[The risk of variant Creutzfeldt-Jakob disease in the Netherlands and the effect of preventive measures].

Variant Creutzfeldt-Jakob disease (vCJD) is a fatal and untreatable neurological disease, in which pathogenic prions (PrPSc) are involved. There is convincing epidemiological and experimental evidence that vCJD is a human expression of bovine spongiform encephalopathy (BSE). The risk of transmission of pathogenic prions which cause vCJD to humans is influenced by the species barrier, genetic susceptibility of the host, dose of infection and route of exposure. Transmission of pathogenic prions from bovines to humans is possible through meat products containing nerve and lymphatic tissue, and through medical products derived from bovine material. Human to human transmission is, in principle, also possible via blood and blood-derived products, human organs and tissues for transplantation, and through surgical instruments. Preventive measures to reduce transmission from bovines to humans have been introduced step by step in the Netherlands since 1989. With proper implementation, the current risk of becoming infected by Dutch meat products is small. It is very likely, however, that in the past decade BSE-infected bovines have entered the food chain. The Dutch population has also been exposed to foreign infected meat products. Measures to prevent human to human transmission are currently being improved in the Netherlands. It is expected that cases of vCJD will occur in the Netherlands in the future, but the number cannot be estimated accurately. The presence of PrPSc in both the livestock and in the human population in the Netherlands constitutes a permanent public health threat and is a reason for continued vigilance and active prevention.