B106 - BOVINE CYSTICERCOSIS

IDevice Icon

B106 - BOVINE CYSTICERCOSIS

Nature of the disease
Bovine cystercosis, also known as bladder worm or beef tape worm, is a parasitc zoonosis due to the cestode Taenia saginata. It causes few symptoms in the animal but it is an important zoonosis.
Classification
OIE, List B disease
Susceptible species
The beef is a intermediate host and man is the final host.
Distribution
Bovine cysticervosis is worldwilde distributed. In the Pacific it is only reported in Australia and New Zealand.
Clinical signs 
In animals there is usually no clinical sign associated. However heavy infections may cause myocarditis andheart failure associated with developing cysts in the heart.
Post-mortem findings 
Lesions consist of cysticerci in cysts, they are 5-8 mm by 3-5 mm, translucid and filled with a brownish to pinkish liquid, sometimes the 'head' of the metacestodes can be see as a white spot. Cysts are essentially found in the following muscles:
  • Heart,
  • Tongue,
  • Masseters and Diaphragm,
  • Shoulder muscles
  • Intercostal muscles,
  • Oesaphage

More rarely cysts are found in the liver, the lungs and the brain.

Differential diagnosis 
Lesions must be differentiated from sarcosporidiosis and toxoplasmosis.
Specimens required for diagnosis 
The diagnosis is usually made during meat inspection. However serologic test has been developed.
Transmission
Beef usually get infected by grazing on pasture contaminated by human feces (which can come from sewage water or direct pollution). Occasionally in-utero contamination occurs.

Human get infected by eating unproperly cooked meat (<60°C)

Risk of introduction   
Introduction could occur through importation of infected cattle, meat or material contaminated by human feces. Humans can also introduce it into the country.
Control / vaccines  
Control is done through public hygien and proper meat inspection at slaughterhouse.

Cysts can be destroyed by freezing  at -18°C for 5 days or at -10°C for 10 days or by cooking at 56°C for 5 minutes.

References
  • BUSSIERAS J, CHERMETTE R, Helminthologie In Parasitologie Vétérinaire, Ecole Nationale Vétérinaire D'Alfort, 1992, p 237-241;
  • Office International des Epizooties, 2002
  • SOULSBY EJL, Helminths, Echinococcus In Helminths, Arthropods and Protozoa of Domesticated Animals, Lea and Febiger Inc, 7th ed, 1982, Philadelphia, p 107-111
  • The importation into New Zealand of Meat and Meat Products, Stuart C. McDiarmid, Wellington, 1991, p. 65-67