Faculty of Veterinary Science, University of Sydney, Camden, NSW, Australia.
School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, Australia.
Prev Vet Med. 2014 Mar 1;113(4):565-79. doi: 10.1016/j.prevetmed.2014.01.016. Epub 2014 Jan 21.
Highly pathogenic porcine reproductive and respiratory syndrome (PRRS) has spread through parts of south-east Asia, posing a risk to Australia. The objective of this study was to assess the probability of infection of a feral or domestic pig in Australia with highly pathogenic PRRS following ingestion of illegally imported raw pork. A conservative scenario was considered in which 500 g of raw pork was imported from the Philippines into Australia without being detected by border security, then discarded from a household and potentially accessed by a pig. Monte Carlo simulation of a two-dimensional, stochastic model was used to estimate the probability of entry and exposure, and the probability of infection was assessed by incorporating a virus-decay and mechanistic dose-response model. Results indicated that the probability of infection of a feral pig after ingestion of raw meat was higher than the probability of infection of a domestic pig. Sensitivity analysis was used to assess the influence of input parameters on model output probability estimates, and extension of the virus-decay and dose-response model was used to explore the impact of different temperatures and time from slaughter to ingestion of the meat, different weights of meat, and the level of viraemia at slaughter on the infectivity of meat. Parameters with the highest influence on the model output were the level of viraemia of a pig prior to slaughter and the probability of access by a feral pig to food-waste discarded on property surrounding a household. Extension of the decay and dose-response model showed that small pieces of meat (10 g) from a highly pathogenic PRRS viraemic pig could contain enough virus to have a high probability of infection of a pig, and that routes to Australia by sea or air from all highly pathogenic PRRS virus endemic countries were of interest dependent on the temperature of the raw meat during transport. This study highlighted the importance of mitigation strategies such as disposal of food-waste from international traffic as quarantine waste, and the need for further research into the probability of access to food-waste on properties by feral pigs.
高致病性猪繁殖与呼吸综合征（PRRS）已在东南亚部分地区传播，对澳大利亚构成威胁。本研究旨在评估澳大利亚的野猪或家猪在摄入非法进口的生猪肉后感染高致病性 PRRS 的概率。本研究考虑了一种保守的情况，即在没有被边境安全部门发现的情况下，从菲律宾进口 500 克生猪肉进入澳大利亚，然后从一户人家丢弃，并可能被一头猪接触到。使用二维随机模型的蒙特卡罗模拟来估计进入和暴露的概率，并通过纳入病毒衰减和机制剂量反应模型来评估感染的概率。结果表明，野猪摄入生肉后感染的概率高于家猪。敏感性分析用于评估输入参数对模型输出概率估计的影响，并扩展病毒衰减和剂量反应模型以探索不同温度和从屠宰到摄入肉的时间、肉的不同重量以及屠宰时的病毒血症水平对肉的传染性的影响。对模型输出影响最大的参数是屠宰前猪的病毒血症水平以及野猪接触家庭周围财产丢弃的食物垃圾的可能性。衰减和剂量反应模型的扩展表明，来自高致病性 PRRS 病毒血症猪的小块肉（10 克）可能含有足够的病毒，从而使猪感染的概率很高，并且来自所有高致病性 PRRS 病毒流行国家的海上或空中进入澳大利亚的途径取决于运输过程中生肉的温度。本研究强调了减轻策略的重要性，例如将来自国际交通的食物垃圾作为检疫废物进行处理，以及需要进一步研究野猪接触财产上食物垃圾的概率。
