scholarly journals Urban habituation, ecological connectivity and epidemic dampening: the emergence of Hendra virus from flying foxes ( Pteropus spp.)

2011 ◽  
Vol 278 (1725) ◽  
pp. 3703-3712 ◽  
Author(s):  
Raina K. Plowright ◽  
Patrick Foley ◽  
Hume E. Field ◽  
Andy P. Dobson ◽  
Janet E. Foley ◽  
...  
Keyword(s):  
Temporal Pattern ◽  
Laboratory Data ◽  
Case Fatality ◽  
Domestic Animal ◽  
Hendra Virus ◽  
Flying Foxes ◽  
Anthropogenic Transformation ◽  
Population Immunity ◽  
Animal Populations ◽  
Flying Fox

Anthropogenic environmental change is often implicated in the emergence of new zoonoses from wildlife; however, there is little mechanistic understanding of these causal links. Here, we examine the transmission dynamics of an emerging zoonotic paramyxovirus, Hendra virus (HeV), in its endemic host, Australian Pteropus bats (fruit bats or flying foxes). HeV is a biosecurity level 4 (BSL-4) pathogen, with a high case-fatality rate in humans and horses. With models parametrized from field and laboratory data, we explore a set of probable contributory mechanisms that explain the spatial and temporal pattern of HeV emergence; including urban habituation and decreased migration—two widely observed changes in flying fox ecology that result from anthropogenic transformation of bat habitat in Australia. Urban habituation increases the number of flying foxes in contact with human and domestic animal populations, and our models suggest that, in addition, decreased bat migratory behaviour could lead to a decline in population immunity, giving rise to more intense outbreaks after local viral reintroduction. Ten of the 14 known HeV outbreaks occurred near urbanized or sedentary flying fox populations, supporting these predictions. We also demonstrate that by incorporating waning maternal immunity into our models, the peak modelled prevalence coincides with the peak annual spill-over hazard for HeV. These results provide the first detailed mechanistic framework for understanding the sporadic temporal pattern of HeV emergence, and of the urban/peri-urban distribution of HeV outbreaks in horses and people.

scholarly journals A New Hendra Virus Genotype Found in Australian Flying Foxes

2021 ◽  
Author(s):  
Jianning Wang ◽  
Danielle E Anderson ◽  
Kim Halpin ◽  
Xiao Hong ◽  
Honglei Chen ◽  
...  
Keyword(s):  
Genetic Relatedness ◽  
Phylogenetic Analyses ◽  
Inflammatory Lesion ◽  
Hendra Virus ◽  
Virus Genotype ◽  
Flying Foxes ◽  
Qrt Pcr ◽  
Genotype 2 ◽  
Pcr Assays ◽  
Flying Fox

Abstract Background Hendra virus (HeV) has caused lethal disease outbreaks in humans and horses in Australia. Pteropid bats (flying foxes) are the wildlife reservoir from which the virus was first isolated in 1996. Following a heat stress mortality event in Australian flying foxes in 2013, a novel HeV variant was discovered. This study describes the subsequent surveillance of Australian flying foxes for this novel virus over a nine year period using qRT-PCR testing of bat tissues submitted primarily for Australian bat lyssavirus (ABLV) diagnosis. Genome sequencing and characterisation of the novel HeV variant was also undertaken. Methods Spleen and kidney samples harvested from flying fox carcasses were initially screened with two real-time qRT-PCR assays specific for the prototype HeV. Two additional qRT-PCR assays were developed specific for the HeV variant first detected in samples from a flying fox in 2013. Next-generation sequencing and virus isolation was attempted from selected samples to further characterise the new virus. Results Since 2013, 98 flying foxes were tested and 11 were positive for the new HeV variant. No samples were positive for the original HeV. Ten of the positive samples were from grey-headed flying foxes (GHFF, Pteropus poliocephalus), however this species was over-represented in the opportunistic sampling (83% of bats tested were GHFF). The positive GHFF samples were collected from Victoria and South Australia and one positive Little red flying fox (LRFF, Pteropus scapulatus) was collected from Western Australia. Immunohistochemistry (IHC) confirmed the presence of henipavirus antigen, associated with an inflammatory lesion in cardiac blood vessels of one GHFF. Positive samples were sequenced and the complete genome was obtained from three samples. When compared to published HeV genomes, there was 84% sequence identity at the nucleotide level. Based on phylogenetic analyses, the newly detected HeV belongs to the HeV species but occupies a distinct lineage. We have therefore designated this virus HeV genotype 2 (HeV-G2). Attempts to isolate virus from PCR positive samples have not been successful. Conclusions A novel HeV genotype (HeV-G2) has been identified in two flying fox species submitted from three states in Australia, indicating that the level of genetic diversity for HeV is broader than first recognised. Given its high genetic relatedness to HeV, HeV-G2 should be considered a zoonotic pathogen.

scholarly journals A new Hendra virus genotype found in Australian flying foxes

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Jianning Wang ◽  
Danielle E. Anderson ◽  
Kim Halpin ◽  
Xiao Hong ◽  
Honglei Chen ◽  
...  
Keyword(s):  
Genetic Relatedness ◽  
Phylogenetic Analyses ◽  
Inflammatory Lesion ◽  
Hendra Virus ◽  
Virus Genotype ◽  
Flying Foxes ◽  
Qrt Pcr ◽  
Genotype 2 ◽  
Pcr Assays ◽  
Flying Fox

Abstract Background Hendra virus (HeV) has caused lethal disease outbreaks in humans and horses in Australia. Flying foxes are the wildlife reservoir from which the virus was first isolated in 1996. Following a heat stress mortality event in Australian flying foxes in 2013, a novel HeV variant was discovered. This study describes the subsequent surveillance of Australian flying foxes for this novel virus over a nine year period using qRT-PCR testing of tissues from flying foxes submitted primarily for Australian bat lyssavirus diagnosis. Genome sequencing and characterisation of the novel HeV variant was also undertaken. Methods Spleen and kidney samples harvested from flying fox carcasses were initially screened with two real-time qRT-PCR assays specific for the prototype HeV. Two additional qRT-PCR assays were developed specific for the HeV variant first detected in samples from a flying fox in 2013. Next-generation sequencing and virus isolation was attempted from selected samples to further characterise the new virus. Results Since 2013, 98 flying foxes were tested and 11 were positive for the new HeV variant. No samples were positive for the original HeV. Ten of the positive samples were from grey-headed flying foxes (GHFF, Pteropus poliocephalus), however this species was over-represented in the opportunistic sampling (83% of bats tested were GHFF). The positive GHFF samples were collected from Victoria and South Australia and one positive Little red flying fox (LRFF, Pteropus scapulatus) was collected from Western Australia. Immunohistochemistry confirmed the presence of henipavirus antigen, associated with an inflammatory lesion in cardiac blood vessels of one GHFF. Positive samples were sequenced and the complete genome was obtained from three samples. When compared to published HeV genomes, there was 84% sequence identity at the nucleotide level. Based on phylogenetic analyses, the newly detected HeV belongs to the HeV species but occupies a distinct lineage. We have therefore designated this virus HeV genotype 2 (HeV-g2). Attempts to isolate virus from PCR positive samples have not been successful. Conclusions A novel HeV genotype (HeV-g2) has been identified in two flying fox species submitted from three states in Australia, indicating that the level of genetic diversity for HeV is broader than first recognised. Given its high genetic relatedness to HeV, HeV-g2 is a zoonotic pathogen.

scholarly journals Challenges and Opportunities Developing Mathematical Models of Shared Pathogens of Domestic and Wild Animals

2018 ◽  
Vol 5 (4) ◽  
pp. 92 ◽  
Author(s):  
Kathryn Huyvaert ◽  
Robin Russell ◽  
Kelly Patyk ◽  
Meggan Craft ◽  
Paul Cross ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Domestic Animals ◽  
Domestic Animal ◽  
Pathogen Transmission ◽  
Management Actions ◽  
Animal Populations ◽  
Challenges And Opportunities ◽  
Conservation Concern ◽  
Transmission Pathways ◽  
And Control

Diseases that affect both wild and domestic animals can be particularly difficult to prevent, predict, mitigate, and control. Such multi-host diseases can have devastating economic impacts on domestic animal producers and can present significant challenges to wildlife populations, particularly for populations of conservation concern. Few mathematical models exist that capture the complexities of these multi-host pathogens, yet the development of such models would allow us to estimate and compare the potential effectiveness of management actions for mitigating or suppressing disease in wildlife and/or livestock host populations. We conducted a workshop in March 2014 to identify the challenges associated with developing models of pathogen transmission across the wildlife-livestock interface. The development of mathematical models of pathogen transmission at this interface is hampered by the difficulties associated with describing the host-pathogen systems, including: (1) the identity of wildlife hosts, their distributions, and movement patterns; (2) the pathogen transmission pathways between wildlife and domestic animals; (3) the effects of the disease and concomitant mitigation efforts on wild and domestic animal populations; and (4) barriers to communication between sectors. To promote the development of mathematical models of transmission at this interface, we recommend further integration of modern quantitative techniques and improvement of communication among wildlife biologists, mathematical modelers, veterinary medicine professionals, producers, and other stakeholders concerned with the consequences of pathogen transmission at this important, yet poorly understood, interface.

scholarly journals Determinants of prolonged hospitalization and mortality among leptospirosis patients attending tertiary care hospitals in northeastern state in Peninsular Malaysia: A cross sectional retrospective analysis

2021 ◽  
Author(s):  
Yassin K. Al Hariri ◽  
Syed A.S. Sulaiman ◽  
Amer Hayat Khan ◽  
Azreen S. Adnan ◽  
Sundos Q. Al-Ebrahem
Keyword(s):  
Kidney Diseases ◽  
Tertiary Care ◽  
Laboratory Data ◽  
Significant Proportion ◽  
Case Fatality ◽  
Peninsular Malaysia ◽  
Major Public Health Problem ◽  
Severe Thrombocytopenia ◽  
Factors Associated ◽  
Prolonged Hospitalization

Abstract Objectives Leptospirosis is the most common anthropozoonosis worldwide and imposes a major public health problem in many tropical countries. It is a leading cause of disease burden in form of mortality, morbidity and hospital admission. Identifying patients at high risk for mortality or for prolonged hospitalization may save lives and preserve economy. The aim of the current study was to identify significant factors associated with disease mortality and prolonged hospitalization.Design Cress-sectional retrospective studySettings Tertiary care teaching hospitals in Kelantan, Peninsular Malaysia Participants Adult patients proven to have leptospirosis depending on IgM ELISA were classified into two classes depending on prolonged hospitalization (>7 days or ≤ 7 days) and mortality (fatal cases or non-fatal cases). Patients’ clinico-laboratory data were compared according to these two outcomes using the appropriate statistical test accordingly.Results Of the 525 patients enrolled, 136 (25.9%) had prolonged hospitalization. The mean length of stay was 6.77 ± 5.68 days. Logistic regression analysis identified acute kidney injury (AKI) (OR 2.3), Jaundice (OR 2.7), elevated alanine aminotransferase (ALT) (OR 2), and prolonged prothrombin time (PT) (OR 1.9) independently associated with prolonged hospitalization. Case fatality rate was 6.48% and around one third of fatal cases had prolonged hospitalization of more than seven days. Factors associated with leptospirosis mortality included age > 40 years (p<0.001), patients presented with tachypnea (p=0.002), pulmonary infiltrate (p<0.001), T-wave changes (p<0.001), atrial fibrillation (p=0.013), conducting abnormality (p<0.001), chronic kidney diseases (p<0.001), multiple organ dysfunctions (p<0.0010), respiratory failure (p<0.001), pneumonia (p<0.001), sepsis (p=0.004), low venous PH (p=0.042), AKI (P<0.001), elevated AST (p<0.001) or ALT (p=0.004), hypoalbuminemia (p<0.001), rhabdomyolysis (p<0.001), severe thrombocytopenia (p=0.042), prolonged PT (p<0.001) or prolonged aPTT (p<0.017).Conclusions Significant proportion of leptospirosis patients (25.9%) had prolonged hospital stay and less proportion died (6.48%). Early identifying patients with factors associated with prolonged hospitalization and death will positively impact practitioners’ decisions regarding the proper and fast course of management including ICU admission

scholarly journals Evaluation of surveillance system for pneumonia in children below five years, Tema Metropolis, Ghana, 2012 – 2016

2020 ◽  
Vol 54 (2) ◽  
pp. 11-17
Author(s):  
Dora Dadzie ◽  
Adolphina Addo-Lartey ◽  
Nana Peprah ◽  
Ernest Kenu
Keyword(s):  
Surveillance System ◽  
Laboratory Data ◽  
Case Fatality ◽  
Information Management System ◽  
Case Definition ◽  
Health Staff ◽  
Suspected Case ◽  
Surveillance Systems ◽  
District Health ◽  
Under Five

Background: We evaluated the pneumonia surveillance system in Tema Metropolis to determine whether it is meeting its objectives and to assess its attributes.Design: Descriptive primary and secondary data analysisData Source: We interviewed health staff on the system’s operation and resources. We also extracted 2012-2016 surveillance dataset for under-five pneumonia cases and deaths from the District Health Information Management System for review.Participants: Health staffIntervention: The Centers for Disease Control (CDC) updated guidelines for evaluating surveillance systems was used to assess system attributes. Main outcome measure: state of the pneumonia surveillance system in TemaResults: A suspected case was defined as fast breathing in any child < 5 years old. The case definition was easy to apply, even at the community level. From 2012 to 2016, a total of 3,337 cases and 54 deaths (case fatality rate 1.6%) was recorded from 13 (23.6%) of 55 health facilities. Two epidemics were missed by the district because data were not being analysed. There were no laboratory data on antimicrobial resistance. Although reporting timeliness increased from 28.1% in 2012 to 83% in 2016, data inconsistencies existed between reporting levels.Conclusion: The surveillance system for under-five pneumonia in Tema Metropolis is simple, stable, flexible, timely,but of low sensitivity and acceptability, and only partly meeting its objectives. Major shortcomings are lack of laboratory data, non-use of data and low representativeness.Keywords: Under-five Pneumonia, Surveillance System Evaluation, Tema, GhanaFunding: The study was supported by a grant to author DB by the President’s Malaria Initiative (PMI) -CDC CoAg 6NU2GGH001876

scholarly journals A comparison of nutritional value of native and alien food plants for a critically endangered island flying-fox

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250857
Author(s):  
Laura A. Pulscher ◽  
Ellen S. Dierenfeld ◽  
Justin A. Welbergen ◽  
Karrie A. Rose ◽  
David N. Phalen
Keyword(s):  
Plant Species ◽  
Soluble Sugars ◽  
Critically Endangered ◽  
Food Plants ◽  
Nutritional Requirements ◽  
Nutritional Content ◽  
Alien Plant ◽  
Flying Foxes ◽  
Christmas Island ◽  
Flying Fox

Habitat loss and alteration are two of the biggest threats facing insular flying-foxes. Altered habitats are often re-vegetated with introduced or domestic plant species on which flying-foxes may forage. However, these alien food plants may not meet the nutritional requirements of flying-foxes. The critically endangered Christmas Island flying-fox (CIFF; Pteropus natalis) is subject to habitat alteration and the introduction of alien food plants, and therefore is a good model species to evaluate the potential impact of alien plant species on insular flying-foxes. In this study, we evaluated nutritional content of native food plants to determine how flying-foxes historically met their nutritional requirements. Furthermore, we compared the nutritional content of native and alien fruits to predict possible impacts of alien plants on insular flying-foxes. Native and alien fruits and flowers, and native foliage (leaves, petals, and petioles) commonly consumed by the CIFF were collected and evaluated for soluble sugars, crude protein, non-fiber carbohydrates, and nine minerals. Evaluation of native food plants suggests that flying-foxes meet energy requirements by consuming fruit and nectar. However, fruit and nectar are low in protein and essential minerals required for demanding life periods; therefore, flying-foxes likely supplement their diets with pollen and foliage. Thus, flying-foxes require a diverse array of plants to meet their nutritional requirements. Compared to native fruits, alien fruits contained significantly higher non-fiber carbohydrates, and this may provide an important energy source, particularly from species that bear fruit year-round. Median mineral concentrations in alien fruit species, however, were deficient compared to native fruits, suggesting major (or even seasonal) shifts in the proportion of alien species in the CIFF diet could lead to nutritional imbalances. This study confirms the need to quantify nutritional parameters in addition to feeding ecology when evaluating habitat quality to inform conservation actions that can be applied both locally and globally.

scholarly journals Lyssaviruses and rabies: current conundrums, concerns, contradictions and controversies

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 184 ◽  
Author(s):  
Charles Rupprecht ◽  
Ivan Kuzmin ◽  
Francois Meslin
Keyword(s):  
Rabies Virus ◽  
Case Fatality ◽  
Cost Effective ◽  
Relative Distribution ◽  
Canine Rabies ◽  
Effective Strategies ◽  
Program Support ◽  
Animal Populations ◽  
Populations At Risk ◽  
Causative Agents

Lyssaviruses are bullet-shaped, single-stranded, negative-sense RNA viruses and the causative agents of the ancient zoonosis rabies. Africa is the likely home to the ancestors of taxa residing within the GenusLyssavirus, FamilyRhabdoviridae. Diverse lyssaviruses are envisioned as co-evolving with bats, as the ultimate reservoirs, over seemingly millions of years. In terms of relative distribution, overt abundance, and resulting progeny, rabies virus is the most successful lyssavirus species today, but for unknown reasons. All mammals are believed to be susceptible to rabies virus infection. Besides reservoirs among the Chiroptera, meso-carnivores also serve as major historical hosts and are represented among the canids, raccoons, skunks, mongooses, and ferret badgers.  Perpetuating as a disease of nature with the mammalian central nervous system as niche, host breadth alone precludes any candidacy for true eradication. Despite having the highest case fatality of any infectious disease and a burden in excess of or comparative to other major zoonoses, rabies remains neglected. Once illness appears, no treatment is proven to prevent death. Paradoxically, vaccines were developed more than a century ago, but the clear majority of human cases are unvaccinated. Tens of millions of people are exposed to suspect rabid animals and tens of thousands succumb annually, primarily children in developing countries, where canine rabies is enzootic. Rather than culling animal populations, one of the most cost-effective strategies to curbing human fatalities is the mass vaccination of dogs. Building on considerable progress to date, several complementary actions are needed in the near future, including a more harmonized approach to viral taxonomy, enhanced de-centralized laboratory-based surveillance, focal pathogen discovery and characterization, applied pathobiological research for therapeutics, improved estimates of canine populations at risk, actual production of required vaccines and related biologics, strategies to maximize prevention but minimize unnecessary human prophylaxis, and a long-term, realistic plan for sustained global program support to achieve success in disease control, prevention, and elimination.

scholarly journals Impact of first-wave COronaVIrus disease 2019 infection in patients on haemoDIALysis in Alsace: the observational COVIDIAL study

2020 ◽  
Vol 35 (8) ◽  
pp. 1338-1411 ◽  
Author(s):  
Nicolas Keller ◽  
François Chantrel ◽  
Thierry Krummel ◽  
Dorothée Bazin-Kara ◽  
Anne Laure Faller ◽  
...  
Keyword(s):  
Laboratory Data ◽  
Case Fatality ◽  
Patient Characteristics ◽  
Complete Recovery ◽  
High Rate ◽  
Atypical Symptoms ◽  
Reactive Protein ◽  
Risk Of Death ◽  
Included Patient

Abstract Background There are only scarce data regarding the presentation, incidence, severity and outcomes of coronavirus disease 2019 (COVID-19) in patients undergoing long-term haemodialysis (HD). A prospective observational study was conducted in eight HD facilities in Alsace, France, to identify clinical characteristics of HD patients with COVID-19 and to assess the determinants of the risk of death. Methods All HD patients tested positive for COVID-19 from 5 March to 28 April 2020 were included. Collected data included patient characteristics, clinical features at diagnosis, laboratory data, treatments and outcomes. Results Among 1346 HD patients, 123 tested positive for COVID-19. Patients had a median age of 77 years (interquartile range 66–83), with a high number of comorbidities (3.2 ± 1.6 per patient). Symptoms were compatible in 63% of patients. Asthenia (77%), diarrhoea (34%) and anorexia (32%) were frequent at diagnosis. The delay between the onset of symptoms and diagnosis, death or complete recovery was 2 (0–5), 7 (4–11) and 32 (26.5–35) days, respectively. Treatment, including lopinavir/ritonavir, hydroxychloroquine and corticosteroids, was administered in 23% of patients. The median C-reactive protein (CRP) and lymphocyte count at diagnosis was 55 mg/L (IQR 25–106) and 690 Ly/µL (IQR 450–960), respectively. The case fatality rate was 24% and determinants associated with the risk of death were body temperature {hazard ratio [HR] 1.96 [95% confidence interval (CI) 1.11–3.44]; P = 0.02} and CRP at diagnosis [HR 1.01 (95% CI 1.005–1.017); P &lt; 0.0001]. Conclusions HD patients were found to be at high risk of developing COVID-19 and exhibited a high rate of mortality. While patients presented severe forms of the disease, they often displayed atypical symptoms, with the CRP level being highly associated with the risk of death.

scholarly journals Physiological stress and Hendra virus in flying-foxes (Pteropus spp.), Australia

PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0182171 ◽  
Author(s):  
Lee McMichael ◽  
Daniel Edson ◽  
Craig Smith ◽  
David Mayer ◽  
Ina Smith ◽  
...  
Keyword(s):  
Physiological Stress ◽  
Hendra Virus ◽  
Flying Foxes
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