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The article discusses the expanding host ranges, cross-species infection, zoonotic risk and food safety of hepatitis E virus (HEV) as of 2016. Topics include the two distinct strains of HEV namely genus Orthohepevirus and genus Piscihepevirus, genetic identification of HEV strains from animal species including swine, rabbit and deer, and zoonotic infection of genotypes 3 and 4 HEV.

Porcine circovirus type 2 (PCV2) vaccination has been effective in protecting pigs from clinical disease and today is used extensively. Recent studies in vaccinated populations indicate a major PCV2 genotype shift from the predominant PCV2 genotype 2b towards 2d. The aims of this study were to determine the ability of the commercial inactivated PCV2a vaccine Circovac® to protect pigs against experimental challenge with a 2013 PCV2d strain and prevent transmission. Thirty-eight pigs were randomly divided into four groups with 9–10 pigs per group: NEG (sham-vaccinated, sham-challenged), VAC (PCV2a-vaccinated, sham-challenged), VAC + CHAL (PCV2a-vaccinated and PCV2d-challenged), and CHAL (sham-vaccinated, PCV2d-challenged). Vaccination was done at 3 weeks of age using Circovac® according to label instructions. The CHAL and VAC + CHAL groups were challenged with PCV2d at 7 weeks of age and all pigs were necropsied 21 days post-challenge (dpc). The VAC-CHAL pigs seroconverted to PCV2 by 21 days post vaccination (dpv). At PCV2d challenge on 28 dpv, 3/9 VAC and 1/9 VAC + CHAL pigs were seropositive. NEG pigs remained seronegative for the duration of the study. Vaccination significantly reduced PCV2d viremia (VAC + CHAL) at dpc 14 and 21, PCV2d fecal shedding at dpc 14 and 21 and PCV2d nasal shedding at dpc 7, 14 and 21 compared to CHAL pigs. Vaccination significantly reduced mean PCV2 antigen load in lymph nodes in VAC + CHAL pigs compared to CHAL pigs. When pooled serum or feces collected from VAC + CHAL and CHAL pigs at dpc 21 were used to expose single-housed PCV2 naïve pigs, a pooled fecal sample from CHAL pigs contained infectious PCV2 whereas this was not the case for VAC + CHAL pigs suggesting reduction of PCV2d transmission by vaccination. Under the study conditions, the PCV2a-based vaccine was effective in reducing PCV2d viremia, tissue loads, shedding and transmission indicating that PCV2a vaccination should be effective in PCV2d-infected herds. [ABSTRACT FROM AUTHOR]

Abstract: Infection with the Torque teno sus virus (TTSuV) is believed to be common yet limited information is available on the epidemiology of TTSuV. The objectives of this study were to develop novel and improve existing diagnostic methods for TTSuV infection and to investigate the prevalence of TTSuV species 1 (TTSuV1) and 2 (TTSuV2) in the USA. Three hundred and four blood or fetal thoracic fluid samples were collected from pigs on 40 US farms in 12 States. Samples were collected from fetuses and in pre-suckle neonates (n =73), suckling pigs (1–20 days of age; n =27), nursery pigs (21–55 days of age; n =60), finisher pigs (8–25 weeks of age; n =90) and adults (>25 weeks of age; n =54). Samples were tested by a new quantitative differential real-time PCR for TTSuV1 and TTSuV2 DNA and by ELISA for detection of anti-TTSuV2-antibodies. The prevalence of TTSuV1 DNA ranged from 8.2% (fetuses and neonates) to 81% (finisher pigs) and the prevalence of TTSuV2 DNA ranged from 3.7% (suckling pigs) to 67% (finisher pigs). Evidence of fetal TTSuV infection was minimal. Mixed infection of TTSuV1 and TTSuV2 was seen in 6.7% of the nursery pigs, 52.2% of the finisher pigs, and 22.2% of the mature pigs. The prevalence of TTSuV1 was higher than that of TTSuV2. Anti-TTSuV2 antibodies were not detected in the fetuses and neonates and the seroprevalence of TTSuV2 was between 3.8% and 100% in growing pigs. The results of this study indicate that vertical transmission may not be a main route of TTSuV transmission in pigs in the USA. [Copyright &y& Elsevier]