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Summary: Using next‐generation sequencing on vesicular swab and serum from swine from the USA exhibiting lameness and vesicles, porcine pegivirus (PPgV) was first identified and genetically characterized in the United States. Further screening using RT‐PCR revealed that 24 of 159 (15.1%) serum samples were positive for PPgV. Future studies are needed to understand clinical impacts of the virus. [ABSTRACT FROM AUTHOR]

Influenza A virus ( IAV) surveillance using pre-weaning oral fluid samples from litters of piglets was evaluated in four ˜12 500 sow and IAV-vaccinated, breeding herds. Oral fluid samples were collected from 600 litters and serum samples from their dams at weaning. Litter oral fluid samples were tested for IAV by virus isolation, quantitative reverse transcription-polymerase chain reaction (q RT- PCR), RT- PCR subtyping and sequencing. Commercial nucleoprotein ( NP) enzyme-linked immunosorbent assay ( ELISA) kits and NP isotype-specific assays ( Ig M, Ig A and Ig G) were used to characterize NP antibody in litter oral fluid and sow serum. All litter oral fluid specimens ( n = 600) were negative by virus isolation. Twenty-five oral fluid samples (25/600 = 4.2%) were q RT- PCR positive based on screening ( Laboratory 1) and confirmatory testing ( Laboratory 2). No hemagglutinin ( HA) and neuraminidase ( NA) gene sequences were obtained, but matrix ( M) gene sequences were obtained for all q RT- PCR-positive samples submitted for sequencing ( n = 18). Genetic analysis revealed that all M genes sequences were identical ( Gen Bank accession no. ) and belonged to the triple reassortant influenza A virus M gene ( TRIG M) previously identified in swine. The proportion of Ig M- and Ig A-positive samples was significantly higher in sow serum and litter oral fluid samples, respectively ( P < 0.01). Consistent with the extensive use of IAV vaccine, no difference was detected in the proportion of Ig G- and blocking ELISA-positive sow serum and litter oral fluids. This study supported the use of oral fluid sampling as a means of conducting IAV surveillance in pig populations and demonstrated the inapparent circulation of IAV in piglets. Future work on IAV oral fluid diagnostics should focus on improved procedures for virus isolation, subtyping and sequencing of HA and NA genes. The role of antibody in IAV surveillance remains to be elucidated, but longitudinal assessment of specific antibody has the potential to provide information regarding patterns of infection, vaccination status and herd immunity. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome virus ( PRRSV)-contaminated semen from boars is a route of transmission to females, and early detection of PRRSV infection in boars is a key component in sow farm biosecurity. The purpose of this study was to determine the optimum diagnostic specimen(s) for the detection of acute PRRSV infection in boars. Individually housed boars ( n = 15) were trained for semen and oral fluid collection and then vaccinated with a commercial PRRSV modified live virus vaccine. Starting on the day of vaccination and for 14 days thereafter, oral fluid specimens were collected daily from all boars. The 15 boars were subdivided into three groups of 5, and serum, blood swabs and 'frothy saliva' were collected at the time of semen collection on a 3-day rotation. Frothy saliva, derived from the submandibular salivary gland, is produced by aroused boars. Semen was centrifuged, and semen supernatant and cell fractions were tested separately. All samples were randomly ordered and then tested by PRRSV real-time quantitative reverse-transcription polymerase chain reaction assay ( rRT- PCR) and PRRSV antibody ELISA. In this study, a comparison of serum, blood swab, and oral fluid rRT- PCR results found no statistically significant differences in the onset of detection or proportion of positives, but serum was numerically superior to oral fluids for early detection. Serum and oral fluid provided identical rRT- PCR results at ≥5 day post-vaccination. Likewise, the onset of detection of PRRSV antibody in serum, oral fluid and frothy saliva was statistically equivalent, with serum results again showing a numerical advantage. These results showed that the highest assurance of providing PRRSV-negative semen to sow farms should be based on rRT- PCR testing of serum collected at the time of semen collection. This approach can be augmented with oral fluid sampling from a random selection of uncollected boars to provide for statistically valid surveillance of the boar stud. [ABSTRACT FROM AUTHOR]