Lated to farm traits and farming practices. The farm ing scale (mediumsize and familyscale farms, linked for the number of pigs and sows) was identified as a danger element associated to HEV seroprevalence It was also shown that HEV seroprevalence was signifi cantly higher in organic farms than in traditional ones . Several highrisk rearing practices were reported, the key ones being late weaning, mingling practices in the nursery stage and poor hygiene . Biosecurity measures including requiring a shower upon entry had been also located to be protective components with respect to theSalines et al. Vet Res 
:Web page ofTable Quantified threat things related using a high HEV seroprevalence in pig farmsDi Bartolo et al. Li et al. Jinshan et al. Hinjoy et al. Walachowski et al. Number of sows HEV seroprevalence . vs . HEV seroprevalence on familyscale farms vs in largescale farms (p .) Quantity of pigs HEV seroprevalence ranged from to , vs to Mediumsized farms compared with big farmsOR . Presence of bird faeces inside the pig houseOR . Duration on the nursery down period daysOR . Distance involving pit manure and slatted floor in fattening premises cmOR
. Mingling of pigs from various premises involving ML281 site farrowing and nursery stagesOR . Pen size in nursery rooms pigspenOR . Rutjes et al. OR odds ratio.HEV seroprevalence on organic farms vs on conventional farms HEV seroprevalence on freerange farms vs on standard farms prevalence of faecal HEV RNA shedding . A seasonal influence around the prevalence of HEV RNA among swine was also reported, with a big peak in March pril fol lowed by a smaller peak in September ctober . European wild boars are recognized as a potential reser voir of HEV Furthermore, some experimental stud ies evidenced that HEV strains could be transmitted from European wild boars (Sus scrofa) to domestic pigs . Even though no study straight connected HEV prevalence in pig farms to speak to with wild boars, they may play a poten tial function within the swine HEV epidemiology in freeranged pig production units. The part of wild boars as HEV danger expo positive for domestic pigs would deserve additional 3-Amino-1-propanesulfonic acid site investigation. HEV infection qualities and dynamics on pig farms. HEV infection options in pigs Age at HEV infection and sheddingThe age at infection was only sporadically reported in the literature, with only 3 studies inferring PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/24934505 from sero logical final results the window within which infection took place. Just about each of the studies carried out on pig farms only reported the age at shedding, and not the age at infection. Determined by a largescale seroprevalence survey conducted in Japan, the average age at infection was estimated to variety from . to . days with more than of infec tions occurring among the ages of and days . The outcomes of a longitudinal study on three French farms were really distinctive, most HEV infections occurring in between and days of age . Applying Spanish data, Andraud et al. estimated the age at infection amongst . and . days . According to serological information from lon gitudinal studies in six pig herds, passive immunity was shown to delay early HEV infection of piglets by about weeks in all but one particular farm on which the dynamics of infec tion were related, whatever the animals’ initial serological status. Although the protective role of passive immunitycannot be denied, the latter case highlighted the powerful interaction in between farmspecific husbandry and hygiene practices as well as the HEV transmission course of action . HEV infection dynamics have in t.Lated to farm characteristics and farming practices. The farm ing scale (mediumsize and familyscale farms, linked for the number of pigs and sows) was identified as a risk issue related to HEV seroprevalence It was also shown that HEV seroprevalence was signifi cantly greater in organic farms than in conventional ones . Several highrisk rearing practices have been reported, the principle ones becoming late weaning, mingling practices in the nursery stage and poor hygiene . Biosecurity measures for instance requiring a shower upon entry were also identified to be protective components with respect to theSalines et al. Vet Res :Page ofTable Quantified risk factors associated using a high HEV seroprevalence in pig farmsDi Bartolo et al. Li et al. Jinshan et al. Hinjoy et al. Walachowski et al. Number of sows HEV seroprevalence . vs . HEV seroprevalence on familyscale farms vs in largescale farms (p .) Quantity of pigs HEV seroprevalence ranged from to , vs to Mediumsized farms compared with huge farmsOR . Presence of bird faeces inside the pig houseOR . Duration on the nursery down period daysOR . Distance amongst pit manure and slatted floor in fattening premises cmOR
. Mingling of pigs from diverse premises involving farrowing and nursery stagesOR . Pen size in nursery rooms pigspenOR . Rutjes et al. OR odds ratio.HEV seroprevalence on organic farms vs on conventional farms HEV seroprevalence on freerange farms vs on conventional farms prevalence of faecal HEV RNA shedding . A seasonal influence around the prevalence of HEV RNA amongst swine was also reported, using a significant peak in March pril fol lowed by a smaller sized peak in September ctober . European wild boars are recognized as a possible reser voir of HEV Additionally, some experimental stud ies evidenced that HEV strains might be transmitted from European wild boars (Sus scrofa) to domestic pigs . Although no study straight related HEV prevalence in pig farms to speak to with wild boars, they may play a poten tial function within the swine HEV epidemiology in freeranged pig production units. The role of wild boars as HEV danger expo sure for domestic pigs would deserve additional investigation. HEV infection characteristics and dynamics on pig farms. HEV infection capabilities in pigs Age at HEV infection and sheddingThe age at infection was only sporadically reported in the literature, with only 3 studies inferring PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/24934505 from sero logical outcomes the window within which infection took place. Just about all the research performed on pig farms only reported the age at shedding, and not the age at infection. According to a largescale seroprevalence survey conducted in Japan, the typical age at infection was estimated to range from . to . days with much more than of infec tions occurring among the ages of and days . The outcomes of a longitudinal study on three French farms had been quite distinctive, most HEV infections occurring among and days of age . Applying Spanish data, Andraud et al. estimated the age at infection in between . and . days . Based on serological data from lon gitudinal studies in six pig herds, passive immunity was shown to delay early HEV infection of piglets by 
about weeks in all but one farm on which the dynamics of infec tion had been comparable, whatever the animals’ initial serological status. Even though the protective function of passive immunitycannot be denied, the latter case highlighted the robust interaction involving farmspecific husbandry and hygiene practices as well as the HEV transmission course of action . HEV infection dynamics have in t.
