Data from: 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 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.

背景：狂犬病是非洲资源受限社区中一种严峻却遭忽视的公共卫生威胁，该病毒在当地有主自由游荡家犬种群中持续循环存续。通过大规模犬只疫苗接种可实现狂犬病消除，但这类犬群的快速更替阻碍了群体免疫 (herd immunity) 所需的疫苗接种临界覆盖率的维持。明晰自由游荡家犬种群的动态特征，可为狂犬病防控的大规模犬只疫苗接种行动的规划与实施提供科学依据。
方法/主要结果：我们在南非姆普马兰加省某社区搭建了犬只健康与人口监测系统，对该划定地理范围内的全部有主家犬种群开展监测。我们对2012年1月1日至2014年1月1日这24个月期间的人口统计学指标进行了量化，并通过模拟疫苗接种覆盖率随时间的衰减趋势，评估了这些指标对狂犬病防控的指导意义。监测期间，该犬群总规模下降了10%。2012年种群年增长率为+18.6%，2013年则为-24.5%。粗年出生率（每1000犬年观测数）在2012年为451，2013年为313。粗年死亡率在2012年为406，2013年为568。2013年，雌性犬的死亡率显著高于雄性（死亡率比 (mortality rate ratio, MRR)=1.54，95%置信区间 (confidence interval, CI)=1.28~1.85）。在0~3月龄年龄组中，接种狂犬病疫苗的犬只死亡率显著低于未接种犬只（2012年：MRR=0.11，95%CI=0.05~0.21；2013年：MRR=0.31，95%CI=0.11~0.69）。模拟结果显示，在年度疫苗接种行动中达到70%的接种覆盖率，可使覆盖率维持在群体免疫临界阈值以上至少12个月。
结论与意义：本研究结果为世界卫生组织 (World Health Organization) 基于经验提出的年度疫苗接种行动70%接种覆盖率目标提供了实证依据。即便在增长率极高、种群更替极快的高度动态犬群中，达成该覆盖率仍可发挥有效防控作用。这进一步增强了学界对通过大规模疫苗接种在非洲消除犬狂犬病可行性的信心。