Parasites Flashcards
1
Q
Hookworm Basics
A
Type: GI nematode
Where: worldwide, warm humid soil
Reservoir: human
Second most common helminth
2
Q
Hookworm Lifecycle
A
- Filariform larvae penetrate skin and travel through blood
- To lungs, up trachea, coughed and swallowed
- In GI tract, mature and reproduce
- Eggs released in feces
3
Q
Hookworm Infection
A
Allergic reaction at entry
Pneumonitis
GI symtoms
Anemia
4
Q
Hookworm Laboratory
A
Non bile stained segmented eggs
5
Q
Ascaris Lumbricoides Basics
A
Type: GI nematode, roundworm
Where: warm countries, poor sanitation
Reservoir: human
Risk: children
Third most common helminth
6
Q
Ascaris Lumbricoides Lifecycle
A
- Egg ingested, hatches, pierce intesinal wall
- Travel through lungs, trachea, coughed and swallowed
- In GI tract, mature and reproduce
- Eggs released in feces
7
Q
Ascaris Lumbricoides Infection
A
Pneumonitis
Liver, gallbladder, bile duct dissemination
Childhood malnutrition, stunted physical and mental growth
8
Q
Ascaris Lumbricoides Laboratory
A
Knobby coated, bile stained egg
Visible adult worm can pass in stool
9
Q
Enterobius Vermicularis Basics
A
Type: GI nematode pinworm
Where: worldwide, temperate climates
Reservoir: human
Most common helminth
10
Q
Enterobius Vermicularis Lifecycle
A
- Egg ingested, hatch and mature in intestine
- Female lays egg around anus at night
11
Q
Enterobius Vermicularis Infection
A
Itching, secondary bacterial infection, allergic reaction
12
Q
Enterobius Vermicularis Laboratory
A
Anal sticky swab, eggs and worm in microscope view
Treat whole family, clean whole house
13
Q
Strongyloides Stercoralis Basics
A
Type: GI nematode threadworm
Where: warm areas, sub/tropics, Brazil, Thailand
Reservoir: human but some dog and primates
14
Q
Strongyloides Stercoralis Lifecycle
A
- Filariform larvae penetrate skin, travel to intestines, mature and reproduce in GI tract
- Eggs hatch, rhabditiform larvae pass in stool or stay inside and cause autoinfection
15
Q
Strongyloides Stercoralis Infection
And diagnostics
A
Pneumonitis from autoinfection
Can carry enteric bacteria
Hyperinfection in immunocompromised
Heavy load causes inflammation, ulceration
Diagnostic: dult larvae in stool, eggs not usually seen
16
Q
Tirchuris Trichuria Basics
A
Type: GI nematode whipworm
Where: tropical, poor sanitation, heavy rainfall
Reservoir: human
17
Q
Trichuris Trichuria Lifecycle
A
- Eggs ingested, hatch in intestines, mature
- Reproduce and shed eggs
- Eggs released in stool
18
Q
Trichuris Trichuria Infection
And diagnostics
A
High burden: pain, bloody diarrhea, weight loss, prolapse rectum in children
Dianostic: bile stained egg with polar plug
19
Q
Dibothriocephalus Latus Basics
A
Type: GI cestode fish tapeworm
Where: cool lake regions, temperate
Reservoir: animals
Consumption of raw or undercooked fish
20
Q
Dibothriocephalus Latus Lifecycle
A
- Eggs become coracidia, ingested by crustacean, then turn into larvae, crustacean ingested by fish
- Larvae in fish tissue ingested by human
- Mature in GI tract, reproduce
- Eggs shed in stool
21
Q
Dibothrocephalus Latus Infection
And diagnostics
A
Pain, nausea, vomiting, weight loss, low B12
Diagnostics: operculated egg with knob at bottom, proglottid with rosette uterine structure
22
Q
Dipylidium Canium Basics
A
Type: GI cestode
Where: worldwide
Reservoir: cats and dogs
23
Q
Dipylidium Canium Lifecycle
A
- Flea consumes egg packet, oncosphere releases cysticercoid into flea intestine
- Cysticercoid flea consumed by human/animal, matures into adult
- Proglottids are shed in stool and release egg packets
24
Q
Dipylidium Canium Infection
And diagnostics
A
Discomfort, diarrhea, self limiting usually
Diagnostic: egg packets, proglottids in stool
25
Hymenolepis Nana Basics
Type: GI cestode dwarf tapeworm
Where: worldwide, poor sanitation, SE USA, institutions
Reservoir: rodents
| Most common cestode
26
Hymenolepis Nana Lifecycle
| Intermediate host is beetle or flea
1. Egg consumed from contaminated stuff
2. Cysticercoid larvae in intestines mature, reproduce
3. Eggs released in stool
27
Hymenolepis Nana Infection
| And diagnostics
**Autoinfection** possible
Heavy burden: diarrhea, pain, itching, anorexia
Diagnostic: six-hooked embryo and polar filaments
28
Taenia Basics
Type: GI cestode, solium or saginata
Where: C. Asia, E + C Africa
Reservoirs: solium - pig, saginata - cow
29
Taenia Lifecycle
1. Cysticercoid larvae in meat consumed
2. Larvae mature in intestines, reproduce
3. Eggs released in environment
4. Eggs eaten by intermediate host
30
Taenia Infection
| And diagnostics
**Autoinfection** possible
T. solium: can cause cysticercosis, neurocysticercosis - common in Mexico
Diagnostics: solium - 7-15 branches, crown of hooks, saginata - 15-30 branches, no hooks
31
Intestinal Trematodes General
| Where, infection, diagnostic
Where: wherever the snail range is
Heavy infection: discomfort, diarrhea, bowel obstruction, ulcers, weight loss
Diagnostic: eggs/adult fluke in stool or vomit
32
Intestinal Trematode Lifecycle
1. **Metacercariae** in secondary intermediate host (fish, insect, crab, oyster) ingested, excyst and attach to intestine
2. Mature and reproduce, eggs passed in stool
3. Eggs release **miracidia** that infect snails
4. Cercariae released from snail and encyst as metacercariae in secondary intermediate host
33
Entamoeba Histolytica Basics
| + risks
Type: GI protozoan amoeba
Where: C+S America, Africa, Asia, sub/tropics, freshwater
Reservoir: human and animal
Risks: immigrants, HIV positive, tourists, fecally contaminated water/food
34
Entamoeba Histolytica Lifecycle
1. Cysts consumed, excyst in GI tract
2. Trophs remain or invade mucosa/blood vessels, trophs multiply and produce more cysts
3. Cysts and trophs are both passed in stool
35
Entamoeba Histolyica Infection
| and diagnostics
Mild amebiasis: loose stool, pain
Severe: amebic dysentery, bloody stools
Disseminated: rare but invades liver, lungs or brain
Diagnostics: trophozoites with ingested RBCs or cysts in stool, immunodiagnosis, molecular analysis
36
Giardia Lamblia Basics
Type: GI protozoan, flagellate
Where: worldwide, most common in US, northern states, raw water supply, some filtered water too
Reservoir: animal
37
Giardia Lamblia Lifecycle
1. Ingest cysts in contaminated food/water, excyst and trophs released
2. Trophs multiply and produce cysts, both passed in stool
38
Giardia Lamblia Infection
| and diagnostics
Diarrhea, malabsorption, weight loss, **smelly farts af,** greasy stool, lactose intolerance after infection
Diagnostic: **intermittent shedding showers**, cysts and trophs in stool
39
Cystoisospora Belli Basics
Type: GI protozoan coccidian
Where: worldwide, sub/tropics, daycares and institutions
Reservoir: humans
40
Cystoisospora Belli Lifecycle
1. Ingest **sporocyst-containing oocyst** in contaminated stuff
2. Sporocysts excyst and release **sporozoites**, invade epithelial cell, sexual and asexual reproduction
3. Oocysts released in stool
41
Cystoisospora Belli Infection
| and diagnostic
More common in immunocompromised, AIDS, GI disease and dehydration
Diagnostic: microscopy of oocysts
42
Cryptosporidium Basics
Type: GI protozoan, coccidian
Where: worldwide, developing countries, children
Reservoirs: human and animal
43
Cryptosporidium Lifecycle
1. Ingest **sporocyst-containing oocyst** in contaminated stuff
2. Sporocysts excyst and release **sporozoites**, invade epithelial cell, sexual and asexual reproduction
3. Oocysts released in stool
44
Cryptosporidium Infection
| and diagnostics
Acute, watery diarrhea, pain, mild fever, nausea
**50+ stools per day**, heavy fluid loss
Gallbladder infection
Diagnostics: microscopy of oocysts in stool, molecular, immunodiagnosis
45
Cyclospora Cayetanensis Basics
| and risks
Type: GI protozoan, coccidian
Where: worldwide, Mexico, Peru
Reservoir: human
Risks: **raspberries, unwashed veggies**
46
Cyclospora Cayetanensis Lifecycle
1. Ingest **sporocyst-containing oocyst ** in contaminated stuff
2. Sporocysts excyst and release **sporozoites**, invade epithelial cell, sexual and asexual reproduction
3. Oocysts released in stool
47
Cyclospora Cayetanensis Infection
| and diagnostics
Nausea, watery diarrhea lasting 6-7 weeks, immunocompromised diarrhea may last for months
Diagnostic: oocysts in stool
48
Dientamoeba Fragilis Basics
Type: GI protozoan, flagellate (no flagella though lol)
Where: worldwide, crowded places, children
Reservoir: human
49
Dientamoeba Fragilis Lifecycle
1. Trophs ingested in contaminated stuff (possible helminth eggs)
2. Multiply in intestines and tophs released in stool
50
Dientamoeba Fragilis Infection
| and diagnostics
Abdominal discomfort, diarrhea, weight loss, 1-2 weeks
Diagnostics: trophs in stool
51
Blastocystis Basics
Type: GI protozoan, SAR
Where: worldwide
Reservoir: human, farm animals, birds, rodents, fish, cockroaches
52
Blastocystis Lifecycle
1. Ingest cyst from contaminated stuff
2. Replicate in GI tract
3. Cyst and **vacuolar forms** shed in stool
53
Blastocystis Infection
| and diagnostic
Water diarrhea, pain, itching, weight loss, excessive gas
Diagnostic: cysts in stool
54
Wuchereria Bancrofti and Brugia Malayi Basics
Type: blood helminth, filarial worm
Where: India, Africa, Asia
Vector: mosquito
TIme: **night**
55
Wuchereria Bancrofti and Brugia Malayi Lifecycle
1. Mosquito transfers filarial larvae, reside in lymphatics, develops microfilariae
2. Microfilariae migrate to blood at night or lymph (Wuchereria only)
56
Wuchereria Bancrofti and Brugia Malayi Infection
| and diagnostic
Lymphatic filariasis
**Lymphedema/elephantiasis:** fluid collection, swelling in limbs, secondary bacterial infections
**Pulmonary eosinophilia syndrome**
Diagnostic: microfilariae in blood at night, antigen detection any time of day
57
Onchocerca Volvulus Basics
Type: blood helminth, filarial worm
Where: Africa, C+S. America
Vector: blackfly
Time: any time
58
Onchocerca Volvulus Lifecycle
1. Blackfly transfers larvae, develop in nodules in subcutaneous tissue
2. Microfilariae produced, found in skin or lymph
59
Onchocerca Volvulus Infection
| and diagnostics
**River blindness:** second leading infectious cause of blindness in the world
Skin rash - caused by allergic reaction as microfilariae migrate through tissues
Diagnostic: microfilariae in skin snip, biospy, molecular methods
60
Loa Loa Basics
Type: blood helminth, filarial worm
Where: rainforests in Africa, Congo, West Africa
Vector: deerfly
Time: daytime
61
Loa Loa Lifecycle
1. Deerfly transmits larvae, larvae live in tissue up to 17 yrs
2. Microfilariae produced, found in lymphs and lungs
3. Migrate to blood during day
62
Loa Loa Infection
| and diagnostics
Calabar swellings: from allergic reaction to worm, on extremities
Eye worm: visible movement under eye or skin
Diagnostic: calabar swellings, worms in eye or skin, microfilariae in blood
63
Trichinella Spiralis Basics
Type: blood helminth
Where: worldwide, meat eaters, wild game, hunters
Reservoir: animals
64
Trichinella Spiralis Lifecycle
1. Encysted larvae consumed from undercooked meat, released into intestine after contact with gastric acid
2. Mature and reproduce, larvae migrate into muscles
3. Larvae encyst and produce microfilariae, found in lymphs and lungs
65
Trichinella Spiralis Infection
| and diagnostics
Diarrhea, pain, vomiting
Fever, blurred vision
Neurological, heart, breathing problems
Diagnostics: tissue biopsy, antibody, clinical history
66
Toxocara Basics
Type: blood helminth, nematode
Where: worldwide
Reservoir: dog and cat intestine
67
Toxocara Lifecycle
1. Ingest egg or undercooked meat
2. Hatch, larvae penetrate walls and carried by circulation
3. Humans accidental hosts
68
Toxocara Infection
| and diagnostics
Children, self limiting
**Visceral larval migrans (VLM):** fever, coughin, hepatomegaly, caused by repeated infections
**Ocular larva migrans (OLM):** no respiratory symptoms or fever, worm enters eye, inflammation
Diagnostics: history, fecal exam of pets, antibody detection
69
Echinococcus Basics
Type: blood helminth, cestode
Where: Argentina, Peru, Africa, Asia
Reservoir: carnivores
Other: humans accidental hosts
70
Echinococcus Lifecycle
1. Ingestion of egg from contaminated stuff
2. Oncospheres released
3. Hydatid cysts develop in organs
71
Echinococcus Infection
| and diagnostics
**Cystic echinococcus:** hydatid cysts in liver, lungs, can rupture and cause anaphylactic reactions, death
**Alveolar echinococcus:** lesions in liver, liver failure, death
Diagnostic: cyst with paracyte and protoscolices, ultrasound, molecular, antibody
72
Clonorchis Sinensis Basics
Type: blood helminth, liver trematode
Where: Asia
Reservoir: human, dog, cat
73
Clonorchis Sinensis Lifecycle
1. Metacercariae ingested in undercoocked seafood, excyst and move to biliary tract
2. Release eggs in stool
74
Clonorchis Sinensis Infection
| and diagnostics
Abdominal pain, nausea, diarrhea, bile duct cancer
Diagnostic: eggs from stool or duodenal aspirates, imaging/ultrasound
75
Paragonimus Basics
Type: blood helminth, lung trematode
Where: East Asia, Africa, Americas
Reservoir: human and shore feeding animals
76
Paragonimus Lifecycle
1. Metacercariae ingested from undercooked crab/crayfish, excyst
2. Move through system to lungs, mature and released eggs
3. Swallowed or released in stool
77
Paragonimus Infection
| and diagnostics
**Pulmonary:** cough, hard to breath, blood tinged or brown sputum
**Extrapulmonary:** liver, spleen, abdomen, skin, brain
Diagnostics: eggs in stool or sputum, antibody
78
Schistosoma Mansoni
Type: blood helminth, blood trematode
Where: Africa, S. America, Caribbean
Infection: rash at penetration, swimmers itch (cercarial dermatitis), *hepatosplenomegaly*
Diagnostics: eggs in stool, lateral spine
79
Schistosoma Japonicum
Type: blood helminth, blood trematode
Where: East Asia
Infection: rash at penetration site, swimmers itch (cercarial dermatitis), *hepatosplenomegaly*
Diagnostic: eggs in stool, aborted spine
80
Schistosoma Haematobium
Type: blood helminth, blood trematode
Where: Africa, Middle East
Infection: rash, swimmers itch (cercarial dermatitis), bloody urine, bladder cancer
Diagnostics: eggs in urine, terminal spine
81
Promastigote
Leishmania in the insect
82
Epimastigote
Trypanosoma in the insect
83
Trypomastigote
Trypanosoma in blood stream
84
Amastigote
Intracellular form of T. cruzi and Leishmania
85
Trypanosoma Brucei Basics
Type: blood protozoan
*Gambiense:* W+C Africa, mostly human reservoir
*Rhodesiense:* E Africa, mostly animal reservoir, more common in tourists
Vector: tsetse fly
86
Trypanosoma Brucei Lifecycle
1. Tsetse fly injects trypomastigote into bloodstream, carried through body
2. When fly takes blood meal, becomes epimastigote in the fly, transforms into trypomastigote later
87
Trypanosoma Brucei Infection
| and diagnostics
**Rhodesiense**
African sleeping sickness is more acute, reaches CNS within 1 year, haemolymphatic stage, meningoencephalitic stage
Chancre at bite site
**Gambiense**
African sleeping sickness is more chronic, CNS in longer than a year, similar symptoms to rhodesiense
**Diagnostics:** trypomastigote in blood smear, small posterior kinetoplast, central nucleus
88
Trypanosoma Cruzi Basics
Type: blood protozoan
Where: C+S. America, Mexico, animal nesting areas, straw, mud houses
Reservoir: mostly wild animal, human
Vector: reduviid bug
Transmission: blood, transplants, bug feces contamination, congenital
89
Trypanosoma Cruzi Lifecycle
1. Trypomastigotes in *feces* enters near bite wound, invade cells
2. Become intracellular amastigotes > multiply and become trypomastigotes again
3. Epimastigotes inside bug when it consumes it, then turns back into trypomastigotes
90
Trypanosoma Cruzi Infection
| and diagnostics
**Chaga's disease**
Acute: fever, swelling
Chronic: heart, liver, spleen, brain, lymph nodes
Cardiac complications, GI complications, difficulty eating/passing stool, infants can get it congenitally
Diagnostic: large (sub)terminal kinetoplast, central nucleus trypomastigote in blood in acute stage, antibody in chronic stage
91
Leishmania Basics
Type: blood protozoan
Where: sub/tropics, southern Europe
Vector: sand fly
Reservoir: dogs and rodents, humans
Time: evening and night
92
Leishmania Lifecycle
1. Promastigotes injected during sand fly blood meal
2. Turn into amastigotes in macrophages, multiply in tissues, infect other cells
3. Epimastigotes in fly gut, then turn into promastigotes later
93
Leishmania Infection
| and diagnostics
**Cutaneous:** red papule, lesion, intense itching, ulcerate, scars
Diagnostic: amastigotes in tissue, molecular
**Visceral (kala-azar):** gradual onset of fever, diarrhea, anemia, invade liver, kidney, spleen, can be lethal
Diagnostics: amastigotes in tissue or bone marrow, antibody, molecular
**Mucocutaneous:** destruction of facial mucous membranes
94
Plasmodium Basics
Type: blood protozoan, malaria
Where: sub/tropics, worldwide, Africa, airports
Vector: anopheles mosquito
**Species**
P. falciparum: most severe, in Africa, infects all RBCs
P. vivax: outside Africa, infects young retics
P. ovale: infects young retics
P. malariae: infects older RBCs
95
Plasmodium Lifecycle
1. Sporozoite injected during blood meal, infect liver cells, mature into schizonts
2. Schizonts rupture and release merozoites, infect RBCs, mature
96
Plasmodium Fevers
Benign tertian fever: every 48 hours, vivax and ovale
Benign quartan fever: every 72 hours, malariae
Malignant tertian fever: falciparum
97
Plasmodium Infection
Cold, hot, sweating phases in adults
Cerebral, anemia, hemoglobinuria, pulmonary edema, blood abnormalities, cardiovascular shock and damage,
Vomiting, aches, fever, nausea
Diagnostics: parasite in RBCs, antibody/antigen, molecular
| Vaccine available
98
Babesia Basics
Type: blood protozoan
Where: NE. America, China,
Vector: tick
Species: B. microti
99
Babesia Lifecycle
1. Sporozoite injected by tick, tick must stay on skin for 36-48 hrs to transmit parasite
2. Enter blood cells and reproduce
Humans are dead end hosts
100
Babesia Infection
| And diagnostics
Flu like symptoms, sweating, fever, anemia, renal failure
Severe in immunocompromised, elderly, people with no spleen
Diagnostics: maltese cross, parasite in blood smear
101
Trichomonas Vaginalis Basics
Type: urogenital tract protozoan, flagellate
Where: worldwide, women
Transmission: trophs
102
Trichomonas Vaginalis Infection
| and diagnostics
Men: asymptomatic, irritation in penis, burning
Women: yellow green discharge, odor, discomfort in area
Pregnant women: deliver early, baby low weight, transmit to baby, easier to get HIV, difficult to clear HPV
Diagnostics: motile trophs microscopy, strawberry cervix
103
Acanthamoeba General
**Type**: free living amoeba
**Transmission**: cyst or troph enters eye, nasal, or broken skin
**Infection**: chronic granulomatus amebic encephalitis, mental status change, double vision, keratitis, skin leasions in immunocompromised, cysts in brain
**Diagnostics**: trops/cysts in smears or corneal scraping
104
Naegleria Fowleri General
**Type**: free living amoeba
**Where**: fresh water, contaminated tap water
**Transmission**: trophs enter body through nasal, into brain
**Infection**: primary amebic meningoencephalitis, fever, stiff neck, death
**Diagnostics**: trophs in CSF or tissue
105
Toxoplasma Gondii Basics and Lifecycle
Type: tissue protozoan
Where: worldwide, house cat
Transmission: foodborne, accidental ingestion cleaning litterbox, congenital
Lifecycle: ingest oocysts, circulate blood and forms cysts in tissue, remain through lifecycle of host
106
Toxoplasma Gondii Infection
| and diagnostics
**Leading cause of foodborne illness related deaths and hospitalizations**
Flu like symptoms
**Severe**: damage to brain, eyes, organs in immunosuppressed
Can reactivate
**Congenital:** infection in 1st trimester severe neonate disease, infection in 3rd trimester infant usually asymptomatic at birth
Chorioretinitis, hydrocephalus, intracranial calcifications
Eye disease
**Diagnostics:** cysts in tissue, antibody, microscopy, molecular
