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P A R T 2
Chemotherapeutic agents
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A protozoan is a parasitic cellular organism. Its life
cycle includes a parasitic phase inside human tissues
or cells.
■■
Malaria is the most common protozoal infection
and is spread to humans by the bite of an
Anopheles
mosquito. The signs and symptoms of malaria are
related to the destruction of red blood cells and
toxicity to the liver.
■■
Antimalarial agents attack the parasite at the various
stages of its development inside and outside the
human body.
OTHER PROTOZOAL INFECTIONS
Other protozoal infections that are encountered in
clinical practice include amoebiasis, leishmaniasis,
KEY POINTS
trypanosomiasis, trichomoniasis and giardiasis. These
infections, which are caused by single-celled protozoa,
are usually associated with unsanitary, crowded condi-
tions and use of poor hygienic practices. People travelling
to other countries may encounter these infections, which
are also now appearing increasingly in Australia and
New Zealand. Box 12.5 discusses the impact of travel
and tourism on the spread of pathogens.
Amoebiasis
Amoebiasis
, an intestinal infection caused by
Entam-
oeba histolytica
, is often known as amoebic dysentery.
E. histolytica
has a two-stage life cycle (see Figure 12.3).
The organism exists in two stages: (1) a cystic, dormant
stage, in which the protozoan can live for long periods
outside the body or in the human intestine, and (2) a
trophozoite stage in the ideal environment—the human
large intestine.
■
■
Provide small, frequent, nutritious meals if GI
upset is severe
to ensure adequate nutrition
.
Monitor nutritional status and arrange a dietary
consultation as needed. Taking the drug with food
may also decrease GI upset.
■
■
Instruct the person concerning the appropriate
dosage regimen and the importance of adhering
to the drug schedule
to enhance knowledge about
drug therapy and to promote compliance
.
■
■
Provide the following teaching:
–– Take safety precautions, including changing
position slowly and avoiding driving and
hazardous tasks, if CNS effects occur.
–– Take the drug with meals and try small, frequent
meals if GI upset is a problem.
–– Report blurring of vision, which could indicate
retinal damage; loss of hearing or ringing in
the ears, which could indicate CNS toxicity;
and fever or worsening of condition, which
could indicate a resistant strain or non-effective
therapy.
Evaluation
■
■
Monitor response to the drug (resolution of
malaria or prevention of malaria).
■
■
Monitor for adverse effects (orientation and affect,
nutritional state, skin colour and lesions, hepatic
function, and visual and auditory changes).
■
■
Evaluate the effectiveness of the teaching plan
(person can name the drug, dosage, possible
adverse effects to watch for and specific measures
to help avoid adverse effects).
■
■
Monitor the effectiveness of comfort and safety
measures and compliance with the regimen.
World travel and the spread of pathogens
Nowadays, people are travelling to more exotic areas of
the world than ever before. Because of this, people are
being exposed to more pathogens than ever before, and
they are also potentially spreading pathogens to different
areas of the world. Pathogens that are endemic in one
area of the world and cause mild disease to the local
population there can be quite devastating in a population
that has not previously been exposed to that pathogen.
World health agencies and governments have
established guidelines for prophylaxis and treatment of
such diseases for travellers. People who are planning
to travel out of the country should contact their local
Health Department or the Australian Government
Department of Foreign Affairs andTrade SmartTraveller
for the latest
information on what prophylactic measures are required
in the area they plan to visit and to learn about potential
health hazards in that area.The information is updated
frequently; treatment and prophylaxis suggestions are
based on current clinical experience in the area and
should be consulted regularly. Nurses should access this
information when working with people who are travelling
to provide pertinent teaching points and to ensure that
appropriate prophylactic measures are taken. Nurses and
midwives caring for people with tropical diseases should
access this information regularly for best treatment
practices.
People who have been travelling to other areas of
the world and who present with any illness should be
questioned about where they travelled, what precautions
(including prophylactic measures) they took, and when
they first experienced any signs or symptoms of illness.
The SmartTraveller website can be consulted about
diagnosis and treatment guidelines for any tropical
disease that is unfamiliar to a healthcare provider, as well
as about what precautions should be used in caring for
such people.
The evidence
BOX 12.5
