The recent incursion of highly pathogenic influenza viruses into dairy cattle opens new insights for influenza virus ecology and its interspecies transmission and may have a significant impact on public health and agriculture. The aim of this study was to determine the stability of a bovine highly pathogenic avian influenza H5N1 virus isolate in the milk byproduct lactose and to evaluate two inactivation methods using industrial procedures. The bovine isolate of the highly pathogenic avian influenza H5N1 virus was stable for 14 days in a concentrated lactose solution under refrigerated conditions. Heat or citric acid treatments successfully inactivated the virus in lactose. This study highlights the persistence of HPAIV in lactose and its efficient inactivation under industrial standards.

Geographical expansion and trans‐continental transmission of the African swine fever virus (ASFV) pose a significant risk to the global swine industry due to its high impact on swine health and agro‐economy. Several different modes of ASFV transmission make it difficult to predict and prevent ASFV introduction to the free area and its spread in the affected area. Indirect transmission through contaminated surfaces could be one of the possible routes to introduce ASFV to the United States due to its high resistance on environmental surfaces and the frequency of international movements. However, there is limited knowledge about environmental samples for ASFV surveillance, when compared to clinical samples from infected pigs. Therefore, the aim of this study was to develop methods for better detection of ASFV DNA in the presence of four different types of organic contaminants: soil, swine feces, feed dust, and their mixture. The presence of organic contaminants negatively affected the sensitivity of ASFV DNA detection. Centrifugation and filtration were crucial for ASFV detection in environmental samples with soil and mixture, whereas filtration reduced the sensitivity of ASFV DNA detection in samples from clean surfaces and swine feces‐ and feed dust‐contaminated surfaces. Detection of ASFV was significantly improved when sampled by the sponge stick with DNA/RNA shield when compared to the cost‐effective sampling strategy, the cotton gauze with phosphate‐buffered saline. These findings highlight the effect of organic contaminants and the use of the nucleic acid stabilization buffer on ASFV diagnostic performance and provide important background for ASFV preparedness.