Loikkanen Emil, Mikkelä Antti, Joutsen Suvi, Tuominen Pirkko, Maunula Leena
Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Risk Assessment Unit, Laboratory and Research Department, Finnish Food Authority, Helsinki, Finland.
Food Environ Virol. 2025 Jan 10;17(1):17. doi: 10.1007/s12560-024-09631-1.
Hepatitis E virus (HEV) is a zoonotic virus that infects humans when virus-containing pork products are consumed. This study aimed to explore MNV (murine norovirus) and HEV inactivation during cold smoking and ripening/fermentation treatments used for salami-like sausages (mettwurst). MNV inactivation was monitored in culture medium solution and in sausage while being subjected to a salami-like sausage manufacturing process. The inactivation of MNV in the solution was also monitored at room temperature (RT) for four weeks. HEV inactivation was monitored in solution during the cold smoking process and at RT. A TCID assay was used to calculate the infectious MNV and HEV titres. MNV survival was modelled using Bayesian inference. MNV load in solution decreased by as much as 4.7 (SD 0.9) log TCID/ml when it was subjected to the cold smoking process. Modelling revealed that 99.999% MNV might be inactivated during the treatment when observed at a level of 95% CI (Bayesian Confidence Interval). On the contrary, MNV load decreased by only 1.8 (0.2) log when stored at RT. The low-titre HEV in solution was inactivated (> 1.1 (0.2) log) when treated, and at RT. However, MNV was resistant in the sausage matrix during the cold smoking process (log reduction of 1.9 (0.5) TCID/ml). Based on modelling, a substantial amount of virus would remain in the product, even when the uncertainty was considered. Hence, viruses, here exemplified by MNV, may not be inactivated from salami-like pork sausages during manufacturing, which poses a risk for consumers in real-life situations.
戊型肝炎病毒（HEV）是一种人畜共患病毒，当食用含有该病毒的猪肉制品时会感染人类。本研究旨在探讨在类似意大利腊肠（德式小香肠）的冷熏和成熟/发酵处理过程中鼠诺如病毒（MNV）和HEV的灭活情况。在类似意大利腊肠的香肠制造过程中，在培养基溶液和香肠中监测MNV的灭活情况。还在室温（RT）下对溶液中的MNV灭活情况进行了四周的监测。在冷熏过程中和室温下监测溶液中HEV的灭活情况。采用TCID试验计算感染性MNV和HEV滴度。使用贝叶斯推理对MNV存活情况进行建模。当溶液中的MNV经过冷熏过程时，其载量降低了多达4.7（标准差0.9）log TCID/ml。建模显示，在95%可信区间（贝叶斯置信区间）水平观察时，在处理过程中99.999%的MNV可能会被灭活。相反，在室温下储存时，MNV载量仅降低了1.8（0.2）log。溶液中低滴度的HEV在处理时以及在室温下均被灭活（>1.1（0.2）log）。然而，在冷熏过程中，MNV在香肠基质中具有抗性（log减少1.9（0.5）TCID/ml）。基于建模，即使考虑到不确定性，产品中仍会残留大量病毒。因此，以MNV为例的病毒在制造过程中可能不会从类似意大利腊肠的猪肉香肠中被灭活，这在现实生活中对消费者构成了风险。
