Page 320 - parasitology for medical and clinical laboratoryprofessionals

300 GLOSSARY

Pseudophyllidean Relates to tapeworms (cestodes), order Rhinitis Inflammation of the nose.
Pseudophyllidae. Rice paddy itch Cercarial dermatitis is the technical name
Pseudopod Means “false foot” and is a temporary extension for a malady that is known invarious geographic locations by
or protrusion of an amoeba that is used for locomotion and different names. In developing countries, swimmer’s itch has
for phagocytosis (surrounding and feeding). been called rice paddy itch, clam diggers itch, and duck fleas.
Pseudopodia Plural form of pseudopod, indicating more Several different parasites can cause reactions after swimming,
than one false foot. but these itch infections usually refer to infestation with trema-
Pulmonary trichomoniasis Trichomoniasis is usually tode parasites.
found as the common sexually transmitted form, but are also Rickettsial organisms Rickettsial diseases and other similar
known to cause bronchopulmonary infections in patients with diseases are caused by a group of gram-negative, obligatively
preexisting pulmonary conditions that weaken the immune intracellular coccobacilli include ehrlichiosis, Q fever, Rocky
system. Mountain spotted fever, and Lyme disease.
Pupa The pupa is one of the life stages of some insects undergo- Ring form Trophozoite form of Plasmodium sp., which cause
ing transformation from the egg through the pupa, larva, nymph malaria.
and adult stages (found only in holometabolous insects). River blindness (onchocerciasis) Onchocerciasis is one
of the leading causes of blindness in the world and is caused
Q by Onchocerca volvulus, a nematode that can live for up to
15 years in the human body but can also live in other mam-
Q fever Acute infection caused by the rickettsia Coxiella bur- mals. Transmission to humans is through the bite of a blackfly.
netii, that is found intracellularly; transmitted through milk, Rocky Mountain spotted fever Acute infectious disease
inhaling dust, or handling stock animals. of the causative agent called Rickettsia rickettsii; transmitted
by ticks of the family Ixodidae, most often by Dermacenter sp.
R or D. variabilis; manifested by a skin rash (bull’s eye rash),
muscular pains, high fever, and skin eruptions, and is endemic
Rabbit fever Term used for tularemia, along with Pahvant throughout North America.
Valley plague, deerfly fever, and Ohara’s fever. Rabbit fever is a Rodents Rodentia is an order of mammals known as rodents
serious infectious disease caused by the bacterium Francisella and is characterized by two continuously growing incisors in
tularensis. the upper and lower jaws which must be kept short by gnaw-
Redbugs Also called chiggers, jiggers, and harvest mites, of ing materials that will grind away the tips of these prominent
the family Trombiculidae; a larval mite that that is parasitic on teeth. Rats, beavers, squirrels, and many other animal species
land vertebrates, and sucks the blood of vertebrates including are rodents.
human beings causing extreme irritation. Romanowski(y) Stain used for determination of malaria,
Redia A larva of certain trematodes that during its life cycle is using thick and thin blood films stained with Giemsa or
produced within the sporocyst; redia are formed within this Romanowski dyes for diagnosis; developed in 1891 by Ernst
sporocyst and develop into additional rediae or to cercariae. Malachowski and Dmitri Leonidovich Romanowsky by
Reduviid bug Member of the order Hemiptera; produces the combining the stains eosin Y and oxidated methylene blue.
genus of the true bugs, some of which prey on man; their bite Rostellum Structure protruding from the leading end of the
may transmit Trypanosoma cruzi, better known as Chagas’s scolex of a tapeworm; possesses spines or hooks for attach-
disease. ment in the intestines.
Relapsing fever Illness that is characterized by a recurring Roundworm Nematodes parasitic to humans as well as other
high fever; disease is transmitted through the bites of both in- organisms. Several different species of these worms cause in-
fected lice and ticks; disease produces episodic stages of high fections in the intestines.
fever accompanied by chills, headache, muscle pain, and
nausea; these signs and symptoms may recur every week or S
10 days for up to several months.
Repellent The term generally refers to a substance applied SAF Sodium acetate, acetic acid, formalin.
to skin, clothing, or other surfaces to discourage insects and Sand gnats Known by various names depending on location.
other arthropods from remaining in a given area or landing on A number of species or genera of flying, biting, blood-sucking
the body. dipterans found in sandy areas. In the United States, the sand-
Reservoir host A reservoir host serves as a source of infec- fly may refer to certain horse flies known as greenheads.
tion and potential reinfection of hosts such as humans by sus- Sandflies Flies are dipterans, meaning two-winged; the genus
taining a parasite when no suitable host is available. Phlebotomus is known in Africa to transmit onchocerciasis,
Rhabditiform larva Rhabditiform larvae are passed in the caused by a filarial worm Onchocerca volvulus.
stool and can either molt twice and become infective filariform Sarcoptidae The family of the order Acarina, this mite is re-
larvae (direct development) or undergo four separate moltings sponsible for scabies (itch) in humans and mange in other ani-
and become free living adult males and females that mate and mals. The species most often responsible for these conditions
produce fertilized ova from which rhabditiform larvae hatch. is Sarcoptes scabiei.