H5N1 lifespan and transmission

Loam was talking about the possibility that bird feathers could spread the disease and so I wondered how long the lifespan of the virus is and what other methods could bring the disease into western countries.


It can live in air for up to five days:

The virus has a lifespan of 4-5 days only in air, and can travel a distance of up to 2-3 km. The virus gets killed at temperatures above 56 deg C. It is highly susceptible to disinfectants containing detergents, Iodine, and pH below 5.

www.blonnet.com...

It can be transported via contaminated feathers:

Poultry meat from the country has been banned, but BBC Radio 4's Farming Today reported that duck, chicken and turkey feathers were still being imported.

Professor Hugh Pennington said the virus could survive in faecal material on the feathers, some of which are used in making pillows.

news.bbc.co.uk...

Migratory birds could be carriers and spread the virus through droppings:

Wild birds shed the virus. Infected migratory waterfowl, the natural carriers of bird flu viruses, shed the virus in their droppings, saliva and nasal secretions.

and feed, water or soil:

Domestic poultry become infected from contact with these birds or with contaminated water, feed or soil. They may also catch the disease the same way humans contract conventional flu — by inhaling the airborne virus.

and crowded and/or unsanitary conditions:

Open-air markets, where eggs and birds are often sold in crowded and unsanitary conditions, are hotbeds of infection and spread the disease into the wider community. Cock fighting, rampant throughout much of Asia, has also been implicated in the spread of bird flu

www.cnn.com...

How disease is spread and how to stop it:
www.mayoclinic.com...



[edit on 30-9-2005 by DontTreadOnMe]

Excellent post....

All just really a plane ride away...eh?

I don't like the potential bioterror implications of this. Since 4-5 days in air, does freezing extend that time? I saw an upper temperature range, but not a lower one.

[edit on 30-9-2005 by loam]

I was trying to find out a lower temp range, too. So far, no luck.
I always thought most "germs" did poorly in cooler temperatures.

I did find some more information on an OSHA website. Cool temperatures appear to allow the virus to remain alive for long periods of time. This is NOT good news:

In an agricultural setting, animal manure containing influenza virus can contaminate dust and soil, causing infection when the contaminated dust is inhaled. Contaminated farm equipment, feed, cages, or shoes can carry the virus from farm to farm. The virus can also be carried on the bodies and feet of animals, such as rodents. "The virus can survive, at cool temperatures, in contaminated manure for at least three months. In water, the virus can survive for up to four days at 72º F and more than 30 days at 32º F. For the highly pathogenic form (of influenza A), studies have shown that a single gram of contaminated manure can contain enough virus to infect 1 million birds."

www.osha.gov...

DontTreadOnMe

This article answers, indirectly, some of our questions. More ominously, however, are its direct implications. It probably merits its own thread.

Big thaw could unleash ancient plague

London: As global warming melts the world's ice sheets, rising sea levels are not the only danger. Viruses hidden for thousands of years may thaw and escape - and we will have no resistance to them...


"We routinely keep viruses at -80ûC when we want to store them in the lab, so viruses can certainly survive freezing, but they are often fragile to processes such as freeze-thaw," explains Geoffrey Smith, head of the virology department at Imperial College London.

In the lab it is possible to defrost viruses gently, but outside they are subject to climatic extremes. Only viruses that contain the tough protein coat, like ToMV, are likely to be able to retain all the information they need while being repeatedly frozen and defrosted. This rules out plenty of human viruses, but still leaves a few very nasty options like smallpox, polio, hepatitis A and influenza.

It is believed that the influenza virus is the most likely to emerge from the freeze/thaw process in a fit enough state to re-infect humans. What is more, an ancient version of human influenza could be a very potent weapon. One worrying scenario would be the creation of a super virus via the recombination of ancient and modern strains...

[edit on 1-10-2005 by loam]

Originally posted by DontTreadOnMe
I did find some more information on an OSHA website. Cool temperatures appear to allow the virus to remain alive for long periods of time. This is NOT good news:

www.osha.gov...

Times like these I wish I could "way above" a mod. Good find -- disturbing but good.

So if we were thinking that a cold winter would give us a chance to re-group we are mistaken?

Thanks, justme

I'm stille looking for various phrases that will give me the info I'm looking for. I found this and although I find it too medical for me to understnad, it does seem to show how the 1918 pandemic became so deadly

The explosive spread of the influenza virus during the 1918 pandemic that killed some 20 million people worldwide was likely enabled by the unique structure of a protein on the virus's surface, researchers are reporting. The newly determined structure of the viral protein reveals that the 1918 strain of influenza underwent subtle alterations that enabled it to bind with deadly efficiency to human cells, while retaining the basic properties of the avian virus from which it evolved.

Researchers Determine Reason for Deadly Spread of 1918 Influenza

[edit on 1-10-2005 by DontTreadOnMe]