H7N9 virus closer to being human transmissible than other bird flu viruses

[Shiloh]

Source: http://www.ottawacitizen.com/health/...648/story.html

H7N9 virus closer to being human transmissible than other bird flu viruses
By Helen Branswell, The Canadian Press May 23, 2013 2:40 PM


TORONTO - A new study shows that the H7N9 flu virus can pass between ferrets, even sometimes spreading by airborne transmission.

While the airborne spread wasn't highly efficient, the work suggests this virus is more closely adapted to spread among mammals than other bird flu viruses.

The research was done by researchers in China, Hong Kong, the United States and Toronto and is published in the journal Science...

[Shiloh]

Re: H7N9 virus closer to being human transmissible than other bird flu viruses

Source: http://www.eurekalert.org/pub_releas...-fps052313.php

Public release date: 23-May-2013
Contact: Anne A. Oplinger
aoplinger@niaid.nih.gov
301-402-1663
NIH/National Institute of Allergy and Infectious Diseases

Ferrets, pigs susceptible to H7N9 avian influenza virus
NIH-funded study examined transmissibility of emerging virus

Chinese and U.S. scientists have used virus isolated from a person who died from H7N9 avian influenza infection to determine whether the virus could infect and be transmitted between ferrets. Ferrets are often used as a mammalian model in influenza research, and efficient transmission of influenza virus between ferrets can provide clues as to how well the same process might occur in people. The research was supported, in part, by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.

The researchers dropped H7N9 virus into the noses of six ferrets. A day later, three uninfected ferrets were placed inside cages with the infected animals, and another three uninfected ferrets were placed in cages nearby. All the uninfected ferrets inside the cages became infected, while only one of three placed in nearby cages became infected. The team concluded that the virus can infect ferrets and be transmitted between ferrets both by direct contact and, less efficiently, by air. The scientists detected viral material in the nasal secretions of the ferrets at least one day before clinical signs of disease became apparent. The potential public health implication of this observation is that a person infected by H7N9 avian influenza virus who does not show symptoms could nevertheless spread the virus to others.

The researchers also infected pigs with the human-derived H7N9 virus. In natural settings, pigs can act as a virtual mixing bowl to combine avian- and mammalian-specific influenza strains, potentially allowing avian strains to better adapt to humans. New strains arising from such mixing have the potential to infect humans and spark a pandemic, so information about swine susceptibility to H7N9 could help scientists gauge the pandemic potential of the avian virus. Unlike the ferrets, infected pigs in this small study did not transmit virus to uninfected pigs, either through direct contact or by air. All the infected ferrets and pigs showed mild signs of illness, such as sneezing, nasal discharge, and lethargy, but none of the infected animals became seriously ill.

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ARTICLE:

H Zhu et al. Infectivity, transmission and pathogenesis of human-isolated H7N9 influenza virus in ferrets and pigs. Science DOI: 10.1126/science.1239844 (2013).

WHO:

NIAID Director Anthony S. Fauci, M.D., is available to discuss this research.

CONTACT:

To schedule interviews, please contact Anne A. Oplinger, (301) 402-1663, aoplinger@niaid.nih.gov.

This research was supported, in part, through contract HSN266200700005C.

NIAID conducts and supports research?at NIH, throughout the United States, and worldwide?to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.

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[Giuseppe]

Re: H7N9 virus closer to being human transmissible than other bird flu viruses

The fact that the pathogenesis in ferrets model does not full match the observed pattern in humans casts some doubts about the conclusion from these kind of study, for other point of views, much interesting.

[Giuseppe]

Re: H7N9 virus closer to being human transmissible than other bird flu viruses

[Source: Virology Blog, full text: (LINK).]

Inefficient influenza H7N9 virus aerosol transmission among ferrets

23 May 2013 | Vincent Racaniello


There have been 131 confirmed human infections with avian influenza H7N9 virus in China, but so far there is little evidence for human to human transmission. Three out of four patients report exposure to animals, ?mostly chickens?, suggesting that most of the infections are zoonoses. Whether or not the virus will evolve to transmit among humans is anyone?s guess. Meanwhile it has been found that one of the H7N9 virus isolates from Shanghai can transmit by aerosol among ferrets, albeit inefficiently.

(?)

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[gsgs]

Re: H7N9 virus closer to being human transmissible than other bird flu viruses

apparently

what mustn't be asked
what reporters mustn't speculate about
what is taboo for researchers to talk about
what noone dares to address
--------------------------------------
what labs did already try to reassort it with other viruses
what labs did already try to passage it in some animals
--------------------------------------
((and what were the results))


or
how long will it take until they know about such results
and maybe tell it to WHO or their government

[gsgs]

Re: H7N9 virus closer to being human transmissible than other bird flu viruses

The fact that the pathogenesis in ferrets model does not full match
the observed pattern in humans casts some doubts about the conclusion from these kind of study,
for other point of views, much interesting.

I think transmissibility is different from pathogenesis.

Pathogenesis entirely depends on the host-biochemics
while transmissibility in big parts happens in the air, outside the host.
How the virus travels to reach the next nose, how it survives in
temperature and humidity.
OK, also how it is emitted and then re-grasped


ferrets match humans quite well in transmissibility.
See seasonal flu, H5N1, H9N2.
Is there a counterexample ?

http://www.cidrap.umn.edu/cidrap/content/influenza/swineflu/news/jul0209h1n1.html

http://www.pnas.org/content/108/29/12084.full

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0002923

https://www.sciencemag.org/content/336/6088/1534.abstract

http://www.sciencemag.org/content/315/5812/655.abstract

http://ftp.censa.edu.cu/ict/Biblioteca%20IA/Base%20de%20datos%20IA/IA_RiskAnalays.Data/PDF/dejonga333340-2062096128/dejonga333340.pdf

[Giuseppe]

Re: H7N9 virus closer to being human transmissible than other bird flu viruses

I agree that ferrets are one of the best influenza transmissibility and pathogenesis models.

We have to take into account that host response to viral infections depends from multiple variables and thus predictions of the future behaviour of a novel pathogen cannot be entirely match actual scenarios on the ground.

To note, in addition, that so far observed clinical course of H7N9 in humans fails to demonstrate sign of rhinopharingitis (no 'cold' symptoms').

Like patients with other avian influenza infections, patients with H7N9 virus infection were not reported to have a sore throat or rhinorrhea. Conjunctivitis, a common finding with H7 human infections,was also not reported among the patients in our study. Diarrhea or vomiting was reported in 13.5% of patients in our study, as compared with 42 to 70% of patients with H5N1 virus infection. Rhabdomyolysis, which was present in 9.9% of the patients in our study, has also been reported in children infected with pandemic H1N1 virus.

Full text. N Engl J Med 2013. DOI: 10.1056/NEJMoa1305584

[gsgs]

Re: H7N9 virus closer to being human transmissible than other bird flu viruses

humans have 200-300 different cell-types, I saw a list recently

but I didn't see a table how many of each we have and were they are

that table in computer-readable form would be useful
(divide the body into ~100 regions/organs)

and then the same for ferrets, please !

and mice and guinnea-pigs
chickens,pigs,mallards,Asian domestic ducks

it should exist. heck, we have the whole genome,3B nucleotides