Darryn Knobel

Dr. Darryn Knobel

School of Veterinary Medicine, Ross University, Basseterre, St Kitts, Saint Kitts and Nevis
orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 June 2005
Verified
Journal Article
Closed access
DKDarryn Knobel
Darryn Knobel
SCSarah Cleaveland
Sarah Cleaveland
PCPaul G Coleman
Paul G Coleman
EFEric Fevre
Eric Fevre
MMMartin I Meltzer
Martin I Meltzer
FMFrançois-Xavier Meslin
François-Xavier Meslin

23 February 2010 in PLOS Neglected Tropical Diseases
Verified
Journal Article
Open access
PDF file
TLTiziana Lembo
Tiziana Lembo
KHKatie Hampson
Katie Hampson
MKMagai T. Kaare
Magai T. Kaare
EEEblate Ernest
Eblate Ernest
DKDarryn Knobel
Darryn Knobel
SCSarah Cleaveland
Sarah Cleaveland
Canine rabies causes many thousands of human deaths every year in Africa, and continues to increase throughout much of the continent. This paper identifies four common reasons given for the lack of effective canine rabies control in Africa: (a) a low priority given for disease control as a result of lack of awareness of the rabies burden; (b) epidemiological constraints such as uncertainties about the required levels of vaccination coverage and the possibility of sustained cycles of infection in wildlife; (c) operational constraints including accessibility of dogs for vaccination and insufficient knowledge of dog population sizes for planning of vaccination campaigns; and (d) limited resources for implementation of rabies surveillance and control. We address each of these issues in turn, presenting data from field studies and modelling approaches used in Tanzania, including burden of disease evaluations, detailed epidemiological studies, operational data from vaccination campaigns in different demographic and ecological settings, and economic analyses of the cost-effectiveness of dog vaccination for human rabies prevention. We conclude that there are no insurmountable problems to canine rabies control in most of Africa; that elimination of canine rabies is epidemiologically and practically feasible through mass vaccination of domestic dogs; and that domestic dog vaccination provides a cost-effective approach to the prevention and elimination of human rabies deaths. Elimination of canine rabies has been achieved in some parts of the world, but the disease still kills many thousands of people each year in Africa. Here we counter common arguments given for the lack of effective canine rabies control in Africa presenting detailed data from a range of settings. We conclude that (1) rabies substantially affects public and animal health sectors, hence regional and national priorities for control ought to be higher, (2) for practical purposes domestic dogs are the sole maintenance hosts and main source of infection for humans throughout most of Africa and Asia and sufficient levels of vaccination coverage in domestic dog populations should lead to elimination of canine rabies in most areas, (3) the vast majority of domestic dog populations across sub-Saharan Africa are accessible for vaccination with community sensitization being of paramount importance for the success of these programs, (4) improved local capacity in rabies surveillance and diagnostics will help evaluate the impact of control and elimination efforts, and (5) sustainable resources for effective dog vaccination campaigns are likely to be available through the development of intersectoral financing schemes involving both medical and veterinary sectors.

1 October 2006 in Veterinary Microbiology
Verified
Journal Article
Closed access
SCSarah Cleaveland
Sarah Cleaveland
MKMagai Kaare
Magai Kaare
DKDarryn Knobel
Darryn Knobel
MLM. Karen Laurenson
M. Karen Laurenson

22 August 2013 in PLOS Neglected Tropical Diseases
Verified
Journal Article
Open access
PDF file
STSunny E. Townsend
Sunny E. Townsend
ISI Putu Sumantra
I Putu Sumantra
PUPudjiatmoko
Pudjiatmoko
GBGusti Ngurah Bagus
Gusti Ngurah Bagus
EBEric Brum
Eric Brum
KHKatie Hampson
Katie Hampson
Canine rabies is one of the most important and feared zoonotic diseases in the world. In some regions rabies elimination is being successfully coordinated, whereas in others rabies is endemic and continues to spread to uninfected areas. As epidemics emerge, both accepted and contentious control methods are used, as questions remain over the most effective strategy to eliminate rabies. The Indonesian island of Bali was rabies-free until 2008 when an epidemic in domestic dogs began, resulting in the deaths of over 100 people. Here we analyze data from the epidemic and compare the effectiveness of control methods at eliminating rabies. Using data from Bali, we estimated the basic reproductive number, R0, of rabies in dogs, to be ∼1·2, almost identical to that obtained in ten–fold less dense dog populations and suggesting rabies will not be effectively controlled by reducing dog density. We then developed a model to compare options for mass dog vaccination. Comprehensive high coverage was the single most important factor for achieving elimination, with omission of even small areas (<0.5% of the dog population) jeopardizing success. Parameterizing the model with data from the 2010 and 2011 vaccination campaigns, we show that a comprehensive high coverage campaign in 2012 would likely result in elimination, saving ∼550 human lives and ∼$15 million in prophylaxis costs over the next ten years. The elimination of rabies from Bali will not be achieved through achievable reductions in dog density. To ensure elimination, concerted high coverage, repeated, mass dog vaccination campaigns are necessary and the cooperation of all regions of the island is critical. Momentum is building towards development of a strategy for the global elimination of canine rabies, and this study offers valuable new insights about the dynamics and control of this disease, with immediate practical relevance. Canine rabies continues to cause tens of thousands of horrific deaths worldwide, primarily in Asia and Africa. Momentum is building towards development of a global elimination strategy for canine rabies, but questions remain over how best to eliminate rabies epidemics. This paper uses data generated from the recent high-profile rabies outbreak in Bali, Indonesia to evaluate different control options. We find that, despite high dog densities, the spread of rabies on the island was remarkably similar to canine rabies spread elsewhere, suggesting that the practice of dog culling is an ineffective control strategy. We then simulate rabies transmission and spread across the island and compare the effectiveness of mass dog vaccination strategies in terms of how many lives are saved and how long it will take for elimination to be achieved. We find that the effectiveness of campaigns is not improved by being more reactive or synchronized but depends almost entirely upon reaching sufficient coverage (70%) across the population in successive campaigns. Even small ‘gaps’ in vaccination coverage can significantly impede the prospects of elimination. The outputs of this study provide the kind of evidence needed by rabies program coordinators to help design effective national control programmes, and to build the evidence-base to drive forward the development and implementation of effective global rabies policy.

15 May 2007 in Journal of The Royal Society Interface
Verified
Journal Article
Closed access
JHJo Halliday
Jo Halliday
AMAnna Meredith
Anna Meredith
DKDarryn Knobel
Darryn Knobel
DSDarren J Shaw
Darren J Shaw
MBMark Bronsvoort
Mark Bronsvoort
SCSarah Cleaveland
Sarah Cleaveland
The dynamics of infectious diseases are highly variable. Host ranges, host responses to pathogens and the relationships between hosts are heterogeneous. Here, we argue that the use of animal sentinels has the potential to use this variation and enable the exploitation of a wide range of pathogen hosts for surveillance purposes. Animal sentinels may be used to address many surveillance questions, but they may currently be underused as a surveillance tool and there is a need for improved interdisciplinary collaboration and communication in order to fully explore the potential of animal sentinels. In different contexts, different animal hosts will themselves vary in their capacity to provide useful information. We describe a conceptual framework within which the characteristics of different host populations and their potential value as sentinels can be evaluated in a broad range of settings.

12 October 2006 in Nature
Verified
Journal Article
Closed access
PDF file
DHD. T. Haydon
D. T. Haydon
DRD. A. Randall
D. A. Randall
LMLouise Matthews
Louise Matthews
DKDarryn Knobel
Darryn Knobel
LTL. A. Tallents
L. A. Tallents
MLM. K. Laurenson
M. K. Laurenson