Variant Creutzfeldt-Jakob disease and exposure to fractionated plasma products.

BACKGROUND: The risk to public health of onward transmission of variant Creutzfeldt-Jakob disease (vCJD) via blood transfusion and plasma product administration is of on-going concern, particularly with the recent reported detection of abnormal prion protein in a person with haemophilia. OBJECTIVES: To describe the history of fractionated plasma product exposure in clinical cases of vCJD in the UK. METHODS: Through examination of records held at the National CJD Surveillance Unit (from relatives, general practices and hospitals). RESULTS: Nine out of 168 UK vCJD cases had a history of receipt of fractionated plasma products on 12 different occasions (1 pre-vCJD risk in 1970, the remaining between 1989-1998). According to the UK CJD Incident Panel risk assessment criteria, 11 were low-risk products and one was low or medium risk. CONCLUSION: It is unlikely that any of the UK vCJD clinical cases to date were infected through exposure to fractionated plasma products. However, the possibility that such transmission may result in vCJD cases in the future cannot be excluded

Possible transmission of variant Creutzfeldt-Jakob disease by blood transfusion.

BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD) is a novel human prion disease caused by infection with the agent of bovine spongiform encephalopathy (BSE). Epidemiological evidence does not suggest that sporadic CJD is transmitted from person to person via blood transfusion, but this evidence may not apply to vCJD. We aimed to identify whether vCJD is transmissible through blood transfusion. METHODS: The national CJD surveillance unit reported all cases of probable or definite vCJD to the UK blood services, which searched for donation records at blood centres and hospitals. Information on named recipients and donors was provided to the surveillance unit to establish if any matches existed between recipients or donors and the database of cases of vCJD. Recipients were also flagged at the UK Office of National Statistics to establish date and cause of death. FINDINGS: 48 individuals were identified as having received a labile blood component from a total of 15 donors who later became vCJD cases and appeared on the surveillance unit's register. One of these recipients was identified as developing symptoms of vCJD 6.5 years after receiving a transfusion of red cells donated by an individual 3.5 years before the donor developed symptoms of vCJD. INTERPRETATION: Our findings raise the possibility that this infection was transfusion transmitted. Infection in the recipient could have been due to past dietary exposure to the BSE agent. However, the age of the patient was well beyond that of most vCJD cases, and the chance of observing a case of vCJD in a recipient in the absence of transfusion transmitted infection is about 1 in 15000 to 1 in 30000

A case-control study of sporadic Creutzfeldt-Jakob disease in the United Kingdom: analysis of clustering.

BACKGROUND: The authors investigated whether cases of sporadic Creutzfeldt-Jakob disease (CJD) had lived closer to one another at some time in life than individuals without sporadic CJD. Such a phenomenon would be compatible with some cases resulting from transmission. METHODS: UK sporadic CJD cases occurring from 1990 to 1998 were identified. Age-, sex- and hospital-matched controls were recruited. Lifetime residential histories were obtained by interview, usually with a proxy respondent. With use of Monte Carlo simulation, the residential proximity of cases during various time periods was compared with that expected in the absence of any clustering, using the information collected on the controls. RESULTS: Two hundred twenty sporadic CJD disease cases and 220 controls were included. Cases lived closer together than might be expected in the absence of any disease-clustering mechanism. This evidence became stronger as the critical period during which residential proximity was required to have occurred extended further into the past. CONCLUSIONS: These findings are consistent with some sporadic Creutzfeldt-Jakob disease (CJD) cases resulting from exposure to a common external factor. The rarity of sporadic CJD suggests that repeated point-source outbreaks of infection are more likely to explain our observations than direct case-to-case transmission. Identifying sources of such outbreaks many years after the event will be extremely difficult