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Flashcards in Lice and Fleas Deck (26):
1

What are the three types of human lice?

Pediculus humanus capitis (head louse)
Pediculus humanus corporus (body louse)
Pthirus pubis (pubic/crab louse)

2

Which lice type is known to spread disease?

only the body louse

3

How are lice spread?

through person-person contact, NOT through animals

4

How do lice move?

crawling. cannot hop or fly
they are wingless but have claws

5

What are some defining physical characteristics of lice?

wingless
have 6 legs
antennae have no more than 5 segments
abdomens are longer than wide

6

How can head lice potentially cause disease?

secondary bacterial infections caused by scratching

7

What do adult head lice do to avoid detection?

they can change colour to be the same as the host's hair

8

How can you get rid of head lice?

use insecticide shampoo for the adults, and use a nit comb to pull out the nits from the hair

9

How long does it take for the nits to hatch?

one week

10

Where do body lice live?

in the seems and linings of unwashed clothing, blankets and sheets.
only move to the skin to feed because people do not usually have a lot of body hair

11

When will body lice die?

after 1-2 weeks of not having a blood meal

12

Which diseases can body lice spread?

epidemic typhus, trench fever, and louse-borne relapsing fever

13

How can linens be rid of body lice?

washing in very hot water

14

Where on the body are pubic lice found?

attached to coarse hair, including pubic hair, eyebrows, eyelashes, beard, moustache, chest, armpits, etc
their bodies are wider and their legs further dispersed to grasps these hairs

15

How can you be rid of pubic lice?

using insecticide shampoo and a nit comb for the eggs

16

When will pubic lice die?

after 24-48 hours of not having a blood meal

17

What are the distinctive features of fleas?

6 legs
wingless
have long hind legs that allow them to jump
a disproportionate small head
bodies are laterally compressed
no attaching appendages

18

What kind of pathogens can fleas transmit?

bacteria (bubonic plague), protozoa, and helminthes (Dipylidium caninum)

19

What are the four main species of fleas that infest humans?

cat flea: Ctenocephalides felis
dog flea: Ctenocephalides canis
human flea: Pulex irritans
rat flea: Xenopsylla cheopis

20

How can the cat and dog flea be differentiated?

the cat flea has mouth combs that are approximately all the same length
the front dog comb is half the length of the second comb

21

Which diseases can Ctenocephalides species cause?

rickettsial diseases including Rickettsia typhi
also spotted fever, typhus, and scrub typhus
intermediate hosts for some tapeworms

22

How can the human flea species be distinguished from the rest?

it does not have any combs

23

What does the human flea do?

salivary proteins can cause allergic reactions

24

What diseases does the rat flea transmit?

bubonic plague (Yersinia pestis) and endemic typhus (aka murine typhus)

25

Does the rat flea have ctenidia (combs)?

no

26

How can flea infections be treated?

itching can be treated with antihistamine or hydrocortisone creams
using dehumidifiers (eggs need humidity to hatch) + air conditioning (adults need a certain temp) + vacuuming