Blood and Tissue Nematodes Flashcards
(70 cards)
1
Q
General characteristics of blood and tissue nematodes
A
- Not common in U.S.
- Man is often an accidental or intermediate host
- Often from eating undercooked beef, fish, pork, etc.
- Some serologic tests for diagnosis, but lack specificity
2
Q
Common name for Trichinella spp
A
None
3
Q
Common name for Dracunculus medinensis
A
Guinea worm
4
Q
Common name for Baylisascaris procyonis
A
None
5
Q
Common name for Wuchereria bancrofti
A
None
6
Q
Common name for Brugia malayi
A
None
7
Q
Common name for Loa loa
A
African eyeworm
8
Q
Common name for Onchocerca vulvulus
A
None
9
Q
Common name for Dirofilaria immitis
A
Dog heartworm
10
Q
Common name for Pediculus humanus
A
Body louse
11
Q
Common name for Pediculus capitus
A
Head louse
12
Q
Common name for phthiris pubis
A
Pubic louse (“crabs”)
13
Q
Usually caused by ingestion of raw/undercooked pork, bear, and other meat
A
Trichinella spp
14
Q
Usually caused by ingestion of copepods containing larvae from “step down” wells
A
Dracunculus medinensis
15
Q
Usually caused by exposure to infected raccoons
A
Baylisascaris procyonis
16
Q
Usually infected by a mosquito vector (Culex)
A
Wuchereria bancrofti
17
Q
Usually infected by mosquito vector (Anopheles, Aedes)
A
Brugia malayi
18
Q
Usually infected by fly vector (Chrysops spp)
A
Loa loa
19
Q
Usually infected by blackfly or buffalo fly (Simulium)
A
Onchocerca vulvulus
20
Q
Usually infected by midges (small 2-winged fly) or blackfly
A
Mansonella spp
21
Q
Usually infected by mosquito vector
A
Dirofilaria immitis
22
Q
Trichinella spp
- Diagnostic form
- Infective form
A
- Diagnostic: larvae ingested in infected meat
- Infective: encapsulate in striated muscle (active muscles, eye, diaphragm)
23
Q
Dracunculus medinensis
- Diagnostic form
- Infective form
A
- Diagnostic: copepods containing larvae
- Infective: adults
24
Q
Wuchereria bancrofti
- Diagnostic and infective form
A
Microfilariae in blood
25
Brugia malayi
| - Diagnostic and infective form
Microfilariae in blood
26
Loa loa
| - Diagnostic and infective form
Microfilariae in blood
27
Onchocerca vulvulus
| - Diagnostic and infective form
Microfilariae in blood
28
Mansonella spp
| - Diagnostic and infective form
Microfilariae in blood
29
Dirofilaria immitis
| - Diagnostic and infective form
Microfilariae in blood
30
Clinical manifestations of Trichinella spp
Triad of symptoms
- Periorbital edema
- Muscle pain and tenderness
- Eosinophlia 20-90%
31
Clinical manifestations of Baylisascaris procyonis
- Rapid neurological deterioration
- Blood and CSF eosinophilia
- NOT FOUND IN STOOL
- Potential biological warfare agent!!!
32
Clinical manifestations of Wuchereria bancrofti
- Chronic infections lead to elephantiasis (obstruction of lymphatics, fibrosis)
- May also involve kidneys
33
Clinical manifestations of Brugia malayi
More distal extremity involvement (below knee, below elbow)
34
Clinical manifestations of Loa loa
- Subcutaneous, painful Calabar swellings (appear and reappear in different areas)
- Adults can often be seen migrating across surface of eye
- May have neurologic complications
35
Clinical manifestations of Onchocerca vulvulus
- Adults encapsulated in fibrous tumors in subcutaneous tissues (trunk, extremities, scalp)
- Wrinkling, thickening of skin ("lizard skin")
- Nodules can measure up to 25mm (size of quarter) on most parts of body
- Blindness occurs when microfilariae collect in cornea or iris
36
Clinical manifestations of Marsonella spp
- Rash
- Slight fever
- non-serious infection
37
Clinical manifestations of Dirofilariae immitis
- Adults live in chambers of dog's heart (infarction)
- Adults can lodge in pulmonary arteries (coin lesions) but don't reach maturity in humans
- No microfilariae in humans
38
Diagnosis of Trichinella spp
- Muscle biopsy (encysted larvae) → squash prep (spiral form), cross-sectioned mounts
39
Diagnosis of Dracunculus medinensis
Blister-like papule on arm/leg
40
Diagnosis of Baylisascaris procyonis
- Morphologic identification of larvae in tissue sections in autopsy
- Radiology (white matter disease)
41
Diagnosis of Wuchereria bancrofiti
Depending upon regions of world, infections either nocturnal or subperiodic (day)
42
Diagnosis of Brugia malayi
Examine blood at blood at night for microfilariae (thick or thin smear)
43
Diagnosis of Loa loa
Examine blood during the day for microfilariae (thick or thin smear)
44
Diagnosis of Onchocerca vulvulus
Skin snip → cross section of adult worms and microfilariae
45
Diagnosis of Dirofilaria immitis
Examine coin lesion from surgery/biopsy
46
Treatment and preventation of Dracunculus medinensis
Treatment
- Winding worm around stick
- Secondary infection is common if breakage of worm occurs
Prevention
- Filtration of water to remove copepods (gauze, t-shirts, filters, etc.)
- Covering water source (from copepods and infected people)
47
These microfilariae are sheathed, no nuclei at tip or cephalic space
Wuchereria bancrofti
48
- These microfilariae are sheathed, space b/w last two nuclei at tip of tail and cephalic space
- Sheath stains pink on Giemsa stained blood smear
Brugia malayi
49
These microfilariae are sheathed, nuclei are continuous to tip of tail
Loa loa
50
These microfilariae are non-sheathed and have no nuclei in tip of tail
Onchocerca vulvulus
51
These microfilariae have no sheath
Mansonella spp
52
Is stool the best specimen choice for identifying blood and tissue nematodes?
NO!!!!
53
Largest adult Nematode
Dracunculus medinensis
54
Life cycle of Trichinella spp
Larvae ingested in infected meat → intestine → mature adults which produce live-born larvae → penetrate intestinal wall → circulate to all areas of the body → encapsulate in striated muscle
55
Life cycle of Dracunculus medinensis
Humans ingest copepods containing larvae → larvae released in intestines → larvae burrow through intestinal wall to connective tissue → larvae mature to adult → female migrates to surface of arm/leg to release larvae into water → larvae ingested by copepods
56
Adults living in various lymphatic or other tissues
Filariae
57
Microfilariae (larvae) are released in ____
Blood
58
Life cycle of Wuchereria bancrofti
- Adults live in lymphatics (esp. lower extremities) → obstruction of lymphatics
- Female worms release microfilariae into blood that are ingested by mosquito where parasite completes its life cycle
59
Life cycle of Brugia malayi
- Adults live in lymphatics (esp. lower extremities) → obstruction of lymphatics
- Female worms release microfilariae into blood that are ingested by mosquito where parasite completes its life cycle
60
Life cycle of Loa loa
Adults migrate through subcutaneous tissue (calabar swellings and migration across eye)
61
Flattened dorsoventrally
Lice
62
This insect has 3 pairs of clawed legs attached to the thorax and large hind legs for jumping, and transmit bacterial infections
Fleas
63
This arachnida has a chitenous shield, mouth part attachedt o fused globular body, has no head or attennae, 4 pairs of legs in adults, transmits diseases (RMSF, Lyme, Babesiosis)
Ticks
64
This arachnida has no chitenous shield, 8 short legs, burrows into the skin and lays eggs, causes scabies (endemic in U.S.)
Mites
65
Types of Arachnida
- Ticks
- Mites
- Spiders
- Scorpions
66
Clinical disease caused by Trichinella spp
Trichinosis
67
Clinical disease caused by Wuchereria bancrofti
Bancroftian filariasis or elephantiasis
68
Clinical disease caused by Brugia malayi
Brugian filariasis or elephantiasis
69
Clinical disease caused by Loa loa
Calabar swellings appear and reappear in different areas
70
Clinical disease caused by Onchocerca vulvulus
Onchocercosis ("River blindness")
