26. Arthropods (lice, part 1)

Question 1

where can lice be found?

Answer 1

on people’s heads, and human bodies, including the pubic areas

Question 2

how do human lice survive?

Answer 2

by feeding on human blood

Question 3

what do both males and females (immature and adult) require to complete their development?

Answer 3

blood meals

Question 4

which is the only louse known to spread disease?

Answer 4

body louse

Question 5

how are lice infections spread most commonly?

Answer 5

by close person to person contact

Question 6

do cats, dogs and other pets play a role in transmission of human lice?

Answer 6

no

Question 7

how do lice move?

Answer 7

by crawling

Question 8

can lice fly or jump?

Answer 8

no

Question 9

do lice have wings?

Answer 9

no

Question 10

what do lice have on their legs? what are they for?

Answer 10

claws that grip and hold onto their shafts

Question 11

how many legs do lice have?

Answer 11

6 legs

Question 12

how many segments do the antennae have?

Answer 12

5 segments

Question 13

what is the shape of their abdomens?

Answer 13

longer than they are wide

Question 14

are the lice found in different parts of the body the same?

Answer 14

no, they are different from each other

Question 15

what are the three types of lice found on humans?

Answer 15

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

Question 16

what is the head louse?

Answer 16

Pediculus humanus capitis

Question 17

what is the body louse, clothes louse?

Answer 17

Pediculus humanus corporis

Question 18

what is the “crab” louse or pubic louse?

Answer 18

Pthirus pubis

Question 19

among who, is head lice most common?

Answer 19

among preschool and elementary school-aged children and their household members and caretakers

Question 20

are head lice known to transmit disease?

Answer 20

no

Question 21

what is a common malignancy associated with head lice?

Answer 21

secondary bacterial infections of the skin resulting from scratching (any lice infestation)

Question 22

is getting head lice related to cleanliness?

Answer 22

no

Question 23

what is the most common way to get head lice?

Answer 23

head to head contact with an already-infected person

Question 24

what is head lice’s means of camouflage?

Answer 24

they can change their color to match the hair of the infected person

Question 25

how are lice treated?

Answer 25

with lice-killing shampoos and rinses (insecticides), and nit combs should be used to comb nits and lice from the hair shaft

Question 26

what are nits?

Answer 26

lice eggs, laid by the adult female at the base of the hair shaft nearest the scalp

Question 27

how long to nits take to hatch?

Answer 27

1 week

Question 28

what does the nit hatch into?

Answer 28

nymphs

Question 29

what does the lice nymph resemble?

Answer 29

they look like adult head louse, but is the size of a pinhead

Question 30

after how many molts are nymphs mature?

Answer 30

3 molts

Question 31

how many days after hatching are lice nymphs are eventually adults?

Answer 31

about 7 days

Question 32

how many legs do adult lice have? how many claws?

Answer 32

6 legs, each having a claw

Question 33

what color is adult lice?

Answer 33

tan to greyish white

Question 34

who is larger in lice, females or males?

Answer 34

females are usually larger than males

Question 35

how many nits do female lice lay per day?

Answer 35

up to 8

Question 36

how long can lice live on a person’s body?

Answer 36

up to 30 days

Question 37

where do body lice live that is different from other lice?

Answer 37

body lice prefer to live in the seams and linings of unwashed clothing, blanket and sheets and only move to the skin to feed

Question 38

how long without blood meals can body lice go before they die?

Answer 38

1 to 2 days

Question 39

where are the nits of body lice found?

Answer 39

Although body lice usually deposit their nits on unwashed clothing fibers, the nits are sometimes found on body hair as well

Question 40

are body lice known to spread disease?

Answer 40

yes

Question 41

what can body lice spread in terms of diseases?

Answer 41

epidemic typhus
trench fever
louse-borne relapsing fever

Question 42

is louse-borne epidemic typhus wide spread?

Answer 42

no

Question 43

do outbreaks of louse-borne epidemic typhus still occur? if yes, when?

Answer 43

yes, in times of war, civil unrest, natural or man-made disasters, and in prisons where people live together in unsanitary conditions

Question 44

where does Louse-borne typhus still exist?

Answer 44

in places where climate, chronic poverty, and social customs or war and social upheaval prevent regular changes and laundering of clothing

Question 45

how us body lice infestation diagnosed?

Answer 45

by finding eggs and crawling lice in the seems of clothing or feeding on skin

Question 46

how is a body louse infestation treated?

Answer 46

by improving the personal hygiene of the infected person, including assuring a regular (at least weekly) change of clean clothes

Question 47

how do you treat the environment of an infected person?

Answer 47

Clothing, bedding, and towels used by the infested person should be laundered using hot water (at least 55°C) and machine dried using the hot cycle

Question 48

where can pubic lice be found?

Answer 48

• usually attached to pubic hair
• can also be found in the eyebrows, eyelashes, beard, moustache, chest, armpits, etc
• any course hair

Question 49

what is the common name for pubic lice?

Answer 49

crabs

Question 50

why do pubic lice prefer the pubic regions?

Answer 50

they are adapted to grasp hairs that are rather widely spaced from each other

Question 51

how is pthiriasis usually spread?

Answer 51

through sexual contact

Question 52

what would kill pubic lice?

Answer 52

lice-killing lotion

Question 53

what do you do after killing the pubic lice?

Answer 53

you have to comb them out with a fine toothed comb because most nits will still be attached to the hair