Brainscape's Knowledge GenomeTM

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


See full index

Foundations 7 > Parasitology 1 > Flashcards

Parasitology 1 Flashcards

1
Q

Parasite lifestyle factors

A 
Host 
Establish productive infection
Evade host mechs
Maintain host viablity and potential spread
Successful transmission
Not all stages are infective for humans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Productive infection establishment

A

Needs to get to right tissue
Non-productive infection can cause serious pathology
May be within host or move to another host

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

How do parasites circumvent various host physical response

A

Cross skin via vectors and direct penetration
Adhere to GI tract to prevent peristalsis
Sequester to venous/arterial circulation to avoid blood flow

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

Parasite and immune interactio

A

2 way street…parasite adapts based on immune response

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

Parasitic dzs nomrally

A

Long term chronic

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

Parasitic dz not always evident…when does it become evident

A

Change in host status or reactivation due to changes in pathogen

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

Acute dz outcomes

A

Pathogen or host induced pathology leads to resolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Sub clinical outcomes

A

Immune response leads to potential pathology leads to sterile resolution
Chronic infection…change in immune status leads to symptomatic dz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Actue dz with mild and non-specific dz outcomes

A

Immune response leads to chronic infection…change in immune status and symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Protozoa

A

Single celled eukaryotes

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

Metazoa

A

Made up of helminths (worms), arthropods (everything else but snails) and molluscs (snails)

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

Main function of arthropods

A

Act as vectors and reservoirs for dz

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

Amoebae
Flagellates
Sporozoa
Ciliates

A

Crawling motion on a substrate
Use of one of more whip like flagella (includes Kinetoplastids)
Gliding motility
Hair like cilia

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

Helminth classifications

A

Nematoda (roundworms)
Cestoda (tapeworms)
Trematoda (tissue and blood flukes)
All endoparasites

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

Host

A

Animal where a parasite can establish an infection

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

Definitive vs intermediate host

A

Def - adult phase (metazoa) or sexual reproductive phase (proto)
Int - Larval (metazoa) or asexual (protozoa)…obligatory for completion of life cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Accidental host

A

Host that is a dead end for a given parasite…still leads to pathology and dz

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

Transmission to def host allows

A

Sexual recombination and diversity

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

Transmission to IM host allows

A

Higher levels of parasite in the population

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

Environmental cyts

A

Mechanism to surive in envrionment in absence of a host

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

Dormant state within host

A

Permits transmission…often a cyst

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

How are parasites transferred from vertebrae to vertebra

A

Carniverous
Close contact with animals
Infected waste
Sexual activity or handling of tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Life cycle stages reflect

A

Adaptations to environments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Helminth development

A

Egg to larval to mature to mating back to egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Incubation period

A

Time from acquisition to appearance of symptoms - hours to years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Prepatent period

A

Time from acquisition to detection - days to years

Can be shorter than incubation…often detect cyst form in feces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Patent period

A

Time in course of parasitic dz during which parasitic organisms can be demonstrated in the body…don’t need symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Most parasitic dz have

A

Acute and chronic infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Most common parasitic dz

A

Intestinal roundworms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Amoebae protozoa

A

Entamoeba histolyyica

Acanthamoeba

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Amoebae/giardia/trichomonas common themes

A 
Evolutionarily among earliest
Facultative anaerobes using carb metab
Lack mitochondria
EC parasite adhere to epithelium (don't invade)
Cause contact dependent cytotoxicity
Divide like bacteria (binary fission)
Killed by metronidazole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Cyst forms of protozoa

A

Designed for transmission
Non-replicative
Survive in environment
Typically infectious form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Trophic forms of protozoa

A

Actively replicating, active growhti nthe host, not involved in transmission

ALL protozoa have trophic, not all have environmental cyst

34
Q

Entamoeba histolytica life cycle

A

Infection with cysts
Cyst wall disrupted in GI tract and release 4 nuclei amoeba
Trophozoites form after division
Trophozoites divide in intestine and differentiate back into cysts
Cysts deposited in feces

35
Q

EH trophozoites can move

A

To portal vein where they can establish liver infection (extraintestinal)
Also can get to lungs, diaphragm, and brain

36
Q

Intestinal amebiasis characteristics

A

Bloody and mucoid diarrhea
Blood in the stool with lack of leukocytes
Look for cysts or trophozoites
Trophozoites may be laden with erythrocytes

37
Q

Acute symptoms of intestinal amebiasis

A

Ab pain, bloody mucoid diarrhea, flatulence and ab tenderness
May last 2-21 days

38
Q

Chronic symptoms of intestinal amebiasis

A

Occassional bloody diarrhea, weight loss, fatigue

39
Q

Most people with intestinal amebiasis are

A

Asymptomatic and shed cysts

40
Q

Extraintestinal symptoms of amebiasis via EH

A

Pain in upper right quadrant..tender and enlarged liver with abscess, fever, weight loss

41
Q

EH effect on liver

A

Amebic hepatitis…lysis and digestion of hepatocytes

42
Q

Other sites of EH

A

Lungs, skin, brain…cysts never outside of intestine

43
Q

GI tract Entamoeba species

A

E dispar…oftne confused with EH

44
Q

DIagnosis of EH

A

Trophozoites with RBCs in the stool or 4 nucleus containing cysts in the stool
Tenderness in upperright quadrant (use Xray and CAT scan to confimr)
Trophozoites in sputum (lung)
CAT scan/MRI for brain

45
Q

2 other pathogenic amoebae besides EH

A

Acanthamoeda castellani
Naegleria fowleri

Free living envrionemtal organisms
Cause severe dz in both healthy and immunocompromised individuals
Acquired swimming in warm lakes

46
Q

Acanthamoeba castellani eye infection

A

Conjunctivits, keratitis, and uveitis…contact lens wearers
Diagnose by culturing
Keep contacts clean and avoid swimming in wamr lakes

47
Q

Acanthamoeba castellani CNS involvement

A

Invades CNS through olfactory bulb
Causes GAE - seizures, brain disturbs, headaches, death
Cannot be detected in the CSF

48
Q

Tx of GAE and ocular infection by acanthamoeba

A

Ketoconazole and surgical excision

Topical azole and cessation of contact lens use

49
Q

Naegleria Fowleri…including tx and diagnosis

A

Infects healthy young people (often water sports)
Causes PAME with trophozoites but NO cysts
Death in days (1-3 day incubation)
Can see them in CSF
Amphtericin B to treat
Try to diagnosie with culture

50
Q

important flagellate to remember

A

Giardia lamblia

51
Q

Giardia lamblia life cycle

A

Flagellated diplomonades with 2 nuclei (look like eyes)
ingest cysts, replicate by binary fission and attach to intest epithelium…upper and small intestine are preferred

Cysts have 4 nuclei
Trophozoites have 2

52
Q

Beaver fever symptoms

A

Severe cramps
Non-bloody foul smelling diarrhea with greasy stool due to malabsorption of fat
Asymptomatic will shed cysts for years
Incubation = 3-21 days

53
Q

Giardia cysts

A

Resitant to chlorination but not to filtration

Infects many different animals, not just humans

54
Q

Giardiasis is most prevlanet

A

Cause of non-bacteiral diarrhea in the US

55
Q

Risk factors for giardiasis

A

Unfiltered or unboiled water while hiking (Beaver fever)
Fecal oral
Immune suppresssion

56
Q

Patholgy of giardia

A

Attach to intestinal epithelium and efface the villi

57
Q

Sporozoa we need to know

A

Plasmodium (malaria)

Toxoplasma gondii

58
Q

Anopheles mosquito

A

Used to spread malaria
Only females will spread
Obtaining bloodmeal is essential for eggs
Lay 4-5 clutches per lifetime

Where plasmodia undergo completion of their sexual cyce

59
Q

Malaria life cycle

A

Passed to humans…goes to liver as asymptomatic…invades erythrocytes

Completes cycle in mosquito

60
Q

Plasmodium falciparum

A

Majority of malrial deaths
6-12 PP period
May not have defined fever periodicity

61
Q

PLasmodium vivax

A

Most common cause
Benign tertian malaria
10-17 PPP

62
Q

Plasmodium ovale

A

Similar to vivax

14 PPP

63
Q

Plasmodium malariae

A

Mildest dz but longest

28-35 PPP

64
Q

Time of infection of malaria

A

Bite to when the erythrocytic cycle commences and symptoms are present…also defines how long it takes to detect

65
Q

Symptoms of malaria

A

During erythrocytic stage…high dever with defined periodicity
Tertian - day 1 and 3 (vivax)
Quartan - fever on day 4 (seen in plasmodium malarium)

66
Q

Cerebral malaria

A

Infected erythrocytes have knobs that make them sticky to linings and RBCs…this causes blockages which leads to multiple strokes
Renal and pregnancy complications can result from P falciparum

67
Q

AIDS associated opportunistic

A

Toxoplasmosis

68
Q

Opportunistic pathogens

A

Don’t normally cuase symptoms in healthy, but will in immunocomporomised

69
Q

Life cycle of toxoplasmosis gondii

A

Cat is the definitive host…bradyzoite becomes oocyst…oocyst leaves in the feces and goes to another anuimal…shifts between bradyzoite (chronic) and tachyzoite (actue)…bradyzoite can be transmitted to humans via undercooked meats

Then can transfer tachyzoite to child

70
Q

Clinical spectrum of toxo

A

Congenital
Cerebral toxoplasmosis (from AIDS)
ocular

71
Q

Most severe toxo complicaton

A

Toxoplasmic encephalitis…tissue cysts form in brain and muscle

72
Q

Toxoplamsosis encephalitis

A

Cerebral abscess leads to multifacotiral neurological symtpoms…lethal if untreated

Txs do not target dormant so you need lifelong tx

73
Q

COngintal toxo

A

if mother has no ABs, then still at risk but no infection at time
If IgG, then no risk
If IgM, then potential risk to fetus

74
Q

Conginetal toxo exposures and when symptoms occur

A

If 3rd trimester, generally no effect
Can occur in under 26 weeks
Mild dz to spontaneous abortion
Chorioretinitis is typically the first to show…could include failure to thrive, and a bunch of other things

Most (75%) are subclinical

75
Q

Toxoplasmic hydrocephaly symtpoms

A

Hydrocephalus
Retinochorditis
intracerebral calcifcation
Psycho/motor retardation

76
Q

Ocular toxoplasmosis

A

Consequence of congintally acquired
Could occur in 10-20 years after birth
Untreated could lead to blindness

77
Q

Cryptosporidium

A

Diarrheal dz in immunocompromised patients
Does NOT penetrate into cells
Sexual cycle occurs in GI tract and not restircted to single host species

78
Q

Life cycle of cryptosporidum

A

Oocyst ingested contained 4 sporozoites…oocysts attach…8 new merozoites form from schizogony…differnetiate into male and female gametocytes that then begin process of oocyst formation

79
Q

Symptoms of crypto

A

Ab pain, dirrhea for 3-10 days
Often mistaken for food poisoning

Life-threatening in AIDS patients - persistant dirrhea, malabsorption with severe weight loss

80
Q

Risk factors for crypto

A

Both animal and human feces
Contam water sources (can be filtered)
Conditions of crowding
Contact with animal waste

81
Q

Diagnosis and tx of crypto

A

Oocysts in the feces and PCR approaches

No effective tx…just rehydrate and control

Foundations 7 (19 decks)

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