Volume 1: Findings and Conclusions
6. Protecting human health
CJD surveillance
Surveillance recommended by the Southwood Working Party and the Tyrrell Committee
The CJD Surveillance Unit established
How the surveillance system worked
PHLS excluded from CJD surveillance

Surveillance recommended by the Southwood Working Party and the Tyrrell Committee

499 Although the Southwood Working Party thought that it was most unlikely that BSE would have any implications for human health, they considered how BSE might appear, and be recognisable, if it did transmit to humans.

500 The Southwood Working Party noted in their Report that it was a reasonable assumption that, were BSE to be transmitted to humans, the clinical disorder would closely resemble CJD. They suggested that consideration be given to whether specialist branches of the medical profession, such as neurologists, should be made aware of the emergence of BSE so that they could report any atypical cases or changing patterns in the incidence of CJD. They also suggested that epidemiologists should be advised to watch for any such changing patterns.

501 CJD surveillance was also considered by the Tyrrell Committee. The Tyrrell Report gave the highest priority to the monitoring of all UK cases of CJD over the following two decades.

The CJD Surveillance Unit established

502 In December 1989 Dr Robert Will, then a consultant neurologist, applied to the Department of Health for a research grant for a project on CJD surveillance. Between 1979 and 1982, Dr Will had worked with Professor Bryan Matthews on various studies relating to the surveillance and analysis of CJD cases in England and Wales. Dr Will's proposal was accepted and the CJD surveillance project began on 1 May 1990 at the Western General Hospital in Edinburgh. It covered the whole of the UK and developed links with the surveillance networks of other countries.

503 The main objectives of the CJD Surveillance Unit (CJDSU) study were to identify any change in the epidemiological characteristics of CJD and to assess the extent to which any such changes were linked to the occurrence of BSE. The CJDSU was expected to document and publish any changes in the clinical or other characteristics of CJD, or in the epidemiology of the disease, and conduct investigations into the cause of these changes. The CJDSU summarised its progress and findings in a series of annual reports. These annual reports were supplemented by Dr Will informing SEAC and DH of developments.

How the surveillance system worked

504 The CJDSU needed to establish a system for the surveillance of CJD that would be able to detect any changes in epidemiology or clinical characteristics, as a result of the emergence of BSE. The main factors investigated included the number of cases of CJD, geographical distribution of cases and occupational incidence.

505 Primarily, this surveillance was achieved by seeking and obtaining direct referral of any suspect cases of CJD from neurologists. These professionals were also asked to report all cases of subacute dementing illnesses or progressive cerebellar dysfunction in specific occupational groups (including farmers and slaughtermen). However, as a precaution, all death certificates mentioning CJD were also obtained and assessed.

506 A standard questionnaire was used to obtain data relevant to diagnosis and ascertainment of possible risk factors. The questionnaire used by the CJDSU was based on the previous one developed by Dr Will for his work with Professor Matthews. It included sections on patients' initial symptoms, past medical history, family history, social history (residential, occupation, diet), exposure to animals, clinical history and results of diagnostic investigation. Minor changes were made to it before it was used in 1991 and subsequent alterations were made throughout the period 1991-95, as knowledge of CJD developed.

507 Unlike BSE, CJD was not made a notifiable disease. The possibility of making CJD a notifiable disease was not supported by either the Chief Medical Officer or Dr Will. Dr Will considered that in order to make CJD a notifiable disease, specific diagnostic criteria would have to be established. Some cases might then be missed as there might be a reluctance to notify cases that did not fulfil the criteria absolutely. Dr Will's view was supported by the European Union Surveillance Group in 1994. Recent data from this Group have lent some further support to Dr Will's view. The introduction of notification in Slovakia resulted in a decrease in the number of referrals.

PHLS excluded from CJD surveillance

508 The Public Health Laboratory Service (PHLS) did not become involved in CJD surveillance until after 20 March 1996. The PHLS is a public body with responsibility for providing a microbiological and epidemiological service to health authorities and local authorities for the diagnosis, control and prevention of infection and communicable diseases. It operates in England and Wales only, but has close working links with the parallel arrangements in Scotland and Northern Ireland.

509 PHLS officials repeatedly raised concerns with DH about the exclusion of their service from CJD surveillance. Since the PHLS's expertise was in communicable diseases, DH officials were concerned that PHLS involvement in the CJD monitoring process might indicate a belief that CJD could be spread from person to person. However, several other reasons were also given to the PHLS by DH for the decision. These included the possibility of unnecessary duplication of work and concern about PHLS priorities.

510 The decision to place the responsibility for surveillance with a small research team of dedicated medical scientists headed by a clinical neurologist with extensive experience in CJD was entirely correct. In 1989 the PHLS did not have expertise in CJD and, most importantly, there was (and still is) no established laboratory test for either CJD screening or for diagnosis in suspect cases. We commend the sterling work of the CJDSU team, who so promptly detected the emergence of vCJD and so efficiently established the clinical and pathological characteristics of the disease. While we have formed the view that the PHLS could have contributed to various aspects of the task assigned to the CJDSU, assistance from the PHLS would not have enabled identification of vCJD at any earlier date. We do not criticise those who concluded that the task of monitoring CJD should be left to the Surveillance Unit set up for that purpose.