Avian-origin H3N2 canine influenza virus circulating in farmed dogs in Guangdong, China

Abstract

Since 2006, more and more cases of the infectious H3N2 canine influenza virus (CIV) in pet dogs have been reported in southern China. However, little is known about the prevalence situation of H3N2 CIV infections in farmed dogs in China. This is the first systematic epidemiological surveillance of CIV in different dog populations in southern China. Two virus strains A/Canine/Guangdong/1/2011(H3N2) and A/canine/Guangdong/5/2011(H3N2) were isolated from canine nasal swabs collected at one dog farm in Guangzhou and the other farm in Shenzhen. Sequence and phylogenetic analysis of eight gene segments of these viruses revealed that they were most similar to the newly isolated canine H3N2 viruses in dogs and cats from Korea and China, which originated from avian strain. This indicates that H3N2 CIV may be a common pathogen for pet and farmed dog populations in southern China at present. Serological surveillance has shown that the infection rate of this avian-origin canine influenza in farmed dogs and in pet dogs were 12.22% and 5.3%, respectively; as determined by the ELISA. The data also suggested that transmission occurred, most probably by close contact, between H3N2 CIV infected dogs in different dog populations in recently years. As H3N2 outbreaks among dogs continue in the Guangdong province (located very close to Hong Kong), the areas where is densely populated and with frequent animal trade, there is a continued risk for pets H3N2 CIV infections and for mutations or genetic reassortment leading to new virus strains with increased transmissibility among dogs. Further in-depth study is required as the H3N2 CIV has been established in different dog populations and posed potential threat to public health.

Origins and Evolutionary Dynamics of H3N2 Canine Influenza Virus

“…Since the discovery of H3N2 CIV in 2007, most studies have focused on the genetic and virological characterization of individual isolates (6, 16, 18-21, 23, 25, 26) and on clinical and epidemiological investigations (20,(22)(23)(24). Here we compiled all the publicly available complete genome sequences of CIV and carried out a comprehensive phylogenetic analysis to elucidate its evolutionary history.…”

“…However, a subsequent study showed that H3N2 CIV was already present in China in 2006 (16), and serological surveys using archived sera from dogs in South Korea showed evidence of CIV H3N2 infections as early as 2005 (17). Since then, H3N2 CIVs have often been isolated in dogs in both China and South Korea, indicating that this virus is stably circulating in the Asian canine population (18)(19)(20)(21)(22). Moreover, the geographical distribution of this virus is rapidly expanding, as it has also been isolated in dogs in Thailand (23).…”

Evidence of pandemic H1N1 influenza exposure in dogs and cats, Thailand: A serological survey

“…Canine influenza viruses have been reported in many countries starting from the outbreak of equine origin H3N2 in the US, 2004 (Crawford et al, ). CIV subtype H3N2 have been reported in South Korea, China and Thailand (Bunpapong et al, ; Li et al, ; Lin, Zhao, Zeng, Lu, & Liu, ; Song et al, ; Su et al, ; Sun et al, ). Inter‐species transmission between dogs and cats have also been reported (Kim et al, ).…”

Detection prevalence of H5N1 avian influenza virus among stray cats in eastern China

“…But as only two of the 1,020 serum samples evidenced previous H5N1 infection, the results showed that the transmission of H5N1 AIV seems very low, at least this strain of H5N1 HP‐AIV belongs to Clade 2.3.2 and that the H5N1 infections in poultry did not significantly affect the rural animal shelters or suburban environment in eastern China. Indeed, until now, no evidence of H5N1 AIV infection in stray cat population were performed in areas where cats and dogs could be potentially exposed to AIV [Wan et al, ; Paltrinieri et al, ; Piccirillo et al, ; Su et al, ]. As H5N1 outbreaks among avian continue in the region, and dogs and cats in China have been confirmed that they can infect with H5N1 AIV and other subtype AIVs, there is a continued risk for feline H5N1 virus infections.…”