L21: Fleas, Bugs and Flies

Question 1

What are fleas

Answer 1

small insects that feed on animal and human blood
many species, most parasitic on mammals (rats) and birds

*prefer animals but will bite people

*reelvant cause vector of pathogens they transmit through feeding hosts or fecal contamination to open wound

Question 2

List common flea species and assocated hosts

Answer 2

4 main affected species:
1. Cat flea – Ctenocephalides felis (despite the name, it is common on dogs, other pets and domestic animals)
2. Dog flea – Ctenocephalides canis
3. Human flea – Pulex irritans
4. Oriental rat flea – Xenopsylla cheopis

Question 3

Discuss the microbes tranmitted by flease

Answer 3

Bacteria
▪ Ctenocephalides are vectors of Rickettisa cause rickettsial disease and Bartonella henselae causing cat scratc disease

▪ Xenopsylla cheopis transmitting T.petisi which causes plague and flea bourne murine thypus

Protozoa
▪ Xenopsylla cheopsis intermediate hosts for al rodent-borne trypanosomes

Helminths
▪Ctenocephalides intermediate hosts for cestode Hymenolepis and Dipylidium

P.irritians not vector but cause allergic reaction cause of salivary proteins

Question 4

heavy infections lead to

Answer 4

anemia especially in young animals

Question 5

Distinctive Features of Important Flea Species

Answer 5

Cat
*3-4
*sloping elongated head
*has ctendia comb strcutures
*genal and pronotal comb almost same length

Dog
*3-4
*rounded head wit ctednia
*genal comb is shorter than protonal

P.irritans
*1-4
*no ctednia in head
*front of head it sounded no meral rod

Xeno
*1-4
*head no ctednia
*front of head is rounded
meral rod present
*WORLDWIDE

Question 6

Describe flea morphology

Answer 6

*2-6 mm and very small head
*bilaterly compressed to allow easy movement through hair and feather
*mouthparts for piercing skin and sucking blood
*light brown, no wings, enlarged hind limbs to jump 100x their body length

Question 7

Flease life cycle

Answer 7

adult fleas
eggs
larval stage
pupa stage
adult fleas

Question 8

5 key flea treatment

Answer 8

sanitation where they breed and wash bedding, vacum

pet treatment for every pet and wash then then comp then, use soap with insecticide to kill adults

home treatment same time as pet to disrupt flea cycle

follow up because life cycle is complex some may be reisitanct to insectides so its an ongoing process

use antiitching cream like antihistamines or hydrocortisone

Question 9

Prevention and control of flease

Answer 9

limit pet going to flea aras

use repellent, clean up, lower humidity, lowering temps

keep rodents and wild animals away

Question 10

Which bugs are medically important and 2 closely related that infect humans

Answer 10

2 familieis of Hemiptera
1. Reduviidae: Kissing bugs (also called Assassin bugs – winged)
2. Cimicidae: Bed bugs (wingless. The focus of this lecture)

Two closely related species of bed bugs that commonly infest humans are:
1. Cimex lectularius – the common bed bug, cosmopolitan in distribution
2. Cimex hemipterus – the Indian bed bug, restricted to the tropics and sub-tropics

Question 11

Bugs

Answer 11

found where humans are, remain hidden, and exit hiding spot when its dark or dim to feed on hosts

adult and nympals stages of Cimex must take warm blooded meals, human becomes incidental hosts of the bat/birds cimex

all bed bugs are incomplete metamorphic

Question 12

The Life Cycle of Bed Bugs

Answer 12

eggs, nymph, adult

Question 13

The Life Cycle of Bed Bugs

Answer 13

Traumatic insemination: Also known as hypodermic insemination, is a forceful mating tactic that involves a male bed bug inserting its genitalia into the non-genital tissue of a female bedbug by stabbing through the exoskeleton. Sperm is released into the female’s hemolymph and migrates through the circulation to the ovaries, resulting in fertilization

Question 14

Clinical Presentation & Diagnosis of Bed Bug Infestations and treatment

Answer 14

Clinical
*bites cause of allergic reaction salivary they have anticoagulatans and anethetics
*but they are ineffective vectors of disease

Diagnosis
*often misdiagnosed but you know from breakfast lunch and dinner pattern
*see adults and lymphs n ear when bitten
*heavily infected smell from salivary bed bug order

Treatment
*self limiting
only need antisepic location to prevent secondary

can use antihistamines to manage itching

use insecticide in homes but professional pest control is needed

better to prevent it instead od treating it

Question 15

What are flies, wings, order, types

Answer 15

Dipter true fly order

winged with 2 pairs attached to thoraz
complete metamorphosis and classified by biting (blood sucking) or non biting

Question 16

Types of flies and pathogencicy with examples

Answer 16

Biting: are vectors and spread sandflies (leishmaniasis), blackflies
(onchocerciasis), mosquitos (malaria, filariasis) and tsetse flies (sleeping sickness)

Non biting: flies deposit eggs, from which larvae emerge and feed on
host tissues and exudates
=>These larvae are pathogenic during development and live within the tissue
of the infected host – they are obligate parasites and cause a condition
known as myiasis

Question 17

What is flu myiasis

Answer 17

parasitic infection where larvae are bured in host tissues usually

*they borrow in healthy or nectoric with mandibular oooks and protelytic enxzymes

*if they belong to genera that parasit animals they may also do humans

*can be obligatory, faculative or accidental (in humans

Question 18

Name fly genera that cause myiaiss

Answer 18

Dermatobia hominis – human bot fly (A common species in Canada)
✓ Cochliomyia hominivorax – screwworm fly (New World)
✓ Chrysomya bezziana – screwworm fly (Old World)
✓ Cordylobia anthropophaga – tumbu fly

Question 19

Give example of facultative myais causer

Answer 19

g. Musca domestica and Lucilia illustris

Question 20

Life Cycle of Dermatobia hominis – human bot fly

Answer 20

adult, eff, larvae, pupate, adults

Question 21

Life Cycle of Other Myiasis-Causing Flies

Answer 21

screwwom flies
Gravid female screwworm flies lay
eggs on (or around the edges of) a
superficial wound or mucous
membranes of a body orifice. Eggs
hatch into larvae that burrow into
the wound or flesh of the orifice.
Larvae feed on living tissue
CAUSES WOUND MYIASIS they can leave subdermal tissue and go through body tissue

house flies
Gravid female house flies lay eggs
on moist, decaying material
(garbage, feces). Larvae feed on
decaying organic material. When
larvae invade host tissues, they can
cause myiasis, feeding on decaying
and necrotic tissue. This is rare

tubmu flies
Gravid female tumbu flies lay eggs
on soil contaminated with urine or
feces, and damp clothes. Emerging
larvae can survive for up to 2 weeks
in the soil. They attach to any host
they encounter and penetrate the
skin. Larvae feed on living tissue.

Question 22

Flies: Clinical Presentation of Myiasis

Answer 22

its classified by site
cutanouse: furuncular, migratory, wound

ocular:ophthalomyiasis

nasopharyngeal, aureal, genitourinary, intestinal, cerebral, oral

can get bad, kill livestock and cause secondary infections

Question 23

How to treat myiasis

Answer 23

phyical removal of larvae if bad then do surgery if the larvae has migrated

no approved treamtn

antibodies for secondary exposure
AT THE END OF THE DAY JUST PREVENT IT

Question 24

how to remove larva from myiasis

Answer 24

punch biopsy with blade to frm a whole where its ejected

then u extracted it and it heels