Srinka Agricultural Research Center, ARARI, P.O. Box 74, Woldia, Ethiopia.
Department of Veterinary Epidemiology and Public Health, College of Veterinary Medicine and animal science, University of Gondar, P.O. Box 196, Gondar, Ethiopia.
Prev Vet Med. 2020 Aug;181:104673. doi: 10.1016/j.prevetmed.2019.04.002. Epub 2019 Apr 8.
Foot and mouth disease (FMD) is contagious, acute viral disease of all cloven-hoofed animals. The disease is endemic in Ethiopia and causes multiple outbreak every year all over the country. While it is important to understand to the transmission dynamics of FMD outbreaks for appropriate control intervention, no such study has been done in Ethiopia. Thus, the aims of this study were to estimate the basic reproduction number (R) of FMD and simulate FMD transmission dynamics of FMD in Amhara region of Ethiopia. Basic reproduction number (R) was estimated from age stratified sero-prevalence data through maximum likelihood estimation. A stochastic SIR (susceptible-infectious-recovered) compartmental FMD model was formulated and parameterized using literature and age stratified sero-prevalence field data. The R of FMD in the region was estimated to be 1.27 (95%CI: 1.20-1.34). The simulation of the SIR model showed only 24% (95% CI: 16-32%) of the infection introduced in the region caused major outbreaks. Out of the major outbreaks 25% of them tend to persist in the region. Major outbreaks cause 38.9% (95% CI: 38.8-39.1%) morbidity and 0.0019% (95% CI: 0.0018-0.0020%) mortality in cattle and the outbreaks stayed for an average of 690 days (95%CI: 655-727). Validation of the model prediction with farmer's field experience indicated a fairly similar result especially for the predicted morbidity caused by outbreaks. This study revealed low transmission of FMD within the Amhara region cattle population indicating not very high vaccination coverage is needed, if control through vaccination is envisaged at regional level. However, owing to several simplified assumptions made during the modeling, this conclusion should be taken cautiously.
口蹄疫（FMD）是一种传染性的、急性的、所有偶蹄动物的病毒性疾病。该病在埃塞俄比亚流行，每年在全国范围内都会发生多次暴发。虽然了解 FMD 暴发的传播动态对于采取适当的控制干预措施很重要，但埃塞俄比亚尚未进行过此类研究。因此，本研究旨在估计 FMD 的基本繁殖数（R）并模拟埃塞俄比亚阿姆哈拉地区的 FMD 传播动态。通过最大似然估计从年龄分层血清流行率数据中估计基本繁殖数（R）。制定了一个随机 SIR（易感-感染-恢复）房室 FMD 模型，并使用文献和年龄分层血清流行率现场数据进行参数化。该地区 FMD 的 R 估计为 1.27（95%CI：1.20-1.34）。SIR 模型的模拟结果表明，该地区引入的感染中只有 24%（95%CI：16-32%）会导致大规模暴发。在这些大规模暴发中，其中 25%的暴发有持续存在的趋势。大规模暴发会导致 38.9%（95%CI：38.8-39.1%）的牛群发病率和 0.0019%（95%CI：0.0018-0.0020%）的死亡率，暴发持续时间平均为 690 天（95%CI：655-727）。将模型预测与农民的田间经验进行验证表明，结果非常相似，尤其是暴发引起的预测发病率。本研究表明，FMD 在阿姆哈拉地区牛群中的传播速度较低，这表明如果计划在区域层面通过接种疫苗进行控制，则不需要非常高的疫苗接种覆盖率。然而，由于在建模过程中做出了几个简化的假设，因此应谨慎得出这一结论。
