract:Background: Animal-borne orthopoxviruses, like monkeypox, vaccinia and the closely related Cowpox virus, are all capable of causing zoonotic infections in humans, representing a potential threat to human health. The disease caused by each virus differs in terms of symptoms and severity, but little is yet know about the reasons for these varying phenotypes. They may be explained by the unique repertoire of immune and host cell modulating factors encoded by each virus. In this study, we analysed the specific modulation of the host cell’s gene expression profile by Cowpox, monkeypox and vaccinia virus infection. We aimed to identify mechanisms that are either common to orthopoxvirus infection or specific to certain orthopoxvirus species, allowing a more detailed description of differences in virus-host cell interactions between individual orthopoxviruses. To this end, we analysed changes in host cell gene expression of HeLa cells in response to infection with Cowpox, monkeypox and vaccinia virus, using whole-genome gene expression microarrays, and compared these to each other and to non-infected cells. Results: Despite a dominating non-responsiveness of cellular transcription towards orthopoxvirus infection, we could identify several clusters of infection-modulated genes. These clusters are either commonly regulated by orthopoxvirus infection or are uniquely regulated by infection with a specific orthopoxvirus, with major differences being observed in immune response genes. Most noticeable was an induction of genes involved in leukocyte migration and activation in Cowpox and monkeypox virus-infected cells, which was not observed following vaccinia virus infection. Conclusion: Despite their close genetic relationship, the expression profiles induced by infection with different orthopoxviruses vary significantly. It may be speculated that these differences at the cellular level contribute to the individual characteristics of Cowpox, monkeypox and vaccinia virus infections in certain host species.
-
Cowpox virus but not Vaccinia virus induces secretion of CXCL1, IL-8 and IL-6 and chemotaxis of monocytes in vitro
Virus research, 2012Co-Authors: Daniel Bourquain, Andreas NitscheAbstract:Orthopoxviruses are large DNA viruses which can cause disease in numerous host species. Today, after eradication of Variola virus and the end of vaccination against smallpox, zoonotic Orthopoxvirus infections are emerging as potential threat to human health. The most common causes of zoonotic Orthopoxvirus infections are Cowpox virus in Europe, Monkeypox virus in Africa and Vaccinia virus in South America. Although all three viruses are genetically and antigenically closely related, the human diseases caused by each virus differ considerably. This observation may reflect different capabilities of these viruses to modulate the hosts’ immune response. Therefore, we aimed at characterizing the specific cytokine response induced by Orthopoxvirus infection in vitro. We analysed the gene expression of nine human pro-inflammatory cytokines and chemokines in response to infection of HeLa cells and could identify an upregulation of cytokine gene expression following Cowpox virus and Monkeypox virus infection but not following Vaccinia virus infection. This was verified by a strong induction of especially IL-6, IL-8 and CXCL1 secretion into the cell culture supernatant following Cowpox virus infection. We could further show that supernatants derived from Cowpox virus-infected cells exhibit an increased chemotactic activity towards monocytic and macrophage-like cells. On the one hand, increased cytokine secretion by Cowpox virus-infected cells and subsequent monocyte/macrophage recruitment may contribute to host defence and facilitate clearance of the infection. On the other hand, given the assumed important role of circulating macrophages in viral spread, this may also point towards a mechanism facilitating delivery of the virus to further tissues in vivo.
