- Small cysts in the muscle of cattle that have eaten pastures contaminated with the infective stage of the human tapeworm (Tania saginata).
- This can lead to the development of Cysticerius Bovis or Beef Measles.
- The adult tapeworm typically has little impact in human hosts, occasionally cystic intermediate stages can lodge in the brain producing neurological signs.
- Muscles most affected in cattle are diaphragm, heart, tongue and jaw muscles.
- Cysts are detected at meat inspection and require trimming to ensure the meat is not consumed by humans.
- Infected humans pass eggs in their faeces, which if they find their way onto pasture may be consumed by grazing cattle.
- This can be sewerage/septic overflow or runoff, or by inadequate treatment of run-off water or by migratory birds who have had access to sewerage sites.
- After consuming infected pastures, the eggs hatch in the animal’s gut and migrate through the body to form cysts in target muscles.
- Humans who eat live cysts (in infected and rare-cooked beef) go on to develop adult tapeworms in their small intestine.
- Infected cattle show no outward signs of infection and there is no production loss.
- Cysts are diagnosed at meat inspection.
- Infected cattle are traced to their property of origin and the property is subject to follow-up to determine how the cattle became infected.
- Other cattle from the property are subject to more detailed meat inspection until the problem resolves.
- This is because routine meat inspection may not detect all infected carcases.
- There is no treatment for cattle infected with Beef Measles.
- Infected humans (or households) take a treatment course for tapeworm.
- Preventing tapeworm eggs entering grazing pasture is the key to lowering the risk of Cysticerius Bovis or Beef Measles.
- This can include fencing and management of septic and sewerage system drainage, suitable treatment of effluent and exclusion of cattle from contaminated pasture.
- Cooking beef beyond rare (at least to 57°C) and/or freezing beef (10 days at -10°C) will kill the cysts and prevent human infection.