ticks and mites

Question 1

What characteristics do acarines have and what organisms are acarines

Answer 1

Ticks and mites
8 legs
no antennae
cephalothorax
abdomen

Question 2

what types of ticks are there

Answer 2

hard (ixodidae)

soft (argasidae)

Question 3

life cycle of hard ticks

Answer 3

eggs in gelitanous mass, larvum with 6 legs, 1 instar nymph with 8 legs, adult

Question 4

how can you distinguish male and female hard ticks

Answer 4

m- large scutum

f-small scutum

Question 5

ticks:

length of time on host and drop off into ?

Answer 5

Hard
long, vegetation

Soft
short, home

Question 6

why do hard ticks have high vector potential

Answer 6

firmly attached and persistent feeders
trans-ovarial transmission
trans-stradial transmission
live long
ticks are reservoir and vector
slow feeding aids dispersal
wide host range - 3 host ticks

Question 7

hard ticks transmit…..

Answer 7

kyasanur forest disease (Arbovirus)
Rickettsiae tick typhus
tick paralysis
tick borne encephalitis

Question 8

Control of hard ticks

Answer 8

treat livestock
ivermectin
personal protection
ULV

Question 9

most important genus of soft ticks

Answer 9

ornithodoros

Question 10

life cycle soft ticks

Answer 10

eggs, larvum 6 legs, nymph 4 instars, adult

just get bigger at each stage
each stage blood feeds

Question 11

morphological features of soft ticks

Answer 11

no scutum
no visible mouthparts
coxal organs
engorges and fills with blood

Question 12

soft ticks transmit…

Answer 12

tick borne relapsing fever (endemic relapsing fever)

• Borrelia duttonii
• transmitted through saliva and coxal fluid
• recurring fevers

Question 13

control soft ticks

Answer 13

sweep floor, solid floors in housing, raise beds off floor, repellants, ibn

Question 14

how can you distinguish between ticks and mites

Answer 14

mites have hypostome without teeth
no scutum
don’t swell up after feeding like soft ticks

Question 15

two types of mites

Answer 15

sarcoptes scabei- scabies mites

leptotrombidium- chigger mites- scrub typhus

Question 16

life cycle of sarcoptes scabei

Answer 16

1. female burrows through skin feeding on cell and tissue liquid, male looks for female, deposits eggs
2. larvae (1) and nymph (3) found in moulting pockets
3. mature to adult

Question 17

how is scabies transmitted

Answer 17

skin to skin contact

Question 18

treatment of scabies

Answer 18

benzyle benzoate, permethrin cream, oral ivermectin, treat whole family

Question 19

what is a complication of scabies

Answer 19

crusted norweigan scabies- scabies hyperinfestation of immunocompromised
extensive skin scaling and crusting
highly contagious

Question 20

what is scrub typhus parasite

Answer 20

orienta tsutsugamushi

Question 21

where is scrub typhus found

Answer 21

asia

Question 22

life cycle of chigger mite

Answer 22

1. eggs laid in vegetation
2. larvae wait on vegetation, blood feed on rodents
3. larvae drops to ground to moult
4. nymph
5. adult free living in soil

Question 23

where are chigger mites found and why

Answer 23

mite islands- nymphs and adults need arthropod prey

Question 24

prevention of scrub typhus

Answer 24

boots and trousers, clothing impregnated with repellant, clear mite islands, acaricidal spraying, doxycycline for high risk groups