Pigs in southern China infected with avian flu

Researchers report for the first time the seroprevalence of three strains of avian influenza viruses in pigs in southern China, but not the H5N1 avian influenza virus. Their research, published online ahead of print in the Journal of Clinical Microbiology, has implications for efforts to protect the public health from pandemics.

Influenza A virus is responsible both for pandemics that have killed millions worldwide, and for the much less severe annual outbreaks of influenza. Because pigs can be infected with both human and avian , they are thought to serve as "mixing vessels" for genetic reassortment that could lead to pandemics, and pigs have been infected experimentally by all avian H1-H13 subtypes. But natural transmission of avian influenza to pigs has been documented only rarely.

In the study, from 2010-2012, Guihong Zhang and colleagues of the College of Veterinary Medicine, South China Agricultural University, Guangzhou, People's Republic of China, tested 1080 21-25 week old pigs for H3, H4, H5, and H6 subtypes of avian influenza virus, and H1 and H3 subtypes of virus. Thirty-five percent of the serum samples were positive for H1N1, and 19.7 percent were positive for H3N2 swine , and 0.93 percent, 1.6 percent, and 1.8 percent were positive, respectively, for the H3, H4, and H6 subtypes of avian . However, no serum samples collected in 2001 were positive for any of these viruses, indicating that transmission into swine was recent.

Given the recent transmission of avian influenzas into swine, "We recommend strongly that the pork industry worldwide should monitor the prevalence of influenza in pigs, considering their important role in transmitting this virus to humans," says Zhang.

Previously, novel reassortant H2N3 influenza viruses were isolated from US pigs, which "were infectious and highly transmissible in swine and ferrets without prior adaptation," according to a 2009 paper in the Journal of Molecular and Genetic Medicine by Wenjun Ma et al. Those viruses resembled, but were not identical to the H2N2 human pandemic virus of 1957.


Explore further

Long-term study of swine flu viruses shows increasing viral diversity

More information: A copy of the manuscript can be found online at bit.ly/asmtip1212d. Formal publication is scheduled for the February 2013 issue of the Journal of Clinical Microbiology.
Journal information: Journal of Clinical Microbiology

Citation: Pigs in southern China infected with avian flu (2012, December 19) retrieved 20 September 2019 from https://phys.org/news/2012-12-pigs-southern-china-infected-avian.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more