Back to warmwell.com


http://www.promedmail.org/pls/promed/f?p=2400:1001:2493171580729818066::NO::F2400_P1001_BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,32753


Subject: PRO/AH/EDR> Anthrax, bovine - UK (Wales

 

N.B. This is an EXTRACT showing only the Promed moderator's comment. For the full page please use the URL above.
- --
ProMED-mail
<promed@promedmail.org>

[A number of comments: Firstly, while the major tenor of the
government response is to calm fears, there is a suspicion of a
present lack of experience. For example: "The small farm has been
sealed off, with the remaining herd of suckler cows confined to their
field while tests  continue." Quarantine is routine for a limited
period after vaccination, usually 14 to 21 days,  but why not mention
vaccination and exactly what tests on the suckler cows? Or are they
attempting soil sampling? If the latter, I wish them good luck as it
is much harder than many  realise even with modern techniques. And I
do hope that they vaccinated those cows.

Secondly, the pattern of UK anthrax outbreaks in the past 25 years is
essentially no longer from contaminated livestock feed --- the
Wrexham pigs were a notable exception --- but usually occur following
an environmental disturbance, such as trenching, bulldozing, or river
dredging, disturbing buried spores at cattle grave sites or occur in
relation to mills & tanneries that handled contaminated imported hair
& hides. This is a common epidemiologic pattern once an area is
considered to be in a true sporadic state epidemiologically.

Thirdly: About 18 months ago, with Peter Durr's help & assistance, I
attempted a file review of  the past 100 outbreaks in the UK. We got
about 25 replies and then it dried up as the regional  Defra chiefs
refused to recall the files from their archives. Two dozen survey
docs do not an hypothesis challenge. If Defra would like me to
continue and participate, please contact me.

Lastly: by  the nature of this disease it is frankly hard to find a
farm that has not had an outbreak in the  past 100 years. Thus the
observation that it has "recurred" proves nothing. If one could plot
where recurrences are truly probable, one might then come up with
some soil parameters favouring spore survival, other than the usual
high calcium levels combined with high pH and presence of organic
matter in the soil.

At one time the UK had some 425 outbreaks each year over the course
of decades thanks to contaminated feed. Once this was cleaned up, the
rate dropped precipitously to the present situation when years go by
without cases. It is now frankly a rare event subject to specific
trigger events and as time goes by, it will potentially become even
rarer, as spores are not immortal and can also lose their plasmids
over time. Otherwise we would be vaccinating cattle annually in
Europe & North America. We don't. And we have a situation where
livestock veterinarians are ignorant of the disease (not having seen
much of it during their careers), which delays recognition. This is
further exaggerated in the UK where far too many farmers are now too
poor to regularly employ a veterinarian. This Welsh outbreak is a
good example as 5 cows had to die before it was diagnosed.

I am mildly puzzled at the timing. April is early for this disease in
the UK for it to be due to environmental exposure; theoretically
dirty feed is available year round. But without details one can only
muse about possible sources. And before anyone comes up with claims
of Lazarus spores, my colleague & good friend Peter Turnbull once
investigated an outbreak in Dorset, southern England, where some 5-6
steers were affected from a cow buried some 60 plus years previously;
Peter located the grave in the pasture and showed the presence of
viable spores in the surface soil. - Mod.MHJ]

[The below "see also" list is a selection of anthrax outbreaks in the
USA, Canada, Europe and Australia posted on ProMED-mail through the
years.  It is not the "complete collection" but rather a sampling to
demonstrate how anthrax continues to be a sporadic problem in
developed countries, in keeping with the moderator comment above by
Mod.MHJ. - Mod.MPP]


http://www.promedmail.org/pls/promed/f?p=2400:1001:2493171580729818066::NO::F2400_P1001_BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,32753

. This is an EXTRACT showing only the Promed moderator's comment. For the full page please use the URL above.