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close this bookWHO Recommended Surveillance Standards (WHO; 1999; 157 pages)
View the documentAcknowledgements
View the documentAcronyms
View the documentIntroduction
View the documentNational Coordination of Communicable Disease Surveillance
View the documentExplanatory notes
View the documentSurveillance activities: criteria and WHO Department
View the documentCommunicable disease contacts in Regional Offices
close this folderDiseases
View the documentB20-B21-B22-B23-B24 AIDS
View the documentA22 Anthrax
View the documentA23 Brucellosis
View the documentA00 Cholera
View the documentA81.0 Creutzfeldt-Jakob disease
View the documentA90, A91 Dengue fever (A90) including Dengue haemorrhagic fever (DHF) & Dengue shock syndrome (DSS, A91)
View the documentA36 Diphtheria
View the documentB72 Dracunculiasis (Guinea worm disease)
View the documentA98.3, A98.4 Ebola-Marburg viral diseases
View the documentA83.0 Japanese encephalitis
View the documentB74 Lymphatic filariasis
View the documentB96.3 Haemophilus influenzae type b
View the documentB15-B17 Acute viral hepatitis
View the documentB20-B24 HIV infection
View the documentJ10, J11 Influenza
View the documentA96.2 Lassa fever
View the documentA48.1 Legionellosis
View the documentB55.1, B55.2 Cutaneous leishmaniasis
View the documentLeishmania / HIV co-infections
View the documentB55.0 Visceral leishmaniasis
View the documentA30 Leprosy
View the documentA27 Leptospirosis
View the documentB50-54 Malaria
View the documentB05 Measles
View the documentA39 Meningococcal disease
View the documentA87 Viral meningitis
View the documentB73 Onchocerciasis
View the documentA37.0 Pertussis
View the documentA20 Plague
View the documentA36 Poliomyelitis
View the documentA82 Rabies
View the documentA02.0 Salmonellosis
View the documentB65 Schistosomiasis
View the documentA50-52 Syphilis
View the documentA33 Tetanus, neonatal
View the documentB56-0, B56-1 African trypanosomiasis
View the documentB57 American trypanosomiasis
View the documentA15-A19 Tuberculosis
View the documentA75.3 Scrub typhus
View the documentA95.9 Yellow fever
open this folder and view contentsSyndromes
View the documentAnnex 1 Software free and in the public domain
View the documentAnnex 2 Proposed surveillance definitions
View the documentAnnex 3 Role and use of Geographic Information Systems (GIS) and mapping for epidemiological surveillance

A81.0 Creutzfeldt-Jakob disease


The incidence of Creutzfeldt-Jakob Disease (CJD) and its variants is not currently monitored in many parts of the world. In 1996 a new variant of CJD (nvCJD) was recognized in the United Kingdom. An etiological link has since been confirmed between nvCJD and the agent of bovine spongiform encephalopathy (BSE). The size of the population exposed and susceptible to this agent in the United Kingdom is not known; this, in addition to uncertainties relating to the potential length and distribution of the incubation period, complicate any useful prediction of the future number of nvCJD cases. Other populations may have also been exposed to the agent through importation of live cattle or cattle by-products from BSE-affected countries, or through the use of medicinal or cosmetic products containing affected bovine tissues. Global surveillance of the new variant and other forms of CJD shall lead to a better understanding of the disease, including potential causes of iatrogenic CJD as well as the distribution of various hereditary forms. It shall also provide information towards protection against the risks of disease.


1. Sporadic CJD

(a) Possible CJD:


• Progressive dementia; and

• EEG atypical or not known and

• Duration <2 years and

• At least 2 out of the following 4 clinical features: myoclonus, visual or cerebellar disturbance, pyramidal/extrapyramidal dysfunction, akinetic mutism

(b) Probable CJD:
(in the absence of an alternative diagnosis from routine investigation)


• Progressive dementia; and
• At least 2 of the following 4 clinical features:
• Myoclonus
• Visual or cerebellar disturbance
• Pyramidal/extrapyramidal dysfunction
• Akinetic mutism and
• A typical EEG, whatever the clinical duration of the disease, and/or
• A positive 14-3-3 assay for CSF and a clinical duration to death <2 years

(c) Confirmed (definite) CJD:


• Neuropathological confirmation; and/or
• Confirmation of protease-resistant prion protein (PrP) (immunocytochemistry or Western blot) and/or
• Presence of scrapie-associated fibrils

2. Iatrogenic CJD


• Progressive cerebellar syndrome in a recipient of human cadaver-derived pituitary hormone; or
• Sporadic CJD with a recognized exposure risk

3. Familial CJD


• Confirmed or probable CJD plus confirmed or probable CJD in a first degree relative and/or
• Neuropsychiatric disorder plus disease-specific PrP mutation


Note: For purposes of surveillance, includes Gerstmann-Sträussler-Scheinker (GSS) syndrome and fatal familial insomnia (FFI).

4. New variant CJD (nvCJD)

New variant CJD cannot be diagnosed with certainty on clinical criteria alone at present. On the basis of the few neuropathologically confirmed cases, the diagnosis of nvCJD should be considered as a possibility in a patient with a progressive neuropsychiatric disorder and at least 5 of the following 6 clinical features:


• Early psychiatric symptoms
• Early persistent paraesthaesia/dysaesthesia
• Ataxia
• Chorea/dystonia or myoclonus
• Dementia
• Akinetic mutism

The suspicion of nvCJD for surveillance purposes is strengthened by the following:


• No history of potential iatrogenic exposure

• Clinical duration >6 months

• Age at onset <50 years

• No PrP gene mutation

• EEG does not show the typical periodic appearance

• Routine investigations do not suggest an alternative diagnosis

• Magnetic Image Resonance shows abnormal symmetrical and bilateral high signals from the pulvinar on axial T2- and/or proton-density-weighted images

A patient with a progressive neuropsychiatric disorder and 5 out of the 6 clinical criteria mentioned earlier plus all of the criteria of suspicion listed immediately above should be considered as a suspect case of nvCJD for surveillance purposes.

Confirmed (definite)

Neuropathology is mandatory for the diagnosis of definite nvCJD: the use of cerebral biopsy in living patients is to be discouraged unless its purpose is to arrive at an alternative diagnosis of a treatable disorder. Autopsy (or postmortem biopsy of the brain where autopsy is not possible) is strongly encouraged in any suspect case of CJD. See under "special aspects" for the neuropathological criteria in CJD and other human transmissible spongiform encephalopathies.


One centre should be identified at central level to carry out surveillance.

All reporting should be case-based.

All definite, probable and possible cases should be notified by the appropriate health care professionals (usually physicians, neurologists, psychiatrists, neuropathologists) to the centre responsible for surveillance.


Note: Death registrations should be checked in order to identify cases not detected by routine surveillance.


Case-based data for reporting


• Subtype and classification of CJD
• Age, sex, country of birth, geographical information, occupation
• Date of onset, date of death
• Vital status (alive, dead)


Number of cases by subtype, classification, occupational group, geographical area.

Number of cases by year of death, by age at death.

Sex ratio.



• Plot the trend in incidence of CJD subtypes

• Detect clusters of cases requiring further investigation

• Identify risk factors for disease


Neuropathological criteria for CJD and other human transmissible spongiform encephalopathies can be summarized as follows:

Creutzfeldt-Jakob disease: sporadic, iatrogenic (recognized risk) or familial (same disease in first degree relative or disease-associated PrP gene mutation):


• Spongiform encephalopathy in cerebral and/or cerebellar cortex and/or subcortical grey matter; and/or

• Encephalopathy with prion protein (PrP) immunoreactivity (plaque and/or diffuse synaptic and/or patchy/perivacuolar types)

New variant CJD


• Spongiform encephalopathy with abundant PrP deposition, in particular multiple fibrillary PrP plaques surrounded by a halo of spongiform vacuoles ('florid' plaques, 'daisy-like' plaques) and other PrP plaques, and amorphous pericellular and perivascular PrP deposits especially prominent in the cerebellar molecular layer

Gerstmann-Sträussler-Scheinker (GSS) disease: (in family with dominantly inherited progressive ataxia and/or dementia and one of a variety of PrP gene mutations):


• Encephalo(myelo)pathy with multicentric PrP plaques
• Thalamic degeneration, variable spongiform change in cerebrum

• Spongiform encephalopathy in the Fore population of Papua New Guinea


Regional Offices

See Regional Communicable Disease contacts on section "Communicable disease contacts in Regional Offices".

Headquarters: 20 Avenue Appia, CH-1211 Geneva 27, Switzerland

Communicable Diseases Surveillance and Response (CSR)


E-mail: meslinf@who.ch / outbreak@who.ch
Tel: (41 22) 791 2575/4687/2111
Fax: (41 22) 791 4893/0746 attn CSR
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