Trichuriasis + Amoebiasis + Ancylostomiasis

Question 1

Trichuria in Humans, Non-human primates –

Answer 1

T. trichuria

Question 2

Trichuria in Domestic and wild Canids

Answer 2

T. vulpis

Question 3

Trichuria in Domestic pigs and boars

Answer 3

T. suis

Question 4

Trichuriasis is caused by which parasites?

Answer 4

Various species of Trichuris (WHIPWORMS)

Question 5

Trichuris spp. have a direct life cycle and mature in a single host. True or false?

Answer 5

True

Question 6

Disinfection for Trichuris spp

Answer 6

Dehydration
Sunlight
Temperature ˂ -9oC or ˃ 52oC
2% glutaraldehyde
1% sodium hypochlorite

Question 7

Trichuriasis is often ssymptomatic in humans. True or false?

Answer 7

False. Asymptomatic.

Question 8

Symptoms of heavy Trichuriasis infection

Answer 8

Chronic diarrhoea which may be bloody
 Abdominal pain and distension
 Nausea
 Vomiting
 Flatulence
 Headache
 Weight loss

 Malnutrition
 Anaemia
 Nervousness, anorexia, urticaria – reported in some individuals.
 Untreated severe infections can lead to clubbing of the fingers in
children.
 Complications may include rectal prolapse, especially in children,
appendicitis, colitis and proctitis

Question 9

Diagnosis of trichuriasis

Answer 9

Laboratory examination of stool smear for ova and parasites. Eggs are oval, yellowish-brown and thick-shelled with 2 polar plugs.

Question 10

Treatment of trichuriasis

Answer 10

• Drug of choice for children is mebendazole.
• Albendazole is an alternative drug but its efficacy is slightly lower than
  that of mebendazole.
• Oxantel pamoate can also be used.

Question 11

Amoebiasis is caused by

Answer 11

Entamoeba histolytica

Question 12

Which Entamoeba specie is a commensal?

Answer 12

Entamoeba dispar is a harmless commensal.

Question 13

Other Entamoeba species infecting humans are

Answer 13

E. moshkovskii
E. hartmannii
E. gingivalis
Endolimax nana
Iodamoeba butschlii.

Question 14

90% of amoebiasis infections are asymptomatic. True or false?

Answer 14

True

Question 15

How is amoebiasis spread?

Answer 15

Spread is mostly through faecal-oral route, by ingestion of cysts and also through contaminated vegetables fertilized by faeces and foods and water handled by unclean hands.

Question 16

Clinical manifestations of amoebiasis

Answer 16

Abdominal discomfort, bloating, irregular bowel habits, intermittent dysentery with or without blood/mucous, tenesmus with bloody mucoid diarrhoea, abdominal tenderness, toxic megacolon and symptoms and signs of peritonitis secondary to
perforation.

Question 17

Extraintestinal manifestations of amoebiasis

Answer 17

Fever, pain in right lower chest, appetite
disturbances, breathlessness, cough with or without expectoration and breathlessness, occasionally mild jaundice, rarely convulsions.

Question 18

Amoebiasis diagnosis

Answer 18

• Fresh liquid stool examination showing hematophagus trophozoites with Charcot-Leyden crystals
• Sigmoidoscopic scrapings of ulcers
• Indirect hemagglutination assay (IHA) and
  ELISA are diagnostic.
• PCR

Question 19

Presence of only cysts in asymptomatic amoebiasis individuals is not
diagnostic. Why?

Answer 19

Cysts of E. dispar (non-invasive and harmless)
are indistinguishable from those of invasive E. histolytica.

Question 20

What is the WHO-recommended therapy for amoebiasis?

Answer 20

Combination therapy with luminal and tissue amoebicides

Question 21

Examples of tissue amoebicides

Answer 21

MC TOSN treats tissue amoebiasis

Metronidazole
Tinidazole
Ornidazole
Secnidazole
Nitazoxanide
Chloroquine

Question 22

Examples of luminal amoebicides

Answer 22

DIPQ are luminal amoebiasis

Diloxanide Furoate
Quinodochlor
Iodochlorhydroxyquine
Paromomycin

Question 23

Why are luminal amoebicides recommended?

Answer 23

To prevent relapses following the course of
tissue amoebicides

Question 24

Drugs used to treat ascariasis

Answer 24

Mebendazole
Pyrantel pamoate
Piperazine citrate
Levamisole
Albendazole.

Question 25

Who is the source of ascariasis?

Answer 25

Humans

Question 26

How do humans get eggs in Ancylostomiasis

Answer 26

Humans come in contact with plants, larvae
penetrate unbroken skin, larvae migrate in blood stream to heart and lung, migrate up trachea and swallowed, adults mature and mate in small intestine, and eggs passed in
faeces.

Question 27

Clinical manifestations of Ancylostomiasis

Answer 27

Hypochromic microcytic anaemia
of iron deficiency
Maculopapular rash and pruritus at site
of penetration
Cough
Rales
Eosinophilia
Epigastric pain
Nausea, vomiting and diarrhoea.

Question 28

Ancylostomiasis treatment

Answer 28

Mebendazole
Pyrantel pamoate
Bephenium
Hydroxynaphthoate
Tetraclorethylene
Albendazole.

Question 29

What are the virulence factors for entamoeba?

Answer 29

Adhesion molecules
Proteases
Haemolysins
Contact-dependent cytolysis
Phagocytic activity

Question 30

Amoebiasis complications

Answer 30

Secondary to severe toxaemia, perforation of the bowel
Toxic megacolon
Rupture of the hepatic abscess into pleura, lung, peritoneum, pericardium, skin and
subcutaneous tissue.

Question 31

Asymptomatic amoebiaisis cyst carriers should always be treated. True or false?

Answer 31

False. They should not be.

Question 32

Source of ancylostoma and necator

Answer 32

Humans, cats

Question 33

Explain the development of Ancylostoma

Answer 33

• Eggs passed into faecal material, develop in the environment
• Larvae gets into plants and molt, humans come in contact with plants
• Larvae penetrate unbroken skin, larvae migrate in blood stream to heart and lung, migrate up trachea and swallowed
• Adults mature and mate in small intestine, and eggs passed in faeces.