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Flashcards in Worms Deck (99)
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1
Q

What are three types of worms

A
  1. Nematodes (roundworms)
  2. Trematodes (flatworms)
  3. Cestodes (tapeworms)
2
Q

Where are nematodes found

A
  1. Intestines

2. Tissues

3
Q

Where are trematodes found

A
  1. Blood
  2. Liver
  3. Lung
  4. Intestinal
4
Q

Where are cestodes found

A
  1. Non invasive

2. Invasive

5
Q

Can adults worms reproduce outside the body

A

No, they require specific environmental conditions of the host

6
Q

What is the pre-patent period

A

Interval between infection and appearance of eggs in the stool

7
Q

Where are intestinal nematodes transmitted

A

From human to human via eggs or larvae

Faecal-oral spread

8
Q

Why is the egg or larva no infectious when first passed

A

Because it needs to undergo a period of development in the soil

9
Q

What is ascariasis

A

Infection of the intestines with nematodes

10
Q

How long is the ascaris lumbricoid

A

15-30 cm long

11
Q

How long does the ascaris lumbricoid live for

A

A year or more

12
Q

Pre-patent period of ascaris lumbricoid

A

60-75 days

13
Q

Sundrome is associated with larval migration through the lung

A

Loeffler’s syndrom e

14
Q

How long does it take for Loeffler’s syndrome to occur

A

10-14 days after infection commenced

15
Q

What is the effect of adult worm migration through the body

A

Asymptomatic

Leads to malnutrition

16
Q

How do diagnose for, infection

A

Stool microscopy for eggs

17
Q

How is worm infection treated

A

Piperazine, pyrantel
Levasimole
Mebendazole

18
Q

What does Hookworm cause

A

Ancyclostoma Duodenal

Nectar Americanus

19
Q

How does Hookworm enter the body

A

Through the soil if you’re barefooted

20
Q

Life-expectancy of hookworm

A

1-5 years

21
Q

Pre-patent period of the hookworm

A

40-100 days

22
Q

What is the most common reason for iron deficiency

A

Infection by hookworm

23
Q

Life cycle of the hookworm

A
  1. Filiform larvae penetrate exposed skin and migrate to the lungs
  2. Break out into alveoli are swallowed and develop into adults at the small intestines
  3. Adults attach to mucosa of duodenum and jejunum
  4. Females produce eggs that are passed into the soil with faeces and hatch within 24 hours
  5. Infectious filariform larvae develop after 5-10 days in moist soils
24
Q

Clinical features of hookworm

A
  1. Ground itch (At site of entry of larvae)
  2. Mild pulmonary symptoms due to migration
  3. Iron-deficiency
25
Q

How is Hookworm treated

A

Iron supplements (Pyrantel, mebendazole)

26
Q

PPP of Enterobius Vermicularis

A

40 days

27
Q

Lifespan of Enterbius

A

56 days

28
Q

Lifecycle of Enterobius

A
  1. Females emerge from anus at night
  2. Lays eggs around the anus and dies
  3. Eggs embryonate within 4-6 hours causing scratching and eggs under fingernails
  4. Formites contaminated with infective eggs
  5. Ingested eggs move to duodenum where they hatch
  6. Mature adults migrate to caecum
29
Q

Four clinical features of Enterobius

A
  1. Prunitis ani
  2. Appendicitis
  3. Vaginal penetration
  4. Paranasal sinuses
30
Q

Diagnosis of enterobius

A

Microscopy sellotape strip from perineal region

31
Q

Treatment of enterobius

A

Iron supplements

32
Q

PPP of whipworms

A

70-90 days

33
Q

How long are whipworms

A

2-5 cm long

34
Q

Life cycle of whipworms (Trichuris Trichuria)

A
  1. Eggs are ingested by a suitable host
  2. Immature larvae hatch from eggs when they arrive at small intestine
  3. Larvae pass into large intestines
  4. Larvae embedded in the mucosa via thin anterior ends, reach sexual maturity and mate
  5. Trichuris app are found in the caecum, ascending colon and throughout the colon
  6. Eggs passed into environment in host faeces
  7. Embryonation in moist soil takes 21 days
35
Q

Where is whipworm found

A

Large bowel

36
Q

`Clinical features of whipworms

A
Asymptomatic
Co-ecists with ascaris lumbricoides
Trichuriasis 
Bloody diarrhoea
Reactal prolapse
Anaemia
37
Q

What does Stronglyloides stercoarlis cause

A

Strongyloidiasis

38
Q

Length of Strongyloid

A

2mm

39
Q

PPP of strongyloid

A

17-28 days

40
Q

Life cycle of strongyloides stercoarlis

A
  1. Filariform larvae penetrate the host’s skin and migrate to lungs via blood
  2. Larvae break out into alveoli, crawl over glottis and swallowed
  3. Development in Jejunum
  4. Eggs laid after ingestion
  5. Small no. eggs laid be females whose head is burrowed in sub-mucosa of small intestines
  6. Eggs hatch immediately in intestines and rhabditiform larvae passed into faces
  7. Infectious filariform larvae develop in the intestines and penetrate tract or perianal skin.
41
Q

Clinical features of Strongyloides

A
  1. Pruritis at larval entry
  2. Larval migration into lungs
  3. Malabsorption with eosinophilia
  4. Skin rashes due to auto-infection
  5. Hyperinfection syndrome
42
Q

What type of worm is larva migrans caused by

A

Toxocara canis and T cati

43
Q

Life cycle of larva migrant

A

Eggs ingested and develop into larva

44
Q

Clinical features of larva migrant

A
  1. Children effected

2. Pyrexia, eosinophilia and hepatomegaly

45
Q

How do we diagnose larva mirgans

A

Serology

46
Q

How is larva migrant treated

A

Mebendazole

Albendazole

47
Q

What is Ocular Toxocariasis

A
  1. Larvae trapped in retina
  2. Granulomatous reaction takes place
  3. Causes blindness and increased retinal mass
48
Q

What condition can we accidentally diagnose a patient with ocular toxocariasis with

A

Retinoblastoma

49
Q

Diagnosis of ocular toxocariasis

A

Serology and antigen detection in aqueous humour

50
Q

What causes cutaneous larva migrant

A
  1. Dog hookworms and ancyclostoma canine
51
Q

Clinical feature so cutaneous larva migrant

A

Lesions at sites where larvae penetrate

52
Q

How is cutaneous larva migrant spread

A

Contact with dog faeces

53
Q

How is cutaneous larva migrant treated

A

Topical.systemic thiabendazole and topical cryotherapy

54
Q

Life cycle of anisakiasis

A
  1. Definitive host is infected when eating food
  2. Adult ascarides found in stomach
  3. Passed through host faeces
  4. Eaten by marine animals
  5. Migrates into tissues of fish, squid
55
Q

PPP of Dracunculus medinesnsis

A

1 year

56
Q

Length of Dracunculus

A

100 cm

57
Q

Life cycle of Dracunculus medinesnsis

A

Man swallows cyclops sp in contaminated water

  1. Infected larvae liberated digestive juices and penetrate the gut wall
  2. Larvae develop and occupy subcutaneous tissues
  3. After one year, female’s head approach skin where a blister forms
  4. Blister bursts and larvae leaves through discharge
58
Q

Clinical feature of Dracunculus

A
  1. Localised pain and urticaria at site where worm protrudes
  2. Tetanus
  3. Blisters
59
Q

Diagnosis of dracunculus

A

Drop of water on ulcer promotes egg release

60
Q

Treatment of Dracunculus

A
  1. Wind out worm

2. Mebendazole

61
Q

Why do we use mebendazole

A

Eases extraction

62
Q

How do we prevent further infection by dracunculus

A

Sieve of water

63
Q

What worm causes elephantiasis

A

Wuchereria Bancroftii

64
Q

How is Wuchereria Bancroftii diagnosed

A

Demonstration of microfilaria in blood taken between 11 and 1 am

Serology

65
Q

How is Wuchereria Bancroftii treated

A

DEC and Ivermectin

66
Q

What is Onchocerciasis

A

Hanging groin, river blindness

67
Q

Where are worms found in Loa Loa

A

Retina

68
Q

Life cycle of Trichina Spirals

A
  1. Larvae digested from muscle enter epithelial lining and becomes sexually mature
  2. Male and female worms in intestinal wall mate and produce larvae
  3. Newborn larvae pass through lymphatic system into the blood
  4. Larvae encyst ini striated muscle
  5. Infected meat is ingested by humans and carnivorous or omnivorous animals
69
Q

What causes Trichinosis

A

Trichiniella Spiralis

70
Q

Clinical features of Trichinella in muscles

A
  1. Asymptomatic
  2. GI disturbance as worms develop
  3. Fever, headache, cough at 8 weeks
  4. Periorbital oedema, haemorrhage
  5. Splinter haemorrhage
  6. Neurological signs (deafness)
  7. Myocarditis
  8. Pneumonitis
71
Q

What meat is Tania Saginatum found

A

Beef

72
Q

Length of Tania Saginatum

A

5-10 metres

73
Q

Lifespan of tania saginatum

A

30 years

74
Q

PPP of tania saginatum

A

12 weeks

75
Q

Life cycle of Tania Saginatum

A

Caught by eating undercooked beef containing cysts

76
Q

Clinical features of tania saginatum

A

Asymptomatic

Proglottids may emerge from human anus

77
Q

Diagnosis of tania saginatum

A

Stools of eggs and proglottids

78
Q

Treatment of taenia saginatum

A

Niclosamide

Praziquantel

79
Q

Life cycle of Taenia Solium

A
  1. Solex attaches to intetsine
  2. Adult tapeworm
  3. Gravid proglottid in faeces or environment
  4. Onchosphere hatches and penetrates intestine wall
  5. Cystercus in lungs, brain, eye or connective tissue
80
Q

What worm causes neurocysticercosis

A

Pork tapeworm

81
Q

What tapeworm causes HYDATID DISEASE

A

Echinococcua Granulosus - DOG

82
Q

What is caused by Echinococcus Multilocularis

A

Alveococcosis

83
Q

How can we get Diphyllobothrium latum

A

Fish

84
Q

What is sparganosis

A

An infection caused by Diphyllobothrium Latum

85
Q

What is the intermediate host used by flukes to spread

A

Snail

86
Q

Where are flukes found

A

Blood
Liver
Lung
Bowel

87
Q

Name an adult fluke

A

Schistosoma

88
Q

Normal life span of a fluke

A

3-5 years

89
Q

How long is an adult fluke

A

12 cm

90
Q

What does Schistosoma infection cause

A

Katayama fever

91
Q

What is Katayama fever

A

An initial immune-complex mediated illness 2-4 weeks after exposure

92
Q

What proportion of patients infected with Schistosomia have Katayama fever

A

50%

93
Q

Why is Katayama physiologically caused

A

T-cell mediated immune response to egg surfaces leads to cytokine release

IL-12 can suppress egg-induce pathology (mediated by INF-gamma)

Granuloma development

Fibrosis if egg laying continues

94
Q

Where do adult S haematobium reside

A

Liver

95
Q

Where do S haematobium egg migrate to

A

Bladder

96
Q

What damage can S haematobium do in the bladder

A
  1. Pseudopapillomata (granulomatous lesions)
  2. Obstructive uropathy (reversible if short duration and treated)
  3. Calcified bladder
  4. Squamous cell bladder cancer
  5. Kidney stones
97
Q

Clinical features of S mansoni

A
  1. Asymptomatic
  2. Iron deficiency
  3. Hepatosplenomegaly
  4. Pseudopolyposis
  5. Fibrosis of liver
  6. Portal vein hypertension
98
Q

How is Schistosomia caused

A
  1. Serology
  2. Urine (time-consuming)
  3. Stool (67% positive)
  4. Rectal Biopsy
  5. Ultrasound
99
Q

How is Schistosomia-caused infection treated

A
  1. Praziquantel
  2. Isoquinoline
  3. Metriphonate
  4. Oxamniquine

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