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

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

Development of an enzyme immunoassay for detection of antibodies against Coccidioides in dogs and other mammalian species

Coccidioides is a soil-dwelling fungus that causes coccidioidomycosis, a disease also known as Valley fever, which affects humans and a variety of animal species. Recent findings of Coccidioides in new, unexpected areas of the United States have demonstrated the need for a better understanding of its geographic distribution. Large serological studies on animals could provide important information on the geographic distribution of this pathogen. To facilitate such studies, we used protein A/G, a recombinant protein that binds IgG antibodies from a variety of mammalian species, to develop an enzyme immunoassay (EIA) that detects IgG antibodies against Coccidioides in a highly sensitive and high-throughput manner. We showed the potential of this assay to be adapted to multiple animal species by testing a collection of serum and/or plasma samples from dogs, mice, and humans with or without confirmed coccidioidomycosis. We then evaluated the performance of the assay in dogs, using sera from dogs residing in a highly endemic area, and found seropositivity rates significantly higher than those in dogs of non-endemic areas. We further evaluated the specificity of the assay in dogs infected with other fungal pathogens known to cross-react with Coccidioides. Finally, we used the assay to perform a cross-sectional serosurvey investigating dogs from Washington, a state in which infection with Coccidioides has recently been documented. In summary, we have developed a Coccidioides EIA for the detection of antibodies in canines that is more sensitive and has higher throughput than currently available methods, and by testing this assay in mice and humans, we have shown a proof of principle of its adaptability for other animal species.Open Access Journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Comparison of AGID and EIA results for dog sera from confirmed coccidioidomycosis cases and healthy controls.

<p>Comparison of AGID and EIA results for dog sera from confirmed coccidioidomycosis cases and healthy controls.</p

Corresponding table for ROC curve analysis.

<p>Corresponding table for ROC curve analysis.</p

Detection of IgG antibodies against <i>Coccidioides</i> from multiple mammalian species using protein A/G.

<p>EIA units from healthy and <i>Coccidiodes</i>-infected mouse, dog, and human sera/plasma samples. The y-axis is split with a scale of 0–1.5 EIA units and of 1.5–20 EIA units.</p

Comparison of EIA reactivity in sera from dogs residing in endemic (Arizona), non-endemic, and newly endemic (Washington) areas.

<p>Comparison of EIA reactivity in sera from dogs residing in endemic (Arizona), non-endemic, and newly endemic (Washington) areas.</p

Comparison of characteristics between Arizona dogs with positive and negative presence of IgG antibodies.

<p>Comparison of characteristics between Arizona dogs with positive and negative presence of IgG antibodies.</p

ROC curve analysis shows a high degree of diagnostic accuracy for the assay.

<p>Sensitivity and 1-Specificity were plotted for healthy dogs (n = 25) and dogs confirmed with coccidioidomycosis (n = 37). Estimated area under the curve (A) is 0.97.</p