EH, that's an outstanding post. I do have a problem with one paragraph:
B. If a genetic transformation sufficient to allow easy human to human transmission, the chain of transmission can be still be stopped if it is caught early enough. If ALL humans who show symptoms of H5N1 are isolated, and those who have been exposed are quarantined, then even a successfully mutated virus variant can be stamped out.
When there are multiple vectors for the mutated virus i.e. pigs and possibly other mammals, then eradicating it in humans will not stop the spread, imho.
Cats are also thought to be possible infection vectors for H5N1 strains of avian flu (Kuiken et al, 2004).
I tend to agree with you Judith Anne. As there are multiple vectors and the countries that this is going to be coming out of have a very different view on certain kinds of animals many of us consider pets. In particular is the domestic house-cat that has been considered a possible vector in the spread of H5N1.
My house-cat is truly a house cat as she is housebound. The neighbors cat though being a domestic cat is not a house-cat even though he uses their domicile for shelter. Keeping that in mind I would be concerned for all those people who keep cats in ex. Europe. Ignorance of the possiblity of a vector bearing infected cat, their pet, as a possible killer of humans.
If that becomes the case we will see the mass killing of not only poultry and pigs, but also domestic cats. I think this is a very real possiblity that people who have never had contact with poultry/pigs, but keep a domestic cat may risk their lives to keep their precious pet.
Good point, and I agree. However, the mutated variant has to get loose in the relevant animal population for this to happen.
Stamping it out in the affected humans would need to be coupled with measures to keep the mutated form from spreading within the potential animal hosts in the area. Culling the kind of animals the disease was thought to have been transmitted from would have to occur. (I suspect that is the explanation for culling $1 billion of Russian poultry, and the Chinese focus on pigs in an H5N1 infected region.)
Personally, I do not think it can be kept in the box. But we have to try.
http://en.rian.ru/russia/20050802/41078180.html
Russia
UPDATE: Quarantine imposed on all poultry farms in Russia
21:53 | 02/ 08/ 2005
MOSCOW, August 2 (RIA Novosti) - A quarantine has been introduced at all poultry farms in Russia after the bird flu virus was discovered in the Novosibirsk region (Siberia), the Agriculture Ministry said.
According to the Federal Service for Veterinary and Phytosanitary Supervision, research shows the bird disease was caused by the H5N1 virus and preliminarily spread by migrant birds from South East Asia. The bird flu was discovered in 14 settlements in five districts of the Novosibirsk region, in a village of the Altai Territory (southern Siberia), and in a village of the Tyumen region (West Siberia).
Information is being verified in other regions where bird deaths have been reported.
The incineration of diseased birds and of birds that may have come in contact with them in a number of villages suspected of bird flu outbreaks allowed the virus to be localized.
The Federal Service for Veterinary and Phytosanitary Supervision is doing everything possible to control and eliminate the areas of infection and is taking sanitary measures, including instructing the population on rules of sanitation for poultry. Experts have been assigned to the Novosibirsk and Tyumen regions and the Altai Territory to assist in conducting epidemic countermeasures.
I have been reading this thread but I am having difficulty sorting out the issues here. It seems, at least from initial data, that we do not have one epidemic (i.e. H5N1, but possibly several). The way I count them is: (please comment and correct)
1. We have the H5N1 Avian Flu that so far primarily affects birds. Future threats are large scale human infection and also, separately, the destruction of poultry and pigs.
2. There is Ebola in China. Moreover, we have multiple strains of Ebola in China. Therefore, there seems to be a lot of it.
3. There is apparently a variant of Avian Flu that has genetic similarity to Ebola. Indeed, in one posting it was reported that 18 nucleotide pairs were identical. The implication is that this was a hybrid variant, perhaps caused by genetic recombination of Ebola and Avian Flu. This variant (if it indeed does exist) has the potential of being a superbug.
4. There is a somewhat undetermined swine disease that some have called "Streptococcus suis". However, that is in doubt. This disease might be either the H5N1 Avian Flu or perhaps the Avian / Ebola hybrid. This one is of concern because the number of human infections has gone from 1 to about 150 in 2.5 months (a 15 day e-folding time). Moreover, the case lethality is high (~80% or so).
There is also the general concern that any of these variants can be spread either by human to human or by bird/pig to human. If sufficient animals were infected, the human to human transmission might not be necessary for a general pandemic.
So....
Have I sorted this out correctly??? Comments and corrections please??
The most significant threat then, if I have sorted this out correctly, is the so called "Streptococcus suis" which may really be H5N1 or the Ebola/Avian hybrid. The reasons are: 1) the rapid growth (15 day e-folding time) in the human cases, and 2) the potential for high contagion and lethality.
It might be possible to calculate the probability of the 18 nucleotide pair identity between Ebola and Avian if someone can tell me the total length of the two viral genomes (in base pairs), and the general structural similarity. (I thought they were quite different). I would also need to know the general rate of random mutations in virii (which should be a standard number). We could at least determine whether the random mutation is possible or whether a recombination event has occurred.
Thanks