INTESTINAL PARASITES AND ANTIPARASITIC AGENTS
Section I. INTRODUCTION
Throughout recorded history, humans have been infected by parasites, from
single cell protozoa to large worms, living in their gastrointestinal systems. Each type of
parasite presents certain medical problems as well as economic losses because of
disability and loss of productivity. Parasite control is of vital concern to the military.
Sanitary procedures can be used to prevent infestation in many cases. In instances in
which infestation has occurred, you will be called upon to dispense medications to rid
these parasites from the soldiers' bodies.
IMPORTANT TERMS AND DEFINITIONS PERTAINING TO INTESTINAL
a. Parasitism. Parasitism is an obligatory relationship in which one organism,
the parasite is metabolically dependent on another organism, the host. The host may or
may not be harmed by being infested with the parasite.
b. Normal Flora. Normal flora consists of microorganisms that are normally
found in or on the body in the absence of disease.
c. Ectoparasite. An ectoparasite is a parasite that lives on the outer surface of
d. Endoparasite. An endoparasite is a parasite that lives inside the host.
e. Anthelmintic Drug. An anthelmintic drug is a chemical substance used to
eradicate or reduce in numbers helmintic parasites (worms) in the intestinal tract or
tissue of a human.
f. Purge. A purge is the administration of a cathartic (laxative) to a patient in
order to remove parasites from the patient's intestines after the patient has taken an
anthelmintic drug. (Anthelmintic agents do not always kill worms in the gastrointestinal
tract; some agents only paralyze them. By giving a purge, the worms that are in the
intestines can be removed from the gastrointestinal tract).