[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

CHAPTER 8 The Nematodes
213
Treatment
No medications are indicated if the infected
person has a non–life-threatening strain of the
disease. These patients are instructed to get
plenty of rest, supplemented by adequate fluid
intake, fever reducers, and pain relievers. Patients
with severe infections that may be potentially
life-threatening are usually treated with prednisone.
Thiabendazole may also be given, even
though research to date indicates that the effectiveness
of this medication is questionable. Under
appropriate conditions, steroids may also be
administered.
Prevention and Control
Thorough cooking of meats, especially from
animals known to harbor T. spiralis, is paramount
to the eradication of this parasite. It has
been determined that proper storage of these
meats, at below-zero temperatures (i.e., −15° C
[59° F] for 20 days or −30° C [86° F] for 6 days)
will greatly decrease the viability of the organism.
Furthermore the avoidance of feeding pork
scraps to hogs is also necessary to break the T.
spiralis life cycle.
Quick Quiz! 8-19
The specimen of choice for the identification of Trichinella
spiralis is which of the following? (Objective 8-9)
A. Cerebral spinal fluid
B. Stool
C. Skeletal muscle
D. Urine
Quick Quiz! 8-20
The diagnostic stage of Trichinella spiralis is which of
the following? (Objective 8-6)
A. Encysted larvae
B. Cysts
C. Eggs
D. Adult worms
Quick Quiz! 8-21
Trichinosis is acquired via which of the following?
(Objective 8-6)
A. Swimming in contaminated water
B. Consuming contaminated water
C. Ingestion of contaminated food
D. Inhalation of contaminated air droplets
Dracunculus medinensis
(Drah-kung”ku-lus/med”in-en’-sis)
Common name: Guinea worm.
Common associated disease and condition
names: Dracunculosis, dracunculiasis, guinea
worm infection.
Morphology
Larvae. There are two larval stages (Table
8-18). The diagnostic stage, also known as the
first stage or rhabditiform larvae, is relatively
small, measuring an average size of 620 by
15 µm. The tail makes up about one third of the
body length and culminates in a point. The thirdstage
larvae, which reside in an intermediate
host, have not been well described.
Adults. Considered as one of the largest adult
nematodes, the average elongated female Dracunculus
medinensis measures approximately
840 mm long by 1.5 mm wide (Table 8-19). The
female possesses a prominent blunt, rounded
anterior end. The rarely seen adult male is smaller
than the female, measuring only 21 by 0.4 mm.
TABLE 8-18
Dracunculus medinensis
First-Stage Larva: Typical
Characteristics at a Glance
Parameter
Description
Average size 620 by 15 µm
Tail characteristics Consumes one third of
body length; culminates
in a point