scholarly journals Modelling the influence of naturally acquired immunity from subclinical infection on outbreak dynamics and persistence of rabies in domestic dogs

2021 ◽  
Vol 15 (7) ◽  
pp. e0009581
Author(s):  
Susannah Gold ◽  
Christl A. Donnelly ◽  
Rosie Woodroffe ◽  
Pierre Nouvellet
Keyword(s):  
Control Strategies ◽  
Empirical Studies ◽  
Population Level ◽  
Domestic Dogs ◽  
Domestic Dog ◽  
Acquired Immunity ◽  
High Exposure ◽  
Common Assumption ◽  
Canine Rabies ◽  
Low Levels

A number of mathematical models have been developed for canine rabies to explore dynamics and inform control strategies. A common assumption of these models is that naturally acquired immunity plays no role in rabies dynamics. However, empirical studies have detected rabies-specific antibodies in healthy, unvaccinated domestic dogs, potentially due to immunizing, non-lethal exposure. We developed a stochastic model for canine rabies, parameterised for Laikipia County, Kenya, to explore the implications of different scenarios for naturally acquired immunity to rabies in domestic dogs. Simulating these scenarios using a non-spatial model indicated that low levels of immunity can act to limit rabies incidence and prevent depletion of the domestic dog population, increasing the probability of disease persistence. However, incorporating spatial structure and human response to high rabies incidence allowed the virus to persist in the absence of immunity. While low levels of immunity therefore had limited influence under a more realistic approximation of rabies dynamics, high rates of exposure leading to immunizing non-lethal exposure were required to produce population-level seroprevalences comparable with those reported in empirical studies. False positives and/or spatial variation may contribute to high empirical seroprevalences. However, if high seroprevalences are related to high exposure rates, these findings support the need for high vaccination coverage to effectively control this disease.

scholarly journals Investigation of the temporal roaming behaviour of free-roaming domestic dogs in Indigenous communities in northern Australia to inform rabies incursion preparedness

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Elizabeth K. Maher ◽  
Michael P. Ward ◽  
Victoria J. Brookes
Keyword(s):  
Risk Factors ◽  
Control Strategies ◽  
Indigenous Communities ◽  
Domestic Dog ◽  
Northern Australia ◽  
Remote Communities ◽  
Canine Rabies ◽  
Torres Strait ◽  
Associated Risk Factors ◽  
The Impact

Abstract Australia is canine rabies free but free-roaming, domestic dog populations in remote northern communities are at risk of an incursion due to proximity to rabies-endemic south-east Asia. Unrestricted contact between dogs could facilitate rabies spread following an incursion, and increase the impact on both dogs and people. Whilst dog vaccination is the foundation of rabies prevention, control strategies could be enhanced by understanding the temporal pattern of roaming and associated risk factors, so that movement restrictions can be targeted. Global positioning system datasets from 132 dogs in eight Indigenous communities in the Torres Strait and Northern Peninsula Area (NPA) of Australia were analysed using regression methods. The influence of risk factors (including age, sex, location, season and hour of day) on dogs’ distance from their residences were assessed. Dogs roamed furthest in the NPA and during the dry season. Daily peaks in mean roaming distance were observed at 1000–1100 hrs and 1700–1800 hrs in the Torres Strait, and 1700–1800 hrs in the NPA. These findings demonstrate that understanding community-specific temporal roaming patterns can inform targeted movement restrictions during an outbreak of rabies in remote communities in northern Australia.

scholarly journals Synchronous cycles of domestic dog rabies in sub-Saharan Africa and the impact of control efforts

2007 ◽  
Vol 104 (18) ◽  
pp. 7717-7722 ◽  
Author(s):  
Katie Hampson ◽  
Jonathan Dushoff ◽  
John Bingham ◽  
Gideon Brückner ◽  
Y. H. Ali ◽  
...  
Keyword(s):  
Large Scale ◽  
Domestic Dogs ◽  
Sub Saharan Africa ◽  
Domestic Dog ◽  
Eastern Africa ◽  
Prevention Measures ◽  
Persistent Problem ◽  
Canine Rabies ◽  
Continental Scale ◽  
The Impact

Rabies is a fatal neurological pathogen that is a persistent problem throughout the developing world where it is spread primarily by domestic dogs. Although the disease has been extensively studied in wildlife populations in Europe and North America, the dynamics of rabies in domestic dog populations has been almost entirely neglected. Here, we demonstrate that rabies epidemics in southern and eastern Africa cycle with a period of 3–6 years and show significant synchrony across the region. The observed period is shorter than predictions based on epidemiological parameters for rabies in domestic dogs. We find evidence that rabies prevention measures, including vaccination, are affected by disease prevalence and show that a simple model with intervention responses can capture observed disease periodicity and host dynamics. We suggest that movement of infectious or latent animals combined with coordinated control responses may be important in coupling populations and generating synchrony at the continental scale. These findings have important implications for rabies prediction and control: large-scale synchrony and the importance of intervention responses suggest that control of canine rabies in Africa will require sustained efforts coordinated across political boundaries.

scholarly journals Dynamics of a morbillivirus at the domestic–wildlife interface: Canine distemper virus in domestic dogs and lions

2015 ◽  
Vol 112 (5) ◽  
pp. 1464-1469 ◽  
Author(s):  
Mafalda Viana ◽  
Sarah Cleaveland ◽  
Jason Matthiopoulos ◽  
Jo Halliday ◽  
Craig Packer ◽  
...  
Keyword(s):  
Canine Distemper Virus ◽  
Large Scale ◽  
Control Strategies ◽  
State Space Model ◽  
Domestic Dogs ◽  
Domestic Dog ◽  
Canine Distemper ◽  
Natural Ecosystems ◽  
Serengeti Ecosystem

Morbilliviruses cause many diseases of medical and veterinary importance, and although some (e.g., measles and rinderpest) have been controlled successfully, others, such as canine distemper virus (CDV), are a growing concern. A propensity for host-switching has resulted in CDV emergence in new species, including endangered wildlife, posing challenges for controlling disease in multispecies communities. CDV is typically associated with domestic dogs, but little is known about its maintenance and transmission in species-rich areas or about the potential role of domestic dog vaccination as a means of reducing disease threats to wildlife. We address these questions by analyzing a long-term serological dataset of CDV in lions and domestic dogs from Tanzania’s Serengeti ecosystem. Using a Bayesian state–space model, we show that dynamics of CDV have changed considerably over the past three decades. Initially, peaks of CDV infection in dogs preceded those in lions, suggesting that spill-over from dogs was the main driver of infection in wildlife. However, despite dog-to-lion transmission dominating cross-species transmission models, infection peaks in lions became more frequent and asynchronous from those in dogs, suggesting that other wildlife species may play a role in a potentially complex maintenance community. Widespread mass vaccination of domestic dogs reduced the probability of infection in dogs and the size of outbreaks but did not prevent transmission to or peaks of infection in lions. This study demonstrates the complexity of CDV dynamics in natural ecosystems and the value of long-term, large-scale datasets for investigating transmission patterns and evaluating disease control strategies.

Studying Populations of Online Communities

2019 ◽  
pp. 173-193
Author(s):  
Benjamin Mako Hill ◽  
Aaron Shaw
Keyword(s):  
Online Communities ◽  
Information Diffusion ◽  
Diffusion Processes ◽  
Empirical Studies ◽  
Population Level ◽  
Study Groups ◽  
Population Based ◽  
Large Majority ◽  
Community Processes ◽  
Published Research

While the large majority of published research on online communities consists of analyses conducted entirely within individual communities, this chapter argues for a population-based approach, in which researchers study groups of similar communities. For example, although there have been thousands of papers published about Wikipedia, a population-based approach might compare all wikis on a particular topic. Using examples from published empirical studies, the chapter describes five key benefits of this approach. First, it argues that population-level research increases the generalizability of findings. Next, it describes four processes and dynamics that are only possible to study using populations: community-level variables, information diffusion processes across communities, ecological dynamics, and multilevel community processes. The chapter concludes with a discussion of a series of limitations and challenges.

Does context matter? Examining robbery reporting in a high crime country

2021 ◽  
pp. 174889582110313
Author(s):  
Wilson Hernández ◽  
Katrina R Heimark
Keyword(s):  
Latin America ◽  
Multilevel Modeling ◽  
Empirical Studies ◽  
Crime Rates ◽  
Violent Victimization ◽  
The World ◽  
Victimization Rate ◽  
Global North ◽  
Low Levels ◽  
High Crime

Most empirical studies that examine why individuals report property crimes to the police have focused on Global North countries where crime rates are low. This study is situated in the most violent area of the world, Latin America, and examines Peru, which has the highest robbery victimization rate in the Americas. This article examines the applicability of theories of crime reporting in this Global South context using a large sample and multilevel modeling. We find that trust in the police has no impact on the reporting of the robbery of one’s cellphone, purse or wallet. The theories of rational choice and Black’s stratification of law provide strong explanations for the reporting of robbery of these personal items. Individuals of higher social status and those who reside in districts with low levels of social disadvantage are more likely to report, as well as those who have experienced violent victimization.

Successful cloning of coyotes through interspecies somatic cell nuclear transfer using domestic dog oocytes

2013 ◽  
Vol 25 (8) ◽  
pp. 1142 ◽  
Author(s):  
Insung Hwang ◽  
Yeon Woo Jeong ◽  
Joung Joo Kim ◽  
Hyo Jeong Lee ◽  
Mina Kang ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Canis Lupus ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Fusion Rate ◽  
Domestic Dogs ◽  
Domestic Dog ◽  
Canis Lupus Familiaris ◽  
Cloning Efficiency ◽  
Donor Cells

Interspecies somatic cell nuclear transfer (iSCNT) is an emerging assisted reproductive technology (ART) for preserving Nature’s diversity. The scarcity of oocytes from some species makes utilisation of readily available oocytes inevitable. In the present study, we describe the successful cloning of coyotes (Canis latrans) through iSCNT using oocytes from domestic dogs (Canis lupus familiaris or dingo). Transfer of 320 interspecies-reconstructed embryos into 22 domestic dog recipients resulted in six pregnancies, from which eight viable offspring were delivered. Fusion rate and cloning efficiency during iSCNT cloning of coyotes were not significantly different from those observed during intraspecies cloning of domestic dogs. Using neonatal fibroblasts as donor cells significantly improved the cloning efficiency compared with cloning using adult fibroblast donor cells (P < 0.05). The use of domestic dog oocytes in the cloning of coyotes in the present study holds promise for cloning other endangered species in the Canidae family using similar techniques. However, there are still limitations of the iSCNT technology, as demonstrated by births of morphologically abnormal coyotes and the clones’ inheritance of maternal domestic dog mitochondrial DNA.

Comparison of immunohistochemical profiles of ovarian germ cells in dysgerminomas of a captive maned wolf and domestic dogs

2021 ◽  
pp. 104063872110199
Author(s):  
Rafael B. Rosa ◽  
Matheus V. Bianchi ◽  
Paula R. Ribeiro ◽  
Fernando F. Argenta ◽  
Andréia Vielmo ◽  
...  
Keyword(s):  
Germ Cells ◽  
Poor Prognosis ◽  
Expression Profiles ◽  
Clinical Signs ◽  
Domestic Dogs ◽  
Domestic Dog ◽  
Placental Alkaline Phosphatase ◽  
Immunohistochemical Expression ◽  
Cytoplasmic Expression ◽  
Maned Wolf

We characterized the immunohistochemical expression profiles of dysgerminomas from a 16-y-old maned wolf and 13 domestic dogs using the following biomarkers: Sal-like protein 4 (SALL4), octamer-binding transcription factor 3/4 (OCT3/4), placental alkaline phosphatase (PLAP), c-kit, and vimentin. The maned wolf had nonspecific and long-standing clinical signs of lethargy, anorexia, and weight loss, and was euthanized because of poor prognosis. At autopsy, the left ovary was effaced by a 12 × 8 × 6 cm mass, comprised of anaplastic cells with a mitotic count of 20 mitoses in 10 high power fields. Dysgerminomas from 7 of 13 domestic dogs had nuclear expression of SALL4. Dysgerminomas from the maned wolf and 2 domestic dogs had both nuclear and cytoplasmic expression of SALL4. Cytoplasmic expression of PLAP and OCT3/4 was present in dysgerminomas from the maned wolf and 3 (PLAP) or 4 (OCT3/4) domestic dogs. All dysgerminomas expressed vimentin. Membranous c-kit expression was rare in the dysgerminoma from the maned wolf, and variable in dysgerminomas from 4 domestic dogs. A dysgerminoma from a domestic dog had cytoplasmic expression of c-kit. SALL4 is a useful marker to confirm germ cell origin of dysgerminoma in canids.

Introduction to pertussis transmission and epidemiological dynamics

Pertussis ◽  
2018 ◽  
pp. 6-25
Author(s):  
Pejman Rohani ◽  
Samuel V. Scarpino
Keyword(s):  
Control Strategies ◽  
Age Distribution ◽  
Population Level ◽  
Vaccine Uptake ◽  
Effective Control ◽  
Transmission Potential ◽  
Epidemic Period ◽  
The Impact ◽  
Pertussis Epidemiology

Resolving the long-term, population-level consequences of changes in pertussis epidemiology, arising from bacterial evolution, shifts in vaccine-induced immunity, or changes in surveillance, are key challenges for devising effective control strategies. This chapter reviews some of the key features of pertussis epidemiology, together with the underlying epidemiological principles that set the context for their interpretation. These include the relationship between the age distribution of cases and pertussis transmission potential, the impact of vaccine uptake on incidence, periodicity and age incidence, as well as spatially explicit recurrent pertussis epidemics and associated extinction frequency. This review highlights some of the predictable and consistent aspects of pertussis epidemiology (e.g. the systematic increase in the inter-epidemic period with the introduction of whole-cell vaccines) and a number of important heterogeneities, including variations in contemporary patterns of incidence and geographic spread.

The biology of ageing

2012 ◽  
pp. 1507-1512
Author(s):  
Alan H. Bittles
Keyword(s):  
Allostatic Load ◽  
Empirical Studies ◽  
Functional Decline ◽  
Twin Studies ◽  
Population Level ◽  
Major Influence ◽  
Control Group ◽  
Major Life ◽  
Age Related ◽  
Physiological Dysregulation

Although old age is readily recognizable, methods to define and measure the underlying biological processes are much less amenable to study. For this reason, life expectancy has been widely used as a surrogate measure of ageing, as well as to monitor economic progress at national and regional levels. It is generally acknowledged that lifespan is a constitutional feature of the human phenotype, and twin studies have indicated that 25–33 per cent of the variance in human longevity is genetic in origin. External factors including lifestyle can also exert a major influence, as illustrated by the current mean life expectancies of 79 and 86 years for males and females in Japan, whereas the comparable figures for Botswana are 35 and 33 years, respectively. The importance of genetic inheritance as a determinant of extended survival has been illustrated by population level studies in Okinawa, an island prefecture of southern Japan with a very high prevalence of long-lived individuals. On the island, the mortality rates of the male and female siblings of centenarians were approximately half those of birth cohort-matched, non-centenarian siblings. These findings parallel an earlier study of the family of Jeanne Calment, who died in France in 1997 aged 122 years. Of her 55 relatives, 24 per cent had lived to >80 years compared to just 2 per cent of a matched control group. However, it remains unclear whether the enhanced lifespan of individuals who exhibit above average longevity is due to a slowing of the overall ageing process or is primarily associated with resistance to major life-threatening pathologies. The concept of an ‘allostatic load’, potentially involving the neuroendocrine, sympathetic nervous, immune and cardiovascular systems, and metabolic pathways, has been advanced to describe the lifetime costs of adapting to physical and psychological stresses. According to this hypothesis, while the actions of biological mediators of stress can be initially beneficial to health, chronic stimulation results in regulatory imbalance and subsequent pathophysiological changes. Empirical studies have indicated increased physiological dysregulation and functional decline at >70 years of age, which would imply that predicted global increases in the numbers of older persons will be accompanied by disproportionately larger groups of individuals with major age-related pathologies.

scholarly journals Ochratoxin A affects oocyte maturation and subsequent embryo developmental dynamics in the juvenile sheep model

2020 ◽  
Author(s):  
Maria Elena Dell’Aquila ◽  
Shafaq Asif ◽  
Letizia Temerario ◽  
Antonella Mastrorocco ◽  
Giuseppina Marzano ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Embryo Development ◽  
Oocyte Maturation ◽  
Oxidative Status ◽  
Fine Tuning ◽  
Mitochondrial Activity ◽  
Sheep Model ◽  
High Exposure ◽  
Low Levels

Abstract The genotoxic and nephrotoxic mycotoxin Ochratoxin A (OTA) has also been reported to have adverse effects on oocyte maturation and embryo development. Previous studies on the effects of OTA on female fertility have used micromolar concentrations, but no information is available to date on effects in a more relevant nanomolar range. This study used a juvenile sheep model to evaluate the effects of oocyte exposure to low levels of OTA on maturation, fertilization, and embryo development. Further, it was investigated whether different mechanisms of action of OTA could be responsible for varying toxic effects at different levels of exposure. Cumulus-oocyte-complexes (COCs) were exposed to 10 μmol/L–0.1 nmol/L OTA during in vitro maturation and evaluated for cumulus viability, oocyte maturation, and bioenergetic/oxidative status. COCs were subjected to in vitro fertilization, embryo culture, and embryo quality assessment via morphology, viability, bioenergetic/oxidative status, and time-lapse monitoring. At micromolar concentrations, OTA induced cytotoxic effects, by reducing cumulus expansion and oocyte maturation. OTA altered temporospatial dynamics of zygote pronuclear formation and embryo morphokinetics. Blastocysts, even morphologically normal, were found to undergo collapse events, which were probably related to boosted blastocyst mitochondrial activity. At nanomolar concentrations, OTA did not affect COC morpho-functional parameters, but impaired oocyte ability to prevent polyspermy and increased blastocyst apoptosis. In conclusion, in the female germ cell, cytotoxic nonspecific effects characterize OTA-induced toxicity at high exposure levels, whereas fine tuning-mode effects, not associated with altered cell viability and integrity, characterize OTA toxic action at low levels.

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