a. General. Examine the product to detect any parasites present in the product
and classify them as being parasites. A parasite is any organism that grows on or in
another organism in such a way to damage or harm the other organism.
b. Beef Measles (Cysticercus bovis). This parasite, commonly called C. bovis
or beef measles, often occurs in cattle. It is the infective stage of a tapeworm of man,
Taenia saginata. Man acquires the tapeworm by eating improperly cooked infective
beef. When the beef animal consumes the infective stage, the larvae migrate to specific
tissues and form a cyst. It is the cyst that we are trying to locate in the product. The
cyst is found chiefly in jaw muscles, heart, diaphragm, and any red muscle of the beef
carcass. Hopefully, the cyst will be found on postmortem examination of the beef
carcass. Carcasses of cattle displaying lesions of C. bovis should be condemned if the
infestation is extensive. If the infestation is not extensive, the carcass is passed for food
after removal of the cysts and after the carcass is held continuously at a temperature
not higher than 15F (-10C) for a period of not less than ten days.
c. Pork Measles (Cysticercus cellulosae). This disease is known as pork
measles. The cystic form of Taenia solium, pork tapeworm of man, produces the
bladder worm, C. cellulosae, in its intermediate host, the swine. The cysts are found in
subcutaneous tissues, striated muscles, and other tissues of the pork carcass. Affected
muscles may resemble grapelike clusters of cysts. A carcass affected with pork
measles is unfit for food.
d. Liver Flukes. Fasciola hepatica and Fascioloides magna are two different
types of liver flukes that may infest the livers of cattle and sheep. The liver flukes live in
the bile ducts of the liver, but they may migrate to other tissues of the carcass. The
diaphragm, lungs, and skeletal muscles are occasionally affected, and the lesions
contain a characteristic black pigment. The infested liver has uneven surfaces due to
great damage and encapsulation of the parasite in the organ. There is also
characteristic black pigmentation of the liver and lymph nodes of the region. Affected
livers are unfit for food, regardless of the extent of the infestation. The other affected
parts of the carcass must be trimmed and removed. Trimming is done to remove any
scar tissue and pigmentation due to migration of the flukes.
e. Other Parasites. There are several other parasites of importance to man.
However, they can normally be detected in meats only by the use of a microscope.
(1) Sarcocystis. This involves parasitic protozoa. The ingested spore-
containing cyst reaches the small intestine, the spores are freed, and they multiply and
migrate to muscular tissue, where they grow and develop into sarcocysts. No human
deaths caused by this parasite have been reported.