Seroprevalence of dogs in Hong Kong to human and canine influenza viruses

Evaluation of a SARS-CoV-2 Surrogate Virus Neutralization Test for Detection of Antibody in Human, Canine, Cat, and Hamster Sera

Surrogate neutralization assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that can be done without biosafety level 3 containment and in multiple species are desirable. We evaluate a recently developed surrogate virus neutralization test (sVNT) in comparison to 90% plaque reduction neutralization tests (PRNT₉₀) in human, canine, cat, and hamster sera. With PRNT₉₀ as the reference, sVNT had sensitivity of 98.9% and specificity of 98.8%. Using a panel of immune sera corresponding to other coronaviruses, we confirm the lack of cross-reactivity to other coronaviruses in SARS-CoV-2 sVNT and PRNT₉₀, except for cross-reactivity to SARS-CoV-1 in sVNT.

Surrogate neutralization assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that can be done without biosafety level 3 containment and in multiple species are desirable. We evaluate a recently developed surrogate virus neutralization test (sVNT) in comparison to 90% plaque reduction neutralization tests (PRNT₉₀) in human, canine, cat, and hamster sera. With PRNT₉₀ as the reference, sVNT had sensitivity of 98.9% and specificity of 98.8%. Using a panel of immune sera corresponding to other coronaviruses, we confirm the lack of cross-reactivity to other coronaviruses in SARS-CoV-2 sVNT and PRNT₉₀, except for cross-reactivity to SARS-CoV-1 in sVNT.

Tropism of SARS-CoV-2, SARS-CoV and influenza virus in canine tissue explants

Background

Human spillovers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to dogs and the emergence of a highly contagious avian-origin H3N2 canine influenza virus have raised concerns on the role of dogs in the spread of SARS-CoV-2 and their susceptibility to existing human and avian influenza viruses, which might result in further reassortment.

Methods

We systematically studied the replication kinetics of SARS-CoV-2, SARS-CoV, influenza A viruses of H1, H3, H5, H7, and H9 subtypes, and influenza B viruses of Yamagata-like and Victoria-like lineages in ex vivo canine nasal cavity, soft palate, trachea, and lung tissue explant cultures and examined ACE2 and sialic acid (SA) receptor distribution in these tissues.

Results

There was limited productive replication of SARS-CoV-2 in canine nasal cavity and SARS-CoV in canine nasal cavity, soft palate, and lung, with unexpectedly high ACE2 levels in canine nasal cavity and soft palate. Canine tissues were susceptible to a wide range of human and avian influenza viruses, which matched with the abundance of both human and avian SA receptors.

Conclusions

Existence of suitable receptors and tropism for the same tissue foster virus adaptation and reassortment. Continuous surveillance in dog populations should be conducted given the many chances for spillover during outbreaks.

Canine and Feline Influenza

Influenza virus infections of carnivores-primarily in dogs and in large and small cats-have been repeatedly observed to be caused by a number of direct spillovers of avian viruses or in infections by human or swine viruses. In addition, there have also been prolonged epizootics of an H3N8 equine influenza virus in dogs starting around 1999, of an H3N2 avian influenza virus in domestic dog populations in Asia and in the United States that started around 2004, and an outbreak of an avian H7N2 influenza virus among cats in an animal shelter in the United States in 2016. The impact of influenza viruses in domesticated companion animals and their zoonotic or panzootic potential poses significant questions for veterinary and human health.

Serosurvey of pandemic H1N1 influenza A virus in dogs in Andalusia (southern Spain)

In April 2009, a new influenza A virus (IAV) subtype (A(H1N1)pdm09) spread worldwide and triggered the first human influenza pandemic of the 21st century. Since then, exposure to the pandemic H1N1 IAV has been confirmed in different animal species. Serological evidence and clinical infection with A(H1N1)pdm09 have been reported in canines, but the information available about the role of dogs in the epidemiology of this IAV subtype is still very limited in Europe. A cross-sectional study was carried out to determine the seroprevalence of A(H1N1)pdm09 in dogs in southern Spain, a region with endemic seasonal circulation in human. Sera from 750 companion dogs were collected during the period 2013-2016. Antibodies against pandemic H1N1 IAV were analysed using the haemagglutination inhibition test. Positive samples were also tested by single radial haemolysis assay. Seropositivity was only confirmed by both methods in one (0.13%; 95% CI: 0.00-0.38) adult animal sampled in 2013. To the best of the authors' knowledge, this is the first report of A(H1N1)pdm09 exposure in dogs in Spain. The low seroprevalence obtained indicates a limited exposure history to A(H1N1)pdm09 IAV in dogs in this country and suggests a low risk of transmission of this zoonotic IAV subtype between humans and dogs.

Serologic investigation of influenza A virus infection in dogs in Poland

The 2 predominant circulating subtypes of influenza A virus in the dog population, equine-origin H3N8 and avian-origin H3N2, constitute a potential zoonotic risk. We determined the prevalence of influenza A antibodies in 496 dogs in Poland and found 2.21% of sera positive by commercial ELISA. Hemagglutination inhibition (HI) assays indicated 7.25% of sera positive using equine H3N8, swine H3N2, and pandemic H1N1 antigens, with the most frequently detected immune response being to H3N2. Considering interspecies transfer, reassortment ability, and close contact between dogs and humans, infections of dogs with influenza A virus should be monitored.