Brainscape's Knowledge GenomeTM

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


See full index

Rob's Microbiology MCD > Micro 9: Parasitic infection > Flashcards

Micro 9: Parasitic infection Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Define infection

A

invasion by and growth of
pathogenic microorganisms
within the body

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

Define disease

A 
a disordered or incorrectly functioning
organ, part, structure, or system of
the body resulting from the effect of
genetic or developmental errors,
infection, poisons, nutritional deficiency
or imbalance, toxicity, or unfavorable
environmental factors; illness;
sickness; ailment.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define parasite

A

organism living in or on the host and dependent on it for nutrition - causing damage

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

Distinguish types of parasite

A

Endoparasite: protazoa and metazoa. = parasites that live inside the body of the host

Ectoparasite = parasites that live on the outer surface of the host and generally attach themselves during feeding

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

What is protozoa

A

single celled organisms

Eukaryotes (genome within a nucleus, complex organelles in cytoplasm)

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

t/f pathogenesis of protozoa is constant

A

F

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

T/F protozoa infection is associated with eosinophilia

A

F

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

What can be a route of protozoa infection

A

Some have insect vectors (eg malaria)

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

Examples of protozoa

A

amoeba, coccidiae, ciliae, flagellates

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

What are metazoa

A

Multicellular organisms (Helminths/worms)

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

Differentiate the type of parasites that metazoa and protozoa are

A

Protozoa are often obligate intracellular parasites

Metazoa are free living, not within cells

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

T/F all metazoa invade tissue

A

F. Some just inhabit gut (geohelminths), other invade tissues

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

T/F metazoa is associated with eosinophilia.

A

T Eosinophilia – if invade blood

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

2 types of amoeba. Which is dangerous

How are you infected by these

A 
Entamoeba histolytica (=INVASIVE) 
, Entamoeba dispar (=COMMENSAL)

Infection occurs by ingestion of mature cysts in food or water, or on hands contaminatd by faeces

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

How common is amoeba infection and how deadly

A

10% of world infected with E.histolytica

3rd most common cause of parasitic death

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

Most common causes of parasitic death

A

Schichtomiasis, malaria, E. histolytica

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

What is the incubation and the symptoms associated with E.histolytica (an amoeba) infection

A

90% of infections are asymptomatic; rest range from dysentery to amoeba liver abscess

Incubation as short as 7 days. Invasion occurs during first 4 months

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

T/F e.histolytica also infects other mammals

A

F Humans are the only reservoir,

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

Outline how E. histolytica gains access to the body and its effect on GI tract

A

enter the small intestine and
release active amoebic parasites (trophozoites),

These invade epithelial cells of large intestine –> ULCERS

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

How can E. histolytica escape the GI tract and invade other structures

A

Infection can then spread from the
intestines to other organs, e.g. liver, lungs and brain, via the
venous system.

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

What is the effect of invasive amoebiasis

A

most often causes an amoebic liver abscess, but may affect the lung, heart, brain, urinary tract and skin.

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

Can the disease be spread by asymptomatic carriers?

A

Yes Asymptomatic carriers pass cysts in the feces and the
asymptomatic carriage state can persist indefinitely. Cysts
remain viable for up to 2 months.

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

Diagnoss of amoebiasis?

Treatment?

A

Wet mount (look for in stools)

Nitroimidazole derivatives (act on trophozoite, but not on cysts)

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

T/F coccidia infections, in the same way as E. histolytica (which is invasive amoeba), is only a human disease

A

F.Coccidial infection in humans are mostly zoonoses

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

Examples of coccidia

A

Plasmodium species (malaria)

Toxoplasma (toxoplasmosis, fine normally but v dangerous for foetus)

Cryptosporidium (diarrhoea in immunocompormised)

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

Route of infectin for coccidia

A

Mosquito borne

Cats

Water

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

Explain what is meant by a vector and list two specific examples, naming the diseases they transmit.

A

Malaria (plasmodium from coccidian protozoa) –> female Anopheles

Loa loa eye infection=loaiasis (=.filaria roundworm metazoa) Vector is chrysops.

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

Types of plasmodium

A

P. falciparum, P. malariae, P. ovale, P. vivax and P. knowlesi

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

Types of host for malaria (plasmodium)

A

humans and female Anopheles mosquitoes

Bite at night, breed in water

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

Stages of the life cycle that occur in human for malaria

A

Liver and blood stages

then mosquito stages too

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

Symptoms of malaria, and when do they appear

A

Variable…. 7 days to months

Fever, headache, chills, vomiting, muscle pain, paryoxysm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Complication of malaria

A

Cerebral malaria (swelling of the brain,seizures, coma)

Severe anemia (destruction of red cells)

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

Treatment of uncomplicated and complicated malaria

A

Uncomplocated:
-chloroquine

Severe:
-Artemisinin-based combination therapy (ACT) for P. Falciparum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Diagnosis of malaria

A

blood film, Giemsa stained

or rapid antigen staining test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Toxoplasmosis infection type and route of infection. Who is it a problem in

A

Toxoplasma gondii

 • eating undercooked meat of animals harboring tissue cysts
• consuming food or water contaminated with cat feces
• by contaminated environmental samples
• blood transfusion
•  transplacentally from mother
to fetus.

PROBLEM IN PREGNANT WOMEN AND IMMUNOSUPPRESSED PEOPL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is effect of toxopasma gondii in immunocompromised people

A

develop central nervous system disease, brain lesions, pneumonitis or retinochoroiditis among other risks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How is toxoplasma gondii diagnosed

A

Serological test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What does cryptosporidium cause

A

diarrhea, fever, nausea, vomiting in humans

39
Q

What is the typical patient for cryptosporidiu

A

very common in HIV+ patients presenting with diarrhea.

40
Q

Diagnosis and treatment for cryptosporidium

A

Diagnosis: stool examination.

Treatment: fluid rehydration.

41
Q

Example of ciliates

A

Balantidium coli

=Balantidiasis

42
Q

Reservoir for balantidium coli

A

pigs, rodents, primates

Worldwide distruution

43
Q

Symptoms for balantidium coli

A

Most people infected with Balantidium coli => no symptoms.

Immunocompromised patients may experience more severe signs and symptoms: persistent diarrhea, dysentery, abdominal pain, weight loss, nausea, and vomiting. If left untreated, perforation of the colon can occur.

44
Q

Diagnosis of balantidium coli? is it treatable

A

Stool

Yes

45
Q

Example of flagellates

A

Giardia lamblia (Giardiasis)

Trichomonas

Leishmania

46
Q

How common is giardia lamblia- where is it found

A

Giardiasis: commonest, globally distributed, water-borne protozoal
infection.

47
Q

What is a trophozoite

A

a growing stage in the life cycle of some sporozoan parasites, when they are absorbing nutrients from the host.

48
Q

Outline life cycle of giardia lamblia

How can they be excluded from drinking water

A

Flagellated trophozooites attach by their suckers to surface of the
duodenal or jejunal mucosa

Ovoid cysts are able to survive standard chlorination procedures,
filtration is required to exclude them from drinking water

49
Q

Symptoms from giardia lamblia

A

Most people infected with giardia lamblia => no symptoms.

ACUTE SYMPTOMS

Diarrhoea
Greasy stools that tend to float
Stomach or abdominal cramps
Upset stomach or nausea/vomiting
Dehydration (loss of fluids)
50
Q

Treatment and diagnosis of giardia lamblia

A

Stool exam (cysts or trophozoites)

Treatment: metronidazole/tinidazole

51
Q

How do you catch trichomonas compared to other flagellate giardia lamblia

A

Trichomonas= Exclusively Transmitted sexually

giardia lamblia= water- borne

52
Q

How common Is trichomoniasis

A

It is estimated to be the most common, curable, non-viral sexually transmitted infection in the UK, with nearly 6000 new cases per year.

53
Q

Where the infection of trichomoniasis

A

In women the organism is found in the vagina, urethra and paraurethral glands; in men infection is usually of the urethra.

54
Q

Symptoms of trichomoniasis infection

A

F: 10-50% none. Vaginal discharge, vulval itching, dysuria, or offensive odour (non-specific)

Male: 15 to 50% of men are asymptomatic. discharge and/or dysuria.

55
Q

Complication of trichomoniasis infection

A

Detrimental outcome on pregnancy and is associated with preterm delivery and low birth weight.

56
Q

Implication of trichomoniasis for HIV+

A

There is growing evidence that trichomonas infection may enhance HIV transmission and there may be an increased risk of TV infection in those that are HIV positive.

57
Q

Diagnosis and treatment of trichomoniasis

A

Diagnosis
Microscopy: Detection of motile trichomonads in swab/urine- Trichomonas Rapid Test

Treatment
metronidazole

58
Q

Types of metazoa

A

Roundworms, flatworms, flukes

59
Q

What type of organisms are metazoa

A

Metazoa= helminths

Complex muticellular parasites

60
Q

What are the lifecycles of metazoan like

A

Cycles may involve insect vectors and intermediate hosts

61
Q

T/f few metazoan infections are zoonoses

A

T For most, humans are the definitive host - few are zoonoses (acquired from
animals)

62
Q

T/f you can consume a worm and have a helminth infection

A

F: Adult worms cannot multiply in man - number of adults related to infection (eggs cause the problem)

(lay eggs/microfilaria, larvae)

63
Q

Highest burden of helminth infection what age

A

0-10

64
Q

What is the commonest helminth infection worldwide

A

Ascariasis
Trichuriasis
Hookworm infection
Schistosomiasis

65
Q

Examples of roundworms (=nematodes)

A

Ascaris, hookworm, Filaria, Strongyloides

66
Q

Length of ascaris worm

A

The adult males are ~15-30cm long and females ~20-35cm

67
Q

Life cycle of ascariasis

A

Adult worms in small intestine. Produce 240000 eggs per day

Eggs excreted in faeces. Fertile eggs become infective after 18 days-several weeks.

Infective eggs swallowed e.g water

Larvae hatch, invade intestinal mucosa, portal system to liver, systemic system to lung, penetrate alveolar walls.

Asecend bronchial tree, swallowed, and develop into adult worms in small intestine.

68
Q

How long foes it take from ingestion of infective eggs to adult female.

How long do adult worms livee

A

Between 2 and 3 months are required from
ingestion of the infective eggs to oviposition by the
adult female.

Adult worms can live 1 to 2 years.

69
Q

Symptoms of ascariasis

A

Infection with Ascaris lumbricoides often causes
no symptoms

Large number= abdominal pain/intestinal obstruction

Malnourishment (adults feed on content of small intestine) in large infections.

Penetration of lung can cause Loeffler’s pneumonia. (pools of blood and dead epithelial cells clog air spaces in lungs)

70
Q

Hook worm example, length (and how they attach) and symptoms

A

Ancylostoma duodenale

  • Fe deficiency anaemia
  • Gastrointestinal and nutritional/metabolic symptoms
  • respiratory symptoms

about 1cm long and curved.
They are attached by their
buccal capsules to the villi
of the small intestine

71
Q

Lifecycle of hookworm (a nematode)

A

Larvae are carried through the blood vessels to the heart and then to the lungs. They penetrate into the pulmonary alveoli, ascend the bronchial tree to the pharynx, and are swallowed. The larvae reach the small intestine, where they reside and mature into adults. Adult worms live in the lumen of the small intestine, where they attach to the intestinal wall with resultant blood loss by the host.

(much the same as ascariasis)

72
Q

Treatment for hookworm and diagnosis

A

albendazole and mebendazole

Stool

73
Q

What is whipworm

A

Trichuris Trichiura

It’s a nematode, a type of hookworm which is a type of roundworm

74
Q

Lifecycle of whipworm (=Trichuris Trichiura )

A

The eggs hatch in the small intestine, and release larvae that mature and establish themselves as adults in the colon. The adult worms (approximately 4 cm in length) live in the cecum and ascending colon. The adult worms are fixed in that location

75
Q

Symptoms of hookworm

A

Small amounts of whipworms might not cause any symptoms. But if there are hundreds of worms, then you might have bloody diarrhea and anemia due to severe vitamin and iron loss. The worms leave open wounds, which cause inflammation of the intestinal wall. In some cases you might also develop rectal prolapse.

76
Q

Treatment and diagnosis of hookworm

A

albendazole and mebendazole

stool exam

77
Q

What is lymphatic filariasis

A

The filarial category of roundoworms

can cause lymphatic obstruction leading to elephantiasis

lymphatic obstruction (especially in the legs) can progress to
elephantiasis – can also occur in arm, breast, scrotum
78
Q

Example of a filaria

A

Brugia malayi

(one of the tree causative agents of lympatic filariasis)

Loasiasis (Loa loa, eyeworm)

79
Q

Diagnosis and treatment of filarial roundworms

A

microfilariae are found mainly in the peripheral blood and can be found at peak amounts from 10 p.m. to 4 a.m. During the day, they are present in the deep veins, and during the night, they migrate to the peripheral circulation.
Blood smear or antigen detection with a immunochromatic test (card) or ELISA

albendazole and ivermectin

80
Q

Life cycle of loaiasis

A

Fly takes blood meal from a person, and gives them larvae

The adults in subcutaneous tissue produce sheathed microfilariae, found in peripheral blood

Fly takes another blood mean and the microfilariae shed sheaths, penetrate fky’s midgut and migrate to thoracic muscles

Then fly takes another blood meal and the larvae enter into another person’s blood

81
Q

How do Loaiasis cause eye worms

A

Females (~7cm) migrate through the subcutaneous tissues, may cross the front of the eye under the conjunctiva.

82
Q

Example of flatworm (cestodes)

A

Taenia (Tapeworms)

83
Q

T/F humans are the only definitive host for tapeworm, therefore they do not catch it from animals

A

F…. they catch from pig and beef. Humans are the only DEFINITIVE host, but doesn’t mean it cannot live in other hosts temporarily between transfer

84
Q

Symptoms of taenia infections

A

Most people => no symptoms or mild symptoms.

abdominal pain, loss of appetite, weight loss, and upset stomach.

Active passing of tapeworm segments

85
Q

How long are the taenia flat worms

A

T. saginata taeniasis (size of the worm up to 10m)

T. solium or T. asiatica (~3 m).

T. saginata often experience more symptoms

86
Q

Diagnosis adn treatment of taenia

A

Diagnosis:
Segment in stool or identifcation of eggs in stool

Treatment:
praziquantel

87
Q

T/F for taeni, the eggs of the flatworm must be transferred directly from animal to human

A

F The eggs can survive for days to months in the environment

88
Q

What is cysticercosis

A

TAENI SOLIUM

Commonest acquired cause of epilepsy worldwide

89
Q

Example of fluke worm (=trematodes)

A

Schistosoma

90
Q

Why is schistosomasis life cycle complex

A

Involves snail.

In water, the eggs hatch and penetrate snail

They are then released from snail and penetrate the skin

They migrate through different tissues and transform into male and female and eventually reside in venules.

Eggs moved towards lumen of SI and bladder/uterus

91
Q

Symptoms, diagnoss and treatment of schistosomiasis

A

Symptoms: rash/itchy skin. Fever, chills etc. after couple of months

Adult worms, eggs travel to intestine, liver or bladder, cause inflammation or scarring

Diagosis stool
Treatment praziquantel

92
Q

Ectoparasite examples

A

Sarcoptes scabeie

(scabies)

Pediculus humanus capitis (head louse),
Pediculus humanus corporis (body louse, clothes louse), and
Pthirus pubis (“crab” louse, pubic louse)

93
Q

Treatment for scabies and diagnosis

A

Diagnostic
Appearance of rash + presence of burrows
Treatment
Scabicides

94
Q

Stages of lifecycle for ectoparasites and route of infection

A

Three stages: eggs, nymphs and adult

Transmission by direct contact

Rob's Microbiology MCD (6 decks)

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