[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

CHAPTER 8 The Nematodes
215
Contact with the water creates an environment
of interest to the underlying adult worm.
Step 2. In this step, the adult worm breaks
through the blister and is eager to explore the
outside world.
Step 3. It is important at this juncture to clean
the resulting wound thoroughly.
Step 4. Manual extraction of the entire worm
by winding it around a stick or a similar item
that creates tension constitutes this step.
Step 5. Once the worm is removed, this step
is performed, which consists of applying topical
antibiotics to the wound site as a protective
measure against the emergence of secondary bacterial
infections.
Prevention and Control
The use of properly treated water for consumption,
boiling water suspected of contamination,
prohibiting the practice of drinking and
bathing in the same water, and ceasing the
practice of allowing standing water to be
ingested are all logical guinea worm prevention
and control measures. One of the simplest
means whereby copepods may be removed
from suspected water is to filter it using a finely
meshed filter. This measure has been introduced
into endemic areas. In addition to it being
almost impossible to educate the entire population
in endemic areas, the religious practices of
some people in these areas lead to water contamination.
It is highly unlikely that total eradication
of guinea worm will occur in the near
future.
Notes of Interest and New Trends
The history of D. medinensis dates back to biblical
times. Guinea worms were suspected of
being the “fiery serpents” responsible for a
plague that affected the Israelites who lived
by the Red Sea. This organism was also
described by Egyptian priests, the Greeks, and
the Romans.
Quick Quiz! 8-22
The two morphologic stages present in the Dracunculus
medinensis are which of the following? (Objective
8-6)
A. Eggs and larvae
B. Larvae and adults
C. Eggs and adults
D. None of the above
Quick Quiz! 8-23
The specimen of choice for the recovery of Dracunculus
medinensis is which of the following? (Objective
8-9)
A. Infected ulcer
B. Skeletal muscle
C. Stool
D. Blood
Quick Quiz! 8-24
When humans contract Dracunculus medinensis, the
parasite’s life cycle ceases to continue. (Objective 8-6)
A. True
B. False
C. Unable to determine
LOOKING BACK
Clinical laboratory scientists must take several
considerations into account when identifying
suspicious nematode organisms from patient
specimens. Notation of the specimen type is
crucial to ensure that the correct organism is
ultimately identified because nematodes are
recovered from specific samples. An accurate
measurement of the size and shape of the supected
organism is necessary, not only to speciate the
nematode but also to determine the correct morphologic
form. Furthermore, careful examination
of internal structures must be performed to
confirm the presence and identification of a
suspected parasite. It is also important that