Bovine Spongiform Encephalopathy (BSE) in Europe: History, Controls, and Current Status

BSE ("mad cow disease") is a prion disease of cattle caused by misfolded PrP^Sc protein. The European epidemic (1980s–2000s) was driven by meat-and-bone meal (MBM) feeding.

Epidemiology

• First case: UK 1986. Peak: 37,000 cases/year (1992).
• UK: >180,000 confirmed cases (vast majority).
• Other EU: Ireland, France, Portugal, Switzerland, Germany, Spain, Italy — fewer cases, mostly linked to UK exports.
• vCJD in humans: ~178 UK deaths (linked to BSE-contaminated beef).

Control Measures (EU Regulations)

1. Feed ban: 1994 (ruminant-to-ruminant), 2001 (total mammalian MBM ban for farmed animals).
2. Specified Risk Material (SRM) removal: Brain, spinal cord, skull, vertebral column, tonsils, intestines removed from food/feed chain at slaughter.
3. Surveillance: Active testing of all cattle >48 months (healthy slaughter) and >24 months (emergency slaughter/fallen stock). Rapid tests (ELISA, Western blot).
4. Cohort tracing: Offspring and cohorts of BSE cases culled.
5. Import controls: BSE-risk country restrictions.

Current Status

• Classical BSE: Near eradication. EU: <10 cases/year (mostly atypical/H-type/L-type).
• Atypical BSE: Spontaneous, sporadic, age-related; not feed-related; low zoonotic potential.
• UK regained "negligible BSE risk" status (WOAH) 2023.
• vCJD: declining; blood donation restrictions persist.

Ongoing Vigilance

Surveillance continues. Research on prion strains, environmental persistence, cross-species transmission informs policy. "One Health" approach integrates animal, human, environmental health.