Clinical Studies Department, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia.
PLoS One. 2018 Oct 25;13(10):e0205884. doi: 10.1371/journal.pone.0205884. eCollection 2018.
Dogs are important reservoirs of rabies, a zoonotic viral encephalitis that kills thousands of people in Asia and Africa annually. Mass dog vaccination is recommended for the prevention of rabies in both humans and dogs. Mass vaccinations should be conducted annually but more frequent campaigns may be required in areas with high dog turnover rates. Consequently, a good understanding of dog demography is essential for the control of the disease. The aim of this study was to explore the effect of dog demography on rabies vaccination coverage following a mass vaccination campaign with at least 70% vaccination coverage.
METHODOLOGY/PRINCIPAL FINDINGS: A dog population model was constructed to explore the effect of dog demography on rabies vaccination coverage decline. Important model parameters were identified through a comprehensive literature search on dog demography in Africa. A system dynamics approach was adopted to build a dog population model to simulate the effects of demographic processes on rabies vaccination coverage. Vensim PLE Plus software was used to construct the model. Multivariate sensitivity simulations using data from 22 studies and 12 African countries were performed to investigate the effect of dog turnover rates on vaccination coverage decline. In addition, an adjusted vaccination coverage to estimate the proportion of vaccinated dogs with adequate immunity at 12 months post-vaccination was calculated. The results demonstrated that the vaccination coverage and adjusted vaccination coverage remained over 30% and 20% respectively at 12 months if annual mass vaccinations achieved at least 70% coverage.
CONCLUSIONS/SIGNIFICANCE: The results demonstrated that annual mass vaccination campaigns with at least 70% vaccination coverage would maintain a herd immunity of 20‒45% between campaigns.
狗是狂犬病的重要宿主，狂犬病是一种人畜共患的病毒性脑炎，每年在亚洲和非洲导致数千人死亡。大规模给狗接种疫苗是预防人类和狗狂犬病的建议措施。大规模接种应该每年进行，但在狗周转率较高的地区可能需要更频繁的疫苗接种运动。因此，深入了解狗的种群动态对于控制疾病至关重要。本研究旨在探讨在至少 70%的疫苗接种覆盖率下进行大规模疫苗接种运动后，狗的种群动态对狂犬病疫苗接种覆盖率下降的影响。
方法/主要发现：构建了一个狗种群模型，以探讨狗的种群动态对狂犬病疫苗接种覆盖率下降的影响。通过对非洲狗种群动态的全面文献检索，确定了重要的模型参数。采用系统动力学方法构建了一个狗种群模型，以模拟人口统计学过程对狂犬病疫苗接种覆盖率的影响。使用 Vensim PLE Plus 软件构建了模型。使用来自 22 项研究和 12 个非洲国家的数据进行了多变量敏感性模拟，以调查狗周转率对疫苗接种覆盖率下降的影响。此外，还计算了调整后的疫苗接种覆盖率，以估计接种疫苗后 12 个月具有足够免疫力的接种犬的比例。结果表明，如果每年的大规模疫苗接种覆盖率达到至少 70%，则疫苗接种覆盖率和调整后的疫苗接种覆盖率在 12 个月时仍分别保持在 30%以上和 20%以上。
结论/意义：结果表明，每年至少进行 70%覆盖率的大规模疫苗接种运动，将在两次运动之间维持 20-45%的群体免疫。
