The Experts below are selected from a list of 417 Experts worldwide ranked by ideXlab platform
David T S Hayman - One of the best experts on this subject based on the ideXlab platform.
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maternal antibody and the maintenance of a lyssaVirus in populations of seasonally breeding african Bats
PLOS ONE, 2018Co-Authors: David T S Hayman, Olivier Restif, Daniel L Horton, Anthony R Fooks, Richard Suuire, Kate S. Baker, Angela D. Luis, Clint Leach, Andrew A. CunninghamAbstract:Pathogens causing acute disease and death or lasting immunity require specific spatial or temporal processes to persist in populations. Host traits, such as maternally-derived antibody (MDA) and seasonal birthing affect infection maintenance within populations. Our study objective is to understand how viral and host traits lead to population level infection persistence when the infection can be fatal. We collected data on African fruit Bats and a rabies-related Virus, Lagos Bat Virus (LBV), including through captive studies. We incorporate these data into a mechanistic model of LBV transmission to determine how host traits, including MDA and seasonal birthing, and viral traits, such as incuBation periods, interact to allow fatal Viruses to persist within Bat populations. Captive Bat studies supported MDA presence estimated from field data. Captive Bat infection-derived antibody decayed more slowly than MDA, and while faster than estimates from the field, supports field data that suggest antibody persistence may be lifelong. Unobserved parameters were estimated by particle filtering and suggest only a small proportion of Bats die of disease. Pathogen persistence in the population is sensitive to this proportion, along with MDA duration and incuBation period. Our analyses suggest MDA produced Bats and prolonged Virus incuBation periods allow viral maintenance in adverse conditions, such as a lethal pathogen or strongly seasonal resource availability for the pathogen in the form of seasonally pulsed birthing.
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Maternal antibody and the maintenance of a lyssaVirus in populations of seasonally breeding African Bats.
'Organisation for Economic Co-Operation and Development (OECD)', 2018Co-Authors: David T S Hayman, Baker, Kate S, Cunningham, Andrew A, Fooks, Anthony R, Restif Olivier, Suu-ire Richard, Horton, Daniel L., Luis, Angela D, Leach Clint, Wood JamesAbstract:Pathogens causing acute disease and death or lasting immunity require specific spatial or temporal processes to persist in populations. Host traits, such as maternally-derived antibody (MDA) and seasonal birthing affect infection maintenance within populations. Our study objective is to understand how viral and host traits lead to population level infection persistence when the infection can be fatal. We collected data on African fruit Bats and a rabies-related Virus, Lagos Bat Virus (LBV), including through captive studies. We incorporate these data into a mechanistic model of LBV transmission to determine how host traits, including MDA and seasonal birthing, and viral traits, such as incuBation periods, interact to allow fatal Viruses to persist within Bat populations. Captive Bat studies supported MDA presence estimated from field data. Captive Bat infection-derived antibody decayed more slowly than MDA, and while faster than estimates from the field, supports field data that suggest antibody persistence may be lifelong. Unobserved parameters were estimated by particle filtering and suggest only asmall proportion of Bats die of disease. Pathogen persistence in the population is sensitive to this proportion, along with MDA duration and incuBation period. Our analyses suggest MDA produced Bats and prolonged Virus incuBation periods allow viral maintenance in adverse conditions, such as a lethal pathogen or strongly seasonal resource availability for the pathogen in the form of seasonally pulsed birthing.Wellcome Trust, EU FP7, Royal Society, Alborada Trust
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Support for viral persistence in Bats from age-specific serology and models of maternal immunity
'Springer Science and Business Media LLC', 2018Co-Authors: Peel, Alison J, David T S Hayman, James L N Wood, Baker, Kate S, Broder, Christopher C, Cunningham, Andrew A, Fooks, Anthony R, Garnier Romain, Restif OlivierAbstract:Spatiotemporally-localised prediction of Virus emergence from wildlife requires focused studies on the ecology and immunology of reservoir hosts in their native habitat. Reliable predictions from mathematical models remain difficult in most systems due to a dearth of appropriate empirical data. Our goal was to study the circulation and immune dynamics of zoonotic Viruses in Bat populations and investigate the effects of maternally-derived and acquired immunity on viral persistence. Using rare age-specific serological data from wild-caught Eidolon helvum fruit Bats as a case study, we estimated viral transmission parameters for a stochastic infection model. We estimated mean durations of around 6 months for maternally-derived immunity to Lagos Bat Virus and African henipaVirus, whereas acquired immunity was long-lasting (Lagos Bat Virus: mean 12 years, henipaVirus: mean 4 years). In the presence of a seasonal birth pulse, the effect of maternally-derived immunity on Virus persistence within modelled Bat populations was highly dependent on transmission characteristics. To explain previous reports of viral persistence within small natural and captive E. helvum populations, we hypothesise that some Bats must experience prolonged infectious periods or within-host latency. By further elucidating plausible mechanisms of Virus persistence in Bat populations, we contribute to guidance of future field studies
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Model variables and parameters for the Lagos Bat Virus and Eidolon helvum system.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:Model variables and parameters for the Lagos Bat Virus and Eidolon helvum system.
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Schematic of the model structure.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:The total Bat population is N; susceptible S; exposed E; infectious I; immune R; the proportion becoming infectious ρ; exposed leading to infection Ei; exposed leading to recovery Er; adults a (top); juveniles j (bottom, shaded). Juveniles age at rate ε (see text for M aging); maternally-derived antibody positive juveniles M; having waning immunity at rate ψ; and juveniles are born with a seasonal birth pulse B(t). Lagos Bat Virus transmission was frequency dependent β·S·I/N. Ei become infectious at rate σ (1/incuBation period). Er seroconvert at rate τ (1/seroconversion period). Mortality is omitted for clarity.
Anthony R Fooks - One of the best experts on this subject based on the ideXlab platform.
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maternal antibody and the maintenance of a lyssaVirus in populations of seasonally breeding african Bats
PLOS ONE, 2018Co-Authors: David T S Hayman, Olivier Restif, Daniel L Horton, Anthony R Fooks, Richard Suuire, Kate S. Baker, Angela D. Luis, Clint Leach, Andrew A. CunninghamAbstract:Pathogens causing acute disease and death or lasting immunity require specific spatial or temporal processes to persist in populations. Host traits, such as maternally-derived antibody (MDA) and seasonal birthing affect infection maintenance within populations. Our study objective is to understand how viral and host traits lead to population level infection persistence when the infection can be fatal. We collected data on African fruit Bats and a rabies-related Virus, Lagos Bat Virus (LBV), including through captive studies. We incorporate these data into a mechanistic model of LBV transmission to determine how host traits, including MDA and seasonal birthing, and viral traits, such as incuBation periods, interact to allow fatal Viruses to persist within Bat populations. Captive Bat studies supported MDA presence estimated from field data. Captive Bat infection-derived antibody decayed more slowly than MDA, and while faster than estimates from the field, supports field data that suggest antibody persistence may be lifelong. Unobserved parameters were estimated by particle filtering and suggest only a small proportion of Bats die of disease. Pathogen persistence in the population is sensitive to this proportion, along with MDA duration and incuBation period. Our analyses suggest MDA produced Bats and prolonged Virus incuBation periods allow viral maintenance in adverse conditions, such as a lethal pathogen or strongly seasonal resource availability for the pathogen in the form of seasonally pulsed birthing.
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Model variables and parameters for the Lagos Bat Virus and Eidolon helvum system.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:Model variables and parameters for the Lagos Bat Virus and Eidolon helvum system.
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Sensitivity analysis results.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:Partial rank correlation coefficients (PRCC) for infection maintenance for 1000 simulations for 100 parameter sets for a 25 year time period for our stochastic Eidolon helvum–Lagos Bat Virus model. Positive PRCC indicate increasing a parameter increases infection maintenance. Parameters are: transmission rate β; adult mortality rate μ; juvenile mortality rate δ; disease induced mortality α; probability of becoming infectious ρ; incuBation period σ; carrying capacity K; rate of seroconversion τ; rate of loss of maternally-derived immunity ψ; and annual birth synchrony s. Significance at α = 0.05 is demarcated by the red line. Parameters were varied according to those ranges in Table 1.
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Schematic of the model structure.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:The total Bat population is N; susceptible S; exposed E; infectious I; immune R; the proportion becoming infectious ρ; exposed leading to infection Ei; exposed leading to recovery Er; adults a (top); juveniles j (bottom, shaded). Juveniles age at rate ε (see text for M aging); maternally-derived antibody positive juveniles M; having waning immunity at rate ψ; and juveniles are born with a seasonal birth pulse B(t). Lagos Bat Virus transmission was frequency dependent β·S·I/N. Ei become infectious at rate σ (1/incuBation period). Er seroconvert at rate τ (1/seroconversion period). Mortality is omitted for clarity.
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Lagos Bat Virus Infection Dynamics in Free-Ranging Straw-Colored Fruit Bats (Eidolon helvum)
'MDPI AG', 2017Co-Authors: Richard Suu-ire, James L N Wood, Anthony R Fooks, David Selden, Ashley C. Banyard, Kofi Amponsah-mensah, Silke Riesle, Meyir Y. Ziekah, Yaa Ntiamoa-baidu, Andrew A. CunninghamAbstract:Bats are key species for ecological function, but they are also reservoirs of zoonotic agents, such as lyssaViruses that cause rabies. Little is known about the maintenance and transmission of lyssaViruses in Bats, although the observation of clinically sick Bats, both in experimental studies and wild Bats, has at least demonstrated that lyssaViruses are capable of causing clinical disease in Bat species. Despite this, extensive surveillance for diseased Bats has not yielded lyssaViruses, whilst serological surveys demonstrate that Bats must be exposed to lyssaVirus without developing clinical disease. We hypothesize that there is endemic circulation of Lagos Bat Virus (LBV) in the straw-coloured fruit Bat (Eidolon helvum) in Ghana, West Africa. To investigate this further, longitudinal blood sampling was undertaken quarterly between 2012 and 2014 on wild E. helvum at two sites in Ghana. Serum samples were collected and tested for LBV-neutralizing antibodies using a modified flourescent antibody Virus neutralisation (FAVN) assay (n = 294) and brains from moribund or dead Bats were tested for antigen and viral RNA (n = 55). Overall, 44.7% of the 304 Bats sampled had LBV-neutralising antibodies. None of the brain samples from Bats contained lyssaVirus antigen or RNA. Together with the results of an earlier serological study, our findings demonstrate that LBV is endemic and circulates within E. helvum in Ghana even though the detection of viral infection in dead Bats was unsuccessful. Confirmation that LBV infection is endemic in E. helvum in Ghana is an important finding and indicates that the potential public health threats from LBV warrant further investigation
Andrew A. Cunningham - One of the best experts on this subject based on the ideXlab platform.
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maternal antibody and the maintenance of a lyssaVirus in populations of seasonally breeding african Bats
PLOS ONE, 2018Co-Authors: David T S Hayman, Olivier Restif, Daniel L Horton, Anthony R Fooks, Richard Suuire, Kate S. Baker, Angela D. Luis, Clint Leach, Andrew A. CunninghamAbstract:Pathogens causing acute disease and death or lasting immunity require specific spatial or temporal processes to persist in populations. Host traits, such as maternally-derived antibody (MDA) and seasonal birthing affect infection maintenance within populations. Our study objective is to understand how viral and host traits lead to population level infection persistence when the infection can be fatal. We collected data on African fruit Bats and a rabies-related Virus, Lagos Bat Virus (LBV), including through captive studies. We incorporate these data into a mechanistic model of LBV transmission to determine how host traits, including MDA and seasonal birthing, and viral traits, such as incuBation periods, interact to allow fatal Viruses to persist within Bat populations. Captive Bat studies supported MDA presence estimated from field data. Captive Bat infection-derived antibody decayed more slowly than MDA, and while faster than estimates from the field, supports field data that suggest antibody persistence may be lifelong. Unobserved parameters were estimated by particle filtering and suggest only a small proportion of Bats die of disease. Pathogen persistence in the population is sensitive to this proportion, along with MDA duration and incuBation period. Our analyses suggest MDA produced Bats and prolonged Virus incuBation periods allow viral maintenance in adverse conditions, such as a lethal pathogen or strongly seasonal resource availability for the pathogen in the form of seasonally pulsed birthing.
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Lagos Bat Virus infection study
The Pan African medical journal, 2018Co-Authors: Richard Suuire, Andrew A. Cunningham, Yaa Ntiamoahbaidu, J L N WoodAbstract:Introduction: Bats are reservoirs for many emerging and neglected zoonotic Viruses, including rabies Virus, Severe Acute Respiratory Syndrome (SARS) like coronaVirus, henipaVirus and filoVirus. Fruit Bats of several species are reservoir hosts for Lagos Bat Virus (LBV) with spillover infections documented in dogs, cats and mongoose. The impact of Bat lyssaVirus in Africa is unknown. Methods: investigations of the dynamics of zoonotic Viruses in wild Bats in Ghana identified lyssaViruses (LBV), henipaViruses and filoViruses (Ebola) as zoonotic infections of fruits Bats in Ghana. LBV has not been well studied and its risk for human and animals uncertain. We hypothesized that the inoculation of LBV can cause clinical disease in E. helvum.Results: to investigate the pathobiology and transmission pattern of LBV in fruits Bats, we conducted experimental intracranial inoculation (i.c) of LBV in captive bred and seronegative for Lagos Bat Virus, straw colored fruits Bats (Eidolon helvum) in Accra, Ghana. All 12 infected Bats developed clinical rabies. All the infected Bats died or were euthanized due to welfare concern within one (1) week of infection. All control Bats survived till the end of the experiment. Conclusion: we concluded that intracranial inoculation of Lagos Bat Virus can cause fatal disease in Bats. This paper present the clinical features of the infection study.
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Model variables and parameters for the Lagos Bat Virus and Eidolon helvum system.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:Model variables and parameters for the Lagos Bat Virus and Eidolon helvum system.
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Schematic of the model structure.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:The total Bat population is N; susceptible S; exposed E; infectious I; immune R; the proportion becoming infectious ρ; exposed leading to infection Ei; exposed leading to recovery Er; adults a (top); juveniles j (bottom, shaded). Juveniles age at rate ε (see text for M aging); maternally-derived antibody positive juveniles M; having waning immunity at rate ψ; and juveniles are born with a seasonal birth pulse B(t). Lagos Bat Virus transmission was frequency dependent β·S·I/N. Ei become infectious at rate σ (1/incuBation period). Er seroconvert at rate τ (1/seroconversion period). Mortality is omitted for clarity.
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Sensitivity analysis results.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:Partial rank correlation coefficients (PRCC) for infection maintenance for 1000 simulations for 100 parameter sets for a 25 year time period for our stochastic Eidolon helvum–Lagos Bat Virus model. Positive PRCC indicate increasing a parameter increases infection maintenance. Parameters are: transmission rate β; adult mortality rate μ; juvenile mortality rate δ; disease induced mortality α; probability of becoming infectious ρ; incuBation period σ; carrying capacity K; rate of seroconversion τ; rate of loss of maternally-derived immunity ψ; and annual birth synchrony s. Significance at α = 0.05 is demarcated by the red line. Parameters were varied according to those ranges in Table 1.
Wanda Markotter - One of the best experts on this subject based on the ideXlab platform.
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Lagos Bat Virus, an Under-Reported Rabies-Related LyssaVirus.
Viruses, 2021Co-Authors: Jessica Coertse, Marike Geldenhuys, Kevin Le Roux, Wanda MarkotterAbstract:Lagos Bat Virus (LBV), one of the 17 accepted viral species of the LyssaVirus genus, was the first rabies-related Virus described in 1956. This Virus is endemic to the African continent and is rarely encountered. There are currently four lineages, although the observed genetic diversity exceeds existing lyssaVirus species demarcation criteria. Several exposures to rabid Bats infected with LBV have been reported; however, no known human cases have been reported to date. This review provides the history of LBV and summarizes previous knowledge as well as new detections. Genetic diversity, pathogenesis and prevention are re-evaluated and discussed.
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Pathogenicity and Immunogenicity of Recombinant Rabies Viruses Expressing the Lagos Bat Virus Matrix and Glycoprotein: Perspectives for a Pan-LyssaVirus Vaccine
'MDPI AG', 2017Co-Authors: Joe Kgaladi, Bernhard Dietzschold, Louis Hendrik Nel, Milosz Faber, Wanda MarkotterAbstract:Lagos Bat Virus (LBV) is a phylogroup II lyssaVirus exclusively found in Africa. Previous studies indicated that this Virus is lethal to mice after intracranial and intramuscular inoculation. The antigenic composition of LBV differs substantially from that of rabies Virus (RABV) and current rabies vaccines do not provide cross protection against phylogroup II lyssaViruses. To investigate the potential role of the LBV matrix protein (M) and glycoprotein (G) in pathogenesis, reverse genetics technology was used to construct recombinant Viruses. The genes encoding the glycoprotein, or the matrix and glycoprotein of the attenuated RABV strain SPBN, were replaced with those of LBV resulting in SPBN-LBVG and SPBN-LBVM-LBVG, respectively. To evaluate the immunogenicity of the LBV G, the recombinant RABV SPBNGAS-LBVG-GAS was constructed with the LBV G inserted between two mutated RABV G genes (termed GAS). All the recombinant Viruses were lethal to mice after intracranial (i.c.) inoculation although the pathogenicity of SPBNGAS-LBVG-GAS was lower compared to the other recombinant Viruses. Following intramuscular (i.m.) inoculation, only SPBN-LBVM-LBVG was lethal to mice, indicating that both the M and G of LBV play a role in the pathogenesis. Most interestingly, serum collected from mice that were inoculated i.m. with SPBNGAS-LBVG-GAS neutralized phylogroup I and II lyssaViruses including RABV, Duvenhage Virus (DUVV), LBV, and Mokola Virus (MOKV), indicating that this recombinant Virus has potential to be developed as a pan-lyssaVirus vaccine
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diversity and epidemiology of mokola Virus
PLOS Neglected Tropical Diseases, 2013Co-Authors: Joe Kgaladi, Conrad Martin Freuling, Wanda Markotter, Denise A Marston, Anthony R Fooks, Nicolette Wright, Jessica Coertse, Thomas Muller, Claude T SabetaAbstract:Mokola Virus (MOKV) appears to be exclusive to Africa. Although the first isolates were from Nigeria and other Congo basin countries, all reports over the past 20 years have been from southern Africa. Previous phylogenetic studies analyzed few isolates or used partial gene sequence for analysis since limited sequence information is available for MOKV and the isolates were distributed among various laboratories. The complete nucleoprotein, phosphoprotein, matrix and glycoprotein genes of 18 MOKV isolates in various laboratories were sequenced either using partial or full genome sequencing using pyrosequencing and a phylogenetic analysis was undertaken. The results indicated that MOKV isolates from the Republic of South Africa, Zimbabwe, Central African Republic and Nigeria clustered according to geographic origin irrespective of the genes used for phylogenetic analysis, similar to that observed with Lagos Bat Virus. A Bayesian Markov-Chain-Monte-Carlo- (MCMC) analysis revealed the age of the most recent common ancestor (MRCA) of MOKV to be between 279 and 2034 years depending on the genes used. Generally, all MOKV isolates showed a similar pattern at the amino acid sites considered influential for viral properties.
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Comparison of pathogenic domains of rabies and African rabies-related lyssaViruses and pathogenicity observed in mice
Onderstepoort Journal of Veterinary Research, 2013Co-Authors: Joe Kgaladi, Wanda MarkotterAbstract:Several lyssaVirus species occur in Africa (Rabies Virus, Lagos Bat Virus, Mokola Virus, Duvenhage Virus, Shimoni Bat Virus and Ikoma lyssaVirus), displaying a high sequence diversity between isolates belonging to the same species. There is limited information about comparative pathogenesis of these African lyssaViruses and this precludes authoritative opinion on the potential public and veterinary health impact. In this study, an analysis of representative African lyssaViruses attempted to correlate viral genomic sequence similarities and differences with the corresponding pathogenic profiles observed in mice. The study demonstrated that the Virus isolates evaluated could be lethal to mice when introduced intramuscularly and that different isolates of the same lyssaVirus species differ in their virulence. Using real-time polymerase chain reaction (PCR), viral RNA was detected in brain tissue, but no viral RNA was detected in the salivary glands or blood of mice that succumbed to infection. Comparison of known pathogenic domains indicated that pathogenicity is likely to be dependent on multiple domains. Cumulatively, our results re-emphasised the realisation that the pathogenicity of a lyssaVirus species cannot be deduced based on studies of only a single isolate of the species or a single pathogenic domain.
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comparison of pathogenic domains of rabies and african rabies related lyssaViruses and pathogenicity observed in mice original research
Onderstepoort Journal of Veterinary Research, 2013Co-Authors: Joe Kgaladi, Louis Hendrik Nel, Wanda MarkotterAbstract:Several lyssaVirus species occur in Africa (Rabies Virus, Lagos Bat Virus, Mokola Virus, Duvenhage Virus, Shimoni Bat Virus and Ikoma lyssaVirus), displaying a high sequence diversity between isolates belonging to the same species. There is limited information about comparative pathogenesis of these African lyssaViruses and this precludes authoritative opinion on the potential public and veterinary health impact. In this study, an analysis of representative African lyssaViruses attempted to correlate viral genomic sequence similarities and differences with the corresponding pathogenic profiles observed in mice. The study demonstrated that the Virus isolates evaluated could be lethal to mice when introduced intramuscularly and that different isolates of the same lyssaVirus species differ in their virulence. Using real-time polymerase chain reaction (PCR), viral RNA was detected in brain tissue, but no viral RNA was detected in the salivary glands or blood of mice that succumbed to infection. Comparison of known pathogenic domains indicated that pathogenicity is likely to be dependent on multiple domains. Cumulatively, our results re-emphasised the realisation that the pathogenicity of a lyssaVirus species cannot be deduced based on studies of only a single isolate of the species or a single pathogenic domain.
James L N Wood - One of the best experts on this subject based on the ideXlab platform.
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Support for viral persistence in Bats from age-specific serology and models of maternal immunity
'Springer Science and Business Media LLC', 2018Co-Authors: Peel, Alison J, David T S Hayman, James L N Wood, Baker, Kate S, Broder, Christopher C, Cunningham, Andrew A, Fooks, Anthony R, Garnier Romain, Restif OlivierAbstract:Spatiotemporally-localised prediction of Virus emergence from wildlife requires focused studies on the ecology and immunology of reservoir hosts in their native habitat. Reliable predictions from mathematical models remain difficult in most systems due to a dearth of appropriate empirical data. Our goal was to study the circulation and immune dynamics of zoonotic Viruses in Bat populations and investigate the effects of maternally-derived and acquired immunity on viral persistence. Using rare age-specific serological data from wild-caught Eidolon helvum fruit Bats as a case study, we estimated viral transmission parameters for a stochastic infection model. We estimated mean durations of around 6 months for maternally-derived immunity to Lagos Bat Virus and African henipaVirus, whereas acquired immunity was long-lasting (Lagos Bat Virus: mean 12 years, henipaVirus: mean 4 years). In the presence of a seasonal birth pulse, the effect of maternally-derived immunity on Virus persistence within modelled Bat populations was highly dependent on transmission characteristics. To explain previous reports of viral persistence within small natural and captive E. helvum populations, we hypothesise that some Bats must experience prolonged infectious periods or within-host latency. By further elucidating plausible mechanisms of Virus persistence in Bat populations, we contribute to guidance of future field studies
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Model variables and parameters for the Lagos Bat Virus and Eidolon helvum system.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:Model variables and parameters for the Lagos Bat Virus and Eidolon helvum system.
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Schematic of the model structure.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:The total Bat population is N; susceptible S; exposed E; infectious I; immune R; the proportion becoming infectious ρ; exposed leading to infection Ei; exposed leading to recovery Er; adults a (top); juveniles j (bottom, shaded). Juveniles age at rate ε (see text for M aging); maternally-derived antibody positive juveniles M; having waning immunity at rate ψ; and juveniles are born with a seasonal birth pulse B(t). Lagos Bat Virus transmission was frequency dependent β·S·I/N. Ei become infectious at rate σ (1/incuBation period). Er seroconvert at rate τ (1/seroconversion period). Mortality is omitted for clarity.
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Sensitivity analysis results.
2018Co-Authors: David T S Hayman, Richard Suu-ire, Olivier Restif, Andrew A. Cunningham, Daniel L Horton, Anthony R Fooks, Kate S. Baker, Angela D. Luis, Clint Leach, James L N WoodAbstract:Partial rank correlation coefficients (PRCC) for infection maintenance for 1000 simulations for 100 parameter sets for a 25 year time period for our stochastic Eidolon helvum–Lagos Bat Virus model. Positive PRCC indicate increasing a parameter increases infection maintenance. Parameters are: transmission rate β; adult mortality rate μ; juvenile mortality rate δ; disease induced mortality α; probability of becoming infectious ρ; incuBation period σ; carrying capacity K; rate of seroconversion τ; rate of loss of maternally-derived immunity ψ; and annual birth synchrony s. Significance at α = 0.05 is demarcated by the red line. Parameters were varied according to those ranges in Table 1.
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Lagos Bat Virus Infection Dynamics in Free-Ranging Straw-Colored Fruit Bats (Eidolon helvum)
'MDPI AG', 2017Co-Authors: Richard Suu-ire, James L N Wood, Anthony R Fooks, David Selden, Ashley C. Banyard, Kofi Amponsah-mensah, Silke Riesle, Meyir Y. Ziekah, Yaa Ntiamoa-baidu, Andrew A. CunninghamAbstract:Bats are key species for ecological function, but they are also reservoirs of zoonotic agents, such as lyssaViruses that cause rabies. Little is known about the maintenance and transmission of lyssaViruses in Bats, although the observation of clinically sick Bats, both in experimental studies and wild Bats, has at least demonstrated that lyssaViruses are capable of causing clinical disease in Bat species. Despite this, extensive surveillance for diseased Bats has not yielded lyssaViruses, whilst serological surveys demonstrate that Bats must be exposed to lyssaVirus without developing clinical disease. We hypothesize that there is endemic circulation of Lagos Bat Virus (LBV) in the straw-coloured fruit Bat (Eidolon helvum) in Ghana, West Africa. To investigate this further, longitudinal blood sampling was undertaken quarterly between 2012 and 2014 on wild E. helvum at two sites in Ghana. Serum samples were collected and tested for LBV-neutralizing antibodies using a modified flourescent antibody Virus neutralisation (FAVN) assay (n = 294) and brains from moribund or dead Bats were tested for antigen and viral RNA (n = 55). Overall, 44.7% of the 304 Bats sampled had LBV-neutralising antibodies. None of the brain samples from Bats contained lyssaVirus antigen or RNA. Together with the results of an earlier serological study, our findings demonstrate that LBV is endemic and circulates within E. helvum in Ghana even though the detection of viral infection in dead Bats was unsuccessful. Confirmation that LBV infection is endemic in E. helvum in Ghana is an important finding and indicates that the potential public health threats from LBV warrant further investigation
