Evidence of transmission and risk factors for influenza A virus in household dogs and their owners

Abstract

BackgroundThe possible transmission of influenza A virus between dogs and humans is important, as in Mexico City there are approximately 1·2 million dogs. We present the first evidence of influenza A virus infection in household dogs in Mexico.ObjectivesThe objective of this study was to identify the presence of antibodies against influenza A virus in dogs and their owners, as well as the presence of RNA of influenza A virus in nasal exudates of dogs and, thereby, assess the possible transmission of the virus between humans and dogs.MethodsSerum samples from household dogs and their owners were analyzed to detect the presence of antibodies against three subtypes of human influenza virus (H1N1pdm09, H1N1, and H3N2), as well as subtype H3N8 of equine influenza. We analyzed dog nasal exudates to detect influenza viral RNA. The relationship between the seropositivity of dogs and various factors (age, sex, constantly at home, and seropositivity of owners) was statistically analyzed.ResultsSeroprevalence for human influenza in dogs was 0·9% (1 of 113), and it was 4% (5 of 113) for equine influenza. In humans, seroprevalence was 22% for subtype H1N1pdm09, 20% for subtype H1N1, and 11% for subtype H3N2. No significant association (P > 0·05) was found between seropositivity and any of the assessed factors. Furthermore, no viral RNA was detected in the nasal exudate samples.ConclusionsResults revealed seroprevalence of the influenza virus in household dogs in Mexico City. It can be assumed that dogs are currently becoming infected with different subtypes of influenza viruses.

Evidence for Subclinical Influenza A(H1N1)pdm09 Virus Infection among Dogs in Guangdong Province, China

“…However, like our results, a similarly high seroprevalence (22.5%) of influenza A(H1N1)pdm09 infection was found among U.S. cats, and ϳ10% of the cats were noted to have signs of acute respiratory illness (19). Moreover, during a 2010 (H1N1)pdm09 outbreak in a cat colony in Italy, researchers identified higher seroprevalence (55%) of A(H1N1)pdm09 infection and a higher mortality rate (28%) (7,18). Our findings highlight the limitations of relying upon specimens from dogs with clinical signs of influenza infection for customary studies of A(H1N1)pdm09 in dogs.…”

Epidemiology, ecology and gene pool of influenza A virus in Egypt: Will Egypt be the epicentre of the next influenza pandemic?

“…Equine H7N7 subtype has not been isolated since 1978 103 but H3N8 virus is still evolving. It crossed the species barrier to dogs [104][105][106][107][108] and probably to humans as well. [109][110][111] Swapping of gene segments between equine H3N8, avian, swine and humans IAV has been reported.…”

Infection and Pathogenesis of Canine, Equine, and Human Influenza Viruses in Canine Tracheas

“…Dogs are frequently exposed to human influenza viruses, and previous reports have shown that dogs are susceptible to human influenza viruses (28)(29)(30). As the 2009 pandemic was caused by an IAV that originated in pigs after a series of complex reassortment events that included swine, human, and avian viruses (1), and given the close interaction between humans and dogs, we wanted to determine whether human influenza viruses could infect the same tissues and cells as CIV.…”

“…Human IAVs have not become established in dogs despite serological evidence of exposure and infection (28,30). In fact, before the emergence of H3N8 CIV, dogs had not generally been considered natural hosts of IAVs.…”