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312 Cards in this Set
- Front
- Back
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Definition of parasite
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Worm, protozoa, arthropod (ie, not virus, bacteria, fungus)
|
|
What are the 3 most important stages of the parasite life cycle?
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Infectious, pathogenic, diagnostic
|
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What are the 2 types of hosts?
|
Definitive host, Intermediate host
|
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What defines the definitive host?
|
Parasite is sexually mature, able to reproduce
|
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What defines the intermediate host?
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A host that supports the growth of the parasite
|
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Whats defines an accidental host?
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Parasite cannot grow or reproduce, but may still cause disease
|
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What is the best source of information for treatment of parasitic disease?
|
The Medical Letter
|
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What determines the extent of disease in most parasitic infections?
|
The number of worm eggs or larvae that enter (most worms do not multiply in humans)
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Classification of round worms
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Intestinal (Enterobius, Trichuris, Ascaris, Ancylostoma, Necator, Strongyloides) NEWLINE Tissue (Larva Migrans, Trichinella, Dracunulus)
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Types of filariases
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Wuchereria (Elephantiasis), Onchocerca (River Blindness), Loa Loa (Eye Worm)
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Classification of flat worms
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Flukes (Schistosomes) NEWLINE Tapeworms (Taenia Saginata, Taenia Solium, Diphyllobothrium Latum, Echinococcus Granulosus, Echinococcus Multilocularis)
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Types of schistosomes
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Mansoni, Haematobium, Japonicum
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Classification of arthropods
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Insects (Lice, Fleas, Bugs, Flies) NEWLINE Arachnids (Ticks, Mites, Spiders, Scorpions)
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Definition of protozoa
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Single-celled eukaryote
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|
List the anaerobic protozoa
|
Entamoeba histolytica (Amebiasis), Giardia, Trichomonas Vaginalis
|
|
List the four intestinal parasites
|
Cyclospora, Cryptosporidium, Isospora, Microsporidia
|
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List the three types of malaria parasites
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Falciparum, Vivax, Malariae
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This worm has a ciliated stage
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Schistosome
|
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Pipestem fibrosis is a feature of this worm infection
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Schistosomiasis
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These are the parasitic diseases seen in AIDS patients, in order of frequency
|
1. Pneumocystis (penumonia) NEWLINE2. Toxoplasmosis (encephalitis) NEWLINE3. Cryptosporidiosis (diarrhea) NEWLINE4. Amebiasis (dysentery, invasive dz) NEWLINE5. Visceral leishmaniasis NEWLINE6. Strongyloides hyperinfection (very rare)
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These are the hemoflagellates
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African trypanosomes, Leishmania, Trypanosoma cruzi
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Definition of parasite
|
Worm, protozoa, arthropod (ie, not virus, bacteria, fungus)
|
|
What are the 3 most important stages of the parasite life cycle?
|
Infectious, pathogenic, diagnostic
|
|
What are the 2 types of hosts?
|
Definitive host, Intermediate host
|
|
What defines the definitive host?
|
Parasite is sexually mature, able to reproduce
|
|
What defines the intermediate host?
|
A host that supports the growth of the parasite
|
|
Whats defines an accidental host?
|
Parasite cannot grow or reproduce, but may still cause disease
|
|
What is the best source of information for treatment of parasitic disease?
|
The Medical Letter
|
|
What determines the extent of disease in most parasitic infections?
|
The number of worm eggs or larvae that enter (most worms do not multiply in humans)
|
|
Classification of round worms
|
Intestinal (Enterobius, Trichuris, Ascaris, Ancylostoma, Necator, Strongyloides) NEWLINE Tissue (Larva Migrans, Trichinella, Dracunulus)
|
|
Types of filariases
|
Wuchereria (Elephantiasis), Onchocerca (River Blindness), Loa Loa (Eye Worm)
|
|
Classification of flat worms
|
Flukes (Schistosomes) NEWLINE Tapeworms (Taenia Saginata, Taenia Solium, Diphyllobothrium Latum, Echinococcus Granulosus, Echinococcus Multilocularis)
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|
Types of schistosomes
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Mansoni, Haematobium, Japonicum
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|
Classification of arthropods
|
Insects (Lice, Fleas, Bugs, Flies) NEWLINE Arachnids (Ticks, Mites, Spiders, Scorpions)
|
|
Definition of protozoa
|
Single-celled eukaryote
|
|
List the anaerobic protozoa
|
Entamoeba histolytica (Amebiasis), Giardia, Trichomonas Vaginalis
|
|
List the four intestinal parasites
|
Cyclospora, Cryptosporidium, Isospora, Microsporidia
|
|
List the three types of malaria parasites
|
Falciparum, Vivax, Malariae
|
|
This worm has a ciliated stage
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Schistosome
|
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Pipestem fibrosis is a feature of this worm infection
|
Schistosomiasis
|
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These are the parasitic diseases seen in AIDS patients, in order of frequency
|
1. Pneumocystis (penumonia) NEWLINE2. Toxoplasmosis (encephalitis) NEWLINE3. Cryptosporidiosis (diarrhea) NEWLINE4. Amebiasis (dysentery, invasive dz) NEWLINE5. Visceral leishmaniasis NEWLINE6. Strongyloides hyperinfection (very rare)
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These are the hemoflagellates
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African trypanosomes, Leishmania, Trypanosoma cruzi
|
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This is commonly seen in worm infections
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Eosinophilia
|
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These play a major role in the immune response against worms
|
Eosinophils
|
|
These types of parasitic infections are notable for *not* eliciting eosinophilia
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Worms in the intestine, protozoan infections
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Description of the anatomy of round worms
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Outer tube: impermeable cuticle NEWLINE Inner tubes: tubular gonads, intestines
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T/F: Most round worms release live larvae
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False. Most worms release eggs
|
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This worm causes an asymptomatic or minor intestinal worm infection
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Enterobius (pinworm)
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What are the definitive and intermediate hosts of pinworm?
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Humans are the only hosts
|
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What is the infective stage of Enterobius?
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Embryonated eggs
|
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Where do eggs of Enterobius hatch?
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Small intestine
|
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Where do Enterobius larvae mature?
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Cecum
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Number of eggs produced by female Enterobius
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10,000
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Describe Enterobius egg-laying.
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Female crawls from cecum through colon to anal sphincter where she released UNEMBRYONATED eggs, then dies
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How long does it take for Enterobius eggs to become infectious?
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They become embryonated incredibly fast--within 6 hours--thus this disease is not eradicated by santiary revolution.
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How long do Enterobius eggs remain infectious?
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Less than 2 weeks
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How long does it take for Enterobius to mature after hatching?
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5-6 weeks.
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Diagnostic stage of Enterobius
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Eggs on perianal folds
|
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How is Enterobius diagnosed?
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Scotch tape preparation of perianal eggs.
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Describe the Enterobius egg.
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Thick-walled, colorless shell with developing larva inside, flattened on one side.
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Clinical signs and symptoms of pinworm
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Anal itch
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How many worms does a child with pinworm typically have?
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50 on average
|
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What is the most common worm infection?
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Pinworm. 30% of children and 15% of adults worldwide.
|
|
Complications of pinworm
|
Pinworm neurosis (mother or father paranoid about worms, spend 8 hours/day cleaning, etc.)
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|
Treatment of pinworm
|
Bendazole. It is important to treat the entire family since eggs get everywhere, and re-treat about three weeks later.
|
|
T/F: good sanitary measures can prevent reinfection by pinworm
|
False. Reinfection is almost inevitable. Pinworm is the one worm infection that is not eradicated in the santitary revolution of developed countries.
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Infective stage of Trichuris
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Embryonated eggs
|
|
Diagnostic stage of Trichuris
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Eggs in feces
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Transmission of Trichuris (Whipworm)
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Humans ingest embryonated eggs from human fecal contamination
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Where do eggs of Trichuris hatch?
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Small intestine
|
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Where do Trichuris larvae mature?
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Cecum
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How long does it take for Trichuris to mature after hatching?
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2 months
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How long does it take for Trichuris eggs to become infective?
|
3 weeks (thus this disease is eradicated by sanitation revolution)
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|
Describe Trichuris egg-laying
|
Female releases eggs from within the cecum, which are then excreted out in the feces of the host
|
|
Describe the Trichuris egg
|
Brown egg shell (stained by bile), underdeveloped embryo (older eggs have larval worm)
|
|
These worms anchor themselves to the intestinal mucosa
|
Trichuris (Whipworm); Ancylostoma, Necator (Hookworm)
|
|
The female of this worm type grows to 4 cm long
|
Trichuris (Whipworm)
|
|
This worm lives for several years and produces 8,000 eggs each day
|
Trichuris (Whipworm)
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|
Clinical signs and symptoms of whipworm
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Mild or subclinical; lots of worms can cause diarrhea
|
|
Geographic distribution of Trichuris
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Southeastern rural USA; tropical regions around the world
|
|
Geographic distribution of Enterobius
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Global
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Complications of whipworm
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Anemia, abdominal pain, severe diarrhea, rectal prolapse in exceedingly heavy infections
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Recal prolapse is a complication of this worm infection
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Trichuris (Whipworm)
|
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Anemia can result from infection by these worms
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Trichuris (Whipworm); Ancylostoma, Necator (Hookworm)
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Treatment of whipworm
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Bendazole
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The female of this worm type grows to 35 cm long
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Ascaris, Onchocerca
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These two worms have a relatively simple life cycle, whereas this worm has a relatively complex life cycle
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Enterobius (pinworm), Trichuris (whipworm); Ascaris
|
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Infective stage of Ascaris
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Embryonated eggs
|
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Where do eggs of Ascaris hatch?
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Small intestine
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Where do Ascaris larvae mature?
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Partially mature in the alveoli, fully mature in the small intestine after being re-swallowed
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Migration of Ascaris larvae
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Larvae are tiny after hatching and penetrate into portal circulation, then travel to lung capillaries where they break out into alveoli, and then make their way up the respiratory tree and are re-swallowed
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When do Ascaris worms begin to produce eggs?
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2 months after infection
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How long does it take for Ascaris eggs to become embryonated and therefore infective?
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3 weeks (thus this disease is eradicated by sanitation revolution)
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Diagnostic stage of Ascaris
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Egg in feces
|
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Unmated females of this worm species will lay non-fertilized eggs
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Ascaris
|
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Describe the Ascaris egg
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Lumpy-bumpy surface; thick, yellow-brown shell (bile-stained), underdeveloped unicellular embryo
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Clinical signs and symptoms of Ascaris
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Usually asymptomatic, but may include: exit of adult worm through anus; abdominal pain, n/v; fever; eosinophilia (during larval migration through lung); pneumonitis (only in heavy infection, during larval migration); obstruction
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Complications of Ascaris
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Malabsorption, intestinal obstruction (knotted mass of worms), biliary obstruction (worms in bile duct), pancreatic obstruction, hemorrhagic pneumonitis (during larval migration phase)
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This worm affects mainly children
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Ascaris
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Hemorrhagic pneumonitis is a complication of this worm infection
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Ascaris
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This worm infection is very common in the tropics and occasionally seen in the USA, especially in the southeast
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Ascariasis
|
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How many eggs does an Ascaris female lay per day?
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A lot: 200,000
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How long do Ascaris eggs remain infective?
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Months, though they are destroyed by sunlight or drying, but stable to feezing
|
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Most infections by this worm in New England are by the pig version of the worm via pig fecal contamination
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Ascaris
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Treatment of Ascaris
|
Bendazole
|
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Prevention of Ascaris, Trichuris, Hookworm
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Sanitary disposal of feces
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|
These worms can cause severe anemia
|
Ancylostoma, Necator (Hookworm spp.)
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Diagnostic stage of Hookworms
|
Eggs in feces
|
|
Describe Hookworm egg
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Thin shell
|
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This roundworm enters the human host by penetrating the skin and entering the blood
|
Hookworm
|
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The larval development of these three roundworms is similar
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Ascaris, Hookworm, Strongyloides
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Migration of Hookworm larvae
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Enter through the skin into circulation, then leave via lung capillaries into the alveoli, climb the respiratory tree and are swallowed, then complete maturation in the small intestine
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Survival time of infectious Hookworm larvae outside of host
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Less than 6 weeks
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Clinical signs and symptoms of Hookworm
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Papule and erythema at site of entry ("ground itch/dew itch"), transient pulmonary sx with eosinophilia in heavy infection
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Ground itch/dew itch
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Caused by Hookworm and Strongyloides infections
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The female of this worm type grows to 1 cm long
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Hookworm
|
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This worm secretes anticoagulant and sucks blood
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Hookworm
|
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Lifespan of Hookworms in hosts
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5 years
|
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Number of eggs produced by female Hookworm
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10,000 eggs/day
|
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Complications of hookworm
|
Anemia with marginal iron deficiency, mental retardation in children with chronic anemia on account of hookworm infection
|
|
Great improvement in the infection of children in rural southeastern USA by this worm has been seen over the course of the last century
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Hookworm
|
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Treatment of hookworm
|
Bendazole
|
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Patients with this worm infection may require iron supplements or even transfusion
|
Hookworm (due to severe anemia)
|
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Prevention of these diseases is mainly by the wearing of shoes
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Hookworm, Strongyloides
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This worm is notable for being able to multiply extensively in humans and produce life-threatening disease
|
Strongyloides
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This worm has three interrelated life cycles
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Strongyloides
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These are the three life cycles of Strongyloides
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Parasitic (hookworm-like), Free-living, Autoinfective (hyperinfection)
|
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The eggs of this worm are laid in the host, and then hatch in the host without being excreted
|
Strongyloides
|
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Duration of infection until egg-laying begins in Strongyloides
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1 month
|
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This worm burrows into small intestine mucosa and lays eggs there
|
Strongyloides
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Diagnostic stage of Strongyloides
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Larva in feces
|
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Infective stage of Strongyloides
|
Larva
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Infective stage of Hookworm
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Larva
|
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Hatching site of Stronglyloides
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Intestine
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Hatching site of Hookworm
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Outside of host
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Free-living larvae are seen in these two worms' lifecycles
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Hookworm, Strongyloides
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Newly hatched larvae of this worm are excreted in the feces
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Strongyloides
|
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The free-living forms of this worm are able to mate and lay eggs
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Strongyloides (not Hookworm)
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T/F: free-living, reproducing Strongyloides are able to infect hosts
|
False. They must differentiate into infectious larvae to infect humans
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Define autoinfection in Strongyloides infection
|
Larvae that hatch in the host mature into infectious larvae that penetrate intestinal wall or perianal skin and eventually reach lungs via circulatory system
|
|
Infection by this worm is usually lifelong
|
Strongyloides (due to autoinfection)
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Describe Strongyloides larva
|
Short buccal cavity, hour-glass shaped esophagus, genital promordium, anus
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The female of this worm type grows to 2 mm long
|
Strongyloides
|
|
Clinical signs and symptoms of Strongyloides
|
Usually asymptomatic, but may include: mild cutaneous and pulmonary sx, diarrhea, nausea, abdominal pain, eosinphilia
|
|
Infection by this worm may result in a long-term (decades), low-grade infection
|
Strongyloides
|
|
Recurrent gram-negative bacteremia is a feature of this worm infection
|
Strongyloides (E.coli is carried by penetrating worm into the intestinal mucosa)
|
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Hyperinfection may result in immunocompromised patients with this worm
|
Strongyloides
|
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Complications of Strongyloides
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Diarrhea, nausea, abdominal pain, pulmonary and cutaneous symptoms, hyperinfection
|
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Features of hyperinfection seen in Strongyloides
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High fever, dyspnea, gram negative septicemia
|
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Treatment of Strongyloides
|
Bendazole
|
|
Geographic distribution of Stronglyoides and Hookworm
|
Tropical and warm temperate climates (previously including southeastern USA)
|
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This disease is caused by infection of a human by a roundworm species that does not recognize humans as natural hosts
|
Larva migrans
|
|
The intestinal phase is not seen in infections with these roundworms in humans
|
Larva migrans
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This disease is caused by an Ascaris-like intestinal round worm of dogs (or, less commonly, cats)
|
Visceral larva migrans
|
|
This infection is most common in children under 4 years old
|
Visceral larva migrans
|
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T/F: Most visceral larva migrans infections are asymptomatic
|
True
|
|
This disease may mimic retinoblastoma
|
Retinal involvement in visceral larva migrans
|
|
Fever and hepatomegaly may be seen in this round worm infection
|
Visceral larva migrans
|
|
A history of pica or dog contact suggests this diagnosis
|
Visceral larva migrans
|
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Liver biopsy can be diagnostic in patients with this infection
|
Visceral larva migrans (migrating larvae seen on bx)
|
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Treatment of visceral larva migrans
|
Bendazole
|
|
Most infections by this worm are self-limiting in less than 1 year
|
Visceral larva migrans (larvae become enclosed in granulomata)
|
|
Prevention of visceral larva migrans
|
Treat dogs to eliminate their round worms, avoid dog feces
|
|
Cause of cutaneous larva migrans
|
Dog and cat hookworm
|
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Cause of visceral larva migrans
|
Ascaris-like worm of dog (and, less commonly, cats)
|
|
This infection causes local itching and inflammatory response
|
Cutaneous larva migrans
|
|
Rate of movement of worms in cutaneous larva migrans
|
1 cm/day (or less)
|
|
Most infections by this worm are self-limiting in less than 2 months
|
Cutaneous larva migrans
|
|
T/F: The larval track in cutaneous larva migrans leaves a scar
|
True
|
|
The geographical distribution of this worm is prevalent in the southeastern USA
|
Cutaneous larva migrans
|
|
How is cutaneous larva migrans diagnosed?
|
Observation of the characteristic lesion
|
|
Treatment of cutaneous larva migrans
|
Bendazole
|
|
These roundworms release live larvae ("viviparous") instead of laying eggs
|
Trichinella, Dracunculus (guinea worm), Filarial infections (elephantiasis, river blindness, eye worm)
|
|
Transmission of this worm is from carnivore (or ominovore) to carnivore by eating skeletal muscle from the previous host
|
Trichinella
|
|
This infection features encysted larval progency in skeletal muscle
|
Trichinella
|
|
This worm is acquired by eating undercooked pork (or any other carnivore)
|
Trichinella
|
|
Route of invastion of Trichinella
|
Muscle with encysted larva is eaten, larva are released in small intestine, where they invade the mucosa and mature
|
|
Infective stage of Trichinella
|
Larva within meat
|
|
How long after infection by Trichinella does fertilization take place?
|
2 days
|
|
How long after infection by Trichinella are live larvae released?
|
5 days
|
|
How long does the Trichinella worm continue to release larvae?
|
1 month
|
|
How long do Trichinella larvae take to reach maximal size in the muscle?
|
3 weeks
|
|
Survival time of Trichinella larvae in smooth muscle
|
2 years (after which time they die and are calcified)
|
|
Diagnostic stage of Trichinella
|
Encysted larva in striated muscle
|
|
The diagnostic and infective stages of this worm are the same
|
Trichinella (encysted larva in striated muscle)
|
|
What happens to the Trichinella cyst over time?
|
It becomes calcified
|
|
Clinical signs and symptoms of Trichinella early on in heavy infection
|
Diarrhea, gastroenteritis
|
|
Cause of death in Trichinella
|
Migration of larvae to heart and brain
|
|
Clinical signs and symptoms of Trichinella later on in heavy infection
|
Eosinophilia, periorbital edema, diplopia, muscle pain, headache, fever, others (a wide array is possible)
|
|
Various serological tests support diagnosis of infection by this roundworm
|
Trichinella
|
|
Treatment of Trichinella
|
Steroids may be useful; bendazole is recommended but is not proven effective
|
|
Prevention of Trichinella
|
Cook meat, freeze meat (several days); at the population level, stop feeding uncooked pork scraps (via garbage) to pigs
|
|
T/F: In the US, it is illegal to throw out raw pork
|
True
|
|
Geographic distribution of Trichinella
|
Worldwide, except Australia and some Pacific Islands
|
|
Genus of roundworm that causes Guinea Worm
|
Dracunulus (Guinea worm)
|
|
Transmission of Guinea worm
|
Copepods in drinking water containing infectious larvae
|
|
Intermediate host of Dracunulus (Guinea worm)
|
Copepod (tiny crustacean)
|
|
The female of this worm type grows to 1 m long
|
Dracunulus (Guinea worm)
|
|
Diagnostic stage of Dracunulus
|
Larva or adulte female escaping from skin in response to submersion of ulcer in cold fresh water
|
|
Infective stage of Dracunulus
|
Larva (third stage larva)
|
|
Dracunulus (guinea worm) prefers to migrate in subcutaneous tissue, especially in this part of the body
|
Legs
|
|
Life cycle of guinea worm (Dracunulus)
|
Infectious larvae are ingested then penetrate the intestinal wall and enter connective tissue or body cavities where the male and female mate. The female then migrates to superficial cutaneous tissue where she gives birth to live larvae which then escape through the skin
|
|
This worm gives birth by prolapse of the uterus in response to submersion in fresh water
|
Dracunulus (Guinea worm)
|
|
Definitive host of guinea worm (Dracunulus)
|
Human
|
|
If this worm is broken during treatment, larvae are released systemically and severe inflammation can result (hypersensitivity reaction)
|
Dracunulus (Guinea worm)
|
|
Treatment of guinea worm (Dracunulus)
|
Slow extraction of worm over several weeks; surgery; bendazole
|
|
This disease remains a major problem in Sudan
|
Guinea worm (Dracunulus)
|
|
Clinical signs and symptoms of guinea worm (Dracunulus)
|
Painful lesion, frequently with secondary bacterial infection
|
|
Complications of guinea worm
|
Hypersensitivity reaction in response to systemic release of larvae when worm is broken
|
|
Prevention of guinea worm
|
Separate drinking water from bathing/washing/wading water supplies. Filter drinking water. Larvicide treatment of water.
|
|
WHO hopes to eradicate this disease in the near future
|
Guinea worm (Dracunulus)
|
|
Definitive host of filariases in humans
|
Humans
|
|
Humans harbor both the adult worms and their newborn larvae of this class of roundworm
|
Filariasis
|
|
Life cycle of filarial roundworms
|
Insect bite -> injection of mature larvae -> maturation and mating of adult worms -> female releases live first-stage larvae (MICROFILARIAE) -> mirofiliariae circulate in blood or migrate to tissue
|
|
Intermediate host of filarial roundworms
|
Blood-sucking insects
|
|
Diagnostic stage of filarial roundworms
|
Microfiliariae in blood or tissue
|
|
Where do filarial roundworms mature?
|
Thoracic muscles of infected insect
|
|
This worm causes elaphantiasis
|
Wuchereria bancrofti
|
|
This disease is caused by adult worms in the lymphatics
|
Elephantiasis (caused by Wuchereria)
|
|
Intermediate host of Wuchereria
|
Mosquito
|
|
T/F: Wuchereria microfiliariae are pathogenic
|
False. The adult worm, not the microfiliariae cause disease
|
|
Microfiliariae are hard to detect in chronic forms of this disease because there are not many of them
|
Elephantiasis (caused by Wuchereria)
|
|
Treatment of elephantiasis
|
Ivermectin
|
|
This disease could possibly be eradicated over the course of 5 years with universal chemotherapy
|
Elephantiasis (caused by Wuchereria)
|
|
Tropical pulmonary eosinophilia is a complication of infection by this worm
|
Wuchereria bancrofti
|
|
T/F: Tropical pulmonary eosinophilia is a common, fatal complication of Wuchereria infection
|
False. It is a rare (0.5%) but fatal complication
|
|
This worm can cause pulmonary infiltrates
|
Wuchereria bancrofti
|
|
T/F: Tropical pulmonary eosinophilia is solely caused by Wuchereria bancrofti.
|
False. Many types of worms can cause it, but Wuchereria is a common cause of this rare syndrome
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Diagnostic stage of Wuchereria
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Microfiliariae in blood
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Diagnostic stage of Onchocerca (River Blindness)
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Microfiliariae in skin
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Geographic distribution of Wuchereria
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All tropical regions
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Microfilariae of this worm are harmless, but microfilariae of this worm cause disease
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Wuchereria microfiliariae are harmless (the adult form causes disease when it enters the lymphatics), but Onchocerca microfiliariae cause blindness
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Intermediate host of Onchocerca (River Blindness)
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Black fly (genus Simulium)
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This is where to find adult Onchocerca in infected humans
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Subcutaneous nodule at the site of the infecting black fly bite
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Clinical signs and symptoms of Onchocerca
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Dermatitis with severe itching, eye lesions, eosinophilia, subcutaneous nodules
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Microfilariae of this worm cause dermatitis with severe itching
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Onchocerca (River Blindness)
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Pathogenesis of blindness caused by Onchocerca (River blindness)
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Cornea: chronic keratitis and fibrosis NEWLINE Iris: atrophy NEWLINE Retina: chorioretinitis
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T/F: There is an autoimmune mechanism involved in River Blindness
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True.
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Geographic distribution of Onchocerca
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Focal areas of tropical Africa, Central and South America
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Diagnostis of this disease requires microfiliariae on a skin snip or adult worms in biopsy of nodule
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Onchocerca (River Blindness)
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Treatment of River Blindness (Onchocerca)
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Ivermectin (once a year; it kills microfiliariae before they can do harm)
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T/F: Ivermectin kills the adult and microfiliariael forms of Onchocerca
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False. It is only effective against the microfiliariae.
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This is the least serious of filiarial infections
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Loa Loa
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This worm causes symptoms due to migration of the adult worm through subcutaneous tissue
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Loa Loa (Eye Worm)
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T/F: Conjunctival migration is a common finding in Loa Loa (Eye worm)
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False. Only 15% of travelers with Loa Loa present with conjunctival migration; most present with Calabar swellings
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Chrysops is the intermediate host of this worm
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Loa Loa (Eye Worm)
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Intermediate host of Loa Loa
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Chrysops fly
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How long does it take for microfiliariae of Loa loa to mature in its host?
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2 weeks
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Diagnostic stage of Loa loa
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Microfiliariae in blood
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Infective stage of filariasis
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Infective larvae transmitted from the blood-sucking fly to the human
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How long does it take for Loa loa to mature once it has entered its human host
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1 year
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Survival time of Loa loa
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Several years (10-20)
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Calabar Swellings
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Itchy, chicken egg-sized edematous lesion seen in Loa loa infections. Caused by migration of adults (5 cm) through a hypersensitivity mechanism
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Geographic distribution of Loa loa
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Tropical Africa only
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Treatment of Loa loa
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Surgical removal, chemotherapy (DO NOT USE IVERMECTIN)
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Prevention of filiarial diseases
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Avoidance of fly bites
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What are the species, their vectors, and the cause of pathology in the three filarial infections?
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Wuchereria - Mosquito - Adults in lymphatics NEWLINE Ochocerca - Simulium (black fly) - Microfiliariae in tissues NEWLINE Loa loa - Chrysops (fly) - Adults in tissues
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Clinical signs and symptoms of Loa loa
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Calabar swelling, adult migrating in conjunctiva
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What are the three targets against which chemotherapeutic agents against worms are targetted?
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Neural and neuromuscular transmission NEWLINE Cytoskeletal structure (esp microtubules) NEWLINE Energy metabolism
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What three drugs are used to treat helminthic infections
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Bendazoles, Ivermectin, Praziquantel
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T/F: Bendazole is the first choice treatment for roundworm infections
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False. Filarial infections do not respond to bendazoles. Most other roundworm infections do.
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T/F: Filarial infections are treated with ivermectin
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False. Almost all filarial infections CAN be treated with ivermectin, but Loa loa cannot.
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Praziquantel is used to treat this.
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All fluke and adult tape worm infections
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Ivermectin is used to treat this.
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Almost all filarial infections (not Loa loa)
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Bendazoles are used to treat this.
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Almost all roundworm infections (not filarial infections)
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Metronidazole is used to treat this
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Anaerobic protozoa (E. histolytica, Giardia, Trichomonas vaginalis)
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Pyrimethamine and sulfadoxine is used to treat this
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Toxoplasma gondii and chloroquine-resistant malaria
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Bactrim is used to treat this
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Pneumocystis and cyclospora
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Drugs for treatment of malaria
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Chloroquine, mefloquine, pyrimethamine-sulfadoxine, primaquine
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These parasites are hard to treat; most of the availabe drugs are toxic.
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Hemoflagellates
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T/F: Most protozoa are benign
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True. Most protozoa are neither pathogenic nor parasitic
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T/F: Parasitic protozoa are intracellular.
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False. Some parasitic protozoa are intracellular, and some multiply in extracellular fluids (eg, blood). In some species, certain stages are extracellular while others are intracellular.
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How do protozoa differ from worms, pathogenically?
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All protozoa that cause disease in humans must be capable of multiplying in humans (not true of worms) NEWLINE NEWLINEEosinophilia is not a usual sign of protozoal infection
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Metronidazole is useful against these types of parasitic infections
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Infection by anaerobic protozoa
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These three protozoa are anaerobes
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Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis
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Cause of amebiasis
|
Entamoeba histolytica
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This parasite is an extracellular protozoan that grows anaerobically
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Entamoeba histolytica
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The simple life cylce of this protozoa involves only humans
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Entamoeba histolytica
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Transmission of Entamoeba histolytica
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Oral-fecal. Human ingests CYSTS (human fecal contamination)
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What are the three targets against which chemotherapeutic agents against worms are targetted?
|
Neural and neuromuscular transmission NEWLINE Cytoskeletal structure (esp microtubules) NEWLINE Energy metabolism
|
|
What three drugs are used to treat helminthic infections
|
Bendazoles, Ivermectin, Praziquantel
|
|
T/F: Bendazole is the first choice treatment for roundworm infections
|
False. Filarial infections do not respond to bendazoles. Most other roundworm infections do.
|
|
T/F: Filarial infections are treated with ivermectin
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False. Almost all filarial infections CAN be treated with ivermectin, but Loa loa cannot.
|
|
Praziquantel is used to treat this.
|
All fluke and adult tape worm infections
|
|
Ivermectin is used to treat this.
|
Almost all filarial infections (not Loa loa)
|
|
Bendazoles are used to treat this.
|
Almost all roundworm infections (not filarial infections)
|
|
Metronidazole is used to treat this
|
Anaerobic protozoa (E. histolytica, Giardia, Trichomonas vaginalis)
|
|
Pyrimethamine and sulfadoxine is used to treat this
|
Toxoplasma gondii and chloroquine-resistant malaria
|
|
Bactrim is used to treat this
|
Pneumocystis and cyclospora
|
|
Drugs for treatment of malaria
|
Chloroquine, mefloquine, pyrimethamine-sulfadoxine, primaquine
|
|
These parasites are hard to treat; most of the availabe drugs are toxic.
|
Hemoflagellates
|
|
What are the three targets against which chemotherapeutic agents against worms are targetted?
|
Neural and neuromuscular transmission NEWLINE Cytoskeletal structure (esp microtubules) NEWLINE Energy metabolism
|
|
What three drugs are used to treat helminthic infections
|
Bendazoles, Ivermectin, Praziquantel
|
|
T/F: Bendazole is the first choice treatment for roundworm infections
|
False. Filarial infections do not respond to bendazoles. Most other roundworm infections do.
|
|
T/F: Filarial infections are treated with ivermectin
|
False. Almost all filarial infections CAN be treated with ivermectin, but Loa loa cannot.
|
|
Praziquantel is used to treat this.
|
All fluke and adult tape worm infections
|
|
Ivermectin is used to treat this.
|
Almost all filarial infections (not Loa loa)
|
|
Bendazoles are used to treat this.
|
Almost all roundworm infections (not filarial infections)
|
|
Metronidazole is used to treat this
|
Anaerobic protozoa (E. histolytica, Giardia, Trichomonas vaginalis)
|
|
Pyrimethamine and sulfadoxine is used to treat this
|
Toxoplasma gondii and chloroquine-resistant malaria
|
|
Bactrim is used to treat this
|
Pneumocystis and cyclospora
|
|
Drugs for treatment of malaria
|
Chloroquine, mefloquine, pyrimethamine-sulfadoxine, primaquine
|
|
These parasites are hard to treat; most of the availabe drugs are toxic.
|
Hemoflagellates
|
|
T/F: Most protozoa are benign
|
True. Most protozoa are neither pathogenic nor parasitic
|
|
T/F: Parasitic protozoa are intracellular.
|
False. Some parasitic protozoa are intracellular, and some multiply in extracellular fluids (eg, blood). In some species, certain stages are extracellular while others are intracellular.
|
|
How do protozoa differ from worms, pathogenically?
|
All protozoa that cause disease in humans must be capable of multiplying in humans (not true of worms) NEWLINE NEWLINEEosinophilia is not a usual sign of protozoal infection
|
|
Metronidazole is useful against these types of parasitic infections
|
Infection by anaerobic protozoa
|
|
These three protozoa are anaerobes
|
Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis
|
|
Cause of amebiasis
|
Entamoeba histolytica
|
|
This parasite is an extracellular protozoan that grows anaerobically
|
Entamoeba histolytica
|
|
The simple life cylce of this protozoa involves only humans
|
Entamoeba histolytica
|
|
Transmission of Entamoeba histolytica
|
Oral-fecal. Human ingests CYSTS (human fecal contamination)
|
