Infection and pathogenesis of canine, equine, and human influenza viruses in canine tracheas (original) (raw)
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Journal of virology, 2015
The A/H3N8 canine influenza virus (CIV) emerged from A/H3N8 equine influenza virus (EIV) around the year 2000 through the transfer of a single virus from horses to dogs. We defined and compared the biological properties of EIV and CIV by examining their genetic variation, infection and growth in different cell cultures, receptor specificity, hemagglutinin (HA) cleavage, and infection and growth in horse and dog tracheal explant cultures. Comparison of sequences of viruses from horses and dogs revealed mutations that may be linked to host adaptation and tropism. We prepared infectious clones of representative EIV and CIV strains that were similar to the consensus sequences of viruses from each host. The rescued viruses, including HA and NA double reassortants, exhibited similar long-term growth in MDCK cells. Different host cells showed varying levels of susceptibility to infection, but no differences in infectivity were seen when comparing viruses. All viruses preferred α2-3 over α2...
Zoonotic Risk, Pathogenesis, and Transmission of Avian-Origin H3N2 Canine Influenza Virus
Journal of virology, 2017
Two subtypes of influenza A virus (IAV), avian-origin canine influenza virus H3N2 (CIV-H3N2) and equine-origin CIV-H3N8, are enzootic in the canine population. Dogs have demonstrated seroconversion to diverse IAVs and naturally occurring reassortants of CIV-H3N2 and the 2009 H1N1 pandemic virus (pdmH1N1) have been isolated. We conducted a thorough phenotypic evaluation of CIV-H3N2 in order to assess its threat to human health. Using ferret-generated antisera we determined that CIV-H3N2 is antigenically distinct from contemporary human H3N2 IAVs, suggesting there may be minimal herd immunity in humans. We assessed the public health risk of CIV-H3N2×pdmH1N1 reassortants by characterizing in vitro genetic compatibility and in vivo pathogenicity and transmissibility. Using a luciferase minigenome assay, we quantified the polymerase activity of all possible 16 ribonucleoprotein (RNP) complexes (PB2, PB1, PA, NP) between CIV-H3N2 and pdmH1N1 identifying some combinations that were more ac...
Epidemiology and infection, 2015
SUMMARY After an outbreak of pandemic influenza A/H1N1 (pH1N1) virus, we had previously reported the emergence of a recombinant canine influenza virus (CIV) between the pH1N1 virus and the classic H3N2 CIV. Our ongoing routine surveillance isolated another reassortant H3N2 CIV carrying the matrix gene of the pH1N1 virus from 2012. The infection dynamics of this H3N2 CIV variant (CIV/H3N2mv) were investigated in dogs and ferrets via experimental infection and transmission. The CIV/H3N2mv-infected dogs and ferrets produced typical symptoms of respiratory disease, virus shedding, seroconversion, and direct-contact transmissions. Although indirect exposure was not presented for ferrets, CIV/H3N2mv presented higher viral replication in MDCK cells and more efficient transmission was observed in ferrets compared to classic CIV H3N2. This study demonstrates the effect of reassortment of the M gene of pH1N1 in CIV H3N2.
Compendium (Yardley, PA), 2010
Canine influenza virus (CIV) is a newly identified, highly contagious respiratory pathogen of dogs. The clinical disease has high morbidity and low mortality. Diagnosis of canine influenza is based on acute and convalescent serum samples, history, and clinical signs. Phylogenetic analysis has shown that the etiologic agent is an influenza A virus that is closely related to the equine influenza A (H3N8) virus. Data collected thus far support transmission from horses to dogs with horizontal spread in the canine population. This interspecies jump and the close companionship of dogs and people warrant close monitoring of CIV for potential transmission to humans.
Recent evolution of equine influenza and the origin of canine influenza
Proceedings of the National Academy of Sciences of the United States of America, 2014
In 2004 an hemagglutinin 3 neuraminidase 8 (H3N8) equine influenza virus was transmitted from horses to dogs in Florida and subsequently spread throughout the United States and to Europe. To understand the molecular basis of changes in the antigenicity of H3 hemagglutinins (HAs) that have occurred during virus evolution in horses, and to investigate the role of HA in the equine to canine cross-species transfer, we used X-ray crystallography to determine the structures of the HAs from two antigenically distinct equine viruses and from a canine virus. Structurally all three are very similar with the majority of amino acid sequence differences between the two equine HAs located on the virus membrane-distal molecular surface. HAs of canine viruses are distinct in containing a Trp-222 → Leu substitution in the receptor binding site that influences specificity for receptor analogs. In the fusion subdomain of canine and recent equine virus HAs a unique difference is observed by comparison ...
Emergence and Containment of Canine Influenza Virus A(H3N2), Ontario, Canada, 2017–2018
Emerging Infectious Diseases
Canine influenza virus (CIV) A(H3N2) was identified in 104 dogs in Ontario, Canada, during December 28, 2017-October 30, 2018, in distinct epidemiologic clusters. High morbidity rates occurred within groups of dogs, and kennels and a veterinary clinic were identified as foci of infection. Death attributable to CIV infection occurred in 2 (2%) of 104 diagnosed cases. A combination of testing of suspected cases, contact tracing and testing, and 28-day isolation of infected dogs was used, and CIV transmission was contained in each outbreak. Dogs recently imported from Asia were implicated as the source of infection. CIV H3N2 spread rapidly within groups in this immunologically naive population; however, containment measures were apparently effective, demonstrating the potential value of prompt diagnosis and implementation of CIV control measures. C anine influenza virus (CIV) is a regional cause of disease in dogs that has emerged from other host species of influenza A viruses (IAVs) as a result of adaptation and subsequent transmission within the naive dog population (1,2). Two main CIV strains are currently recognized. CIV A(H3N8) is an equine-origin virus that was identified in dogs in the United States in the early 2000s (1) but that is rarely identified now. In contrast, CIV H3N2 emerged in Asia from an avian influenza virus (H3N2) (2,3) and can be found in different regions in Asia (2-4). It was subsequently introduced to the United States on multiple occasions through importation of dogs from South Korea and China (5,6). Within an immunologically naive canine population, CIV can spread widely when introduced to a new dog population, and result in widespread illness and sporadic death. There is also some concern about the potential for CIV H3N2 to recombine with other IAVs (7), including human IAVs, potentially resulting in antigenic shift and creating relatively novel IAVs with broader host range and pandemic potential. Novel CIVs are of concern for canine health because of the naive population and potential for rapid and widespread transmission. International, including transcontinental, movement of dogs is common, and CIV is one of many pathogens that can accompany transported dogs. In 2015, CIV H3N2 was introduced into the United States through the importation of dogs from Asia; the virus continues to circulate in the canine population within the country from that or subsequent importations (5,6,8). Despite its presence in the United States, CIV H3N2 had not been identified in Canada until the end of 2017. We describe the introduction and containment of CIV H3N2 in Ontario, Canada. Outbreak Investigation Clinical testing identified CIV H3N2 in Ontario in December 2017, prompting prospective surveillance and interventions. Initial clinical diagnoses were based on positive H3N2 PCR results from a commercial respiratory PCR panel (IDEXX Laboratories, https://ca.idexx.com). Subsequent testing was performed at the Animal Health Laboratory, University of Guelph (Guelph, ON, Canada), using IAV matrix gene real-time PCR (rPCR) testing of nasal or pharyngeal swab specimens or a repeat of the respiratory PCR panel test. H3N2-specific hemagluttination inhibition (HI) testing was performed at the
The Journal of Infectious Diseases
Background. A single subtype of canine influenza virus (CIV), A(H3N8), was circulating in the United States until a new subtype, A(H3N2), was detected in Illinois in spring 2015. Since then, this CIV has caused thousands of infections in dogs in multiple states. Methods. In this study, genetic and antigenic properties of the new CIV were evaluated. In addition, structural and glycan array binding features of the recombinant hemagglutinin were determined. Replication kinetics in human airway cells and pathogenesis and transmissibility in animal models were also assessed. Results. A(H3N2) CIVs maintained molecular and antigenic features related to low pathogenicity avian influenza A(H3N2) viruses and were distinct from A(H3N8) CIVs. The structural and glycan array binding profile confirmed these findings and revealed avian-like receptor-binding specificity. While replication kinetics in human airway epithelial cells was on par with that of seasonal influenza viruses, mild-to-moderate disease was observed in infected mice and ferrets, and the virus was inefficiently transmitted among cohoused ferrets. Conclusions. Further adaptation is needed for A(H3N2) CIVs to present a likely threat to humans. However, the potential for coinfection of dogs and possible reassortment of human and other animal influenza A viruses presents an ongoing risk to public health.
Equine and canine influenza: a review of current events
Animal Health Research Reviews, 2010
In the past decade, the pandemics of highly pathogenic avian influenza H5N1 and the novel H1N1 influenza have both illustrated the potential of influenza viruses to rapidly emerge and spread widely in animals and people. Since both of these viruses are zoonotic, these pandemics have been the driving force behind a renewed commitment by the medical and veterinary professions to practice One World, One Health for the control of infectious diseases. The discovery in 2004 that an equine origin H3N8 influenza virus was the cause of an extensive epidemic of respiratory disease in dogs in the USA came as a surprise; at that time dogs were thought to be refractory to infection with influenza viruses. In 2007, a second emerging canine influenza was confirmed in Korea, but this time the causal virus was an H3N2 avian influenza virus. This review focuses on recent events associated with equine and canine influenza viruses. While these viruses do not appear to be zoonotic, the close association between humans and dogs, and to a lesser extent horses, demands that we develop better surveillance and control strategies for emerging diseases in companion animals within the context of One World, One Health.