Parasitology-3 Flashcards

1
Q

What symptoms does Enterobius vermicularis cause?

A

Anal pruritus, which is worse at night.

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

How is Enterobius vermicularis diagnosed?

A

Using the tape test to visualize eggs.

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

What are the treatments for Enterobius vermicularis?

A

Bendazoles or pyrantel pamoate

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

What are the main clinical effects of Ascaris lumbricoides infection?

A

Intestinal obstruction at the ileocecal valve
Biliary obstruction, intestinal perforation
Migration to the lungs causing Löeffler syndrome (pulmonary eosinophilia)

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

What is the treatment for Ascaris lumbricoides?

A

Albendazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What symptoms does Strongyloides stercoralis cause?

A

GI symptoms (duodenitis)
Pulmonary symptoms (dry cough, hemoptysis)
Cutaneous symptoms (pruritus)
Can cause hyperinfection syndrome in immunocompromised patients

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

How is Strongyloides stercoralis transmitted?

A

Larvae in soil penetrate the skin; rhabditiform larvae seen in feces under a microscope.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the treatment for Strongyloides stercoralis?

A

Ivermectin or Albendazoles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What symptoms do Ancylostoma spp. and Necator americanus cause?

A

Microcytic anemia due to blood loss from intestinal wall attachment
Cutaneous larva migrans (serpiginous, pruritic rash)

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

How are hookworms transmitted?

A

Larvae penetrate the skin from walking barefoot on contaminated soil or beaches.

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

What are the treatments for hookworm infections?

A

Bendazoles or pyrantel pamoate.

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

What disease does Trichinella spiralis cause?

A

Trichinosis, which includes:

Fever, vomiting, nausea
Periorbital edema
Myalgia (larvae encyst in striated muscle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is Trichinella spiralis transmitted?

A

Ingestion of undercooked pork (most common) or fecal-oral (less likely).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the treatment for Trichinella spiralis?

A

Bendazoles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is Trichuris trichiura transmitted?

A

Fecal-oral route.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the treatment for Trichuris trichiura?

A

Albendazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What disease does Toxocara canis cause?

A

Visceral larva migrans, which can cause:

Inflammation in the liver, eyes (visual impairment), CNS (seizures, coma), and heart (myocarditis)
Many patients remain asymptomatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is Toxocara canis transmitted?

A

Feco oral route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the treatment for Toxocara canis?

A

Albendazoles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What disease does Onchocerca volvulus cause?

A

River blindness (black skin nodules, “black sight”).

21
Q

How is Onchocerca volvulus transmitted?

A

Female black fly bite.

22
Q

What is the treatment for Onchocerca volvulus?

A

Ivermectin (for ‘river blindness’)

23
Q

What disease does Clonorchis sinensis cause?

A

Biliary tract inflammation → pigmented gallstones; associated with cholangiocarcinoma.

24
Q

How is Clonorchis sinensis transmitted?

A

Ingestion of metacercariae (larvae) in undercooked or raw freshwater fish.

25
Q

What is the treatment for Clonorchis sinensis?

A

Praziquantel.

26
Q

What is the common name for Clonorchis sinensis?

A

Chinese Liver fluke

27
Q

What is the life cycle of Clonorchis sinensis?

A

Eggs (from infected human feces) enter freshwater.
Eggs are ingested by snails (first intermediate host) and develop into larvae.
Larvae are released into water and infect freshwater fish (second intermediate host).
Humans ingest infected fish → larvae mature in biliary ducts.

28
Q

How is Clonorchis sinensis diagnosed?

A

Detection of operculated eggs in stool (stool microscopy).

29
Q

What diseases does Schistosoma cause?

A

Schistosoma mansoni & japonicum: Liver/spleen enlargement, fibrosis, inflammation, portal hypertension

Schistosoma haematobium: Squamous cell carcinoma of the bladder (painless hematuria), pulmonary hypertension

30
Q

How is Schistosoma treated?

A

Praziquantel

31
Q

What type of parasite is Schistosoma?

A

A trematode (fluke) that infects blood vessels.

32
Q

What are the three major Schistosoma species affecting humans?

A

Schistosoma mansoni (intestinal & hepatosplenic schistosomiasis)
Schistosoma japonicum (intestinal & hepatosplenic schistosomiasis)
Schistosoma haematobium (urinary schistosomiasis)

33
Q

What is the intermediate host for Schistosoma?

A

Freshwater snails (release infectious cercariae).

34
Q

How is Schistosoma transmitted?

A

Direct skin penetration by cercariae in contaminated freshwater.

35
Q

What disease does Schistosoma mansoni & japonicum cause?

A

Intestinal & hepatosplenic schistosomiasis →

Chronic diarrhea & abdominal pain
Liver fibrosis, hepatosplenomegaly, portal hypertension
Esophageal varices → Risk of variceal bleeding

36
Q

What are the characteristic egg features?

A

S. mansoni: Large lateral spine
S. japonicum: Small lateral spine

37
Q

How does Schistosoma cause portal hypertension?

A

Eggs get trapped in periportal veins, triggering granuloma formation and fibrosis.

38
Q

What disease does Schistosoma haematobium cause?

A

Urinary schistosomiasis, presenting as:

Painless hematuria
Dysuria & bladder wall inflammation
Fibrosis & calcification of the bladder → Hydronephrosis
Increased risk of squamous cell carcinoma of the bladder

39
Q

What is the characteristic feature of S. haematobium eggs?

A

Terminal spine on eggs (seen in urine microscopy).

40
Q

How is Schistosoma diagnosed?

A

Stool (S. mansoni, S. japonicum) or urine (S. haematobium) microscopy → Detects eggs
Serology (ELISA, PCR) for chronic cases
Ultrasound, CT, MRI for liver fibrosis or urinary tract damage

41
Q

What is the treatment for Schistosomiasis?

A

Praziquantel (drug of choice for all species).

42
Q

What is the major difference between Schistosoma and other trematodes?

A

Unlike most trematodes, Schistosoma is dioecious (has separate male & female worms).

43
Q

What is the life cycle of Schistosoma?

A

Eggs are excreted in urine (S. haematobium) or feces (S. mansoni & S. japonicum).
Eggs hatch into miracidia in freshwater and infect snails.
Inside snails, miracidia develop into cercariae, which are released into water.
Cercariae penetrate human skin and enter the bloodstream.
They migrate to their target veins and mature into adult worms.

44
Q

What is the main site of infection for S. mansoni?

A

Mesenteric veins of the intestines & liver.

45
Q

How is S. japonicum different from S. mansoni?

A

More severe liver disease (due to high egg burden).
Eggs are round with a small lateral spine.
Higher chance of brain involvement → seizures, encephalopathy.

46
Q

What is the main site of infection for S. haematobium?

A

Venous plexus of the bladder.

47
Q

What type of hypersensitivity reaction is seen in schistosomiasis?

A

Type IV (delayed-type hypersensitivity) due to chronic granuloma formation.

48
Q

What is “Katayama fever”?

A

Acute schistosomiasis (hypersensitivity reaction to eggs 3-8 weeks post-infection), causing:

Fever, cough, rash, eosinophilia, hepatosplenomegaly.
Seen in travelers returning from endemic areas.

49
Q

What is the gold standard for diagnosing Schistosoma infection?

A

Microscopy of stool or urine for eggs.