Fatal Disease Associated with Swine Hepatitis E Virus and PCV2 Co-infection in Four Weaned Pigs in China21 April 2015
Hepatitis E virus (HEV) and porcine circovirus 2 (PCV2) are prevalent in China but this is the first time that a co-infection has been recorded. Observing severe pathological changes post-mortem, the researchers warn the virus combination could adversely affect the pig industry.
In recent decades, porcine circovirus 2 (PCV2) infection has been recognised as the causative agent of postweaning multisystemic wasting syndrome (PMWS), and has become a threat to the swine industry, according to Ruiping She of China Agricultural University in Beijing and co-authors there and at Hebei University of Engineering in Handan.
They add that hepatitis E virus (HEV) is another high prevalent pathogen in swine in many regions of the world. PCV2 and HEV are both highly prevalent in pig farms in China.
In their paper, published in BMC Veterinary Research, they explain how they characterised the HEV and PCV2 co-infection in two-to three-month-old piglets, based on pathogen identification and the pathological changes observed, in Hebei Province, China.
The pathological changes were severe, and general hyperaemia, haemorrhage, inflammatory cell infiltration and necrosis were evident in the tissues of dead swine, they observed.
PCR was used to identify the pathogen as they tested for eight viruses (HEV, Porcine reproductive and respiratory syndrome virus, PCV2, Classical swine fever virus, Porcine epidemic diarrhoea virus, Transmissible gastroenteritis coronavirus, porcine parvovirus and pseudorabies virus) that are prevalent in Chinese pig farms.
The livers, kidneys, spleens and other organs of the necropsied swine were positive for HEV and/or PCV2. Immunohistochemical staining showed HEV- and PCV2-antigen-positive signals in the livers, kidneys, lungs, lymph nodes and intestine.
The researchers were able to detect HEV and PCV2 co-infection in four out of seven dead pigs from two pig farms in Hebei, China.
They add that the pathological changes were severe, and that the natural co-infection of HEV and PCV2 in pigs in China has rarely been reported before.
She and co-authors speculate that co-infection with PCV2 and HEV may bring some negative effects on pig production and recommend that more attention should be paid to this phenomenon.
Yang Y., R. Shi, R. She, J. Mao, Y. Zhao, F. Du, C. Liu, J. Liu, M. Cheng, R. Zhu, W. Li, X. Wang and M.H. Soomro. 2015. Fatal disease associated with swine hepatitis E virus and porcine circovirus 2 co-infection in four weaned pigs in China. BMC Veterinary Research. 11:77