Page 52 - parasitology for medical and clinical laboratoryprofessionals

32 CHAPTER 2

SUMMARY

Human parasitic infections are possible when conditions Certain medical conditions and general poor
are right. This includes exposure to animals that harbor health of individuals actually make them vulnerable
parasites that may be transmitted to humans. Parasitic in- for contracting parasitic infections. These organisms
fections often are found within isolated and small locations are available for transmission anytime a vector is avail-
with close quarters, but who share common facilities, land, able, or when food is used for transmission of eggs of
and water supplies, where human and animal wastes con- certain parasites, and may affect almost every organ
taminate the land and the produce and other animals that of the body, from the skin to the urogenital tract, the
live there. gastrointestinal tract, blood, muscles, central nervous
Travel to certain countries requires exercising cau- system tissue, and any other organs or systems of the
tion when buying, preparing, and eating food and drink- body, such as the respiratory system. Therefore, there
ing the water. For many parasites, specific vectors must is a parasite to fit almost any geographic location, and
be present in order to effectively spread parasites. Sur- any host that is suitable in parts of the life cycle of the
veillance around the world is accomplished through mil- particular organism.
itary facilities, private charities, and national health care In some populations, there are cultural prac-
organizations such as those provided by the United Na- tices that reduce the risk of contracting a parasite.
tions and the WHO, as well as international branches of Other methods of avoiding infection include careful
the Centers for Disease Control and Prevention (CDCP). cleaning of foods such as those eaten raw in salads.
Conducting epidemiological surveys by these organiza- Boiling water for drinking and food preparation in an
tions aids greatly in tracking the spread of infections and endemic area, and even not eating ice that is available
the treatments that are effective for combating them. locally is extremely important in not becoming a vic-
Signs and symptoms are diverse in parasitic infec- tim. Remember that many of the local inhabitants in
tions, and range from very mild to vague symptoms that a country may be carriers and will exhibit no signs of
are suggestive of other illnesses. Symptoms may be sim- disease, but are still capable of transmitting the para-
ilar for many different species of parasite, and are often sites to others.
mistaken for bacterial or viral infections, which are actu- Medications are tailored to the disease with respect
ally found in greater numbers than are those of parasite to parasite infections. For instance, diarrhea is often the
infections. Pain, bloating, bleeding from a number of sites, best way to rid the body of pathogens, but unfortunately,
allergic reactions with eosinophilia, inflammation, and fe- may be the best way to transmit the disease to others.
ver are common with parasitic infections, even when the So each individual has a responsibility for both him- or
species of parasite is a worm or an amoeba, for instance. herself and others, including the family.

CASE STUDY

1. A 33-year-old man complains to his physician of weight loss and a nonproductive
cough that includes a slightly elevated temperature. He privately admits to be-
ing homosexual with a number of sex partners. The physician requests a sputum
sample and a chest x-ray. The chest x-ray shows numerous infiltrates, suggestive of
pneumonia. What organism or organisms would the physician suspect based on the
information he has received?