110 - Eukaryotic Parasites

Question 1

Parenteric hiost

Answer 1

Host in which the parasite enters the body, doesn’t undergo development but remains infective

Question 2

Intermediate host

Answer 2

Host in which development occurs but the parasite doesn’t reach sexual maturity

Question 3

Definitive host

Answer 3

Host in which parasite reaches sexual maturity

Question 4

Body louse

Answer 4

Pediculus humanis

Question 5

Head louse

Answer 5

Pediculus capitis

Question 6

Crabs

Answer 6

Pediculus pubis

Question 7

Name for infection with lice

Answer 7

Pediculosis

Question 8

What in a lice infection causes itching?

Answer 8

Itching caused by louse saliva when lice are attaching eggs to hair shaft

Question 9

Distribution of louse infections

Answer 9

Worldwide

Question 10

Symptoms of lice
1
2
3

Answer 10

1) Itch.
2) Macules.
3) Secondary infection.

Question 11

What can lice be a vector for?

Answer 11

Rickettsia, spirochetes

Question 12

Scabies Latin name

Answer 12

Sarcoptes scabiei (Arachnids, not insects)

Question 13

Where do scabies live?

Answer 13

Live in tunnels in the epidermis.

Lay eggs as they burrow (moulting pouch).

Question 14

Size of scabes

Answer 14

Less than 0.5mm in size

Question 15

Where do scabies prefer to live?

Answer 15

Favours fingerwebs, elbows, axillae, genitals.

Question 16

Scabies treatment

Answer 16

Single dose of Ivermectin.

Sterilise clothes and bedding

Question 17

Diagnosis of scabies

Answer 17

Detection of mite in scrapings or biopsy

Question 18

What are ticks important vectors for?

Answer 18

Viral
Rickettsial
Protozoal

Question 19

Are humans the definitive host of ticks?

Answer 19

Often not.

Question 20

What can ticks sometimes cause in humans?

Answer 20

Ascending paralysis

Question 21

Type of contact that ticks have with humans

Answer 21

Brief contact. Take a blood meal and then drop off host

Question 22

Distribution of ticks in Australia

Answer 22

Eastern Australia

Question 23

Latin name for ticks

Answer 23

Ixodes holocyclus

Question 24

Diagnosis and treatment of ticks

Answer 24

Detect, remove tick

Question 25

Ticks responsible for paralysis

Answer 25

Females. Males don't take a blood meal

Question 26

Examples of pathogenic protozoal diseases

Answer 26

Malaria, amoebiasis, giardiasis, toxoplasmosis, trypanosomiasis

Question 27

Protozoa

Answer 27

Unicellular, complex, eukaryotic

Question 28

Most-common disease-causing protozoan in humans

Answer 28

Entamoeba histolytica

Question 29

Where does E histolytica invade?

Answer 29

Invades tissues in the colon (faecal-oral transmission)

Question 30

Symptoms of amoebiasis

Answer 30

Prolonged watery diarrhoea, liver abscess

Question 31

Diagnosis of amoebiasis

Answer 31

Faecal cysts, serology (particularly after the diarrhoeal phase)

Question 32

Amoebiasis treatment

Answer 32

Metronidazole + paromomycin, drainage of abscess

Question 33

Immunity to amoebiasis

Answer 33

Poor. Reinfections common

Question 34

Giardia intestinalis 1 2 3

Answer 34

1) Flagellate, primitive eukaryote. 2) Long-lived cysts, so can survive in environment for a long time. 3) Zoonotic

Question 35

Giardia distribution

Answer 35

Worldwide

Question 36

Symptoms of giardiasis

Answer 36

Diarrhoea, might be acute or chronic, with malabsorption.

Question 37

Diagnosis of Giardia

Answer 37

Cysts in faeces

Question 38

Treatment of Giardia

Answer 38

Tinidazole

Question 39

Immunity to Giardia

Answer 39

Poor. Re-infeciton common

Question 40

Toxoplasma gondii features 1 2 3

Answer 40

1) Obligate intracellular parasite 2) Infects all mammals, many birds 3) Most infections from undercooked meat

Question 41

Length of Toxoplasma infection

Answer 41

Lifelong. | Usually asymptomatic in the immunocompetent

Question 42

When can Toxoplasma be dangerous?

Answer 42

Immunocompromised (EG: HIV) | Congenital infection can be serious

Question 43

How does Toxoplasma exist in host?

Answer 43

Circulates in blood, can infect almost any organ (forms cysts in tissues (EG: muscle)

Question 44

Symptoms of Toxoplasma

Answer 44

Asymptomatic. | Sometimes CNS lesions, ocular disease in HIV

Question 45

Treatment of Toxoplasmosis

Answer 45

Often nothing. Bactrim antibiotics if serious

Question 46

Diagnosis of Toxoplasmosis

Answer 46

Serology