Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IDMM > parasites > Flashcards

parasites Flashcards

1
Q

what is a parasite

A

animal or plant living in or on another and drawing nourishment from it

diagnosis of parasitic disease involves exposure history, clinical pattern of illness, ID in stool, blood, tissues, indirect evidence (serology, detection or parasitic antigens, DNA

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

what is a helminth

A

WORM

reproduce SEXUALLY usually within the host

pre-adult stage = OVA and LARVAE that live within or external to the host

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

what are protozoa

A

SMALL, UNICELLULAR organisms

have a nucleus and functioning organelles
reproduce quickly and ASEXUALLY in the host

have have a sexual phase in another host or vector

sub groups are based on motility (i.e amoeba, flagellates, ciliates, sporozoa/amicomplexa)

some protozoa have life stages alternating between proliferative stages (trophozoites) and dormant cysts

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

what are protozoa cysts

A

dormant phase

can survive in harsh conditions

allow the parasitic special to survive without a host

allow for transmission

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

what are protozoa trophozoites

A

actively feeding METABOLIC form of the protozoa

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

what are ectoparasites

A

insects

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

list the 3 classes of parasites

A
  1. protozoa (one celled organisms)
  2. helminths (worms)
  3. ectoparasites (insects)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

list the 3 classes of helminth

A
  1. cestodes (tapeworms)
  2. nematodes (roundworms)
  3. trematodes (flatworms/flukes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

list the 4 classes of protozoa

A
  1. amoeba
  2. ciliates
  3. flagellates
  4. sporozoans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is a definitive host

A

host of a parasite where SEXUAL reproduction of the parasite occurs

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

what is an intermediate host

A

animal essential to the COMPLETION of the LIFE CYCLE of the parasite

transmission requires a reservoir and route of infection

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

nematode body

A

UNsegmented

bilateral symmetry

fully functional digestive tract

long and cylindrical

male and female worms

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

nematode sexes

A

separate

have male and female worms

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

nematode infection/transmission

A

eggs/larvae ingestion, skin penetration, arthropod vector

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

nematode lifecycle

A

eggs –> several larvae stages –> adult stage

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

list 7 nematodes

A
  1. necator americanus (hookworm)
  2. Loa Loa (filaria)
  3. Wucheria bancroft (filaria)
  4. onchocerciasis
  5. ascaris lumbricoides
  6. strongyloides stertocalis
  7. enterobius vermicularis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

hookworm

A

nematode

necator americanus

LARVAL stage of worm penetrates SKIN –> usually through FOOT causing infection in the foot

once it penetrates the skin, it is carried through teh blood vessels

heavy infections can result in childhood anemia

SOIL TRANSMITTED helminth

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

Loa Loa (filaria)

A

nematode

EYE worm

adult conjunctiva migration

transient calabar swellings

diagnosis via serology, microfilaria on BLOOD SMEAR

transmitted via CHRYSOPS fly

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

Wucheria bancroft (filaria)

A

nematode

ELEPHANTITIS

very common in some tropical zones

early symptoms = fever, lymphadenitis, transient edema

late obstruction = chronic edema and skin changes caused by blocked lymphatics

transmitted via MOSQUITO

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

onchoceriasis (filaria)

A

nematode

RIVER BLINDNESS

NO blood invasion

major cause of blindness–> skin disease in Africa and Yemen

diagnosis based on serology, skin snip, nodule biopsy

transmitted with SIMULIAN fly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Ascaris lumbricoides

A

nematode

prototypical roundworm

notable for LUNG MIGRATION phase–> larvae are coughed up, swallowed and mature in gut

excreted eggs need to embryonate in specific environmental conditions in soil before becoming infective–> therefore direct person to person transmission is not possible

heavy infection may result in bowel obstruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Strongyloides stertocalis

A

nematode

MINUTE roundworm

can replicate and completed ENTIRE LIFECYCLE within a HUMAN

infection can persist for a human lifetime

SOIL TRANSMITTED helminth and is often acquired from skin penetration

23
Q

Enterobius vermicularis

A

nematode

PINWORM

very common–> causes PRUTITUS ANI in kids

fecal-oral transmission

persists due to poor hygiene

eggs can persist in local environment

24
Q

cestode body

A

are TAPEWORMS

large, can be up to meters long

live attached to MUCOSA in SMALL INTESTINE of host

use SCOLEX to attach which is an attachment organ with 4 ventral suckers with or without hooks

structure = chain of segments (proglottids) + neck + scolex

25
Q

cestode sexes

A

hemaphroditic

26
Q

cestode infection/transmission

A

can live for decades

infection is via egg/larvae ingestion

27
Q

name a cestode

A

taenia solium (pork tapeworm)

taenia saginatum is cow tapeworm
dipnyllobotherium latum is from uncooked fish
echinococcus is from sheep

28
Q

taenia solium

A

cestode

pork tapeworm

causes NEUROCYSTOCERCOSIS

most medically important tapeworm infection worldwide

most common parasite of CNS

most preventable cause of EPILEPSY

results from undercooked PORK–> humans eat adult tapeworm from pork–> human excretes eggs–> if another human ingests the eggs, eggs hatch and turn into CYSTECERCI in tissues, including in the brain

parenchymal disease (cysts–> degeneration–> calcification–> seizures)

extraparenchymal disease (sub-arachnoid space, ventricles, spine)

most important clinical goal is to CONTROL INFLAMMATION

29
Q

trematode body

A

flatworms/flukes

first intermediate host is SOIL
second intermediate host is FISH/SHELLFISH

dorso-ventrally flattened, unsegmented, leaf-like or cynindrical structure

30
Q

trematode sexes

A

hermaphroditic

31
Q

trematode infection/transmission

A

require 1 or more intermediate hosts

infect through skin penetration or larvae ingestion

32
Q

name 2 trematodes

A
  1. paragonimus westermani

2. schistosomiasis

33
Q

paragonimus westermani

A

trematode

LUNG fluke

reservoir = wild and domestic carnivores

usually asymptomatic–> can have COUGH (often confused with TB, lung cancer)

rare cerebral disease

diagnosis through serology, sputum (eggs), eosinophilia

infection through LARVAE INGESTION

34
Q

schistosomiasis

A

trematode

BLOOD fluke

cause of morbidity in Sub-Saharan Africa

acquired by swimming in freshwater lake or rivers

microscopic CERCARIAE burrow through skin and migrate to blood vessels surrounding target organs –> females lay eggs–> eggs penetrate into tissue through vessel walls –> eggs propelled into lumen –> pass in urine or stool

urogenital = S. haematobium 
intestinal/hepatic = S. mansoni, S. japonicum

acute infection is usually 4 weeks post-exposure and involves fever, diarrhea, eosinophilia

continued egg-laying leads to chronic inflammation and then to cancers, cirrhosis

35
Q

list 5 ectoparasites

A
  1. scabies
  2. head lice
  3. body louse
  4. trench fever (body louse)
  5. bot fly (Dermatobium hominis)
36
Q

which type of protozoa are intestinal protozoa

A

FLAGELLATE

i.e GIARDIA lamblia (“beaver fever”)

37
Q

which type of protozoa are extraintestinal protozoa

A

PLASMODIUM (malaria)

38
Q

list 3 diseases caused by protozoa

A
  1. malaria
  2. leishmania
  3. giardia lamblia
39
Q

malaria vector

A

FEMALE ANOPHELES night-biting MOSQUITO

transmits through BITE

40
Q

malaria species

A 
P. falciparum 
P. vivax
P. ovale
P. malariae
P. knowlesi

50% = falciparum

41
Q

malaria reproduction

A

asexual cycle in RBCs (SHIZOGANY)

sexual reproduction in female anopheles mosquito (SPOROGANY)

42
Q

malaria diagnosis method

A

thick and thin BLOOD SMEAR –> can determine species of plasmodium as well as % RBCs infected (parasitemia)

rapid antigen tests

43
Q

what is the most important parasitic disease

A

malaria–> #1 cause of fever in returning travellers

44
Q

symptoms of uncomplicated malaria

A 
fevers
rigors
headaches
diarrhea
nausea

may be mistaken for viral infection

45
Q

symptoms of complicated malaria

A

from P. FALCIPARUM

evidence of end-organ dysfunction (coma, renal failure)
mortality is 10-20% with Tx

46
Q

P. falciparum

A

infection is a medical emergency
endemic in sub saharan africa
parasites induces formation of sticky “KNOBS” on RBCs which clog small vessels in brain and lungs

47
Q

P. falciparum versus P. vivax

  1. dormant liver stage?
  2. disease severity?
  3. relapse?
  4. asymptomatic carriage?
  5. Tx
A
  1. P. falciparum NO; P. vivax YES
  2. P. falciparum 5% = severe; P. vivax risk of severe disease is not established
  3. P. falciparum NO; P. vivax YES
  4. P. falciparum = common; P. vivax very common
  5. P. falciparum = arteminisin combo therapy; P. vivax = chloroquine + 14 days primaquine
48
Q

Leishmania vector

A

sandfly

49
Q

Leishmania species

A

L. donovani
L. infantum
L. chagasi (chagas disease)

50
Q

Leishmania diagnosis

A

skin biopsy

serology

51
Q

Leishmania Tx

A

amphotericin B

topical ketoconazole

52
Q

Leishmania clinical presentation

A

cause of ulcerated papule

subclinical infection is most common

HIV coinfection = reactivation

fever, lymphadenopathy, hepatomegaly, progressive MASSIVE SPLENOMEGALY

53
Q

giardia lamblia

A

intestinal protozoa (flagellate)

most common GI intestinal protozoal infection in world

fecal oral transmission

may be asymptomatic

causes GI symptoms by EFFACEMENT OF VILLI via inciting inflammation at the intestinal brush border

this means that dietary FATS are absorbed poorly and result in “GREASY” STOOLS that FLOAT in the toilet

NEVER INVASIVE on its own, and will NOT cause bloody diarrhea

IDMM (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions