Lack of exposure of H10N8 avian influenza virus among veterinarians in Guangdong Province, China.

We conducted a retrospective seroepidemiological study for H10N8 avian influenza infection among 400 veterinarians sampled from February 2013 to August 2013 in Guangdong Province, China. None of the veterinarians had evidence of previous infection with the emergent H10N8 AIV. Although there is no evidence of H10N8-infected veterinarian before the first human index case of H10N8 infection in southern China, a more rigorous and long-term surveillance remained essential for early warning of novel reassortant viruses and interspecies transmission events.

Detection of Anaplasma platys in dogs using real-time loop-mediated isothermal amplification.

Anaplasma platys is a parasite of canine platelets that causes infectious cyclic thrombocytopenia. In this study, a novel real-time loop-mediated isothermal amplification (RT-LAMP) method was developed to detect A. platys. RT-LAMP primer sets were designed using a citrate synthase gene sequence and the assay was performed at 63 °C for 30 min. No cross-reactivity was observed with other Anaplasma or Ehrlichia spp. and the method exhibited a similar level of sensitivity in detecting the organism in 58 canine blood samples to that of a nested PCR. This RT-LAMP is a rapid and potentially cost-effective method of diagnosing A. platys infection in dogs.

Complete genome sequence of an avian-like H4N8 swine influenza virus discovered in southern China.

We report here the complete genomic sequence of an avian-like H4N8 swine influenza virus containing an H5N1 avian influenza virus segment from swine in southern China. Phylogenetic analyses of the sequences of all eight viral RNA segments demonstrated that these are wholly avian influenza viruses of the Asia lineage. To our knowledge, this is the first report of interspecies transmission of an avian H4N8 influenza virus to domestic pigs under natural conditions.

Seroprevalence of Toxoplasma gondii infection in dairy cattle in southern China.

BACKGROUND: As an obligate intracellular parasite, Toxoplasma gondii can infect humans and almost all warm-blooded animals. The consumption of raw or undercooked beef and milk is considered a risk for T. gondii infection in humans. However, little is known of T. gondii infection in dairy cattle in metropolitan Guangzhou, southern China. This study was performed to determine the seroprevalence of T. gondii in dairy cattle in Guangzhou, southern China. FINDINGS: Serum samples were collected from 350 dairy cattle on five farms in Guangzhou, China from 2009 to 2010, and all of the 350 serum samples were examined for specific antibodies to T. gondii by indirect hemagglutination antibody test (IHA). The overall seroprevalence of T. gondii in dairy cattle was 5.7% (20/350). Among these examined dairy cattle, dairy cattle which were < 6 year old or ≥ 5 year old had the highest seroprevalence of 12.5% followed by those dairy cattle which were < 5 year old or ≥ 4 year old (8%); dairy cattle with 3 pregnancies had the highest seroprevalence (11.5%), among the examined dairy cattle, although these differences were not statistically significant. CONCLUSIONS: The results of the present survey indicate that T. gondii infection is prevalent in dairy cattle of all age ranges in Guangzhou, southern China, which may be a risk factor for human infection with T. gondii in this region.Dong-Hui Zhou and Fu-Rong Zhao contributed equally.

Generation of E3-deleted canine adenovirus type 2 expressing the Gc glycoprotein of Seoul virus by gene insertion or deletion of related terminal region sequences.

Seoul virus (SEOV) is one of the four hantaviruses known to cause haemorrhagic fever with renal syndrome. The medium genome segment encodes the Gn/Gc glycoproteins of SEOV, which form the major structural part of the virus envelope. Gc and/or Gn are the candidate antigens of hantavirus for induction of a highly immunogenic response for hantavirus vaccine. In this study, the immune response induced by a replication-competent recombinant canine adenovirus type 2 expressing the Gc protein of SEOV was evaluated in BALB/c mice. Sera from immunized mice contained neutralizing antibodies that could specifically recognize SEOV and neutralize its infectivity in vitro. Moreover, the recombinant virus induced complete protection against an intensive infectious challenge with approximately 1000 50 % infective doses for SEOV strain CC-2. Protective-level neutralizing antibodies were maintained for at least 20 weeks. This recombinant virus is therefore a potential alternative to the inactivated vaccine.