Pathology and Viral Antigen Distribution of Lethal Pneumonia in Domestic Cats Due to Pandemic (H1N1) 2009 Influenza A Virus

A novel swine-origin H1N1 influenza A virus has been identified as the cause of the 2009 influenza pandemic in humans. Since then, infections with the pandemic (H1N1) 2009 influenza virus have been documented in a number of animal species. The first known cases of lethal respiratory disease associated with pandemic (H1N1) 2009 influenza virus infection in house pets occurred in domestic cats in Oregon. A 10-year-old, neutered male and an 8-year-old, spayed female domestic short hair cat died shortly after developing severe respiratory disease. Grossly, lung lobes of both cats were diffusely firm and incompletely collapsed. Histologically, moderate to severe, necrotizing to pyonecrotizing bronchointerstitial pneumonia was accompanied by serofibrinous exudation and hyaline membranes in the alveolar spaces. Influenza A virus was isolated from nasal secretions of the male and from lung homogenate of the female cat. Both isolates were confirmed as pandemic (H1N1) 2009 influenza virus by real-time reverse transcriptase PCR (rRT-PCR). Using immunohistochemistry, influenza A viral antigen was demonstrated in bronchiolar epithelial cells, pneumocytes and alveolar macrophages in pneumonic areas. The most likely sources of infection were people in the household with influenza-like illness or confirmed pandemic (H1N1) 2009 influenza. The two cases reported here provide, to the best of the authors’ knowledge, the first description of the pathology and viral antigen distribution of lethal respiratory disease in domestic cats after natural pandemic (H1N1) 2009 influenza virus infection, probably transmitted from humans.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The article is published by Sage Publications on behalf of the American College of Veterinary Pathologists, European College of Veterinary Pathologists, and the Japanese College of Veterinary. The published article can be found at: http://vet.sagepub.com/.Keywords: influenza, pneumonia, pandemic, pH1N1, lung, immunohistochemistry, ca

Isoelectric Focusing of Soluble Proteins in the Characterization of Species and Isolates of \u3ci\u3eNematodirus\u3c/i\u3e (Nematoda: Trichostrongyloidea)

Isoelectric focusing was performed on extracts from Nematodirus spathiger, Nematodirus filicollis, Nematodirus helvetianus, and three geographic isolates of Nematodirus battus. Gender-specific differences were noted within species; however, the overall protein profile of each species and isolate was distinct and reproducible and allowed unequivocal differentiation. A coefficient of similarity (Sm) for males of each species and isolate was calculated, and a dendrogram, based on evaluation of Sm by the unweighted pair-group method with arithmetic means, was produced. Although cluster analysis of the three isolates of N. battus indicates the North American and Weybridge isolates are similar, interpretation of the relationships and thus the history of introduction based on these data is equivocal. Isoelectric focusing is a robust method for establishing identity and has great utility in diagnostics. However, in the absence of selective histochemical staining, interpretation of identity and homology for specific bands and banding patterns is problematic, thus limiting the utility of this method for phylogenetic inference

Best practices for performance of real-time PCR assays in veterinary diagnostic laboratories

The exquisite sensitivity of in vitro amplification assays such as real-time polymerase chain reaction (rtPCR) requires the establishment of thorough and robust laboratory practices. To this end, an American Association of Veterinary Laboratory Diagnosticians (AAVLD) committee of subject matter experts was convened to develop a set of best practices for performance of nucleic acid amplification assays. Consensus advice for the performance of preanalytical, analytical, and postanalytical steps is presented here, along with a review of supporting literature

LöhrChristianeVeterinaryMedicinePathologyViralAntigen.pdf

A novel swine-origin H1N1 influenza A virus has been identified as the cause of the 2009 influenza pandemic in humans. Since then, infections with the pandemic (H1N1) 2009 influenza virus have been documented in a number of animal species. The first known cases of lethal respiratory disease associated with pandemic (H1N1) 2009 influenza virus infection in house pets occurred in domestic cats in Oregon. A 10-year-old, neutered male and an 8-year-old, spayed female domestic short hair cat died shortly after developing severe respiratory disease. Grossly, lung lobes of both cats were diffusely firm and incompletely collapsed. Histologically, moderate to severe, necrotizing to pyonecrotizing bronchointerstitial pneumonia was accompanied by serofibrinous exudation and hyaline membranes in the alveolar spaces. Influenza A virus was isolated from nasal secretions of the male and from lung homogenate of the female cat. Both isolates were confirmed as pandemic (H1N1) 2009 influenza virus by real-time reverse transcriptase PCR (rRT-PCR). Using immunohistochemistry, influenza A viral antigen was demonstrated in bronchiolar epithelial cells, pneumocytes and alveolar macrophages in pneumonic areas. The most likely sources of infection were people in the household with influenza-like illness or confirmed pandemic (H1N1) 2009 influenza. The two cases reported here provide, to the best of the authors’ knowledge, the first description of the pathology and viral antigen distribution of lethal respiratory disease in domestic cats after natural pandemic (H1N1) 2009 influenza virus infection, probably transmitted from humans

LöhrChristianeVeterinaryMedicinePathologyViralAntigen_Figures1-11.tif

A novel swine-origin H1N1 influenza A virus has been identified as the cause of the 2009 influenza pandemic in humans. Since then, infections with the pandemic (H1N1) 2009 influenza virus have been documented in a number of animal species. The first known cases of lethal respiratory disease associated with pandemic (H1N1) 2009 influenza virus infection in house pets occurred in domestic cats in Oregon. A 10-year-old, neutered male and an 8-year-old, spayed female domestic short hair cat died shortly after developing severe respiratory disease. Grossly, lung lobes of both cats were diffusely firm and incompletely collapsed. Histologically, moderate to severe, necrotizing to pyonecrotizing bronchointerstitial pneumonia was accompanied by serofibrinous exudation and hyaline membranes in the alveolar spaces. Influenza A virus was isolated from nasal secretions of the male and from lung homogenate of the female cat. Both isolates were confirmed as pandemic (H1N1) 2009 influenza virus by real-time reverse transcriptase PCR (rRT-PCR). Using immunohistochemistry, influenza A viral antigen was demonstrated in bronchiolar epithelial cells, pneumocytes and alveolar macrophages in pneumonic areas. The most likely sources of infection were people in the household with influenza-like illness or confirmed pandemic (H1N1) 2009 influenza. The two cases reported here provide, to the best of the authors’ knowledge, the first description of the pathology and viral antigen distribution of lethal respiratory disease in domestic cats after natural pandemic (H1N1) 2009 influenza virus infection, probably transmitted from humans

Suggested guidelines for validation of real-time PCR assays in veterinary diagnostic laboratories

This consensus document presents the suggested guidelines developed by the Laboratory Technology Committee (LTC) of the American Association of Veterinary Laboratory Diagnosticians (AAVLD) for development, validation, and modification (methods comparability) of real-time PCR (rtPCR) assays. These suggested guidelines are presented with reference to the World Organisation for Animal Health (OIE) guidelines for validation of nucleic acid detection assays used in veterinary diagnostic laboratories. Additionally, our proposed practices are compared to the guidelines from the Foods Program Regulatory Subdivision of the U.S. Food and Drug Administration (FDA) and from the American Society for Veterinary Clinical Pathology (ASVCP). The LTC suggestions are closely aligned with those from the OIE and comply with version 2021-01 of the AAVLD Requirements for an Accredited Veterinary Medical Diagnostic Laboratory, although some LTC recommendations are more stringent and extend beyond the AAVLD requirements. LTC suggested guidelines are substantially different than the guidelines recently published by the U.S. FDA for validation and modification of regulated tests used for detection of pathogens in pet food and animal-derived products, such as dairy. Veterinary diagnostic laboratories that perform assays from the FDA Bacteriological Analytical Method (BAM) manual must be aware of the different standard