Emergence and Evolution of Novel Reassortant Influenza A Viruses in Canines in Southern China

Abstract

The capacity of influenza A viruses (IAVs) to host jump from animal reservoir species to humans presents an ongoing pandemic threat. Birds and swine are considered major reservoirs of viral genetic diversity, whereas equines and canines have historically been restricted to one or two stable IAV lineages with no transmission to humans. Here, by sequencing the complete genomes of 16 IAVs obtained from canines in southern China (Guangxi Zhuang Autonomous Region [Guangxi]) in 2013 to 2015, we demonstrate that the evolution of canine influenza viruses (CIVs) in Asian dogs is increasingly complex, presenting a potential threat to humans. First, two reassortant H1N1 virus genotypes were introduced independently from swine into canines in Guangxi, including one genotype associated with a zoonotic infection. The genomes contain segments from three lineages that circulate in swine in China: North American triple reassortant H3N2, Eurasian avian-like H1N1, and pandemic H1N1. Furthermore, the swine-origin H1N1 viruses have transmitted onward in canines and reassorted with the CIV-H3N2 viruses that circulate endemically in Asian dogs, producing three novel reassortant CIV genotypes (H1N1r, H1N2r, and H3N2r [r stands for reassortant]). CIVs from this study were collected primarily from pet dogs presenting with respiratory symptoms at veterinary clinics, but dogs in Guangxi are also raised for meat, and street dogs roam freely, creating a more complex ecosystem for CIV transmission. Further surveillance is greatly needed to understand the full genetic diversity of CIV in southern China, the nature of viral emergence and persistence in the region’s diverse canine populations, and the zoonotic risk as the viruses continue to evolve.

Metagenomic analysis of viral nucleic acid extraction methods in respiratory clinical samples

“…1), and even obtained the full PIV3 genome sequence, thus providing sufficient sequence information to confirm virus identity. With whole viral genome sequences, it can also inform likely phenotypes, including drug susceptibility or neutralization serotypes and may prove useful in viral transmission and evolution studies [21,22]. To our best knowledge, this is the first study on viral metagenomics analysis of respiratory clinical samples without pre-treatment approach using the RPMK.…”

When Pigs Fly: Pandemic influenza enters the 21st century

“…The most pronounced change in attitudes towards dogs has been in China, where pet dogs are surging in popularity in urban areas after being banned for many decades. High rates of CIV have been observed in pets in Chinese cities [33]. It remains unclear how populations of meat dogs, strays, and pets interact and collectively contribute to CIV emergence and transmission.…”

“…It remains unclear how populations of meat dogs, strays, and pets interact and collectively contribute to CIV emergence and transmission. A diversity of swine-origin [33], human-origin [34], and reassortant IAVs have been isolated from dogs in Asia but with unknown degrees of onward transmission. High contact rates between canines and humans provides frequent opportunities for zoonotic transmission, and further research is greatly needed to understand the extent to which Asia's rapidly expanding dog populations present a pandemic risk.…”

Peer Review #2 of "Genetic and serologic surveillance of canine (CIV) and equine (EIV) influenza virus in Nuevo León State, México (v0.1)"

“…Nevertheless, some animal species could have a role as a mixing vessel of segments that would give rise to potentially zoonotic subtypes. Among these species, domestic animals such as pet dogs and horses stand out (Parrish et al, 2015;Chen et al, 2018). Because these species are companion animals for humans, the presence of Influenza virus in these species could represent a public health risk for both human and animal populations.…”