Parasitology - Arthropods

Front 1

Classification of lice

Back 1

Insect

Front 2

Classification of fleas

Back 2

Insect

Front 3

Classification of bugs

Back 3

Insect

Front 4

Classification of flies

Back 4

Insect

Front 5

Classification of ticks

Back 5

Arachnid

Front 6

Classification of mites

Back 6

Arachnid

Front 7

Classification of spiders

Back 7

Arachnid

Front 8

Classification of scorpions

Back 8

Arachnid

Front 9

How do arthropods cause human disease?

Back 9

Suck blood, inject toxins, burrow into skin

Front 10

T/F: Ticks live for several years

Back 10

True.

Front 11

Females of several species of this aracnid family secrete a neurotoxin that blocks ACh release, causing paralysis.

Back 11

Tick [same mechanism as botulin toxin]

Front 12

T/F: Ticks can cause paralysis

Back 12

True (female ticks of several species secrete an ACh release-blocking neurotoxin)

Front 13

These are four diseases that are transmited by ticks

Back 13

Rocky Mountain spotted fever (Ricketsia ricketsii), hemorrhagic fevers (arboviruses, eg: WNV, EEE, WEE), tularemia, Lyme disease (Borrelia burgdorferi)

Front 14

Scabies is this type of arthropod

Back 14

Mite (which is a type of arachnid)

Front 15

Life cycle of Sarcoptes scabiei

Back 15

(1) Female burrows into cornified epithelium and lays 2 eggs/day for one month

(2) Larvae hatch, make a separate burrow, and mature into adults

Front 16

Signs and symptoms of scabies

Back 16

Itchy lesions. Itching is worse at night.

Front 17

Common sites of scabies infestation

Back 17

Finger webs, flexor surface of wrist, extension surface of elbow, axillary fold, buttock crease (warm, moist folded areas)

Front 18

Burrows of this mite are not always found--instead, look for erythema, small papules or eczema

Back 18

Sarcoptes scabiei

Front 19

Transmission of scabies

Back 19

Close, personal contact

Front 20

2-4% of outpatient dermatology visits are for this disease

Back 20

Scabies

Front 21

Patients with scabies have on average this many mites.

Back 21

Ten (10)

Front 22

Diagnosis of scabies

Back 22

Biopsy or skin scrape

Front 23

Treatment of scabies

Back 23

Permethrin

Front 24

The itch in scabies is due to this

Back 24

Hypersensitivity reaction (thus even though scabies is cured rapidly with permethrin, sx may persist for weeks)

Front 25

Size of tick vs. size of mite

Back 25

Tick: 5.5 to 7.5 mm
Mite: 0.3 to 0.6 mm (1/10th as small)

Front 26

Latin binomial of black widow spider

Back 26

Latrodectus mactans

Front 27

The venom of this arachnid blocks the release of acetylcholine and causes paralysis

Back 27

Ticks (females of several species)

Front 28

The venom of this arachnid is a peripheral neurotoxin that causes spreading pain and numbness.

Back 28

Black widow spider (Latrodectus mactans)

Front 29

Treatment of black widow spider bite

Back 29

Antitoxin serum

Front 30

The venom of this arachnid is a necrotizing agent that causes edema followed by gangrene and ulceration

Back 30

Brown recluse spider (Loxosceles reclusa)

Front 31

Latin binomial of brown recluse spider

Back 31

Loxosceles reclusa

Front 32

Treatment of brown recluse spider bite

Back 32

Steroids, plastic surgery

Front 33

The venom of this arachnid can kill children, usually by affecting the cardiopulmonary system

Back 33

Scorpion

Front 34

This arachnid delivers its venom through a stinger in the tail

Back 34

Scorpion

Front 35

Relative size of ticks, lice, fleas, mites, bedbugs

Back 35

Tick > flea > louse = bedbug > mite
6 mm > 3 mm > 1 mm > 0.6 mm

Front 36

What are the three types of human lice?

Back 36

Pediculus humanus capitis (head louse)
Pediculus humanus corpus (body louse)
Phthirus pubis (crab louse)

Front 37

Of the three types of human lice, this is the smallest

Back 37

Crab louse (Phthirus pubis)

Front 38

Location of eggs (nits) of body lice (Pediculus humanus corporis)

Back 38

Clothes

Front 39

Life cycle of human lice

Back 39

1 week for egg to hatch, 2 weeks of larvae to mature to adults

Front 40

Lifespan of human lice

Back 40

1 month

Front 41

What is the total number of eggs laid by a single louse during its lifetime

Back 41

100 eggs (in 1 month of life)

Front 42

T/F: Lice, fleas and bedbugs all suck blood

Back 42

True. They suck blood and cause itchy bites

Front 43

Transmission of lice

Back 43

Contact (sexual contact in the case of crab lice)

Front 44

Treatment of lice

Back 44

Gamma-benzene hydrochloride shampoo

Front 45

Lice are vectors of these two bacteria

Back 45

Rickettsia prowazeki (epidemic, recrudescent and sporadic typhus), Borrelia recurrentis (relapsing fever)

Front 46

These lice are relatively common in all social conditions, whereas these lice are seen only in poor sanitary and social conditions

Back 46

Head lice seen in school children everywhere, body lice seen in poor social conditions only

Front 47

Latin binomial of human flea

Back 47

Pulex irritans

Front 48

Life cycle of human Pulex irritans (human flea)

Back 48

(1) Eggs laid in environment
(2) Larvae and pupa mature into adults in 1 month
(3) The adult form can infect humans

Front 49

Rat fleas are vectors of these two bacteria

Back 49

Yersinia pestis (bubonic plague), Rickettsia typhi (endemic "murine" typhus)

Front 50

These insects avoid light and suck blood at night, hiding in crevices and cracks during the day

Back 50

Bedbugs

Front 51

T/F: Bedbugs do not transmit any diseases

Back 51

True.

Front 52

Trypanosoma cruzi has this insect as its host

Back 52

Reduviid bug (Rhodnius)

Front 53

All species of mosquitos lay their eggs here

Back 53

Water

Front 54

T/F: Only female (not male) mosquitoes bite

Back 54

True.

Front 55

T/F: Only female (not male) fleas bite

Back 55

False. Both sexes bite.

Front 56

Diseases transmitted by mosquitoes

Back 56

Yellow fever, eastern equine encephalitis and other arboviruses; malaria; Wuchereria bancrofti (elephantiasis)

Front 57

This is the insect host of leishmaniasis

Back 57

Sand flies (Phlebotomus)

Front 58

Latin genus of Tsetse flies

Back 58

Glossina

Front 59

This is the insect host of African trypanosomiasis

Back 59

Tsetse flies (Glossina)

Front 60

Latin genus of black flies

Back 60

Simulium

Front 61

This insect lays its eggs in rushing water

Back 61

Black fly (Simulium)

Front 62

T/F: Only female (not male) black flies bite

Back 62

True.

Front 63

Intermediate host for Onchocerca volvulus (cause of River Blindness)

Back 63

Black fly (Simulium)

Front 64

This insect glues its eggs to stones or vegetation

Back 64

Black fly (Simulium)

Front 65

Definition of myiasis

Back 65

General term used to describe infection of tissue by larval flies (different species prefer different tissues)

Front 66

Treatment of cutaneous myiasis

Back 66

May require surgical excision

Front 67

T/F: In myiasis, mature larvae pupate in the tissue to produce adults

Back 67

False. In myiasis, mature larvae migrate out of the tissue and pupate in the soil to produce adults.