Page 182 - parasitology for medical and clinical laboratoryprofessionals

162 CHAPTER 7

CESTODIASIS (TAPEWORM CYSTICERCOSIS
INFECTIONS) Cysticercosis is a term related to infection of the pork
tapeworm larvae Taenia solium. Neurocysticercosis
The terms cestodiasis and cystercosis are used synon-
ymously in the tapeworm infection process of animals is the most frequently encountered parasitic infestation
of the central nervous system. In underdeveloped coun-
and humans. Humans can be infected by as many as 40
species of adult tapeworms and approximately 15 lar- tries the disease has been endemic in Latin and South
America, Africa, and rural areas of Eastern Europe and
val forms, mainly as accidental or incidental hosts. This
means that the food source may be the primary host Asia. A recent increase in the condition has been ob-
served in the United States and Canada, predominantly
that is infected, and then is ingested by the accidental
host. Uncooked meat from definitive hosts, when in- in the immigrant populations from South America and
Asia. Humans are considered incidental hosts or ac-
gested, may result in infections of a number of tissues of
the human body, including the formation of cysts in the cidental hosts for the larval stages of several tapeworm
species contracted almost exclusively by ingesting con-
heart, eyes, muscles, and even the brain. Patients with a
history of eating uncooked or undercooked pork, beef, taminated meat or its by-products and wastes. The eggs
hatch in the stomach before the larvae penetrate the wall
and fish and who exhibit signs of new onsets of seizures
may be found to have lesions of the brain from cysts of the intestine and are circulated throughout the system,
with frequent involvement in the brain (Figure 7-1). It is
formed there.

Source: Centers for Disease Control and Prevention (CDC)

FIGURE 7-1 Life cycle of Taenia spp., the causal agents of cysticercosis