Dealing with the ‘silent disease’ – measles

Cases of measles are frequently found in slaughter stock.

An adult Taenia saginata tapeworm. Humans become infected by eating undercooked, infected meat. Once ingested, the cysticercus can reach more than 2m and can survive for years in the small intestine.
Photo: Phil.CDC.gov

‘Measles’ is the term given to the carcass damage that occurs when immature tapeworms encyst in beef, pork or mutton.  There is no connection with human measles (rubella). The latter is caused by a virus, whereas meat measles is caused by a parasite and is more correctly called cysticercosis.

Cysticercosis requires carcass trimming or condemnation to keep the food supply safe, a loss in income for the farmer. In cattle, meat measles is caused by the Taenia saginata tapeworm. It is a ‘silent disease’ – you are unlikely to see any symptoms of ill health on infected animals. Diagnosis is based on a post mortem inspection.

Beef carcasses affected with cysticercosis will contain live, dead or degenerated cysts in the heart, tongue, oesophagus or muscles. The live cyst will appear as a vesicle (balloon) filled with fluid. In most cases, it will be dead, appearing as a small area of fibrotic (hard, thick) tissue that may be calcified and gritty in texture. The muscle tissue may be watery or discoloured.

Ways to reduce the risk of infection of cattle include the following:

Faecal contamination
Avoid faecal contamination of cattle feed and grazing areas. Farm workers and visitors must always practise good hygiene, and proper toilets should be provided.

Human care
Identify farm workers infected with the adult tapeworm and give them effective treatment. Consult your medical practitioner beforehand.

Inspection
Sell your cattle to an abattoir where competent meat inspection is practised so that infected carcasses can be detected before
they are taken to the market.

Information
Educate your farm workers and their families about the life-cycle of T. saginata in an effort to prevent measles.

Tapeworms and humans
Cysticercosis is a zoonotic disease. In fact, cattle are only the tapeworm’s intermediate host – humans are its final host. Humans can also be infected by Taenia solium, found in pork (but are rarely affected by tapeworms found in sheep, such as T. ovis). In both cases, the adult stage develops in the intestine and is acquired through eating improperly cooked, infected meat.

Symptoms include abdominal pain, nausea and itchiness around the anus. A particularly serious manifestation is neurocysticercosis, now accepted as one of the most important causes of epilepsy, particularly in developing nations characterised by poor sanitation, drinking contaminated surface water, and the rapid increase in smallholder pig production.

For more information, contact your vet or local animal technician. 

Sources: Proceedings of  the 10th Annual Congress of the Southern African Society for Veterinary Epidemiology and  Preventive Medicine; Farmers’ Magazine; Small Farms (smallfarms.oregonstate.edu).

Information: 
Educate your farm workers and their families about the life-cycle of T. saginata in an effort to prevent measles.

Tapeworms and humans
Cysticercosis is a zoonotic disease. In fact, cattle are only the tapeworm’s intermediate host – humans are its final host. Humans can also be infected by Taenia solium, found in pork (but are rarely affected by tapeworms found in sheep, such as T. ovis). In both cases, the adult stage develops in the intestine and is acquired through eating improperly cooked, infected meat.

Symptoms include abdominal pain, nausea and itchiness around the anus. A particularly serious manifestation is neurocysticercosis, now accepted as one of the most important causes of epilepsy, particularly in developing nations characterised by poor sanitation, drinking contaminated surface water, and the rapid increase in smallholder pig production.

For more information, contact your vet or local animal technician. 

Sources: Proceedings of the 10th Annual Congress of the Southern African Society for Veterinary Epidemiology and
Preventive Medicine; Farmers’ Magazine; Small Farms (
smallfarms.oregonstate.edu).