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1. BISHAJIT DEBNATH
ID. -113-079-031

2.  It was first described in Britain in 1986.
 The disease is considered to have spread from Great Britain from
export of contaminated Meat-and-Bone-Meal(MBM) in Europe(19
countries reported at least one case of non imported cattle) plus
Israel and Japan.
 BSE was first recognized in the UK in 1988 , which has the
highest yearly incidence of the disease, from its discovery to
2002 more than 180,000 cases were reported.

3. A fatal prion disease of cattle that affects the nervous system,
resembles or is identical with scrapie of sheep and goats, and
is probably transmitted by infected tissue in food called also
mad cow disease.

4.  The infectious agent in BSE is believed to be a specific type of misfolded
protein called a prion.
 Prion = Proteinaceous infectious particle
 Normal Protein: PrPC (C for cellular)
 Prion proteins carry the disease between individuals and cause
deterioration of the brain.
 BSE is a type of transmissible spongiform encephalopathy (TSE)

5.  The natural hosts are cattle.
 Some cases have also occurred in antelopes and feline (cats, tiger,
puma etc).
 A range of other species including mice, pigs, and sheep has been
infected experimentally.
 Humans are thought to be susceptible (vCJD).

6.  United Kingdom
£3.7 billion total by end of 2001-02
In 1996-97
£850 million for compensation
Prior to 1996
£288 million on research,
surveillance, compensation
 Very costly, far reaching disease

7.  Reasons for emergence
- Feed contaminated with scrapie or unknown BSE
- Spontaneous
- Changes in feed processing
 Maternal transmission
- Possible, low risk
- Retrospective offspring culling
 Current thought
- Spread via ingestion of BSE contaminated feed

8.  Humans consuming cattle products infected with BSE can develop vCJD
◦ Brain and spinal tissue
 Consumption of milk and milk products
 Dose required not known
 Genetic susceptibility
◦ All human cases have been homozygous for methionine at codon 129
of PrPC

9.  Incubation: 2-8 years
 Initial neurological signs
◦ Apprehension, fear, easily startled, depressed
 Final stages
Excitable, hyperreflexia, hypermetria, ataxia, muscle fasciculation, tremors.
 Autonomic dysfunction: reduced rumination, bradycardia and altered heart
rhythm
 Hyperesthesia or hyperreflexia.
DEPARTMENT OF MICROBIOLOGY,
PRIMEASIA UNIVERSITY

10.  Terminal state
◦ Decreased rumination
◦ Loss of body weight and condition, despite good appetite
 There is no treatment for BSE
 Affected herds
◦ 2-3% morbidity
◦ 100% mortality

11.  The BSE testing protocol calls for an initial rapid test called an Enzyme-
Linked Immunosorbent Assay (ELISA).
 If the ELISA test is inconclusive, samples are sent for confirmatory testing
to the National Veterinary Services Laboratories (NVSL).
 An immunohistochemistry test is conducted at NVSL and, concurrently, an
OIE-approved Western Blot is conducted at the National Animal Disease
Center (NADC).
 These tests are designed to detect the presence of BSE-specific abnormal
prion protein in the brain tissue.

12. June 24, 2005
- New BSE confirmatory testing protocol
IHC & Western Blot
confirmatory tests
Positive result on either test
considered positive for BSE
“Inconclusive” BSE rapid screening tests.

13. No effective treatment or vaccine
Surveillance program
Blood/plasma donation restrictions
USDA bans importation of ruminants
from countries with BSE.
Persons who have traveled or resided in the
U.K. for 3 or more cumulative months from
1980 to 1996.

14. Bovine spongiform encephalopathy (BSE), commonly
known as mad cow disease, is a fatal neurodegenerative
disease (encephalopathy) in cattle that causes a spongy
degeneration in the brain and spinal cord.
The infectious agent, although most highly concentrated
in nervous tissue, can be found in virtually all tissues
throughout the body, including blood.

15. THANK
YOU
DEPARTMENT OF MICROBIOLOGY, PRIMEASIA UNIVERSITY