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        Special Topics 特別主題 >> Black-faced Spoonbill 黑臉琵鷺 >>  Botulism Vs H5N1
        
(Message started by: bjingbar on Jan 15^th, 2003, 6:59am)

Title: Botulism Vs H5N1
Post by bjingbar on Jan 15^th, 2003, 6:59am

Could somebody explain the differences between Botulism and H5N1, from my understanding having read the BBC report

""Avian botulism is caused by a water-soluble toxin produced by the bacterium Clostridium botulinum. It is a potent neurotoxin. The higher than usual winter temperatures that appear to have triggered the outbreak seem to be consistent with anticipated climate change patterns""

It therefore appears to me that the disease is spread to birds that have been foraging in this affected water.

Where as H5N1 is spread by direct contact from bird to bird.

In an article in the SCMP 14th Jan. headed "Study suggests first link to migratory species" it mentioned that the birds in Kowloon Park and Penfold Park were affected with H5N1.

If this is the case, why was Penfold Park closed? By closing the pond to birds aren't we just forcing these possibly affected birds to go to other areas of Hong Kong, thus spreading the disease over a wider area

Title: Re: Botulism Vs H5N1
Post by 鳥友Ａ on Jan 15^th, 2003, 8:42pm

Clostridium botulinum (肉毒桿菌) is a bacterium (細菌) that causes food poisoning. It makes people and animals sick by producing the toxin botulin (肉毒毒素).

H5N1 is a virus (病毒), which is much smaller than a bacterium. It is related to the viruses that that cause influenza (流行性感冒) in animals, including humans. It does damage by breaking into the body cell of its victim, reproduces itself in large numbers inside and kills the cell. The new viruses break out and in turn affect other cells - somewhat like the creature in the 'Alien' movie.

In the past, viruses that causes influenza among birds do not affect humans.  However a strain of H5N1 virus that affected birds appeared to have mutated so that it can affect humans as well.  It is very dangerous because most humans do not have immunity against such exotic virus.

Migrating birds do carry flu viruses of various strains, but most of these are not harmful to humans.

You can find out more about the above at  the Centers for Disease Control and Prevention in the U.S.:

http://www.cdc.gov/ncidod/diseases/flu/viruses.htm

I think Penfold Park was closed to prevent the general public from making contact with the birds there. I understand that the birds there were kept in quarantine.

Title: Re: Botulism Vs H5N1
Post by bjingbar on Jan 15^th, 2003, 9:47pm

Thank you very much for the explanation & web address