Bovine spongiform encephalopathy: current status and possible impacts

Area of Science:

• Veterinary Medicine
• Epidemiology
• Public Health

Background:

• Bovine spongiform encephalopathy (BSE), a novel transmissible spongiform encephalopathy, emerged in 1985.
• BSE is related to scrapie in sheep and Creutzfeldt-Jakob Disease (CJD) in humans.
• Initial epidemiological data suggested transmission through cattle feed containing infected meat and bone meals.

Purpose of the Study:

• To analyze the epidemiology and control of Bovine Spongiform Encephalopathy (BSE).
• To assess the impact of feed bans on BSE prevalence.
• To investigate potential transmission of BSE to humans, specifically a new variant of Creutzfeldt-Jakob Disease (nvCJD).

Main Methods:

• Monitoring of BSE case numbers in the United Kingdom.
• Implementation and assessment of feed bans for ruminants (1989, 1992).
• Surveillance for a new variant of Creutzfeldt-Jakob Disease (nvCJD).

Main Results:

• BSE cases peaked in the UK in 1992, with a significant decline predicted due to feed bans.
• Confirmed BSE cases decreased from 37,490 in 1992 to an estimated 7,417 in 1996.
• A new variant of CJD (nvCJD) has been confirmed in 28 cases, strongly suspected to be BSE in humans.

Conclusions:

• Feed bans have proven effective in controlling the BSE epidemic in the UK.
• Further culling of cattle populations may accelerate the decline of BSE.
• The potential for BSE transmission to humans, as evidenced by nvCJD, remains a critical public health concern.