[Elizabeth_Zeibig]_Clinical_Parasitology__A_Practi(z-lib.org)

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CHAPTER 1 Introduction
PREVENTION AND CONTROL
Prevention and control measures may be taken
against every parasite infective to humans. Preventive
measures designed to break the transmission
cycle are crucial for successful parasite
eradication. Examples of such measures are listed
in Box 1-5 and include the following: education
programs, use of insecticides and other chemicals,
protective clothing, protective netting,
proper water treatment, good personal hygiene,
proper sanitation practices, proper handling and
preparation of food, and avoidance of unprotected
sexual relations. The vast capital expenditures
required to accomplish these measures are
not available in many endemic countries in the
world. The problem of eradicating parasites is an
ongoing process and is a key goal of international
health groups such as the World Health
Organization (WHO) and Doctors Without
Borders (Médecins Sans Frontières [MSF]).
BOX 1-5
Quick Quiz! 1-6
Which of the following represent examples of available
treatment therapies to combat parasitic infections?
(Objective 1-14)
A. Regulated exercise plan
B. Change in diet
C. Avoidance of vitamin supplements
D. More than one of these: ______________ (specify)
Parasite Prevention and
Control Strategies
Development and implementation of parasite awareness
education programs
Use of insecticides and other chemicals
Use of protective clothing
Use of protective netting
Proper water treatment
Good personal hygiene
Proper sanitation practices
Proper handling, cooking, and protection of food
Avoidance of unprotected sexual relations
Quick Quiz! 1-7
Which of the following are examples of possible
parasite prevention and control measures?
(Objective 1-15)
A. Avoiding the use of insecticides
B. Practicing unprotected sex
C. Practicing proper sanitation practices
D. More than one of these: ________________
(specify)
SPECIMEN PROCESSING AND
LABORATORY DIAGNOSIS
Proper specimen selection and processing are
crucial to parasite recovery. There are a variety
of acceptable specimen types that may be examined
for parasites. Stool is the most commonly
submitted sample for such studies. Typical stool
analysis consists of performing macroscopic and
microscopic techniques on a portion of unpreserved
sample when available. A process to
remove fecal debris, which often resembles
parasitic forms, is performed on a portion of
sample after a preservative is added to it. Microscopic
analysis of the resultant processed
sample follows. This traditional parasite recovery
method, often referred to as an O&P, in
which “O” stands for ova (eggs) and “P” stands
for parasites, is still widely used today.
Other specimens, including blood, tissue biopsies,
CSF, sputum, urine, and genital material,
may also be examined for the presence of parasites.
In some cases, the sample is basically processed
the same as for stool. Other specimens,
such as blood, are traditionally processed differently.
For example, a Giemsa stain followed by
microscopic examination is the procedure of
choice for blood samples submitted for parasite
study.
A number of other traditional and new parasite
recovery techniques are available. Cellophane
tape preparation, a methodology for
recovery of pinworm eggs, and the Enterotest
(string test) for recovery of several parasites are