Parasitology

Question 1

What is a parasite?

Answer 1

An animal living in or on the body of another which gains an advantage of the host

Question 2

What is an ECTOparasite? Give some examples?

Answer 2

Found on the outside (surface) of the host.
Need nutrients to stay attached. They have a divided body and a hard exoskeleton.
Lice (insect with 3 segments)
Mites (arachnids?)

Question 3

What is an ENDOparasite? Give some examples?

Answer 3

Found with the body of the host.
Protozoa (malarial)
helminths (threadworm etc)

Question 4

What are lice?

Answer 4

Ectoparasites that suck blood - their mouth is specialised for piercing skin and sucking

Question 5

What are the 3 species of lice?

Answer 5

Pediculosis capitus (HEAD)
Pediculosis corporis (BODY)
Pediculosis pubis (PUBIC)

Question 6

Where are body lice found?

Answer 6

Usually in the clothes then the go to the body to feed.
Common areas include soft creased areas like the armpit and waistline

Question 7

How are body lice transmitted?

Answer 7

Clothing-clothing contact or skin contact

Question 8

Where do body lice lay their eggs?

Answer 8

In the seams of clothing

Question 9

What areas (not like body areas but like places) would body lice infections be common?

Answer 9

Areas of poor hygiene and crowding such as shelters, refugee camps and hostels

Question 10

What is the only host for body lice?

Answer 10

Humans

Question 11

If body lice fall of a person how soon will they die?

Answer 11

5-7 days

Question 12

How do body lice move around?

Answer 12

CRAWL - do NOT jump, hop or fly

Question 13

How big are body lice?

Answer 13

About the size of a sesame seed

Question 14

What other diseases can body lice be a vector for?

Answer 14

Endemic typhus
Trench fever

Question 15

Why do body lice cause intense itching?

Answer 15

Injection of their saliva into the skin

Question 16

What symptoms may a person with body lice present with?

Answer 16

Intense itching
Eggs on body
Lice crawling in clothing seams (MAGNIFYING GLASS MAY BE NEEDED)
Rash
Red bumps
Thickening or discolouration of skin especially near waist or groin if untreated
Secondary bacterial infection

Question 17

What treatment can be provided for body lice?

Answer 17

Insecticide and symptomatic relief (antihistamines)

Question 18

What insecticides can be used in the treatment of body lice?

Answer 18

Permethrin 5%
Malathion 0.5% (Derbac M)

Question 19

What hygiene measures are needed to help eradicate body lice?

Answer 19

Bathe/shower regularly
Wash clothing at 50 or higher
Store contaminated clothes in a closed container for over 2 weeks –> lice will die with no blood
Deep cleaning areas especially upholstery

Question 20

Who else needs to be made aware if a person has body lice?

Answer 20

Close contacts and people they live with so they can keep an eye out for signs of infection

Question 21

Why do we use the word ‘infection’ and not ‘infestation’?

Answer 21

Less daunting, embarrassing and shameful for the patient

Question 22

What do adult pubic lice look like?

Answer 22

They are about 2mm long and yellow-grey or dusky red

Question 23

Where do pubic lice attach their eggs (nits)?

Answer 23

To the base of coarse hairs in the pubic area but can be on other coarse hair such as eyebrows, eyelashes, beard and armpits

Question 24

Do public lice transmit STIs?

Answer 24

No

Question 25

What test is also reccomended if a person has pubic lice?

Answer 25

Sexual health check up

Question 26

Do condoms protect against pubic lice?

Answer 26

No

Question 27

What is another name for pubic lice

Answer 27

Crabs

Question 28

How long do public lice live?

Answer 28

one to three months

Question 29

How many eggs can a female public louse lay?

Answer 29

300

Question 30

After the eggs hatch, what is the name for the immature pubic louse?

Answer 30

nymph

Question 31

How long does it take to go from nymph to adult pubic louse?

Answer 31

2-3 weeks

Question 32

When trying to identify if a person has a public lice infection what are we looking for?

Answer 32

Adult louse - may have to use a magnifying glass

Question 33

How long can pubic lice live if not on the human body

Answer 33

24 to 48 hours They depend on human blood to survive so rarely leave the body

Question 34

How are pubic lice transmitted?

Answer 34

Close contact Coitus sometimes crawling through clothing and bedding

Question 35

What are some signs and symptoms of pubic lice?

Answer 35

Itching in the affected area - may take a few weeks to present Inflammation or irritation in the affected areas including thighs and lower abdomen Black powder (Lice faeces) in the underwear or on skin Blue spots of skin where lice are biting Tiny blood spots in underwear or skin Eggs (nits) near the hair follicles

Question 36

What is a sign that there are pubic lice in the eyelashes?

Answer 36

Inflammation

Question 37

When is itching caused by pubic lice worsened?

Answer 37

At night as this is when they feed

Question 38

Why is important if a person has pubic lice but no symptoms?

Answer 38

They can still pass the lice on to other people

Question 39

What HAS to used first line for treating public lice?

Answer 39

Insecticides

Question 40

What are two insecticides that can be used to treat pubic lice?

Answer 40

Permethrin 5% (Lyclear cream) Malathion 0.5% (Derbac-M)

Question 41

How are insecticides applied in the treatment of pubic lice?

Answer 41

Apply to the whole body and leave overnight/for 12 hours then wash off Repeat the application after a week

Question 42

Who can permethrin 5% (Lyclear) not be provided to OTC?

Answer 42

People under 18 - would need to see a doctor

Question 43

What is some non-drug management for pubic lice?

Answer 43

Wash clothing and bedding at at least 50 Vacuum the house Treat al contacts at the same time Avoid close contact until treated

Question 44

What should you do if a patient's eyelashes are affected by pubic lice?

Answer 44

REFER

Question 45

What do headlice look like?

Answer 45

Grey-brown insects about 1-3mm long with 3 pairs of legs

Question 46

How many eggs can a female head louse lay in its lifetime? Where are the eggs found?

Answer 46

300 - eggs are attached to the base of the hair shaft

Question 47

How long does it take for headlice eggs to hatch and then mature?

Answer 47

7-10 days to hatch then 10 days to mature

Question 48

How long do head lice live for?

Answer 48

1-2 months

Question 49

What are nits

Answer 49

The empty white egg shell stuck very strongly to the hair

Question 50

Is the presence of nits a sign of current headlice infestation?

Answer 50

No

Question 51

Are nits removed by headlice treatment?

Answer 51

No