scholarly journals Trait-Based Vaccination of Individual Meerkats (Suricata suricatta) against Tuberculosis Provides Evidence to Support Targeted Disease Control

Animals ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 192
Author(s):  
Stuart J. Patterson ◽  
Tim H. Clutton-Brock ◽  
Dirk U. Pfeiffer ◽  
Julian A. Drewe
Keyword(s):  
Disease Control ◽  
Control Strategies ◽  
Vaccination Strategy ◽  
Human Populations ◽  
Infection Rates ◽  
Survival Times ◽  
Control Groups ◽  
Free Living ◽  
Suricata Suricatta ◽  
The One

Individuals vary in their potential to acquire and transmit infections, but this fact is currently underexploited in disease control strategies. We trialled a trait-based vaccination strategy to reduce tuberculosis in free-living meerkats by targeting high-contact meerkats (socially dominant individuals) in one study arm, and high-susceptibility individuals (young subordinates) in a second arm. We monitored infection within vaccinated groups over two years comparing the results with untreated control groups. Being a member of a high-contact group had a protective effect on individuals’ survival times (Hazard Ratio = 0.5, 95% Confidence Interval, CI: 0.29–0.88, p = 0.02) compared to control groups. Over the study, odds of testing positive for tuberculosis increased more than five-fold in control groups (Odds Ratio = 5.40, 95% CI = 0.94–30.98, p = 0.058); however, no increases were observed in either of the treatment arms. Targeted disease control approaches, such as the one described in this study, allow for reduced numbers of interventions. Here, trait-based vaccination was associated with reduced infection rates and thus has the potential to offer more efficient alternatives to traditional mass-vaccination policies. Such improvements in efficiency warrant further study and could make infectious disease control more practically achievable in both animal (particularly wildlife) and human populations.

Modelling the effectiveness of vaccination in controlling bovine tuberculosis in wild boar

2013 ◽  
Vol 40 (5) ◽  
pp. 367 ◽  
Author(s):  
Lucy G. Anderson ◽  
Christian Gortázar ◽  
Joaquin Vicente ◽  
Michael R. Hutchings ◽  
Piran C. L. White
Keyword(s):  
Disease Control ◽  
Wild Boar ◽  
Bovine Tuberculosis ◽  
Vaccination Strategy ◽  
Control Measures ◽  
Effective Strategy ◽  
Short Term ◽  
Free Living ◽  
Western Spain

Context Bovine tuberculosis is a persistent disease of livestock in many parts of the world, especially where wildlife hosts co-exist with livestock. In south-western Spain, despite the widespread implementation of test-and-cull strategies for cattle, the herd prevalence in areas with high wild boar densities remains stable. The control of M. bovis infection in wild boar is likely to be essential for effective disease control in livestock. Methods We developed an individual-based model to evaluate whether vaccinating wild boar piglets with oral bait would be an effective strategy to reduce the prevalence of M. bovis infection in wild boar populations. Specifically, we quantified the proportion of piglets requiring vaccination and the number of years the vaccination programme would need to continue to eradicate bTB from wild boar within 25 years, comparing ‘managed’ populations on hunting estates where supplementary food is provided, with ‘unmanaged’, free-living populations. Successful vaccination was defined as the proportion of piglets that were delivered the vaccine and were effectively protected from infection. Key results Longer-term (25-year) vaccination strategies were more successful than short-term (5-year) strategies at either eradicating M. bovis or reducing it to below 90% of its original prevalence. M. bovis infection could be eradicated under a 25-year vaccination strategy if 80% of piglets were vaccinated in a managed population or 70% of piglets were vaccinated in an unmanaged population. In contrast, 5-year strategies in which 80% of piglets were vaccinated reduced the prevalence of M. bovis only by 27% or 8% in the managed and unmanaged populations, respectively. Conclusions The results of our simulation model, coupled with the promising results of initial vaccine and oral bait-uptake trials in wild boar indicated that vaccination could be an effective strategy to reduce the prevalence of M. bovis infection in wild boar if used in conjunction with other disease-control measures. Implications The vaccination of piglets over a long-term period has the potential to make an important contribution to the eradication of M. bovis infection from wild boar reservoirs in southern Spain.

scholarly journals Impact of Vaccine Failure on the Transmission Dynamics of Measles in Nigeria

2021 ◽  
Author(s):  
Ann Nwankwo ◽  
Enahoro. Iboi ◽  
Daniel Okuonghae
Keyword(s):  
Disease Control ◽  
Control Strategies ◽  
Vaccination Strategy ◽  
Fold Increase ◽  
Transmission Dynamics ◽  
Disease Dynamics ◽  
Vaccine Preventable Disease ◽  
Vaccine Failure ◽  
Vaccination Rates ◽  
Public Health Challenge

AbstractMeasles is a vaccine preventable disease. However, it is still a major public health challenge in Nigeria.We therefore formulate a mathematical model for the transmission of measles with a two dose vaccination strategy and weaning of vaccine derived immunity. Using weekly measles cases for Nigeria in 2020 from the Nigeria Center for Disease Control (NCDC), the model was validated. This modelling study via numerical simulations showed that there is a possibility of disease control with a ten fold increase in the vaccination rates. Also, it was shown that primary vaccine failure has more impact on disease dynamics than secondary vaccine failure. Thus control strategies should not just focus on increase the vaccination rates but also look at measures that will help in reducing primary vaccine failure.

scholarly journals A prognostic dynamic model applicable to infectious diseases providing easily visualized guides: a case study of COVID-19 in the UK

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuxuan Zhang ◽  
Chen Gong ◽  
Dawei Li ◽  
Zhi-Wei Wang ◽  
Shengda D. Pu ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Disease Control ◽  
Control Strategies ◽  
Herd Immunity ◽  
Iterative Algorithms ◽  
Vaccination Strategy ◽  
Control Measures ◽  
Transmission Model ◽  
Government Interventions ◽  
The Uk

AbstractA reasonable prediction of infectious diseases’ transmission process under different disease control strategies is an important reference point for policy makers. Here we established a dynamic transmission model via Python and realized comprehensive regulation of disease control measures. We classified government interventions into three categories and introduced three parameters as descriptions for the key points in disease control, these being intraregional growth rate, interregional communication rate, and detection rate of infectors. Our simulation predicts the infection by COVID-19 in the UK would be out of control in 73 days without any interventions; at the same time, herd immunity acquisition will begin from the epicentre. After we introduced government interventions, a single intervention is effective in disease control but at huge expense, while combined interventions would be more efficient, among which, enhancing detection number is crucial in the control strategy for COVID-19. In addition, we calculated requirements for the most effective vaccination strategy based on infection numbers in a real situation. Our model was programmed with iterative algorithms, and visualized via cellular automata; it can be applied to similar epidemics in other regions if the basic parameters are inputted, and is able to synthetically mimic the effect of multiple factors in infectious disease control.

scholarly journals First Report of Echinococcus ortleppi in Free-Living Wild Boar (Sus scrofa) from Portugal

2021 ◽  
Vol 9 (6) ◽  
pp. 1256
Author(s):  
Teresa Letra Mateus ◽  
Maria João Gargaté ◽  
Anabela Vilares ◽  
Idalina Ferreira ◽  
Manuela Rodrigues ◽  
...  
Keyword(s):  
Wild Boar ◽  
Internal Transcribed Spacer ◽  
Sus Scrofa ◽  
One Health ◽  
Control Strategies ◽  
Free Living ◽  
First Report ◽  
Wildlife Reservoirs ◽  
First Time ◽  
Echinococcus Granulosus Sensu Lato

Cystic echinococcosis (CE) is a zoonosis that is prevalent worldwide. It is considered endemic in Portugal but few studies have been performed on Echinococcus granulosus sensu lato and their hosts. In this study, CE cysts are reported for the first time in a free-living wild boar (Sus scrofa) in Portugal. The presence of the metacestodes in the liver of the wild boar was identified by morphological features, microscopic examination and molecular analysis. The sequencing of part of the DNA nuclear ribosomal internal transcribed spacer-1 (ITS-1) region revealed a G5 genotype that presently corresponds to Echinococcus ortleppi. This is the first report of E. ortleppi in Portugal and to the best of the authors’ knowledge, in Europe. These results suggest that wild boar may be a host of CE, namely, crossing the livestock–wildlife interface, which has important public health implications. Wildlife reservoirs must be taken into account as CE hosts and surveillance of game as well as health education for hunters should be implemented using a One Health approach, with implementation of feasible and tailor-made control strategies, namely, proper elimination of byproducts in the field.

An Audit of Behcet’s Syndrome Research: A 10-year Survey

2010 ◽  
Vol 38 (1) ◽  
pp. 99-103 ◽  
Author(s):  
FEHIM ESEN ◽  
ELIZABETH K. SCHIMMEL ◽  
HASAN YAZICI ◽  
YUSUF YAZICI
Keyword(s):  
Disease Control ◽  
Demographic Data ◽  
Considerable Proportion ◽  
Behçet’S Syndrome ◽  
Control Groups ◽  
Power Calculations ◽  
Behçet's Syndrome ◽  
Behcet’S Syndrome ◽  
Prospective Longitudinal ◽  
Behcet's Syndrome

Objective.Data suggest that the use of disease control groups and proper use of power calculations were neglected in published reports. We surveyed these and other methodological shortcomings in reports published within the last decade about one specific topic, Behcet’s syndrome. We reason that recognizing such methodological shortcomings will lead to better quality clinical and basic science articles.Methods.Articles published in the 15 highest impact factor journals on rheumatology, ophthalmology, dermatology, and general medicine between January 1999 and January 2009 were searched for original reports on Behcet’s syndrome. Study designs (study types and time element), control groups, demographic data, use of power calculations, and reporting of negative results were specifically tabulated.Results.Most studies on Behcet’s syndrome were cross-sectional (83%). Prospective longitudinal studies were few (7%). In a considerable proportion of papers (21%), some basic demographic data were missing. Power calculations were rare (3%) even in randomized controlled trials and were not considered at all in clinical hypothesis-testing. Disease control groups were present in slightly over half of clinical and laboratory original research, while just 13% of genetic association studies included disease controls. Only 12% of all reports concerned mainly negative outcomes.Conclusion.A considerable number of the published research articles have methodological weaknesses. The generalizability of what we observed in Behcet’s syndrome to other research topics needs to be formally studied.

scholarly journals A MEAN FIELD GAME ANALYSIS OF SIR DYNAMICS WITH VACCINATION

2020 ◽  
pp. 1-18
Author(s):  
Josu Doncel ◽  
Nicolas Gast ◽  
Bruno Gaujal
Keyword(s):  
Mean Field ◽  
Vaccination Strategy ◽  
Game Analysis ◽  
Total Cost ◽  
Mean Field Game ◽  
Vaccination Behavior ◽  
Switching Curve ◽  
The One ◽  
The Cost ◽  
Vaccination Period

We analyze a mean field game model of SIR dynamics (Susceptible, Infected, and Recovered) where players choose when to vaccinate. We show that this game admits a unique mean field equilibrium (MFE) that consists in vaccinating at a maximal rate until a given time and then not vaccinating. The vaccination strategy that minimizes the total cost has the same structure as the MFE. We prove that the vaccination period of the MFE is always smaller than the one minimizing the total cost. This implies that, to encourage optimal vaccination behavior, vaccination should always be subsidized. Finally, we provide numerical experiments to study the convergence of the equilibrium when the system is composed by a finite number of agents ( $N$ ) to the MFE. These experiments show that the convergence rate of the cost is $1/N$ and the convergence of the switching curve is monotone.

Observing microscopic phases of lichen life cycles on transparent substrata placed in situ

2005 ◽  
Vol 37 (5) ◽  
pp. 373-382 ◽  
Author(s):  
William B. SANDERS
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Life Cycles ◽  
Potential Significance ◽  
Free Living ◽  
Lichen Community ◽  
One Year ◽  
The One ◽  
Observation Period

The utility of plastic cover slips as a substratum for in situ study of lichen developmental stages is further explored in a neotropical foliicolous lichen community and in a European temperate corticolous community. Twenty-one months after placement in the tropical forest, the cover slips bore foliicolous lichen thalli with several species producing characteristic ascocarps and ascospores, indicating the suitability of the substratum for completion of the life cycle of these lichens. On cover slips placed within the temperate corticolous community, lichen propagules anchored to the substratum with relatively short attachment hyphae but did not develop further within the one year observation period. Intimately intermixed microbial communities of short-celled, mainly pigmented fungi and chlorophyte algae developed upon the transparent substratum. Among the algae, Trebouxia cells, often in groups showing cell division and without associated lichenizing hyphae, were commonly observed. The potential significance of the free-living populations in the life cycle of Trebouxia and in those of Trebouxia-associated lichen fungi is discussed.

Control of flexible manipulators: A survey

Robotica ◽  
2004 ◽  
Vol 22 (5) ◽  
pp. 533-545 ◽  
Author(s):  
M. Benosman ◽  
G. Le Vey
Keyword(s):  
Linear Models ◽  
Control Strategies ◽  
Research Area ◽  
Future Research ◽  
Complex Nature ◽  
Open Problems ◽  
Complex Models ◽  
The Many ◽  
The One ◽  
Flexible Arms

A survey of the field of control for flexible multi-link robots is presented. This research area has drawn great attention during the last two decades, and seems to be somewhat less “attractive” now, due to the many satisfactory results already obtained, but also because of the complex nature of the remaining open problems. Thus it seems that the time has come to try to deliver a sort of “state of the art” on this subject, although an exhaustive one is out of scope here, because of the great amount of publications. Instead, we survey the most salient progresses – in our opinion – approximately during the last decade, that are representative of the essential different ideas in the field. We proceed along with the exposition of material coming from about 119 included references. We do not pretend to deeply present each of the methods quoted hereafter; however, our goal is to briefly introduce most of the existing methods and to refer the interested reader to more detailed presentations for each scheme. To begin with, a now well-established classification of the flexible arms control goals is given. It is followed by a presentation of different control strategies, indicating in each case whether the approach deals with the one-link case, which can be successfully treated via linear models, or with the multi-link case which necessitates nonlinear, more complex, models. Some possible issues for future research are given in conclusion.

scholarly journals Rotavirus in infant-toddler day care centers: Epidemiology relevant to disease control strategies

1988 ◽  
Vol 113 (3) ◽  
pp. 435-441 ◽  
Author(s):  
Alfred V. Bartlett ◽  
Randall R. Reves ◽  
Larry K. Pickering
Keyword(s):  
Disease Control ◽  
Day Care ◽  
Control Strategies ◽  
Day Care Centers

scholarly journals Securitising Covid-19? The Politics of Global Health and the Limits of the Copenhagen School

2021 ◽  
Vol 43 (2) ◽  
pp. 235-257
Author(s):  
Daniel Edler Duarte ◽  
Marcelo M. Valença
Keyword(s):  
Global Health ◽  
Control Strategies ◽  
Security Studies ◽  
Health Security ◽  
Critical Security Studies ◽  
Scientific Controversies ◽  
Copenhagen School ◽  
State Surveillance ◽  
Critical Approaches ◽  
The One

Abstract The COVID-19 pandemic has sparked controversies over health security strategies adopted in different countries. The urge to curb the spread of the virus has supported policies to restrict mobility and to build up state surveillance, which might induce authoritarian forms of government. In this context, the Copenhagen School has offered an analytical repertoire that informs many analyses in the fields of critical security studies and global health. Accordingly, the securitisation of COVID-19 might be necessary to deal with the crisis, but it risks unfolding discriminatory practices and undemocratic regimes, with potentially enduring effects. In this article, we look into controversies over pandemic-control strategies to discuss the political and analytical limitations of securitisation theory. On the one hand, we demonstrate that the focus on moments of rupture and exception conceals security practices that unfold in ongoing institutional disputes and over the construction of legitimate knowledge about public health. On the other hand, we point out that securitisation theory hinders a genealogy of modern apparatuses of control and neglects violent forms of government which are manifested not in major disruptive acts, but in the everyday dynamics of unequal societies. We conclude by suggesting that an analysis of the bureaucratic disputes and scientific controversies that constitute health security knowledges and practices enables critical approaches to engage with the multiple – and, at times, mundane – processes in which (in)security is produced, circulated, and contested.

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