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Bovine spongiform encephalopathy (BSE)


Mad Cow Disease


  • No infectious agent; the disease is due to a conformational change in a host-encoded protein.
  • Notifiable disease : Yes



Typical posture of BSE affected cow (Confirmed Belgian case)

Bovine spongiform encephalopathy (BSE) belongs to the prion diseases which are slow, lethal transmissible neurodegenerative illnesses that affect humans and many animal species.
After the start of the epidemic in the United Kingdom in 1986, BSE became a notifiable disease in European Union in 1990.
In 1997, regulations were applicable for the epidemiosurveillance for ruminant transmissible spongiform encephalopathies (TSE) in EU, including the herd slaughter and compensation policy. In this "passive" surveillance system, clinical suspected cases in the farm or the slaughterhouse were examined for TSE.
These cases were checked by means of histopathological and immunohistochemical examination of the brain as well as by means of an investigation into scrapie associated fibrils (SAF) with the transmission electron microscope. These are nowadays (2013) checked with the ELISA rapid TSE test first and then (depending on the quality of the sample) immunohistochemistry and/or Western blotting for TSE. In addition, histopathological examination is still used, but now (as no more clinical cases have been found in recent years) chiefly in connection with the differential diagnosis.
In this frame, only few cases of BSE were detected from 1997 till 2000 outside UK.
Then the EU developed a method to assess the geographical BSE risk (GBR, comprising class I to IV). In this GBR level, class I is the lowest, meaning that it is highly unlikely that one or more cattle are clinically or pre-clinically infected.

Most of the EU Members States were situated in class III. However, a number of EU countries did not detect any case of BSE before 2001 despite their rather high GBR level.

Therefore, to protect consumer health, the EC imposed the application of rapid BSE tests on all cattle when slaughtered for human consumption above 30 months of age, and on risk populations such as emergency slaughtered animals and animals found dead on the farm ("active" surveillance).

The rapid diagnostic tests in the EU indicated that BSE is indeed present in most EU-27 countries. These data improved the determination of the GBR level.
Histopathological HE staining - BSE
Histopathological HE straining : Typical vacuole in a dentrite of a neurone of the brainstem of a BSE affected cow
Moreover, it was now confirmed that BSE became a worldwide problem, mainly due to imports of contaminated products and animals in the past.
All BSE cases in EU were found to be caused by one strain but recently two (rare) atypical forms of BSE (H-type and L-type or "BASE") were identified.
Since the first BSE cases in the UK in 1987, more than 183.000 BSE cases were confirmed in UK, representing about 98% of all BSE cases in the world.
The epidemic in UK reached its maximum in 1992 with more than 37.000 cases. In 2008, only 17 cases were found. The evolution of the epidemic in UK is depicted below.


Evolution of BSE cases in the United Kingdom - BSE


Outside UK, at the end of 2008, BSE was reported in the Irish Republic (1.630 cases), Portugal (1.036), France (998), Spain (733), Switzerland (467), Germany (416), Italy (143), Nederland (85), Poland (58), Japan (34), Czech Republic (28), Slovakia (23), Denmark (15), Canada (14), Slovenia (8), Austria (6), USA (3), Luxemburg (3), the Sultanate of Oman (2), Liechtenstein (2), Finland (1), the Falkland Islands (1) and Israel (1). Until now, we found 133 cases in Belgium. The last Belgian case was detected in 2006.
A number of BSE preventive measures to protect human and animal health were taken at Belgian and EU level of which the most important are:
  • 1994: Meat and bone meal (MBM) ban in the whole EU (94/38/EC)
  • 1997: Royal Decree on the epidemio-surveillance for TSE and MBM production at 133°C/3bar/20min/100% relative humidity (96/449/EC)
  • 1998: Belgian bovine and ovine Specified risk material (SRM) ban
  • 2000: EU SRM ban (97/534/EC, reinforced by 2000/418/EC)
  • 2001: Compulsory rapid BSE tests on bovines above 30 months (2000/374/EC), total MBM ban, including fishmeal (2000/764/EC), vertebral column above 12 months is SRM (2001/233/EC) and regulation for prevention, control and eradication of TSE and safety of ruminant derived material (gelatin, fat, tallow, cosmetics, medicinal products, mechanically recovered meat, dicalciumphosphate, organic fertilizers, animal waste) (2001/999/EC).
  • 2012: Belgium is listed among the countries with a negligible BSE risk (OIE Resolution N° 16, 80th General Session May 2012)
  • 2013: Belgium tops testing on healthy animals in the slaughter house (1 January 2013).



The cutting of paraffin - embedded brainstem blocs


CODA-CERVA is the Belgian National Reference Laboratory for Bovine Spongiform Encephalopathy.




Stefan Roels

Separation form the herd of a BSE affected cow - BSE
Separation from the herd of a BSE affected cow (Confirmed Belgian case)= behavior linked to BSE suspected cases



-Alexandre Dobly, Jan Langeveld , Lucien van Keulen , Caroline Rodeghiero , Stéphanie Durand , Riet Geeroms , Patrick Van Muylem , Jessica De Sloovere , Emmanuel Vanopdenbosch and Stefan Roels : No H- and L-type cases in Belgium in cattle diagnosed with bovine spongiform encephalopathy (1999-2008) aging seven years and older BMC Veterinary Research 2010, 6:26

- Roels S, Dobly A, De Sloovere J, Geeroms R, Vanopdenbosch E. Listeriosia monocytogenes-associated meniningoencephalitis in cattle clinically suspected of bovine spongigiform encephalopathy in Belgium (1998- 2006). (2009) Vlaams Diergeneeskundig Tijdschrift 78, 177-181

- Roels S, Lausberg P, Letellier C, Vanopdenbosch E. Cerebellar cortical atrophy in a Belgian Blue cow associated with lesions described in Human Norma-Jaeken disease. (2008) Vlaams Diergeneeskundig Tijdschrift 77 (6), 411-414.

- Plouvier B, Berkvens D, Mennens K, Vanopdenbosch E, Roels S and Saegerman S. Actualisation and interval validation of an helping tool for BSE clinical decision in Belgium (2006) Epidémiologie et santé animale 50, 105-111.

- Penders J, Berkvens D, Saegerman C, Praet N, Dispas M, Verbraeken S, Roels S and Thiry E. Estimation of the true BSE prevalence in Belgium during 2002 and 2003 (2005) Epidémiologie et santé animale 47, 113-121.
- Saegerman C., Berkvens D., Claes L., Dewaele A., Coignoul F., Ducatelle R., Cassart D., Brochier B., Costy F., Roels S., Deluyker H., Vanopdenbosch E. & Thiry E.. Population-level retrospective study of neurologically expressed disorders in ruminants before the onset of bovine spongiform encephalopathy (BSE) in Belgium, a geographic BSE risk III country. (2005).. Journal of Clinical Microbiology 43, 862-869.

Immunohistochemical staining of the brainstem of a BSE affected cow : note the multiple (brownish) positive staining
- De Bosschere H, Roels S & Vanopdenbosch E. Atypical Case of Bovine Spongiform Encephalopathy in an East-Flemish Cow in Belgium (2004) Journal of Applied Research in Veterinary Medicine 2 (1), 52-54.
- Gofflot S, El Moualij B, Zorzi D, Melen L, Roels S, Quatpers D, Grassi J, Vanopdenbosch E, Heinen E and Zorzi W. Immuno Quantitative Polymerase Chain Reaction for Detection and Quantification of Prion Protein. (2004) Journal of Immunoassay and Immunochemistry 25(3), 241-258.
- Roels S, De Bosschere H, Saegerman C, Dechamps P, Vanopdenbosch E. BSE : Surveillance and testing in Belgium (2004) . New Food, issue 1, 36-40.
- Saegerman C, Speybroeck N, Roels S, Vanopdenbosch E, Thiry E & Berkvens D. Decision support tools in clinical diagnosis in cows with suspected bovine spongiform encephalopathy (2004). Journal of Clinical Microbiology 42 (1),172-178.
- Vanopdenbosch E and Roels S. BSE: diagnosis and control, the consequences for human health and geographical BSE risk (2004) Le Médecin Vétérinaire du Quebec, 34 (1&2), 94-95.

- Roels S, Walravens K, Saegerman C, Thelissen M, Vanopdenbosch E & Godfroid J. Mycobacterium bovis meningitis in cattle with clinical suspicion of bovine spongiform encephalopathy. (2003)The Veterinary Record 152, 807-808.
- Saegerman C, Speybroeck N, Roels S, Vanopdenbosch E, Thiry E & Berkvens D. Amélioration de la détection d'une maladie émergente : Exemple de l'encephalopathie spongiforme bovine (2003) Epidémiologie et santé animale 44, 61-77.

- Saegerman C, Claes L, Dewaele A, Desmecht D, Rollin F, Hamoir J, Gustin P, Czaplicki G, Bughin J, Wullepit J, Laureyns J, Roels S, Berkvens D, Vanopdenbosch E & Thiry E. . Diagnostic différentiel des troubles à expression nerveuse dans l'espèce bovine en Europe occidentale / Differential diagnosis of neurologically expressed disorders in Western European cattle. (2003) Revue scientifique et technique de l'OIE 22 (1), 61-102.

- Polak M, Rozek W, Rola J, Larska M, Zmudzinski JF, Kozaczynski W, Reichert M, Wijaszka T, Ankiewicz K, Pirog-Komorowska A, Roels S. First cases of BSE in Poland (2002) Medycyna Wet. 58, 852-856
- Roels S, De Meyer G & Vanopdenbosch E. Choroid plexus hyperplasia in an adult cow with clinical suspicion of bovine spongiform encephalopathy (BSE). (2002) . Vlaams Diergeneeskundig Tijdschrift 71, 359-361.
- Roels S, De Meyer G, Tedik K, Foubert R & Vanopdenbosch E. Variation of mass (volume) taken with the calibrated syringe and of the results provided by the Platelia BSE test (BIORAD) upon storage of brain stem samples at - 20°C. (2002) Animal Research 51, 493-499.2001
- Roels S, De Meyer G & Vanopdenbosch E. Encephalopathie spongiforme bovine et variante de la maladie de Creutzfeldt-Jakob : quelques informations concernant l'origine, le diagnostic, l'épidemiologie, l'analyse du risque et l'avenir (2001). Annales de Médecine Vétérinaire 145, 333-341.
- Saegerman C, Deschamps P, Roels S, Petroff K, Geeroms R, Torck G, Dufey J, Fourez R, Hamelrijckx M, Cormann A, Viatour P, De Coninck V, Lomba F, Vermeersch J-P, Hallet L, Lhost O, Leemans M, Vandersanden A, Peharpre D, Brochier B, Costy F, Pastoret PP, Thiry E, Vanopdenbosch E., Epidémiosurveillance de l'encephalopathie spongiforme bovine en Belgique: bilan de l'année 1999. (2001) Annales de Médecine Vétérinaire 145, 47-58

- Debecker D, Roels S en Vanopdenbosch E. BSE onderzoek: opsporen van PrPres door middel van de BIO-RAD Platelia BSE kit. (2000) Vlaams Diergeneeskundig Tijdschrift 69, 382-384.
- Roels S, Charlier G, Letellier C, Meyer G, Schynts F, Kerkhofs P, Thiry E and Vanopdenbosch E. A natural case of bovine herpesvirus 1 meningo-encephalitis in an adult cow. (2000). The Veterinary Record 146 (20), 586-588.
- Vanopdenbosch E, Roels S. BSE en variant CJZ: nieuwe inzichten en achtergrondinformatie. (2000) Vlaams Diergeneeskundig Tijdschrift 69, 371-376.

- Saegerman C, Deschamps P, Vanopdenbosch E, Roels S, Petroff K, Dufey J, Van Caenegem G, Devreese D, Varewyck H, Decraemere H, Desmedt I, Cormann A, Torck G, Hallet L, Hamelrijckx M, Leemans M, Vandersanden A, Peharpre D, Brochier B, Costy F, Mullier P, Thiry E, Pastoret PP. Epidémiosurveillance de l'encephalopathie spongiforme bovine en Belgique: résultats 1998. (1999) Annales de Médecine Vétérinaire 143, 425-436. Epidemiologische bewaking van boviene spongiforme encefalopathie in België: in 1998. (2000) Vlaams Diergeneeskundig Tijdschrift 69, 197-206.

- Vanopdenbosch E, Roels S. Het ontstaan van de BSE-epidemie in het Verenigd Koninkrijk en de huidige stand van zaken in de Europese Unie (1998) Vlaams Diergeneeskundig Tijdschrift 67, 252-258.
- Vanopdenbosch E, Dechamps P, Dufey J, Roels St, Mullier P, Hallet L, Brochier B, Costy F, Pastoret PP. Le Premier Cas d'Encephalopathie Spongioforme Bovine Diagnostique en Belgique (1998) Les Annales de la Médicine Vétérinaire 142, 111-118.