• FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
  • We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.

Negative Role of pigs in pandemic virus creation through reassortment found

E

eladdie

Well-known member
Restricted infectivity of a human-Lineage H3N2 influenza A virus in pigs is hemagglutinin and neuraminidase gene dependent.

Landolt GA, Karasin AI, Schutten MM, Olsen CW.

Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI 53706, USA.

Influenza A viruses cause pandemics at sporadic intervals. Pandemic viruses can potentially be introduced into the human population through in toto transfer of an avian influenza virus or through reassortment between avian and human strains. Pigs are believed to play a central role in the creation of pandemic viruses through reassortment because of their susceptibility to infection with both avian and human influenza viruses. However, we recently found that a human-lineage H3N2 influenza virus was highly restricted in its ability to infect pigs after intranasal inoculation. We hypothesized that this restricted infectivity phenotype was controlled by the hemagglutinin (HA) and neuraminidase (NA). To test this, we infected pigs with reverse genetics-created HA plus NA reassortant viruses. Specifically, introduction of the HA and NA genes of a contemporary H3N2 swine virus into the genetic background of the wholly human virus resulted in a significant increase in virus shedding and pathogenicity. These data indicate that the HA/NA can play important roles in controlling human influenza virus infectivity in pigs. The results further support the premise that a barrier exists to human influenza virus infection in pigs, which may limit the role of pigs in pandemic virus creation through reassortment of human and avian influenza viruses.

http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=16455873&dopt=Abstract
 
Last edited:
Re: Negative Role of pigs in pandemic virus creation through reassortment found

I've sent this to Niman, to ask his opinion. Possibly another here could answer?
 
Re: Negative Role of pigs in pandemic virus creation through reassortment found

eladdie said:
Restricted infectivity of a human-Lineage H3N2 influenza A virus in pigs is hemagglutinin and neuraminidase gene dependent.

These data indicate that the HA/NA can play important roles in controlling human influenza virus infectivity in pigs. The results further support the premise that a barrier exists to human influenza virus infection in pigs, which may limit the role of pigs in pandemic virus creation through reassortment of human and avian influenza viruses.....
Click to expand...

it's hard to comment on an article that requires a subscription.

Given past epidemics that DID come from swine, you're not implying there can be NO re-whatever with swine?

If you review the 109 related articles in PubMed, you'll find examples of pigs as mixing vessels for an assortments of influenzas. see:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8077918&query_hl=2&itool=pubmed_docsum

J Gen Virol. 1994 Sep;75 ( Pt 9):2183-8.Related Articles, Links

Potential for transmission of avian influenza viruses to pigs.

Kida H, Ito T, Yasuda J, Shimizu Y, Itakura C, Shortridge KF, Kawaoka Y, Webster RG.

Department of Veterinary Hygiene and Microbiology, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.

Pandemic strains of influenza A virus arise by genetic reassortment between avian and human viruses. Pigs have been suggested to generate such reassortants as intermediate hosts. In order for pigs to serve as 'mixing vessels' in genetic reassortment events, they must be susceptible to both human and avian influenza viruses. The ability of avian influenza viruses to replicate in pigs, however, has not been examined comprehensively. In this study, we assessed the growth potential of 42 strains of influenza virus in pigs. Of these, 38 were avian strains, including 27 with non-human-type haemagglutinins (HA; H4 to H13). At least one strain of each HA subtype replicated in the respiratory tract of pigs for 5 to 7 days to a level equivalent to that of swine and human viruses. These results indicate that avian influenza viruses with or without non-human-type HAs can be transmitted to pigs, thus raising the possibility of introduction of their genes into humans. Sera from pigs infected with avian viruses showed high titres of antibodies in ELISA and neutralization tests, but did not inhibit haemagglutination of homologous viruses, cautioning against the use of haemagglutination-inhibition tests to identify pigs infected with avian influenza viruses. Co-infection of pigs with a swine virus and with an avian virus unable to replicate in this animal generated reassortant viruses, whose polymerase and HA genes were entirely of avian origin, that could be passaged in pigs. This finding indicates that even avian viruses that do not replicate in pigs can contribute genes in the generation of reassortants. .

PMID: 8077918
 
Re: Negative Role of pigs in pandemic virus creation through reassortment found

AlaskaDenise said:
it's hard to comment on an article that requires a subscription.

Given past epidemics that DID come from swine, you're not implying there can be NO re-whatever with swine?
Click to expand...


Hey, AD

I just post 'em as I see 'em. In this case, I didn't comment on the article I found....

And I also do not have access to ncbi, Which is very reputable and mainstream sorce for biotech.

But as you also know, for every study that claims one thing, other studies can and will show a different thing.

What do I believe? Bird flu may come to H2H by mutation, reassortment, recombination 'a la niman, or combinations of the three above.

Does it matter who is right which mechanism is responsible for the death and destruction of the human race?

We had our chance to spread our seed into space. We blew it.
 
Re: Negative Role of pigs in pandemic virus creation through reassortment found

I thought maybe you had a subscription......I was jealous. :D

But as you also know, for every study that claims one thing, other studies can and will show a different thing.
Click to expand...

You said a mouthful there. There are not only lots of studies and theories, but a lot of well qualified people saying......"we don't know". :rolleyes:

Actually, the related articles are interesting. I read about 3.

I spent quite a bit of time over the last 2 days just reading about HA cleavage. It's interesting that the same results occured in 1918 H1N1 and current H5N1, however the mechanism is SO different. Then comes along one tiny mutation that can blow apart either mechanism.

So while there are definite obstancles to species jumps, there are also definite paths. I go by the trends......more diseases are making the jump from animals to humans, and between species (like from avian to mink for H10 and now H5).

It's well that someone call for a reality check before we jump on our favorite bandwagons. :D

.
 
You must log in or register to reply here.
Back
Top