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Review on the epidemiology and dynamics of BSE epidemics

flounder

Well-known member
How to cite this article: Vet. Res. (2008) 39:15
DOI: 10.1051/vetres:2007053

Review on the epidemiology and dynamics of BSE epidemics

Christian Ducrot1, Mark Arnold2, Aline de Koeijer3, Dagmar Heim4 and Didier
Calavas5

1 INRA Unité d'Épidémiologie Animale, 63122 Saint-Genès-Champanelle, France
2 VLA Sutton Bonington, The Elms, College Road, Sutton Bonington,
Loughborough, LE12 5RB, England
3 Division of Infectious Diseases, Animal Sciences Group, Wageningen,
University and Research Center, PO Box 65, 8200 AB Lelystad, The Netherlands
4 Office vétérinaire fédéral, Schwarzenburgstrasse 155, Case Postale 3003,
Bern, Suisse
5 AFSSA Lyon, Unité Épidémiologie, 31 avenue Tony Garnier, 69364 Lyon Cedex
07, France

(Received 24 April 2007; accepted 23 October 2007 ; published online 11
January 2008)

Abstract - The paper describes how the comprehensive surveillance of bovine
spongiform encephalopathy (BSE) and studies carried out on these data has
enhanced our knowledge of the epidemiology of BSE. Around 7 000 BSE cases
were detected through the screening of about 50 million cattle with rapid
tests in Europe. It confirmed that the clinical surveillance had a poor
capacity to detect cases, and also showed the discrepancy of this passive
surveillance efficiency between regions and production types (dairy/beef).
Other risk factors for BSE were being in a dairy herd (three times more than
beef), having a young age at first calving (for dairy cattle), being
autumn-born (dairy and beef), and being in a herd with a very high milk
yield. These findings focus the risk on the feeding regimen of
calves/heifers. Several epidemiological studies across countries suggest
that the feedborne source related to meat and bone meal (MBM) is the only
substantiated route of infection - even after the feed ban -, while it is
not possible to exclude maternal transmission or milk replacers as a source
of some infections. In most European countries, the average age of the cases
is increasing over time and the prevalence decreasing, which reflects the
effectiveness of control measures. Consistent results on the trend of the
epidemic were obtained using back-calculation modelling, the R0 approach and
Age-Period-Cohort models. Furthermore, active surveillance also resulted in
the finding of atypical cases. These are distinct from previously found BSE
and classified in two different forms based on biochemical characteristics;
their prevalence is very low (36 cases up to 1st September 2007), affected
animals were old and some of them displayed clinical signs. The origin and
possibility of natural transmission is unknown.


Corresponding author: [email protected]

© INRA, EDP Sciences 2008



http://www.vetres.org/index.php?option=article&access=doi&doi=10.1051/vetres:2007053


can't say to much about the 'free full text access', never could open pdf.
i am all for free access.
maybe just my machine though. ...tss

http://www.vetres.org/articles/vetres/pdf/2008/04/v07232.pdf


USA


THE june 2004 enhanced bse surveillance program was flawed from the
beginning, and proven so later by OIG and GAO. also, even cdc's top prion
God says he does not trust them ;

In this context, a word is in order about the US testing program. After the
discovery of the first (imported) cow in 2003, the magnitude of testing was
much increased, reaching a level of >400,000 tests in 2005 (Figure 4).
Neither of the 2 more recently indigenously infected older animals with
nonspecific clinical features would have been detected without such testing,
and neither would have been identified as atypical without confirmatory
Western blots. Despite these facts, surveillance has now been decimated to
40,000 annual tests (USDA news release no. 0255.06, July 20, 2006) and
invites the accusation that the United States will never know the true
status of its involvement with BSE.

http://www.cdc.gov/ncidod/EID/vol12no12/06-0965.htm


PAUL BROWN COMMENT TO ME ON THIS ISSUE

Tuesday, September 12, 2006 11:10 AM


"Actually, Terry, I have been critical of the USDA handling of the mad cow
issue for some years, and with Linda Detwiler and others sent lengthy
detailed critiques and recommendations to both the USDA and the Canadian
Food
Agency."


http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0703&L=sanet-mg&T=0&P=8125


CDC DR. PAUL BROWN TSE EXPERT COMMENTS 2006


The U.S. Department of Agriculture was quick to assure the public earlier
this week that the third case of mad cow disease did not pose a risk to
them, but what federal officials have not acknowledged is that this latest
case indicates the deadly disease has been circulating in U.S. herds for at
least a decade.

The second case, which was detected last year in a Texas cow and which USDA
officials were reluctant to verify, was approximately 12 years old.

These two cases (the latest was detected in an Alabama cow) present a
picture of the disease having been here for 10 years or so, since it is
thought that cows usually contract the disease from contaminated feed they
consume as calves. The concern is that humans can contract a fatal,
incurable, brain-wasting illness from consuming beef products contaminated
with the mad cow pathogen.

"The fact the Texas cow showed up fairly clearly implied the existence of
other undetected cases," Dr. Paul Brown, former medical director of the
National Institutes of Health's Laboratory for Central Nervous System
Studies and an expert on mad cow-like diseases, told United Press
International. "The question was, 'How many?' and we still can't answer
that."

Brown, who is preparing a scientific paper based on the latest two mad cow
cases to estimate the maximum number of infected cows that occurred in the
United States, said he has "absolutely no confidence in USDA tests before
one year ago" because of the agency's reluctance to retest the Texas cow
that initially tested positive.

USDA officials finally retested the cow and confirmed it was infected seven
months later, but only at the insistence of the agency's inspector general.

"Everything they did on the Texas cow makes everything USDA did before 2005
suspect," Brown said. ...snip...end


http://www.upi.com/ConsumerHealthDaily/view.php?StoryID=20060315-055557-1284r


CDC - Bovine Spongiform Encephalopathy and Variant Creutzfeldt ...
Dr. Paul Brown is Senior Research Scientist in the Laboratory of Central
Nervous System ... Address for correspondence: Paul Brown, Building 36, Room
4A-05, ...


http://www.cdc.gov/ncidod/eid/vol7no1/brown.htm



Geographical BSE Risk (GBR) assessments covering 2000-2006

Date : 01.08.2006

http://www.efsa.europa.eu/EFSA/Scientific_Document/GBR_assessments_table_Overview_assessed_countries_2002-2006.pdf


Audit Report

Animal and Plant Health Inspection Service

Bovine Spongiform Encephalopathy (BSE) Surveillance Program - Phase II

and

Food Safety and Inspection Service

Controls Over BSE Sampling, Specified Risk Materials, and Advanced Meat
Recovery Products - Phase III

Report No. 50601-10-KC January 2006

Finding 2 Inherent Challenges in Identifying and Testing High-Risk Cattle
Still Remain

Our prior report identified a number of inherent problems in identifying and
testing high-risk cattle. We reported that the challenges in identifying the
universe of high-risk cattle, as well as the need to design procedures to
obtain an appropriate representation of samples, was critical to the success
of the BSE surveillance program. The surveillance program was designed to
target nonambulatory cattle, cattle showing signs of CNS disease (including
cattle testing negative for rabies), cattle showing signs not inconsistent
with BSE, and dead cattle. Although APHIS designed procedures to ensure FSIS
condemned cattle were sampled and made a concerted effort for outreach to
obtain targeted samples, industry practices not considered in the design of
the surveillance program reduced assurance that targeted animals were tested
for BSE.




USDA/OIG-A/50601-10-KC Page 27

observe these animals ante mortem when possible to assure the animals from
the target population are ultimately sampled and the clinical signs
evaluated.



snip...



http://www.usda.gov/oig/webdocs/50601-10-KC.pdf



GAO-05-51 October 2004 FOOD SAFETY

over 500 customers receiving potentially BSE contaminated beef .....

* GAO-05-51 October 2004 FOOD SAFETY (over 500 customers receiving
potentially BSE contaminated beef) - TSS 10/20/04

October 2004 FOOD SAFETY
USDA and FDA Need
to Better Ensure
Prompt and Complete
Recalls of Potentially
Unsafe Food

snip...

REPORTS

1. Food Safety: USDA and FDA Need to Better Ensure Prompt and Complete
Recalls of Potentially Unsafe Food. GAO-05-51, October 7.tss


http://www.gao.gov/new.items/d0551.pdf


Highlights -

http://www.gao.gov/highlights/d0551high.pdf



3. Mad Cow Disease: FDA's Management of the Feed Ban Has Improved,
but Oversight Weaknesses Continue to Limit Program Effectiveness.
GAO-05-101, Feb. 25.

www.gao.gov/cgi-bin/getrpt?GAO-05-101

Highlights -

www.gao.gov/highlights/d05101high.pdf



SADLY, DEC 2005 SHOWS THAT WE STILL HAVE A SERIOUS PROBLEM WITH BSE/TSE MAD
COW DISEASE FEED


GAO


GAO-06-157R FDA Feed Testing Program

October 11, 2005


SNIP...FULL TEXT 29 PAGES ;


http://www.gao.gov/new.items/d06157r.pdf


Mad Cow Disease: An Evaluation of a Small Feed Testing Program FDA
Implemented in 2003 With Recommendations for Making the Program a Better
Oversight Tool. GAO-06-157R, October 11

http://www.gao.gov/cgi-bin/getrpt?GAO-06-157R


USA MAD COW CASES IN ALABAMA AND TEXAS

***PLEASE NOTE***

USA BASE CASE, (ATYPICAL BSE), AND OR TSE (whatever they are calling it
today), please note that both the ALABAMA COW, AND THE TEXAS COW,both were
''H-TYPE'', personal communication Detwiler et al Wednesday, August 22, 2007
11:52 PM. ...TSS

http://lists.ifas.ufl.edu/cgi-bin/wa.exe?A2=ind0708&L=sanet-mg&T=0&P=19779


USA NOR-98 SCRAPIE UPDATE AUGUST 31, 2007 RISES TO 5 DOCUMENTED CASES


http://nor-98.blogspot.com/


prepared February 20, 2008



Infected and Source Flocks

There were 27 scrapie infected and source flocks with open statuses (Figure
3) as of January 31, 2008. Two new source flocks and one new infected flock
were reported in January (Figure 4) with a total of 22 reported for FY 2008
(Figure 5). ....


snip...


Positive Scrapie Cases

As of January 31, 2008, 58 new scrapie cases have been confirmed and
reported by the National Veterinary Services Laboratories (NVSL) in FY 2008
(Figure 7). Of these, 52 were field cases and 6* were Regulatory Scrapie
Slaughter Surveillance (RSSS) cases (collected in FY 2008 and reported by
February 20, 2008). There were 8 positive cases for January which are
depicted in Figure 8. Seventeen cases of scrapie in goats have been
confirmed by NVSL since implementation of the regulatory changes in FY 2002
(Figure 9). The most recent positive goat cases were from the SAME HERD and
WERE BOTH CONFIRMED IN JANAURY 2008.


snip...


Caprine Scrapie Prevalence Study (CSPS)

CSPS was initiated in May 2007 to estimate the national prevalance of
scrapie in adult goats at slaughter. If no scrapie is found we will be able
to conclude that the prevalence in goats is greater than zero and less than
0.1 percent. AS of January 31, 2008, 2,942 goats have been sampled for
scrapie testing (1,515 in FY 2007 and 1,427 in FY 2008). Collection numbers
by quarter in FY 2008 is shown in Chart 8. To date, no goats have tested
positive for scrapie as part of this surveillance program. HOWEVER, THREE
POSITIVE GOATS have been identified this fiscal year through field
investigations. One was a clinical suspect submitted for testing and THE
OTHER TWO WERE MEMBERS OF THE OF THE BIRTH HERD OF THE CLINICAL CASE.


snip...


please see full text ;


Sent: Tuesday, March 04, 2008 12:00 PM
Subject: [madcow] SCRAPIE DOCUMENTED IN CLINICAL SUSPECT GOAT, WITH TWO MORE DOCUMENTED IN SAME BIRTH HERD OF CLINICAL CASE



http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps



Wednesday, February 27, 2008

BEEF RECALL NATIONWIDE - SCHOOL LUNCH PROGRAM UPDATE


http://downercattle.blogspot.com/2008/02/beef-recall-nationwide-school-lunch.html



TSS
 

Shaft

Well-known member
Thanks Terry. Good article. FYI, I had no problem accessing the PDF.

"In conclusion, epidemiological evidence across several countries suggests that the feedborne source related to MBM is the only
substantiated route of infection, while it is not possible to exclude maternal transmission or milk replacers as a source of some infections.
The majority, if not all, of the cases born after the ban on MBM in ruminant feed have arisen due to continued exposure to contaminated
feed."
 
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