Although viruses of each of the 16 influenza A HA subtypes are potential human pathogens, only viruses of the H1, H2, and H3 subtype are known to have been successfully established in humans. H2 influenza viruses have been absent from human circulation since 1968, and as such they pose a substantial human pandemic risk. In this report, we isolate and characterize genetically similar avian/swine virus reassortant H2N3 influenza A viruses isolated from diseased swine from two farms in the United States. These viruses contained leucine at position 226 of the H2 protein, which has been associated with increased binding affinity to the mammalian ␣2,6Gal-linked sialic acid virus receptor. Correspondingly, the H2N3 viruses were able to cause disease in experimentally infected swine and mice without prior adaptation. In addition, the swine H2N3 virus was infectious and highly transmissible in swine and ferrets. Taken together, these findings suggest that the H2N3 virus has undergone some adaptation to the mammalian host and that their spread should be very closely monitored.avian ͉ reassortant ͉ interspecies transmission

The transmission of pathogens from infected to susceptible hosts may occur through contaminated fomites and inanimate objects. This type of transmission depends on the ability of the pathogens to survive in the environment. In this report, we describe the survivability of two avian respiratory viruses, e.g., avian metapneumovirus and avian influenza virus on 12 different porous and nonporous surfaces. The viruses survived on some of the surfaces for up to 6 days postcontamination but not after 9 days. Both viruses survived longer on nonporous surfaces than on porous ones. One of the reasons for poor survival on porous surfaces could be inefficient elution of virus from these surfaces. These results should be helpful in determining how long the premises should be left vacant after an outbreak of these viruses has occurred in poultry houses.

No abstract

Porcine oral fluids have been used for the detection of Porcine reproductive and respiratory syndrome virus and Porcine circovirus-2. The objective of the present study was to determine whether Influenza A virus (FLUAV) is present in porcine oral fluids at detectable levels and to validate a standard FLUAV molecular diagnostic test for porcine oral fluids. Pen-based oral fluid samples were collected on 3, 4, 5, and 6 days postinfection (DPI) from 4 groups of 6 pigs each that were inoculated intratracheally with A/Swine/Iowa/00239/2004 H1N1 and from 2 untreated or mock-inoculated groups of 6 pigs each that served as negative controls. Individual nasal swabs were also collected from these 36 pigs on 3 and 7 DPI. All oral fluid samples were examined for the presence of FLUAV by matrix gene real-time reverse transcription polymerase chain reaction (real-time RT-PCR) and virus isolation. Nasal swabs were tested initially by virus isolation followed by retest of negative samples with real-time RT-PCR. No oral fluid sample from virus-inoculated pigs was positive by virus isolation, but 15 of 16 positive (94%) oral fluids were positive by real-time RT-PCR. In contrast, virus was isolated from 32 of 48 (67%) nasal swabs collected from virus-inoculated pigs. In addition, 382 of 910 porcine oral fluids collected from pigs in the field between August 1, 2009, and January 31, 2010, were positive by real-time RT-PCR. The results of the present study indicate that pen-based oral fluids provide an easy, effective, and safe collection method for the detection of FLUAV with rapid testing methods such as real-time RT-PCR.

This study was conducted to detect and characterize enteric viruses [rotavirus, turkey astrovirus-2 (TAstV-2), reovirus, and turkey coronavirus] from cases of poult enteritis syndrome (PES) in Minnesota turkeys. Of the intestinal contents collected from 43 PES cases, 25 were positive for rotavirus and 13 for small round viruses by electron microscopy (EM). Of the enteric virus-positive cases by EM (n=27), 16 cases had rotavirus or small round viruses alone and the remaining 11 cases had both viruses. None of the cases were positive for reovirus or coronavirus by EM. However, with reverse transcription-PCR (RT-PCR), 40 cases (93%) were positive for rotavirus, 36 (84%) for TAstV-2, and 17 (40%) for reovirus. None of the cases were positive for turkey coronavirus by RT-PCR. The viruses from all cases were detected either alone or in combination of 2 or 3 by RT-PCR. Thus, 8 (19%) cases were positive for a single virus, whereas a combination of viruses was detected in the remaining 35 (81%) cases. The rota-TAstV-2 combination was the most predominant (n=18 cases). Fifteen cases were positive for all 3 viruses. The rotaviruses had sequence homology of 89.8 to 100% with previously published sequences of turkey rotaviruses at the nucleotide level. The TAstV-2 had sequence homology of 84.6 to 98.7% with previously published TAstV-2, whereas reoviruses had sequence homology of 91.6 to 99.3% with previously published sequences of turkey reoviruses. Phylogenetic analysis revealed that rota- and reoviruses clustered in a single group, whereas TAstV-2 clustered in 2 different groups. In conclusion, a larger number of PES cases was positive for rotavirus, TAstV-2, and reovirus by RT-PCR than with EM. The presence of more than one virus and changes at the genetic level in a virus may affect the severity of PES in turkey flocks.