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Influenza A virus infects many animal species. Zoonotic transmission allows for the introduction of novel influenza A virus strains to the human population, which has the potential to cause the [...]

The commingling of pigs and humans at agricultural fairs has been responsible for most zoonotic influenza A virus (IAV) cases over the past 5 years. During routine IAV surveillance in [...]

Currently, intraoperative tumour margin imaging is not routinely utilized in veterinary medicine. Optical coherence tomography (OCT) allows for real‐time assessment of tissue morphology of 1–2 mm depth. The aims of this study were (1) to compare the histologic and OCT features of excised canine skin and subcutaneous specimens, and (2) to determine the diagnostic accuracy of OCT for surgical margin evaluation. The authors hypothesized that OCT imaging would correlate well with histopathology and that OCT would be sensitive for detection of incomplete margins. Eighty dogs were prospectively enrolled. Tumours were excised, and the surgical margins were imaged using a spectral domain OCT system. The tumour type and completeness of excision were determined by histopathology. Nine blinded observers received training in OCT image interpretation and were then given a set of OCT images and videos. The observers assigned each image/video a grade from 1 (no tumour) to 4 (tumour) and the results were compared to histopathology. The overall median sensitivity and specificity of OCT imaging for detection of incomplete margins were 86.7% and 84.6%, respectively. A potential limitation is that observers had varied experience with OCT image interpretation, ranging from no prior experience to participating in a previous OCT project. OCT is sensitive for detection of incomplete margins and could be a promising real‐time surgical margin imaging modality. Further study is needed to evaluate intraoperative applications of OCT and its impact on tumour recurrence and long‐term outcome. [ABSTRACT FROM AUTHOR]

Background: The influenza A virus (IAV) binds to α‐2,3‐ and α‐2,6‐linked sialic acid (SA) receptors expressed by Madin‐Darby canine kidney (MDCK) cells. The receptor distribution may therefore be important in regulating IAV propagation. Serum‐free medium (SFM) avoids variability in conventional culture medium containing fetal bovine serum (FBS), which can have variable composition and may contain endotoxins. However, little is known about the distribution of SA receptors on cells maintained in SFM. Objectives: We assessed the influence of culture media on MDCK cell SA receptor distribution along with the effect of SA receptor distribution on IAV recovery. We hypothesized that SFM would increase the proportion of α‐2,6‐linked SA receptors present and alter isolate recovery. Methods: Madin‐Darby canine kidney cells were cultured in medium containing FBS and two SFMs. Cell surface distribution of α‐2,6‐ and α‐2,3‐linked receptors was determined using flow cytometry. Recovery of swine‐ and avian‐lineage IAVs from MDCK cells maintained in each medium was quantified as TCID50. Results: Madin‐Darby canine kidney cells cultured in UltraMDCK SFM expressed both SA receptors and supported the growth of both swine‐ and avian‐lineage IAVs. Cells maintained in other medium inconsistently expressed each receptor and the avian IAV grew to lower titers in cells cultured with FBS. Conclusions: Medium conditions altered the distribution of SA receptors present on MDCK cells and affected IAV recovery. Culture in UltraMDCK SFM resulted in cells expressing both receptors and IAVs grew to higher titers than in the other culture condition, indicating that this medium may be useful for culturing IAV from multiple species. [ABSTRACT FROM AUTHOR]

Influenza A virus (IAV) is a zoonotic pathogen threatening animal and public health; therefore, detection and monitoring of IAV in animal populations are critical components of a surveillance program. Swine are important hosts of IAV, wherein the virus can undergo rapid evolution. Several methods (i.e., nasal swabs, nasal wipes, and oral fluids) have been used to collect samples from swine for IAV surveillance. We utilized nasal wipes made from cotton gauze and multiple, polyester or mixed polyester fabrics to compare performance in the molecular detection and isolation of IAV. In vitro experiments revealed that no polyester or mixed polyester fabric was superior to cotton gauze for molecular IAV detection; however, 3 polyester or mixed polyester fabrics yielded significantly more viable IAV than cotton. In a field trial, both cotton gauze and the polyester or mixed polyester fabric yielded similar proportions of IAV isolates from swine. The results indicate that cotton gauze remains a practical and useful material for swine nasal wipes. [ABSTRACT FROM AUTHOR]

Influenza A Viruses (IAV) in domestic swine (IAV-S) are associated with sporadic zoonotic transmission at the human–animal interface. Previous pandemic IAVs originated from animals, which emphasizes the importance of characterizing human immunity against the increasingly diverse IAV-S. We analyzed serum samples from healthy human donors (n = 153) using hemagglutination-inhibition (HAI) assay to assess existing serologic protection against a panel of contemporary IAV-S isolated from swine in the United States (n = 11). Age-specific seroprotection rates (SPR), which are the proportion of individuals with HAI ≥ 1:40, corresponded with lower or moderate pandemic risk classifications for the multiple IAV-S examined (one H1-δ1, one H1-δ2, three H3-IVA, one H3-IVB, one H3-IVF). Individuals born between 2004 and 2013 had SPRs of 0% for the five classified H3 subtype IAV-S, indicating youth may be particularly predisposed to infection with these viruses. Expansion of existing immunologic gaps over time could increase likelihood of future IAV-S spillover to humans and facilitate subsequent sustained human-to-human transmission resulting in disease outbreaks with pandemic potential. [ABSTRACT FROM AUTHOR]

Simple Summary: Mass depopulation involves ending the life of large numbers of animals due to emergency situations, for example, disease epidemics and environmental disasters. Depopulation should be conducted in a way that assures rapid and reliable unconsciousness followed by death. Our review article aimed to summarize depopulation methods available for swine and to highlight gaps in knowledge to guide the focus of future research. Our findings showed that the majority of research has been conducted with inhalable gaseous formulations (e.g., CO2) and that there was a lack of research in methods such as the use of captive bolts, electrocution, and oral formulations. Furthermore, our literature review showed a lack of research in the areas of worker safety, worker emotional health, and on validation of animal-based measures to be used for depopulation welfare assessments. Finally, a safe and reliable manner to induce unconsciousness and death for large populations of swine is lacking and urgently needed for preparedness purposes. Swine mass depopulation refers to the destruction of large numbers of pigs and may include not only animals affected with a disease but also healthy pigs in a facility or surrounding areas. Emerging applications of mass depopulation include reducing welfare issues associated with slaughter delays, which was observed in the United States in 2020 as a result of the Coronavirus disease (COVID-19) pandemic. The objectives of this review were to summarize the available literature on swine depopulation methods and to highlight critical gaps in knowledge. Peer-reviewed articles were identified through a systematic search in electronic databases including Web of Science, MEDLINE, and PubMed. A total of 68 publications were assessed. Gaseous carbon dioxide inhalation was the most commonly reported depopulation method for both small- and large-scale trials. Measurements of consciousness state, which serves to assess suffering and humaneness, appeared to be lacking in a high proportion of the studies. None of the published studies demonstrated an ideally reliable and safe way to induce rapid unconsciousness in large groups of pigs. Development of rapid mass depopulation methods applicable to large groups of pigs is necessary to provide industry partners with suitable and low-cost emergency preparedness procedures while adhering to personnel safety and animal welfare standards. Lastly, there is an urgent need to standardize comprehensive reporting guidelines for depopulation studies. [ABSTRACT FROM AUTHOR]