[1]
Date: Sat 3 Jun 2006
From: Martin Williams
Seeing the H5N1 situation in Indonesia, I wonder whether “integrated”
fish farming plays an important role in sustaining H5N1 [a concern
conservationists have raised. I received an email regarding a truck
load of chicken manure being dumped into a Vietnamese lake each day
as fish food. At one time, FAO promoted such farming methods].
Not that fish catch the flu, but dumping manure and carcasses into
ponds and having them eaten by fish possibly results in ponds that
can be reservoirs for flu virus [and possibility of transfer via farm
fish, in bellies, on skins, or with water if live fish are
transported?].
In this regard, it is interesting that Webster et al. have reported
H5N1 virus surviving for longer in fairly warm water than regular
wild bird flu viruses.
Here is a webpage I’ve done after a quick trip to Indonesia and a
fish farm where catfish were fed on chicken carcasses etc.:
.
I realize that WHO teams in Indonesia are extremely busy, but maybe
they could investigate the realities of this fish pond risk [for
example, if fish farms play a role, just slaughtering poultry is not
adequate for control, especially if a proportion of those poultry are
then used as fish food!].
—
Martin Williams
[Martin William’s website is worth visiting for his photographs of
floating poultry carcasses in a family fish pond in Indonesia. These
photographs better illustrate the risk than our 3 reports on the same
topic. – Mod.MHJ]
[Scholtissek & Naylor indicated in 1988: “Global developments in
aquaculture — the so-called ‘Blue Revolution’ — will mean increased
colocation of people, ducks and pigs”. (Fish farming and influenza
pandemics; Nature 331, 215).
See also “Chicken dung used to feed fish may help spread bird flu” in
20051228.3697, as well as Mod. MHJ’s commentary in 20060518.1396:
“…depositing poultry faeces into the pond water would put any
wildfowl swimming in those waters at a real risk of becoming
infected…Birds faeces repeatedly trucked in for fish food would act
in the same way as a constant risk to birds flying into and out of
the fish pond areas”.
Situations resembling the one described in Indonesia may prevail
in other countries as well. Aquaculture’s potential hazard in HPAI
epidemiology deserves serious consideration and attention, not red
herringing the role of migratory birds in spreading the virus to
longer distances. – Mod.AS]
******
[2]
Date: Sun 4 Jun 2006
From: Joe Dudley
I raised this “fish as fomites” issue with Dr. Robert Webster at the
Rome conference.
Webster said that it was possible that live H5N1 virus could be
present in the intestinal tract of detritus-feeding fish, like carp,
that may eat infected poultry manure or as an environmental
contaminant in the intestinal tract of fish that had been raised in
ponds fertilized with infected poultry manure.
Live virus could also be present as an environmental contaminant in
the water used to transport live fish from farm to market.
Offal from commercial poultry slaughterhouses is reportedly used as a
source of feed for fish farms in Thailand that raise northern
snakeheads (_Channa striata_).
—
Joe Dudley
Chief Scientist, Biosecurity & Bioinformatics
EAI Corporation
SAIC
******
[3]
Date: Sun 4 Jun 2006
From: Simon Shane [Edited]
The point which your correspondents seem to miss is that Indonesian
subsistence farmers live in their poultry houses or rotate their
families through them for security, they drink crudely filtered pond
water, dress birds in the Kampong, and generally have intimate
contact with poultry, live bird dealers and all they come in contact
with!
I am concerned that ProMED is being “used” by the ornithological
fraternity to absolve their feathered constituency of any involvement
in dissemination of H5N1 HPAI. This is understandable, given fairly
widespread and indiscriminate shooting of migratory birds by the
Russians during the 2005 fall migration. There is a lot of blame to
go around, the inherently primitive farming system in Indonesia
(Suharto’s edict against corporate farming placing a 10 000-bird
limit on flocks during the 1980s), lack of veterinary resources,
poverty, ignorance, superstition, etc.
The situation in Thailand is marginally better, especially in the
commercial operations (SAHA, Sun Valley, CP), but HPAI is endemic and
non-reported in the hinterland. China has done an excellent job of
saturation vaccination of the intensive and semi-intensive industry
segments and withholding information which is inconvenient.
My conclusion is that migratory birds acquire infection and either
die if susceptible or serve as transitory shedders, establishing
rolling infections among diverse species. Once HPAI is introduced
into an area, deficiencies in biosecurity, including primitive
farming practices and live bird sales requiring movement by itinerant
traders, disseminates infection. Humans with sialic acid 2-3 glycan
receptors are unfortunately zapped. Please remember that the gene
pool in some of the villages in Indonesia, Turkey and other areas is
very shallow, or to put it another way, sibling rivalry is grounds
for divorce!
—
Simon M. Shane FRCVS, PhD. MBL. dip ACPV
Emeritus Professor
205 Landreth Court
Durham NC 27713
USA
[see also:
Avian influenza, poultry vs migratory birds (22) 20060531.1522
Avian influenza, poultry vs migratory birds (21) 20060522.1446
Avian influenza, poultry vs migratory birds (20) 20060518.1396
2005
—-
Avian influenza – Eurasia (111): Turkey, Asia fish feed 20051228.3697]
……………….lm/mhj/msp/arn/lm
– I have emailed Prof Shane, several of whose ideas perhaps bizarre, inc re rolling infections:
“I am curious re your conclusion “that migratory birds acquire infection and either die if susceptible or serve as transitory shedders, establishing rolling infections among diverse species.”
Evidence being?”