Page 481 - Review of Medical Microbiology and Immunology ( PDFDrive )

mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com
mebooksfree.com mebooksfree.com Common Name Mode of Endemic Areas Diagnosis Treatment mebooksfree.com
mebooksfree.com
mebooksfree.com
PART VI Parasitology
470
TABLE 56–1 Features of Medically Important Nematodes
Primary
Transmission
Species
or Disease
Location
Albendazole,
Eggs on skin
Ingestion of eggs
Enterobius
Intestines
Worldwide
Pinworm
mebendazole, or
pyrantel pamoate
Whipworm
Eggs in stools
Worldwide, especially
Trichuris
Ingestion of eggs
Albendazole
tropics
Ascaris
mebooksfree.com
mebooksfree.com
mebooksfree.com mebooksfree.com Ascariasis Ingestion of eggs Worldwide, especially Eggs in stools Albendazole, mebooksfree.com
mebooksfree.com
mebendazole, or
tropics
ivermectin
Hookworm
Worldwide, especially
Ancylostoma
Albendazole,
Larval penetration of
Eggs in stools
skin
mebendazole, or
tropics (Ancylostoma),
and Necator
pyrantel pamoate
United States (Necator)
Larval penetration of
Ivermectin
Larvae in stools
Strongyloidiasis
Tropics primarily
Strongyloides
skin, also
autoinfection
Larvae in under-
Albendazole plus
Larvae encysted
Worldwide
Trichinosis
Trichinella
prednisone
in muscle;
cooked meat
against larvae;
serology
Mebendazole
against adult
worm
mebooksfree.com
mebooksfree.com mebooksfree.com Onchocerciasis Blackfly bite Worldwidemebooksfree.com Ivermectin mebooksfree.com
mebooksfree.com
Clinical
Japan, United States,
Anisakis
No drug available
Larvae in under-
Anisakiasis
cooked seafood
Netherlands
Wuchereria
Filariasis
Diethylcarbamazine
Mosquito bite
Tissue
Blood smear
Tropics primarily
Skin biopsy
Onchocerca
Africa, Central America
(river
blindness)
Blood smear
Deer fly bite
Loa
Loiasis
Diethylcarbamazine
Tropical Africa
Clinical
Dracunculus
Guinea worm
Ingestion of
Tropical Africa and Asia
Gradual extraction
of worm
copepods in water
Toxocara
mebendazole
migrans
serologic
larvae
Cutaneous larva
Clinical
Albendazole or
Penetration of skin
Ancylostoma
ivermectin
migrans
larvae Visceral larva Ingestion of eggs Worldwide Clinical and Albendazole or
mebooksfree.com
mebooksfree.com
mebooksfree.com mebooksfree.com mebooksfree.com summarized in Table 56–1. The medically important stages mebooksfree.com
increased by interleukin-4, and the number of eosinophils
Features of the medically important nematodes are
is increased by interleukin-5 [IL-5]) (see Chapter 58).
in the life cycle of the intestinal nematodes are described in
Cysteine proteases produced by the worms to facilitate
their migration through tissue are the stimuli for IL-5
Table 56–2, and those of the tissue nematodes are described
production.
in Table 56–3.
INTESTINAL NEMATODES
ENTEROBIUS
ing the worm eggs. The eggs hatch in the small intes-
Disease reservoir or vector. The infection is acquired by ingest-
tine, where the larvae differentiate into adults and
mebooksfree.com
mebooksfree.com
mebooksfree.com mebooksfree.com mebooksfree.com thousands of fertilized eggs on the perianal skin and mebooksfree.com
migrate to the colon. The adult male and female worms
Enterobius vermicularis causes pinworm infection
live in the colon, where mating occurs (Figure 56–2A).
(enterobiasis).
At night, the female migrates from the anus and releases
Important Properties
into the environment. Within 6 hours, the eggs develop
The life cycle of E. vermicularis is shown in Figure 56–1.
into embryonated eggs (Figures 56–3A and 56–4) and
become infectious. Reinfection can occur if they are
Infection occurs only in humans; there is no animal
mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com mebooksfree.com