Serological Surveillance of Influenza A Virus Infection in Swine Populations in Fujian Province, China: No Evidence of Naturally Occurring H5N1 Infect

[tetano]

X.-H. Song 1,2,3*, H. Xiao 1,2,3*, Y. Huang 4*, G. Fu 4 , B. Jiang 5 , Y. Kitamura 1,2 , W. Liu 1,2 , D. Liu 1,2 and G. F. Gao 1,2
1 CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China
2 China?Japan Joint Laboratory of Molecular Immunology and Molecular Microbiology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
3 Graduate University, Chinese Academy of Sciences, Beijing, China
4 Institute of Animal Science and Veterinary Medicine, Fujian Academy of Agricultural Sciences, Fuzhou, China
5 Institute of Animal Science and Veterinary Medicine, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China
Correspondence to George F. Gao. CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China. Tel.: 86-10-64807688; Fax: 86-10-64807598; E-mail: gaof@im.ac.cn

*These authors contributed equally to this work.
Copyright ? 2010 Blackwell Verlag GmbH
KEYWORDS
Serological surveillance ? swine influenza virus ? H5N1
ABSTRACT

Several highly pathogenic H5N1 avian influenza viruses were isolated from swine populations in Fujian Province, China, since 2001. Because it is thought that H5N1 infection in pigs might result in virus adaptation to humans, we surveyed swine populations in Fujian Province in 2004 and 2007 for serological evidence of the infection. Twenty-five pig farms covering all nine administrative districts of Fujian Province were sampled and a total of 1407 serum specimens were collected. The haemagglutination inhibition (HI) tests revealed no evidence of H5 infection and only a few cases of H9 infection. The negative results for H5 infection were further verified by micro-neutralization tests. By contrast, H1 influenza virus infections were prevalent in swine in both surveys according to the results of enzyme-linked immunosorbent assay (ELISA). The H3 infection rate was reduced dramatically in 2007 compared with 2004, when examined by HI and ELISA. In summary, the results imply that the swine populations in Fujian Province had not been affected greatly by the H5N1 avian influenza virus, given that there is no serological evidence that H5N1 influenza virus has infected the pig populations. The reported isolates represent only sporadic cases.

http://www3.interscience.wiley.com/journal/123314172/abstract?CRETRY=1&SRETRY=0

 

[Laidback Al]

Re: Serological Surveillance of Influenza A Virus Infection in Swine Populations in Fujian Province, China: No Evidence of Naturally Occurring H5N1 Infection in Pigs

The results imply that the swine populations in Fujian Province had not been affected greatly by the H5N1 avian influenza virus, given that there is no serological evidence that H5N1 influenza virus has infected the pig populations

That is the good news.

By contrast, H1 influenza virus infections were prevalent in swine in both surveys according to the results of enzyme-linked immunosorbent assay (ELISA)

That is the not so good news.

And the bad news - The apparent increased virulence in H5N1/seasonal flu reassortment that was demonstrated in recent laboratory experiments. see link and link

and from this thread at FT:

This observation reinforces the hypothesis that pigs constitute the inter-host mixing vessel responsible for at least two of the three pandemics in the 20th century.