A descriptive study of the prevalence of atypical and classical scrapie in sheep in 20 European countries
Alexandre Fediaevsky , Sue C Tongue , Maria Noremark , Didier Calavas , Giuseppe Ru and Petter Hopp
BMC Veterinary Research 2008, 4:19doi:10.1186/1746-6148-4-19
Published: 10 June 2008
Abstract (provisional) Background The development of active surveillance programmes for transmissible spongiform encephalopathies of small ruminants across Europe has led to the recent identification of a previously undetected form of ovine prion disease, 'atypical' scrapie. Knowledge of the epidemiology of this disease is still limited, as is whether it represents a risk for animal and/or public health. The detection of atypical scrapie has been related to the use of only some of the EU agreed rapid tests. Information about the rapid tests used is not, as yet, available from public reports on the surveillance of transmissible spongiform encephalopathies in small ruminants. We collected detailed results of active surveillance from European countries to estimate and to compare the prevalence of atypical scrapie and classical scrapie in sheep for each country stratified by each surveillance stream; healthy slaughtered and found dead adult sheep.
Results From the 20 participating countries, it appeared that atypical scrapie was detected in Europe wherever the conditions necessary for its diagnosis were present. In most countries, atypical scrapie and classical scrapie occurred at low prevalence level. The classical scrapie prevalence estimates were more variable than those for atypical scrapie, which appeared remarkably homogeneous across countries, surveillance streams and calendar years of surveillance. Differences were observed in the age and genotype of atypical scrapie and classical scrapie cases that are consistent with previous published findings.
Conclusions This work suggests that atypical scrapie is not rare compared to classical scrapie. The homogeneity of its prevalence, whatever the country, stream of surveillance or year of detection, contrasts with the epidemiological pattern of classical scrapie. This suggests that the aetiology of atypical scrapie differs from that of classical scrapie.
full text ;
USA SCRAPIE 2008
INFECTED AND SOURCE FLOCKS
There were 20 scrapie infected and source flocks with open statuses (Figure 3) as of April, 30, 2008. Twenty eight new infected and source flocks have been designated in FY 2008 (Figure 4); three source flocks were reported in April. ...snip
POSITIVE SCRAPIE CASES
As of April 30, 2008, 122 new scrapie cases have been confirmed and reported by the National Veterinary Services Laboratories (NVSL) in FY 2008 (Figure 6). Of these, 103 were field cases and 19* were Regulatory Scrapie Slaughter Surveillance (RSSS) cases (collected in FY 2008 and reported by May 20, 2008). Positive cases reported for April 2008 are depicted in Figure 7. Eighteen cases of scrapie in goats have been confirmed by NVSL since implementation of the regulatory changes in FY 2002 (Figure 8). The most recent positive goat case was confirmed in February 2008 and originated from the same herd in Michigan as the other FY 2008 goat cases. ...snip
CAPRINE SCRAPIE PREVALENCE STUDY (CSPS)
However, four positive goats have been identified this fiscal year through field investigations. One was a clinical suspect submitted for testing and the other three originated from the birth herd of the clinical case.
ANIMALS SAMPLED FOR SCRAPIE TESTING
As of April 30, 2008, 26,703 animals have been sampled for scrapie testing: 23,378 RSSS, 1,517 goats for the CSPS study, 1,466 regulatory field cases, 270 regulatory third eyelid biopsies, and 72 regulatory rectal biopsies (chart 8).
TESTING OF LYMPHOID TISSUE OBTAINED BY RECTAL BIOPSY WAS APPROVED BY USDA AS AN OFFICIAL LIVE-ANIMAL TEST ON JANUARY 11, 2008. ...
PLEASE NOTE, (FIGURE 6), Scrapie Confirmed Cases in FY 2008 MAP, PA 3, 1**, Two cases-state of ID UNKNOWN, 1 case Nor98-like**
NOT to forget the 5 cases of the NOR-98 atypical scrapie documented in the USA in 2007, in five different states. WHICH pathologically looks like some sub-types of sporadic CJD, of which Stanely Prusiner warns of a public health risk ;
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved September 12, 2005 (received for review March 21, 2005)
Tuesday, June 3, 2008 SCRAPIE USA UPDATE JUNE 2008 NOR-98 REPORTED PA
NOR-98 ATYPICAL SCRAPIE 5 cases documented in USA in 5 different states USA 007