- The mutation of the bird flu virus discovered in the
Crimea, an autonomy on the Black Sea, is unlike any other that has been
found in the world and is extremely dangerous for humans, Ukraine's ICTV
channel reported Friday.
- The above comment is cause for concern. More details
would be useful. Breaking news via media reports is notoriously unreliable,
but the above comments appear to be quite specific. Other reports have
indicated the sero-type is H5N1, so it is unlikely that the change is reassortment
with an H or N human gene, which has not been described previously for
H5N1. The virulence of the H5N1 in the birds also suggests that the H
has retained the polybasic cleavage site characteristic of Asian versions
of HPAI H5N1.
- The change sounds more like a unique polymorphism and
is most likely to be on the H or N, which are the two genes most likely
to have been sequenced first.
- The potential acquisition of S227N on HA exists because
H9N2 contains the appropriate donor sequence and H9N2 is endemic in the
Middle East. However, that polymorphisms has been detected previously
in H5N1 from Hong Kong residents who visited Fujian Province in 2003.
- Of greater concern would be acquisition of some or most
of the mammalian receptor binding domain. H5N1 wild bird flu sequences
have acquired mammalian polymorphism found predominantly in Europe in the
past. Since HPAI H5N1 has not been previously reported to have been in
Europe before the latest serious of infections beginning in August, the
potential for acquiring novel sequences is high.
- In the past Russia has been very forthcoming with sequence
data, which has been included in the OIE reports. Moreover, the have been
prompt in depositing sequences at GenBank, including partial sequences
from Novosibirsk as well as more complete sequences from Tula.
- More deteail on the unique mutation would be useful.
- c. 2005-2006 All Rights Reserved