Avian Flu Found In Chinese Pigs
December 20, 2012

Researchers Find Strains Of Avian Flu In Chinese Pigs

Connie K. Ho for redOrbit.com — Your Universe Online

A new study by researchers in China found pigs that had strains of the avian flu. In the past, avian influenza viruses have been related to death and illness in individuals living in Asia, Africa, Europe, the Pacific and the Near East. The infection of pigs is a concern as it can affect the general population´s health and poses the seriousness of a possible pandemic.

The findings of the study were recently published in the online edition of the Journal of Clinical Microbiology.

"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," explained Guihong Zhang of the College of Veterinary Medicine at the South China Agricultural University in a prepared statement.

In the study, the team of investigators looked at 1,080 pigs between the ages of 21 to 25. They found that these pigs carried the H3, H4, H5, and H6 subtypes of the avian influenza virus along with the H1 and H3 subtypes of swine influenza virus. A serum sample of the pigs showed that 35 percent were positive for H1N1, 19.7 percent were positive for H3N2 swine flu virus, and 0.93 percent, 1.6 percent, and 1.8 percent were positive for the H3, H4, and H6 subtypes of avian influenza A virus, respectively.

The researchers believe that it is important for individuals in the meat industry to monitor the possibility of infection as there can be a transmission from the avian influenza into swine.

“The number of commercial pig farms is certainly increasing in southern China, and most of these are large-scale swine farms. Thus, humans and pigs are in close proximity in farming villages, providing the opportunity for the interspecies transmission of influenza viruses,” wrote the researchers.

“Given the evidence that pigs can sustain re-assortment of human and avian influenza viruses, it is important to be cautious and to enhance surveillance for atypical influenza viruses in pigs as part of our overall pandemic preparedness plans, and that we consider the potential for avian-like SIVs, or the novel re-assortant viruses, to enter the human population.”

Influenza A is a particularly large concern as millions around the world catch the flu every year and thousands die as a result of complications from infection. Infection can pass from pigs to humans and are considered “mixing vessels” for the genetic assortment of viruses that results in pandemics.

According to the U.S. Centers for Disease Control and Prevention's (CDC) avian flu webpage, the virus can be highly contagious and most human infections occur following close or direct contact with infected poultry. As such, the best way to avoid infection is to limit exposure and the CDC provides a list of recommendations for those who work with poultry or with avian influenza outbreaks.

The signs and symptoms of avian influenza can range from conjunctivitis to flu-like symptoms like cough, fever, sore throat and muscle aches. Additionally, affected patients may contract respiratory disease such as pneumonia that may require hospitalization.