Population Dynamics of Owned, Free-Roaming Dogs: Implications for Rabies Control.

BACKGROUND:Rabies is a serious yet neglected public health threat in resource-limited communities in Africa, where the virus is maintained in populations of owned, free-roaming domestic dogs. Rabies elimination can be achieved through the mass vaccination of dogs, but maintaining the critical thresh...

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Main Authors: Anne Conan, Oluyemisi Akerele, Greg Simpson, Bjorn Reininghaus, Jacques van Rooyen, Darryn Knobel
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-11-01
Series:PLoS Neglected Tropical Diseases
Online Access:http://europepmc.org/articles/PMC4636342?pdf=render
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author Anne Conan
Oluyemisi Akerele
Greg Simpson
Bjorn Reininghaus
Jacques van Rooyen
Darryn Knobel
author_facet Anne Conan
Oluyemisi Akerele
Greg Simpson
Bjorn Reininghaus
Jacques van Rooyen
Darryn Knobel
author_sort Anne Conan
collection DOAJ
description BACKGROUND:Rabies is a serious yet neglected public health threat in resource-limited communities in Africa, where the virus is maintained in populations of owned, free-roaming domestic dogs. Rabies elimination can be achieved through the mass vaccination of dogs, but maintaining the critical threshold of vaccination coverage for herd immunity in these populations is hampered by their rapid turnover. Knowledge of the population dynamics of free-roaming dog populations can inform effective planning and implementation of mass dog vaccination campaigns to control rabies. METHODOLOGY/PRINCIPAL FINDINGS:We implemented a health and demographic surveillance system in dogs that monitored the entire owned dog population within a defined geographic area in a community in Mpumalanga Province, South Africa. We quantified demographic rates over a 24-month period, from 1st January 2012 through 1st January 2014, and assessed their implications for rabies control by simulating the decline in vaccination coverage over time. During this period, the population declined by 10%. Annual population growth rates were +18.6% in 2012 and -24.5% in 2013. Crude annual birth rates (per 1,000 dog-years of observation) were 451 in 2012 and 313 in 2013. Crude annual death rates were 406 in 2012 and 568 in 2013. Females suffered a significantly higher mortality rate in 2013 than males (mortality rate ratio [MRR] = 1.54, 95% CI = 1.28-1.85). In the age class 0-3 months, the mortality rate of dogs vaccinated against rabies was significantly lower than that of unvaccinated dogs (2012: MRR = 0.11, 95% CI = 0.05-0.21; 2013: MRR = 0.31, 95% CI = 0.11-0.69). The results of the simulation showed that achieving a 70% vaccination coverage during annual campaigns would maintain coverage above the critical threshold for at least 12 months. CONCLUSIONS AND SIGNIFICANCE:Our findings provide an evidence base for the World Health Organization's empirically-derived target of 70% vaccination coverage during annual campaigns. Achieving this will be effective even in highly dynamic populations with extremely high growth rates and rapid turnover. This increases confidence in the feasibility of dog rabies elimination in Africa through mass vaccination.
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spelling doaj.art-a0dc233ca3104f239c38f80ad5bc091b2022-12-22T03:17:39ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352015-11-01911e000417710.1371/journal.pntd.0004177Population Dynamics of Owned, Free-Roaming Dogs: Implications for Rabies Control.Anne ConanOluyemisi AkereleGreg SimpsonBjorn ReininghausJacques van RooyenDarryn KnobelBACKGROUND:Rabies is a serious yet neglected public health threat in resource-limited communities in Africa, where the virus is maintained in populations of owned, free-roaming domestic dogs. Rabies elimination can be achieved through the mass vaccination of dogs, but maintaining the critical threshold of vaccination coverage for herd immunity in these populations is hampered by their rapid turnover. Knowledge of the population dynamics of free-roaming dog populations can inform effective planning and implementation of mass dog vaccination campaigns to control rabies. METHODOLOGY/PRINCIPAL FINDINGS:We implemented a health and demographic surveillance system in dogs that monitored the entire owned dog population within a defined geographic area in a community in Mpumalanga Province, South Africa. We quantified demographic rates over a 24-month period, from 1st January 2012 through 1st January 2014, and assessed their implications for rabies control by simulating the decline in vaccination coverage over time. During this period, the population declined by 10%. Annual population growth rates were +18.6% in 2012 and -24.5% in 2013. Crude annual birth rates (per 1,000 dog-years of observation) were 451 in 2012 and 313 in 2013. Crude annual death rates were 406 in 2012 and 568 in 2013. Females suffered a significantly higher mortality rate in 2013 than males (mortality rate ratio [MRR] = 1.54, 95% CI = 1.28-1.85). In the age class 0-3 months, the mortality rate of dogs vaccinated against rabies was significantly lower than that of unvaccinated dogs (2012: MRR = 0.11, 95% CI = 0.05-0.21; 2013: MRR = 0.31, 95% CI = 0.11-0.69). The results of the simulation showed that achieving a 70% vaccination coverage during annual campaigns would maintain coverage above the critical threshold for at least 12 months. CONCLUSIONS AND SIGNIFICANCE:Our findings provide an evidence base for the World Health Organization's empirically-derived target of 70% vaccination coverage during annual campaigns. Achieving this will be effective even in highly dynamic populations with extremely high growth rates and rapid turnover. This increases confidence in the feasibility of dog rabies elimination in Africa through mass vaccination.http://europepmc.org/articles/PMC4636342?pdf=render
spellingShingle Anne Conan
Oluyemisi Akerele
Greg Simpson
Bjorn Reininghaus
Jacques van Rooyen
Darryn Knobel
Population Dynamics of Owned, Free-Roaming Dogs: Implications for Rabies Control.
PLoS Neglected Tropical Diseases
title Population Dynamics of Owned, Free-Roaming Dogs: Implications for Rabies Control.
title_full Population Dynamics of Owned, Free-Roaming Dogs: Implications for Rabies Control.
title_fullStr Population Dynamics of Owned, Free-Roaming Dogs: Implications for Rabies Control.
title_full_unstemmed Population Dynamics of Owned, Free-Roaming Dogs: Implications for Rabies Control.
title_short Population Dynamics of Owned, Free-Roaming Dogs: Implications for Rabies Control.
title_sort population dynamics of owned free roaming dogs implications for rabies control
url http://europepmc.org/articles/PMC4636342?pdf=render
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AT bjornreininghaus populationdynamicsofownedfreeroamingdogsimplicationsforrabiescontrol
AT jacquesvanrooyen populationdynamicsofownedfreeroamingdogsimplicationsforrabiescontrol
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