Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MOD Exam 3 > Helminths Infections > Flashcards

Helminths Infections Flashcards

(17 cards)

Start Studying
1
Q 
INTESTINAL NEMATODES (ROUNDWORMS): 
Ascaris lumbricoides
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:
- Ingests eggs

• Morphology:
- Adult attains a length of 20-30 cm

• Clinical Findings:

  1. Asymptomatic in many individuals
  2. Abdominal cramping
  3. Dry cough and fever while larvae are in the lungs
  4. Children may develop malnutrition as worms compete for food

• Diagnosis:

  1. Fecal exam for eggs
  2. Sputum exam may reveal larvae
  3. Eosinophilia

• Miscellaneous:
- If treated with the wrong antibiotic, Ascaris will migrate out of the GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q 
INTESTINAL NEMATODES (ROUNDWORMS): 
Necator americanus (Hookworm)
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:
- Larvae penetrate through skin

• Morphology:
- Adults about 1 cm long

• Clinical Findings:

  1. Diarrhea, abdominal pain, and weight loss
  2. Iron deficiency anemia
  3. Itching at site of skin penetration + rash
  4. Occasional cough with bloody sputum

• Diagnosis:

  1. Fecal exam for eggs (examine quickly, as eggs hatch rapidly)
  2. Sputum exam may reveal larvae
  3. Eosinophilia

• Miscellaneous:
- Ancyclostoma duodenal is another species of hookworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q 
INTESTINAL NEMATODES (ROUNDWORMS): 
Strongyloides stercoralis
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:

  1. Larvae penetrate through skin
  2. Autoinfection

• Morphology:
- Adult females 2mm long

• Clinical Findings:

  1. Vomiting, diarrhea, anemia, and weight loss
  2. Occasional fatal case caused by massive autoinfection (in immunocompromised host)

• Diagnosis:

  1. Fecal exam for larvae (No eggs!)
  2. Enterotest: swallow long nylon string and later pull out - may show larvae
  3. Sputum exam may reveal larvae
  4. Eosinophilia
  5. Antibody and Antigen serum assay

• Miscellaneous:
- Can undergo complete reproduction cycle in the soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q 
INTESTINAL NEMATODES (ROUNDWORMS): 
Trichinella spiralis
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:
- Ingestion of encysted larvae, often found in raw pork

• Morphology:
- Cysts in skeletal muscle

• Clinical Findings:

  1. Fever, abdominal pain and diarrhea
  2. Muscle aches, as larvae migrate to skeletal muscle
  3. Severe cases: larvae migrate to heart and brain

• Diagnosis:

  1. Serologic tests
  2. Muscle biopsy
  3. Increased levels of muscle enzymes circulating in blood
  4. Eosinophilia

• Miscellaneous:
- Always cook pork products well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q 
INTESTINAL NEMATODES (ROUNDWORMS): 
Trichuris trichiura (Whipworm)
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:
- Ingest eggs

• Morphology:
- Egg looks like a football with polar bumps on each end. Adults whip-shaped, 3-5 cm long

• Clinical Findings:

  1. Diarrhea
  2. Abdominal pain

• Diagnosis:

  1. Fecal exam for eggs
  2. NO eosinophilia

• Miscellaneous:
- Eggs must incubate in moist soil for 3-6 weeks before they become infective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q 
INTESTINAL NEMATODES (ROUNDWORMS): 
Enterobius vermicularis (Pinworm)
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:
- Ingest eggs

• Morphology:
- Adult worms 1 cm long

• Clinical Findings:
- Severe perianal itching

• Diagnosis:

  1. Scotch-tape test
  2. Examination of perineum at night may reveal adults seen with the unaided eye
  3. NO eosinophilia

• Miscellaneous:
- Female migrates to perianal area at night to lay eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

BLOOD AND TISSUE NEMATODES (ROUNDWORMS):
Onchocerca volvulus

  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:

  1. Vector = black fly, which breeds in rivers and streams. Since cases cluster nearby, the disease is called “river blindness”
  2. Found in Africa and Central and South America
  3. Reservoir = humans

• Morphology:

  • FILARIAE:
    1. Threadlike adult roundworms
    2. Give birth to live off-spring called microfilariae, which are transmitted via the black fly

• Clinical Findings:
1. Skin nodules: contain adult worms
2. Allergic reaction to microfilariae migrating through the dermis leads to:
A. Pruritic rash with darkened pigmentation
B. Lizard skin: Intraepithelial granulomas, resulting in thick, dry, scaly skin
3. RIVER BLINDNESS: microfilariae migrate through the eye. A marked inflammatory response can occur upon their death, which can lead to blindness

• Diagnosis:
- Skin biopsy reveals microfilariae

• Miscellaneous:
1. Disease is caused by allergic response to both microfilariae and dead adult worms

  1. Hypersensitivity reaction may occur following administration of diethylcarbamazine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q 
BLOOD AND TISSUE NEMATODES (ROUNDWORMS): 
Wuchereria bancrofti (Pacific islands and Africa)

Brugia malayi (Southeast Asia)

  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:
- Vector = mosquito (transmits microfilariae)

• Morphology:

  • FILARIAE:
    1. Threadlike adult roundworms
    2. Give birth to live offspring called microfilariae

• Clinical Findings:
1. FILARIAL FEVER: febrile episodes associated with headache and swollen lymph nodes

  1. ELEPHANTIASIS: following repeat infections, fibrous tissue forms around the dead filariae that accumulate within the lymph nodes. This fibrous tissue plugs up the lymphatic system, resulting in swelling of the legs and genitals. Thick, scaly skin covers the edematous lower extremities, giving the appearance of elephant legs.
  2. TROPICAL PULMONARY EOSINOPHILIA: hypersensitivity reaction that causes bouts of wheezing and coughing, associated with hypereosinophilia
• Diagnosis: 
1. Look for microfilaria in blood drawn at nighttime 
2. Biopsy 
3. Serology 
4. Tropical pulmonary eosinophilia: 
     A. Hypereosinophilia 
     B. Elevated levels of IgE 
     C. Granulomas within lymph nodes, spleen and lung

• Miscellaneous:
1. Disease is caused by allergic response to both microfilariae and dead adult worms located in the lymphatic system

  1. Tropical pulmonary eosinophilia: associated with filarial infection, and responsive to treatment with diethylcarbamazine, but exact etiology still unclear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q 
BLOOD AND TISSUE NEMATODES (ROUNDWORMS):
Dracunculus medinensis (Guinea worm)
  • Transmission?
  • Morphology?
  • Clinical Findings?
A

• Transmission:
1. Larvae within African, Middle Eastern, and Indian freshwater cope-pods (tiny crustaceans) are ingested when drinking freshwater

  1. Larvae penetrate the intestine, and mature beneath the skin

• Morphology:
FILARIAE
1. Threadlike adult round-worms: the female can grow to 100 cm in size

  1. The adult female pokes a loop of her body through the skin, exposing her uterus. When her uterus is exposed to water, thousands of microfilariae are released

• Clinical Findings:
- Allergic symptoms occur during the release of microfilariae: nausea, vomiting, hives, and breathlessness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

BLOOD AND TISSUE NEMATODES (ROUNDWORMS):
Cutaneous larva migrans (Commonly Ancylostoma braziliense- dog hookworm)

  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:
- Occurs in South-eastern U.S.

• Morphology:
- Larvae of dog and cat tapeworms

• Clinical Findings:
- Creeping eruption: larvae of dog and cat hookworms penetrate the skin and migrate beneath the epidermis (a few centimeters per day). A raised, red itchy rash moves with the advancing larvae

• Diagnosis:
- Biopsy of advancing edge of rash

• Miscellaneous:
- Human tissue-invasive nematodes such as Necator americanus and Strongyloides can produce similar creeping eruption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

BLOOD AND TISSUE NEMATODES (ROUNDWORMS):
Visceral larva migrans (most commonly Toxocara canis - dog roundworm)

  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
A

• Transmission:
- Ingestion of eggs

• Morphology:
- Larve of dog round-worms, which can NOT mature in human

• Clinical Findings:
TOXOCARIASIS
- Migration of larvae through the body results in fever, diarrhea, wheezing, hepatitis, and visual loss (from chorioretinitis)

• Diagnosis:

  1. Serology
  2. Eosinophilia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

PLATYHELMINTHES (FLAT WORMS):

  • Schistosomes
  • Schistosoma japonicum
  • Schistosoma mansoni
  • Schistosoma haematobium
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:

  1. Penetrate through exposed skin
  2. Since the eggs must reach freshwater to hatch, schistosomes cannot multiply in humans
  3. Intermediate host = fresh water snail
• Morphology: 
TREMATODES 
1. Eggs 
2. Mature larvae (called cercariae) 
3. Male and female adults

• Clinical Findings:
- SCHISTOSOMIASIS
1. Pruritic skin rash at site of penetration
2. Acute schistosomiasis (KATAYAMA FEVER):
A. Intense transient itching
B. Weeks later: fever, hives, headache, weight loss, cough (lasts about 3 weeks)
3. Complications caused by immune reaction against eggs released by adults hanging out in the veins surrounding the intestine or bladder:
A. Liver: fibrosis of portal venous system - leads to portal hypertension
B. Lung: fibrosis of pulmonary arterioles can lead to pulmonary hypertension
C. Intestine: deposits of eggs lead to inflammatory polyps

• Diagnosis:

  1. Demonstration of eggs in stool or urine samples
  2. Eosinophilia
  3. Ultrasound of the liver will diagnose liver disease

• Miscellaneous:
1. MOLECULAR MIMICRY: incorporation of host antigens onto their surface, which fools the host’s immune system into thinking the schistosomes are NOT foreign

  1. No person to person transmission
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q 
PLATYHELMINTHES (FLAT WORMS): 
Taenia solium (Pork tapeworm)
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
A

• Transmission:

  1. Ingest undercooked pork containing larvae stage
  2. Ingestion of eggs: results in CYSTICERCOSIS

• Morphology:
CESTODES
1. Scolex: head with HOOKS
2. Gravid proglottids: contains eggs and uterus has less than 15 pairs of lateral branches
3. Cysticercus: round, fluid-filled bladder with the larval form within
4. Adult can grow to 2-8 meters

• Clinical Findings:
1. Intestinal infection is usually asymptomatic
2. Cysticercosis: eggs hatch within the small intestine, and larvae travel to muscle, the CNS and/or the eye, where they eventually form calcified cysts that are inflammatory
A. Blindness
B. Neurologic manifestations: seizures, focal neurologic deficits, hydrocephalus blockage of CSF drainage

• Diagnosis:

  1. Fecal exam for eggs or gravid proglottids
  2. CT scan or biopsy of brain or muscle may reveal calcified cysticerci
  3. Eosinophilia occurs with cysticercosis

• Miscellaneous:

  • Cysticerosis: occurs with ingestion of eggs
  • Neurocysticercosis (cysts in brain)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q 
PLATYHELMINTHES (FLAT WORMS): 
Taenia saginata (Beef tapeworm)
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
A

• Transmission:
- Ingest undercooked beef containing larvae stage

• Morphology:
1. Scolex: head with SUCKERS (but NO hooks)
2. Gravid proglottids:
contains eggs and uterus has more than 15 pairs of lateral branches
3. Can grow to 10 meters in length

• Clinical Findings:

  1. Usually asymptomatic
  2. Occasionally develop abdominal discomfort, weight loss and diarrhea

• Diagnosis:
- Fecal exam for eggs or gravid proglottids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q 
PLATYHELMINTHES (FLAT WORMS): 
Diphyllobothrium latum (Fish tapeworm)
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
A

• Transmission:
- Ingest larvae in raw freshwater fish

• Morphology:
- Can grow to 45 meters in length

• Clinical Findings:

  1. Nonspecific abdominal symptoms
  2. Vitamin B12 deficiency, leading to anemia

• Diagnosis:
- Identity eggs or gravid proglottids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q 
PLATYHELMINTHES (FLAT WORMS): 
Hymenolepsis nana (Dwarf tapeworm)
  • Transmission?
  • Morphology?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
Study These Flashcards
A

• Transmission:

  1. Ingest fertilized eggs
  2. AUTO-INFECTION

• Morphology:

  1. Adults grow to 15-50 mm
  2. Eggs are infectious

• Clinical Findings:

  1. Usually asymptomatic
  2. Occasional abdominal discomfort, nausea and vomiting

• Diagnosis:

  1. Fecal exam for eggs
  2. Proglottids are too small to see

• Miscellaneous:
- No intermediate host

17
Q

PLATYHELMINTHES (FLAT WORMS):

Echinococcus (Hydatid Disease)

  • Transmission?
  • Clinical Findings?
  • Diagnosis?
  • Miscellaneous?
Study These Flashcards
A

• Transmission:
- Ingestion of fertilized eggs

• Clinical Findings:
1. HYDATID CYSTS form most often in the liver and lung: The cysts enlarge over 1 to 20 years, producing symptoms by mass effect. These cysts can calcify
A. Liver: abdominal pain, palpable liver mass, biliary obstruction; can be fatal
B. Lung: Cyst may rupture, causing cough or chest pain
2. Leakage of hydatid cyst fluid can cause a severe allergic reaction

• Diagnosis:

  1. CT scan or ultrasound reveals cysts in the liver or lung
  2. Serology

• Miscellaneous:
1. Surgical removal of cysts: extreme caution is required, as leakage of cystic fluid can induce a severe anaphylactic reaction

  1. PAIR-Percutaneous Aspiration, Infusion of scolicidal agent, and Reaspiration
  2. Albendazole or mebendazole are used adjunctively

MOD Exam 3 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions