Flashcards in Bugs & Flies Deck (25):
Which two families of bugs are of medical importance?
Reduviidae= assassin bugs, kissing bugs. carries trypanosoma cruzi
Cimicidae= bed bugs
What are the three species of human bed bugs?
Cimex lectularius: common bed bug. cosmopolitan
Cimex hemipterus: Indian bed bug. restricted to tropical and subtropical regions
Cimex boueti: tropical regions of Africa and South America
Can humans be infected by other bed bug species?
very rare, but can be accidental hosts of Cimex bat and bird species
Where are bed bugs found?
in human habitats, remain hidden in cracks and furniture
How do you know that you have been bitten by a bed bug?
characteristic to have several bite marks because bed bugs take a few blood meals and change position after each one
What does the salivary fluid of bed bugs contain?
anti-coagulants and anesthetics so that the host does not feel the bite
Where do female bed bugs lay their eggs?
they lay about 5 eggs a day in a sheltered area (hidden, not on host)
How many nymphal stages do bed bugs have?
5 nymphal stages that each require a blood meal to molt
How long are the bed big feeding times and how long can they go without a blood meal?
3-10 minutes to feed and can go 6-12 months without a blood meal
What is traumatic insemination?
the unique way bed bugs mate where the male pierces the female's abdominal cavity with his external genitalia to inseminate her
What do bed bugs do to humans?
do not cause disease, but they can cause inflammatory reaction (allergic reaction to saliva)
How can bed bugs be treated?
can use antiseptic creams or lotions to prevent infection after a bite
strong pesticides can be used
What is the order that flies belong to and what are some parasitic species?
-biting midges (filariid nematodes)
-horse and deerflies (filarial eye worm)
-tsetse flies (sleeping sickness)
Which stage of the flies causes disease?
can either transmit other diseases or the larvae can be pathogenic (obligate parasites)
burial of larvae in tissues.
can be an obligatory step or an incidental step, depending on the species
Where does myiasis occur?
may be cutaneous, arterial, intestinal, or urinary, in necrotic or healthy tissue
Which flies cause myiasis in humans?
bot fly, screw worm fly, tumbu fly
Describe the bot fly life cycle
-female fly lays eggs on a blood-sucking arthropod.
-larvae develop in the egg and remain on the vector until it takes a blood meal from a host, at which point the larvae will penetrate the host
-mature larvae drop from the host and pupate
-one month later they molt into adults
some species lay their eggs directly on the host at the site of a wound
What do the flies have on their anterior end and on their on their posterior end?
mandibles on the anterior end
spiracles on the posterior end
How does the new world screw worm infect its host?
female lays eggs directly around the wound
How does the old world screw worm infect its host?
larvae penetrate mucous membranes or necrotic tissue around the eyes, mouth, and nose
Describe the tumbu fly life cycle
cause accidental myiasis
flies lay eggs on soil contaminated with urine and feces
emerging larvae attach to host and penetrate skin
What are the clinical features of bot fly worm infections?
cutaneous swellings on body or scalp that may produce discharges and be painful
How can screw worm fly be more dangerous than other fly infections?
larvae can migrate in the body, may not remain subdermal