COMMUNICABLE DISEASE MANUAL POLICIES / PROCEDURES
CREUTZFELDT-JAKOB DISEASE (CJD)
or
Bovine Spongiform Encephalopathy (BSE)
or
(vCJD) New Variant Creutzfeldt-Jakob Disease
or
Mad Cow Disease
OBJECTIVE:
Control and management of CJD, BSE, or vCJD
DESCRIPTION:
Creutzfeldt-Jakob disease (CJD) is a rapidly progressive, fatal neurodegenerative
disorder believed to be caused by an abnormal isoform of a cellular glycoprotein
known as the prion protein. CJD occurs worldwide and the estimated annual
incidence in many countries, including the United States, has been reported to be
about one case per million population.
The vast majority of CJD patients usually die within one (1) year of illness onset.
CJD is classified as a transmissible spongiform encephalopathy (TSE) along with
other prion diseases that occur in humans and animals. In about 85% of patients,
classic CJD occurs as a sporadic disease with no recognizable pattern of
transmission. A smaller proportion of patients (5 to 15%) develop CJD because of
inherited mutations of the prion protein gene. These inherited forms include
Gerstmann-Straussler-Scheinker syndrome and fatal familial insomnia. Iatrogenic
CJD has been acquired through injection of cadaveric pituitary hormones (growth
hormone and human gonadotropin), dura mater allografts, corneal transplantation,
and instrumentation of the brain at neurosurgery or depth-electrode
electroencephalographic recording. In 1996, an outbreak of vCJD linked to
exposure to tissues from bovine spongiform encephalopathy (BSE)-infected cattle
was reported in the United Kingdom. The best known TSE's affecting animals are
scrapie of sheep, BSE, and a chronic wasting disease of North American deer and
elk.
Classic CJD is an insidious onset with confusion, progressive dementia and
variable ataxia in patients aged 16 to over 80 years, but almost all (more than
99%) are 35 years of age or older. Later, myoclonic jerks appear, together with a
variable spectrum of other neurologic signs. Characteristically, routine laboratory
studies of the CSF are normal and there is no fever. Typical periodic high-voltage
complexes are common on electroencephalogram (EEG).
The disease
progresses rapidly; death usually occurs within 3-12 months (median 4 months,
mean 7 months). Pathologic changes are limited to the CNS.
Bovine spongiform encephalopathy (BSE) or Mad Cow Disease is a progressive
neurodegenerative disorder of cattle that resulted from the feeding of scrapiecontaining sheep meat-and-bone meal to cattle and feeding rendered infected
bovine meat-and-bone meal to calves. BSE was transmitted to humans through
the consumption of beef products and resulted in the creation of a new form of
CJD called variant CJD. Classic CJD differs from vCJD in three (3) ways. Unlike
CJD, vCJD occurs in a younger age group (20-30 years of age). In addition, the
characteristic EEG changes seen with CJD are absent in the vCJD. Finally, the
clinical course of vCJD is typically much longer than CJD (12-15 months versus 36 months).
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Variant CJD not only affects younger people, but has atypical clinical features,
with prominent psychiatric or sensory symptoms at the time of clinical presentation
and delayed onset of neurologic abnormalities, including ataxia within weeks or
months, dementia and myoclonus late in the illness, a duration of illness of at least
six (6) months, and a diffusely abnormal non-diagnostic electroencephalogram.
Incubation period of vCJD from consuming a BSE contaminated product is a
decade or more earlier. Incubation period for Classic CJD is 15 months to 30
years. There is no known treatment for vCJD and it is fatal, with the median age
for death at 28 years of age.
EQUIPMENT:
MDSS User Manual (disease specific form will be found in MDSS. Fax Notification
of Serious Communicable Disease, if confirmed or suspected iatrogenic CJD or
vCJD case. Also MDCH Web site at www.michigan.gov/cdinfo, and
CDC Web site at www.cdc.gov/diseasesconditions/az/a.html
POLICY:
Legal Responsibility: Michigan's communicable disease rules of Act No. 368 of
the Public Acts of 1978, as amended, being 333.5111 of the Michigan Compiled
Laws. Follow-up time; 72 hours post referral AND ENTER INTO MDSS
WITHIN 24 HOURS OF RECEIPT OF REFERRAL.
PROCEDURE:
A.
Case Investigation
1.
Referral received per phone call, laboratory results, or automatically
through MDSS.
2.
Document all case investigation proceedings.
3.
Contact M.D. or client to start process of completing disease specific
form in MDSS.
1.
Immediately notify the CD Supervisor, Medical Director and HD
Emergency Manager of confirmed or suspected cases. Call MDCH
at 517-335-8165 and Regional Epidemiologist. Nurse to Fax
Notification of Serious Communicable Disease Form to MDCH for
confirmed or suspected cases.
f
B.
C.
Lab Criteria for Diagnosis
1.
Classic CJD diagnosis is based on clinical signs and a characteristic
periodic EEG. It can be confirmed by detection of the prion protein
in brain tissue, usually postmortem.
2.
Variant CJD diagnosis can be confirmed only through brain tissue
examination obtained through biopsy or autopsy. A probable case
diagnosis is based on the clinical criteria developed by the United
Kingdom.
Control Measures
1.
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The available evidence indicates that even prolonged intimate
contact with CJD-infected people has not resulted in transmission of
disease. Tissues associated with high levels of infectivity (e.g.
brain, eyes, and spinal cord of affected people) and instruments in
contact with those tissues are considered biohazards; incineration,
prolonged autoclaving at high temperature and pressure and
exposure to a solution of sodium hydroxide of 1N or greater or a
solution of sodium hypochlorite of 5.25% or greater (undiluted
household chlorine bleach) for one (1) hour has been reported to
decrease infectivity. Cerebrospinal fluid should be regarded as
infectious. Person-to-person transmission of CJD by blood, milk,
saliva, urine, or feces has not been reported. These body fluids
should be handled using standard infection control procedures.
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2.
Immunization against prion diseases is not available, and no immune
response to infection has been demonstrated.
3.
Iatrogenic transmission of CJD through cadaveric pituitary hormones
has been obviated by use of recombinant products.
4.
Recognition that CJD can be spread by transplantation of infected
dura and corneas has led to more stringent donor-selection criteria
and improved collection protocols.
5.
Performing a brain autopsy in patients with suspected or clinically
diagnosed CJD is encouraged to confirm the diagnosis and detect
other emerging forms of CJD, such as vCJD.
6.
As a precautionary measure to reduce the theoretical risk of vCJD
transmission to blood product recipients, USA and Canadian
authorities in August, 1999 requested blood centers to exclude from
donating blood, potential donors who spent six (6) or more
cumulative months between January 1, 1980 and December 31,
1996 in the UK (England, Scotland, Wales, Northern Ireland, the Isle
of Man, and the Channel Islands). Also included in this deferral in
the USA were donors who received non-USA licensed bovine insulin
or other injectable products made from cattle in BSE endemic
countries.
7.
To reduce the possible current risk of acquiring vCJD from food,
travelers to Europe or other areas with indigenous cases of BSE or
at possibly increased risk of BSE may wish to consider either:

avoiding beef and beef products altogether or

selecting beef or beef products, such as solid pieces of muscle
meat (versus calf brains or beef products such as burgers and
sausages), which might have a reduced opportunity for
contamination with tissues that may harbor the BSE agent.
8.
Milk and milk products from cows are not believed to post any risk for
transmitting the BSE agent.
9.
The United States Department of Agriculture (USDA) has imposed
multiple firewalls to prevent BSE from entering the United States:
10.
D.
RESOURCES:
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
Severe restrictions on importation of live ruminants, such as
cattle, sheep, goats, and certain ruminant products from all
countries where BSE exists starting in 1989.

Surveillance and testing of U.S. cattle population for the
presence of BSE.

FDA's June 1997 animal feed ban, which is the critical safeguard
to help prevent the spread of BSE through cattle herds by
prohibiting the feeding of mammalian protein to ruminants,
including cattle and preventing cross contamination of ruminant
feed by non-ruminant feed at production lines and facilities. Also
bans the use of poultry feed, plate waste, mammalian blood and
blood products for ruminant feed.

No bovine tissue known to be at risk for BSE may enter the
human food supply (including dietary supplements and
cosmetics). Bovine tissues considered at risk for BSE banned
from the food supply are the brain, skull, eyes, spinal cord,
tonsils, and a portion of the small intestine from all cattle,
regardless of their age or health.
A suspected or confirmed case of CJD for which a special health
response may be needed (iatrogenic disease or vCJD) should be
reported to MDCH by fax or phone and to the Team Leader who will
report to Supervisor, Medical Director and Epidemiologist. If Team
Leader not present, follow above chain of command.
MDSS Case Report
1.
Complete case investigation using disease specific form in MDSS.
2.
Notify CD Supervisor that the case report is ready for review. PHN will
be notified if corrections are needed prior to closing case in MDSS.
3.
CD Supervisor reviews case for completeness and closes MDSS case
report.
Current Red Book
Current Control of Communicable Disease Manual
Current disease specific “Fact Sheet”
Websites: www.cdc.gov/diseasesconditions/az/a.html
www.michigan.gov/cdinfo