Parasitology Lecture Exam 1

Intentional nematodes, Blood & tissue nematodes, & Cestodes

How do you transfer Enterobius Vermicularis (Pinworm)?

Ingestion of the infective egg

What is the infective stage of Enterobius Vermicularis (Pinworm)?

Embryonated eggs

What is the #1 worm infection in the US?

Enterobius Vermicularis (Pinworm)

What is the diagnostic stage of Enterobius Vermicularis (Pinworm)?

Embryonated eggs

What are the symptoms of Enterobius Vermicularis (Pinworm)?

Perianal itching, restlessness, mild nausea/vomiting, mild irritation of intestinal mucosa, vulval irritation (girls)

Where is the distribution of Enterobius Vermicularis (Pinworm)?

Worldwide (mainly among children)

How do you transfer Trichurtis Trichiuta (Whipworm)?

ingestion of infective eggs in fecal matter

What is the infective stage of Trichurtis Trichiuta (Whipworm)?

Embryonated egg

What is the diagnostic stage of Trichurtis Trichiuta (Whipworm)?

Unembruonated eggs found in feces

What are the symptoms of Trichurtis Trichiuta (Whipworm)?

Heavy infection, weight loss and weakness, abdominal pain and tenderness to touch, prolapsed rectum (infants)

Where is the distribution of Trichurtis Trichiuta (Whipworm)?

Warm countries with poor sanitation

What is the 3rd most common intestinal parasite in the US?

Trichurtis Trichiuta (Whipworm)

What is the 2nd most common worm infection in the US?

Ascaris Lumbricoides (Large Intestinal worm)

How do you transfer Ascaris Lumbricoides (Large Intestinal worm)?

ingestion of infective eggs in fecal matter

What is the infective stage of Ascaris Lumbricoides (Large Intestinal worm)?

Embryonated egg

What is the diagnostic stage of Ascaris Lumbricoides (Large Intestinal worm)?

Unembryonated egg found in feces

How do you test for Ascaris Lumbricoides (Large Intestinal worm)?

“Cover slip” egg counting method

What are the symptoms of Ascaris Lumbricoides (Large Intestinal worm) during the tissue phase?

Pneumonia, cough, mild fever, and eosinophilia

What are the symptoms of Ascaris Lumbricoides (Large Intestinal worm) during the intestinal phase?

Obstruction, appendix obstruction, malnutrition, and chronic anemia

True or False: Adult hookworms are found in feces.

False

How do you transfer Nectar Americanus (New World hookworm)?

Penetrate the bottom of the foot

Where do Nectar Americanus (New World hookworm) larvae develop?

Warm moist soil

The adult buccal cavity of Nectar Americanus (New World hookworm) contains what?

Cutting plates

What is the infective stage of Nectar Americanus (New World hookworm)?

Filariform larvae in fecal contaminated soil

What is the diagnostic stage of Nectar Americanus (New World hookworm)?

Eggs found in feces (old feces have more mature embryo)

What are the main symptoms of Nectar Americanus (New World hookworm)?

Severe allergic reaction, ground itch, and eosinophilia

What are the symptoms of Nectar Americanus (New World hookworm) during the tissue phase?

sore throat, coughing, headache, and bloody sputum

What are the acute symptoms of Nectar Americanus (New World hookworm) during the intestinal phase?

Nausea, vomiting, diarrhea or constipation, and weight loss

What are the chronic symptoms of Nectar Americanus (New World hookworm) during the intestinal phase?

Blood loss, iron deficiency anemia (IDA), and hypoproteinemia

The adult Ancylostoma Duodenale (Old World hookworm) buccal cavity contains what?

Four teeth

Where is the distribution of Ancylostoma Duodenale (Old World hookworm)?

Europe, South America, Asia, Africa, and Caribbean

Where is the distribution of Nectar Americanus (New World hookworm)?

North and South America, Asia, India, and Africa

How do you transfer Strongyloides Stercoralis (Threadworm)?

Exposed skin penetration (usually the foot)

What is the diagnostic stage of Strongyloides Stercoralis (Threadworm)?

Rhabditiform (immature) larvae passed in feces

Where are Strongyloides Stercoralis (Threadworm) eggs hatched?

Intestinal mucosa

Where is the distribution of Strongyloides Stercoralis (Threadworm)?

Warm areas/ tropical areas

What is the difference between hookworm and threadworm tails?

Hookworms: pointed

Threadworms: notched

What is the difference between hookworm and threadworm buccal cavities?

Hookworms: long buccal cavity

Threadworms: short buccal cavity

What is the difference between hookworm and threadworm esophagus?

Hookworms: 1 bulb not prominent

Threadworms: 1 bulb (hourglass shape) and prominent

How do you transfer Trichinella Spiralis (Pork/Trichina worm)?

Ingestion of undercooked meat

What is the diagnostic stage of Trichinella Spiralis (Pork/Trichina worm)?

Encysted larvae in striated muscle

What are the symptoms of Trichinella Spiralis (Pork/Trichina worm) during the intestinal phase?

Intestinal edema and inflammation, nausea/vomiting, abdominal pain, diarrhea, and headache

What are the symptoms of Trichinella Spiralis (Pork/Trichina worm) during the migration phase?

High fever, blurred vision, face/eye edema, pleural pains and eosinophilia (death can occur)

What are the symptoms of Trichinella Spiralis (Pork/Trichina worm) during the muscular phase?

Acute local inflammation, edema and pain, larvae encyst in muscle tissues, and weakness/fatigue

Where is the distribution of Trichinella Spiralis (Pork/Trichina worm)?

Worldwide (people who eat meat are at higher risk)

What is the infective stage of Dracunculus Medinensis (Guinea worm)?

Copepod in drinking water

How do you transfer Dracunculus Medinensis (Guinea worm)?

Human ingestion of copepod in drinking water

What is the diagnostic stage of Dracunculus Medinensis (Guinea worm)?

Skin blister or emerging worms

Where is the distribution of Dracunculus Medinensis (Guinea worm)?

Middle East, India, Pakistan, and Africa

How do you transfer Toxocara Canis (Dog/Cat Large Intestinal roundworm)?

Ingestion of larvae in soil

What is the infective stage of Toxocara Canis (Dog/Cat Large Intestinal roundworm)?

Larvae in developed eggs located in soil

How do you transfer Baylisascaris Procyonis (Raccoon roundworm)?

Young children via ingestion

True or False: Bleach can kill Baylisascaris Procyonis (Raccoon roundworm)

False

Bleach removes the outer protein coat, but you need a portable propane torch to kill the parasite

What are the two ways to transfer Anisakis Simplex (Fish/Sea lion roundworm)?

1.) Eating undercooked fish (Intestinal infection)

2.) Chemicals left by the worms in fish flesh (Allergic reaction)

Where is Wuchereria bancrofti found?

Tropical and subtropical areas

How do you transfer Wuchereria bancrofti?

1.) Adult filaria in human tissue produces microfilaria that migrate to lymphatics, blood, or skin 2.) Culex, Aedes, & Anopheles mosquitoes ingest microfilaria 3.) Larvae molt twice inside mosquitoes to become infected filariform larvae 4.) Larvae enter new human host via mosquito bite

What is the intermediate host of Wuchereria bancrofti?

Culex, Aedes, & Anopheles mosquitoes

What is the infective stage of Wuchereria bancrofti?

It develops inside the Culex, Aedes, & Anopheles mosquitoes

What is the diagnostic stage of Wuchereria bancrofti?

Microfilaria in blood

What are the microfilaria features for Wuchereria bancrofti?

Sheathed

Nuclei visible

Tapered tail to a point

Gently curved

What are the symptoms of Wuchereria bancrofti during the acute phase?

Fever & lymphangitis

Where is Brugia malayi found?

Eastern & Southeastern Asia

How do you transfer Brugia malayi?

1.) Adult filaria in human tissue produces microfilaria that migrate to lymphatics, blood, or skin 2.) Mansonia or Anopheles mosquitoes ingest microfilaria 3.) Larvae molt twice inside mosquitoes to become infected filariform larvae 4.) Larvae enter new human host via mosquito bite

What is the intermediate host of Brugia malayi?

Mansonia or Anopheles mosquitoes

What is the infective stage of Brugia malayi?

Takes place inside Mansonia or Anopheles mosquitoes

What is the diagnostic stage of Brugia malayi?

Microfilaria in blood

What are the microfilaria features of Brugia malayi?

Sheath

Tightly curled

Tight-packed nuclear column

Tapered tail

What are the symptoms of Brugia malayi during the acute phase?

Fever & lymphangitis

Where is Loa loa found?

Rainforest belt in Africa

How do you transfer Loa loa?

1.) Adult filaria in human tissue produces microfilaria that migrate to lymphatics, blood, or skin 2.) Mango fly (chrysops) ingest microfilaria 3.) Larvae molt twice inside Mango fly to become infected filariform larvae 4.) Larvae enter new human host via fly bite

What is the intermediate host of Loa loa?

Mango fly (Chrysops)

What is the infective stage of Loa loa?

Takes place inside Mango fly (Chrysops)

What is the diagnostic stage of Loa loa?

Microfilaria in blood or microfilaria migrating through the conjunctiva of the eye

What are the microfilaria features of Loa loa?

Sheath

Nuclei extend to the end of the tail

Dense nuclear column

Coiled

Tapered tail

What are the symptoms for Loa loa?

Subcutaneous edema around the eye, proteinuria & endomyocardial fibrosis

Where is Onchocerca volvulus found?

Central America & equatorial Africa

How is Onchocerca volvulus transferred?

1.) Adult filaria in human subcutaneous tissue produces microfilaria that migrate to lymphatics, blood, or skin 2.) Blackfly (stimulium) ingest microfilaria 3.) Larvae molt twice inside Blackfly (stimulium) to become infected filariform larvae 4.) Larvae enter new human host via fly bite

What is the intermediate host of Onchocerca volvulus?

Blackfly (stimulium)

What is the infective stage of Onchocerca volvulus?

Takes place inside Blackfly (stimulium)

What is the diagnostic stage of Onchocerca volvulus?

Microfilaria in dermis

What are the microfilariae features of Onchocerca volvulus?

No sheath present

Tapered tail with sharp angled end

Nuclei not terminal

What are the symptoms of Onchocerca volvulus?

Fibrotic nodules (onchocercomas), pigmented rash, & blincness

What are the symptoms of Brugia malayi during the chronic phase?

elephantiasis

What are the symptoms of Wuchereria bancrofti during the chronic phase?

elephantiasis

What are some of the main characteristics of cestodes?

Flattened bodies

Involve at least 1 intermediate host

Hermaphroditic

Segments (proglottids)

Scolex has suckers and/or hooks

What are some of the main characteristics of nematodes?

Round bodies (earthworm like)

Non-segmented

Males are smaller than females

Free-living

Reside in GI tracts

Where is Hymenolepis nana located?

Worldwide

How do you transfer Hymenolepis nana?

Ingested egg via contaminated food/water or hand to mouth

What is the infective stage of Hymenolepis nana?

Eggs are infective when released

What is the diagnostic stage of Hymenolepis nana?

Infective eggs found in feces

What are the main egg features of Hymenolepis nana?

6 hooks (3 pairs)

Polar filaments

Colorless shell

What are the main adult features of Hymenolepis nana?

Live in small intestine

4 suckers

What are the symptoms of Hymenolepis nana during a light infection?

Asymptomatic

What are the symptoms of Hymenolepis nana during a heavy infection

Intestinal enteritis

Abdominal pain

Diarrhea

Headache

Dizziness

Anorexia

What is the intermediate host of Hymenolepis nana?

House mouse (not required)

What is the transport host of Hymenolepis nana?

Fleas & Beetles

Where is Hymenolepis diminuta located?

Worldwide

How do you transfer Hymenolepis diminuta?

Cysticercoid larva inside flea or grain beetle

What is the infective stage of Hymenolepis diminuta?

Accidental ingestion of infected flea or grain beetle

What is the diagnostic stage of Hymenolepis diminuta?

Eggs found in feces