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An avian-origin canine influenza virus (CIV) has recently emerged in dogs and is spreading in China. Given that humans have frequent contact with dogs, this has prompted an increased emphasis on biosafety. In this study, we collected 693 nasal swab samples and 800 blood samples from stray dogs in animal shelters to survey canine influenza epidemiology and characterize the evolution of CIV H3N2 in Shanghai. We tested samples for canine influenza antibodies and canine influenza RNA in January–May, 2019, and the results showed that the positive rate was 17.62% by ELISA, 15.75% by microneutralization (MN) assay, and 18.51% by real time RT-PCR, respectively. We also performed phylogenetic and genomic analysis on six H3N2 CIV isolates. The H3N2 viruses which prevailed in Shanghai originated from Beijing and Jiangsu isolates. Phylogenetic analysis showed that the sequences of CIV isolates have multiple amino acid antigenic drifts, deletions, and substitutions. The time of the most recent common ancestor (TMRCA) of HA and NA was 2004 and 2005, respectively. Notably, the substitution, 146S, in hemagglutinin and the deletion in the neuraminidase (NA) stalk region we found in this study warrant attention because they have frequently been identified in human influenza viruses. The potential adaptation of this CIV H3N2 clade to mammals and its public health threat should be further evaluated.

Background Avian influenza viruses represent a growing threat of an influenza pandemic. The co-circulation of multiple H9N2 genotypes over the past decade has been replaced by one predominant genotype-G57 genotype, which displays a changed antigenicity and improved adaptability in chickens. Effective H9N2 subtype avian influenza virus vaccines for poultry are urgently needed. Objective In this study, we constructed H9N2 subtype avian influenza virus-like particle (VLP) and evaluated its protective efficacy in specific pathogen-free (SPF) chickens to lay the foundation for developing an effective vaccine against influenza viruses. Methods Expression of influenza proteins in VLPs was confirmed by Western blot, hemagglutination inhibition (HI) and neuraminidase inhibition (NI). The morphology was observed by electron microscopy. A group of 15 three-week-old SPF chickens was divided into three sub-groups of five chickens immunized with VLP, commercial vaccine and PBS. Challenge study was performed to evaluate efficacy of VLP vaccine. Results and Conclusions The hemagglutinin (HA) and neuraminidase (NA) proteins were co-expressed in the infected cells, self-assembled, and were released into the culture medium in the form of VLPs of diameter ~80 nm. The VLPs exhibited some functional characteristics of a full influenza virus, including hemagglutination and neuraminidase activity. In SPF chickens, the VLPs elicited serum antibodies specific for H9N2, and induced a higher HI titer (as detected by a homologous antigen) than did a commercial H9N2 vaccine (A/chicken/Shanghai/F/1998). Viral shedding from VLP vaccine sub-group was reduced compared with commercial vaccine sub-group and control sub-group. This article is protected by copyright. All rights reserved.

For many years, pseudorabies has been efficiently controlled in China by vaccination. However, a sudden outbreak occurred on many pig farms during 2012-2013. In this study, phylogenetic analysis was carried out with the aim of understanding the genetic relatedness between strains in both populations and comparing strains in China with those circulating in other countries. To obtain more pathogenetic relevant data regarding two pseudorabies virus (PRV) isolates (SH2010 and SH2012) in sheep, we evaluated samples of PRV isolated in Shanghai, China between 2010 and 2012. Based on clinical signs, body temperature variation, and the maximum amounts of viral DNA in unvaccinated/infected sheep, the emerging PRV variant strain, SH2012 was observed to be more highly virulent than the traditional PRV SH2010 strain. The data of the present study will aid in a better understanding of the differences in pathogenicity between the traditional PRV SH2010 strain and the emerging PRV variant strain SH2012.

Porcine delta coronavirus (PDCoV) has been reported in many countries, including the United States, Canada, South Korea, China, Thailand, Vietnam and Laos. In December 2016, clinical diarrhea similar to that caused by porcine epidemic diarrhea virus (PEDV), but with a lower mortality rate, was reported on a swine farm in Shanghai, China. 6 Intestine samples were collected from dead suckling piglets (