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Flashcards in Myiasis Deck (48):
0

What is a myiasis

A Dipteran that parasitizes as a larvae only, and not as an adult

1

Define the 3 groups of myiasis producing flies

Primary myiasis - specific myiasis producers, larvae only found in living tissues
Secondary myiasis - semi-specific myiasis producers, eggs usually laid on dead tissues or decaying plant matter, but sometimes deposit larvae on living host
Tertiary myiasis - accidental myiasis, usually don't develop in flesh, but can survive

2

What is the common term for Sarcophagidae

Flesh flies

3

General physical characteristics of sarcophagidids

About 2x as large as house fly, gray thorax with dark longitudinal stripes abdomen is checkered black and grey

4

Scientific name for blow flies
Other common names for blow flies

Calliphoridae
Bluebottle and greenbottle

5

Why are they called blow flies

Blow their larvae or eggs onto meat

6

What are common hosts of calliphorid myiasis

Rabbit

7

Scientific name for American screwworm

Cochliomyia hominvorax

8

What type of myiasis does the American screwworm produce

Primary myiasis

9

How are American screwworms controlled

X-radiation and release of sterile males

10

Where do American screwworm larvae pupate

Soil

11

What is the only known insect to eat the living flesh of warm-blooded animals

American screwworm

12

What countries have screwworms been eradicated from

USA
Mexico
Panama
Libya

13

What is the major cause of avian myiasis in North America

Blood sucking maggots of the genus Protocallifora

14

What families of fly are involved in obligate myiasis. (Besides screwworms)
As a group, what is their common name

Oestridae
Hypodermatidae
Gasterophilidae
Cuterebridae

Bot flies

15

Where can the host-specific site-specific parasites be found on their hosts (identify host and site)

Oestrus in nasal passages of sheep
Hypoderma in the dorsal subcutis of cattle
Gasteroplilus in the stomach of horses

16

Which bots occasionally affect humans, and how

Oestra deposit larvae in the eyes of shepherd
Hypoderma and Cuterebra migrate subtaneously

17

What is a distinct feature of adult bot flies

Have vestigial mouthparts and energy is deprived from that which was stored when the fly was a larva

18

What time of day are Oestrus most active

During warm times of day, or intervals of sunshine

19

Life history of Oestrus ovis

Larvae deposited I sheep nostril
Larvae crawl to mucosa of nasal passages (2wk). Halt development until warm weather
Migrate to frontal sinus where they mature to 3rd stage larvae

20

What types of signs do Oestrus ovis cause in sheep
How do you treat it

None in mild infections
Sneezing nasal discharge and partial blockage of nasal passages in heavy infection
Tx with ivermectin

21

Name some other nasal bots and their hosts

Rhinoestrus purpureus - horse
Cephalopina - camels
Cephenemyia - cervids

22

Genus and species of gad fly or heel fly

Hypoderma bovis
Hypoderma lineatum

23

What is a warble

Walnut sized lumps on the backs of cattle formed by Hypoderma in the subcutis

24

Life history of Hypoderma

Females glue their eggs to hairs on the legs
H. Lineatum present in winter, H. Bovis present in summer
Eggs hatch and larvae burrow into skin
- h.lineatum present in esophageal tissues 5 mo later
- h.bovis present in spinal canal
Larvae ultimately migrate to sub-q tissues of back: molt twice, and grow larger
When fully developed, emerge and fall to ground to pupate

25

Which genus is associate with migrating lumps in people

Hypoderma

26

Where do different species of Gasterophilus deposit their eggs

G. Nasalis - hairs of intermandibular space
G. Hemorrhoidalis - hairs that adjoin the lips
G. Intestinalis - hairs of forelegs and shoulders

27

Where do first stage Gasterophilus larvae occur

Tunnels in epithelium covering dorsal surface of Rostropovich 2/3 of tongue and in pockets between molar teeth
(Second stage also in mouth in interdental pockets or base of tongue)

28

Where specifically are 3rd stage Gasterophilus larvae usually found

First ampulla of duodenum in horse (nasalis)
Or stomach (intestinalis) above the fluid level

29

What are the preferred hosts of cuterebra species

Rabbits and rodents

30

What specific site are Cuterebra found on within the host

Under the skin

31

Do Cuterebra produce primary, secondary or tertiary myiasis

Primary

32

Life history of Cuterebra

Eggs deposited near animal burrows
Enter through natural body openings
Migrate to subcutaneous tissues, where development to third stage occurs
Larvae drop off host to pupate

33

How often to cuterebrae lay eggs

Once a year in north (univoltine)
Active. Year-round in south

34

Describe migration of cuterebra in the host

Enter natural opening
Move to tracheal tissue
Penetrate thoracic cavity
Penetrate diaphragm
Enter peritoneal cavity
Enter sub-q tissue

Migrates around body 3-6 wks before making it to skin. Majority of growth occurs in sub-q

35

What affect do Cuterebra have on cats

Can develop warbles
Disease from migrating maggots (respiratory signs, neuro disease)

36

Genus species human bot fly

Dermatobia hominus

37

When do the larvae become. Bots

Large maggot stage

38

How are Dermatobia hominus eggs deposited

Eggs deposited on another fly's body with hopes of contacting host... If no other fly, vegetation

39

What stimulates D hominus eggs to hatch

Heat from vertebrate host

40

Why can you not simply pull out a Dermatobia hominid when you spot the anterior end sticking out of a boil-like lesion

Maggot has large spine on its body that make it almost impossible to pull out the maggot without killing it or rupturing it (if maggot dies, increased risk if secondary bacterial infection)

41

Genus and species of the tumbu fly

Cordylobia anthropophaga

42

Where are tombu fly eggs deposited and what are their typical hosts

Eggs deposited in soil
Typical host is rodent. Can infect dog and human

43

What is one way that has been reported as a means for Cordylobia anthropophaga to acquire humans as a host

Hang clothes up to dry and do not iron them

44

Genus and species of Congo floor maggot

Auchmeromyia senegalensis

45

What is particularly unique about the Congo floor maggot

Does not penetrate the skin, instead fastens to the host to suck blood

46

What are common hosts of Auchmeromyia senegalensis

Wart hogs and other large burrowing mammals in Africa

47

What type if human habitations has Auchmeromyia become adapted to

Those with wooden floors