Medical Entomology Flashcards
Medical entomology
– science that deals with _____ of medical importance
arthropods
Mosquitoes
their bites can produce ______, and the bites of some species are ____ to certain individuals.
itchy welts
painful
“Quality of life” can be reduced in areas with high numbers of biting mosquitoes
T/F
T
Mosquitoes
Depending on the species, mosquitoes are vectors of
the _____ that cause malaria,
the _______ that cause filariasis,
and a large number of ____viruses
protozoa
nematode worms
arbo
Mosquitoes
There are an estimated ____ species of mosquitoes in the world
3,200
____ mosquitoes that transmit West Nile Virus.
It also includes nuisance species such as some _____,______,_______ mosquitoes that are aggressive bloodsuckers, but are not known to be vectors of West Nile Virus
Culex
Aedes, Ochlerotatus, and Psorophora
Mosquito as effective vector
Vector competence” refers to the ability of a mosquito to _____________________________
acquire an arbovirus from a reservoir host and later transmit the arbovirus to a susceptible host during the act of taking another blood meal.
Mosquitoe’s vector competence is dependent on the mosquito being a ____________________________________________
suitable host in which the arbovirus survives, undergoes essential development, multiples, and eventually reaches and infects the salivary glands.
Mosquito as effective vector
Vector capacity is determined by a number of factors such as ____________________________________________
Physiological factors also are important, including ____________ by specific arboviruses.
vector competence, and mosquito population density, host preferences, and biting rates.
mosquito immunity to infection
Mosquitoes may be competent, but are not effective vectors if they have _________
low vector capacity
Life cycle of mosquitoes?
Eggs
First larval
Second larval
Third larval
Fourth larval
Pupa
Adult
Which stages of the mosquitoe life cycle survives in aquatic environment?
Larval and pupa
Mosquito control
-______ reduction
–
Adulticiding– Use of ______
-_______
Source
pesticide
Larviciding
Source reduction
Is the ________________________
elimination of water from places where mosquitoes lay eggs.
Larviciding typically involves applying pesticides containing ________ or ———— or _________, to water where mosquito larvae develop
methoprene or Bacillus thuringiensis israelensis or B. sphaericus bacteria
Larviciding
. ____fish (Carassius) and _____ fish (______) can be used for this purpose as well.
Other types of larvicides include those that ______________________ designed to ___________
Gold; carassius
Modquito; Gambusia
cover the surface of the water with thin films of liquid
prevent larvae from obtaining oxygen at the water’s surface.
Preventing mosquito bite
Mosquito Repellents
Repellent products containing ____,______, oil of ________ are recommended by the _____________ (CDC)
The CDC also recommends treating clothing with ________ which acts both as a ______ and an ______.
DEET, picaridin
lemon eucalyptus
Centers for Disease Control and Prevention
permethrin; repellent; insecticide
compounds such as _____,_______, and ______ are purported to be repellents, but research does not support this
citronella, garlic, and vitamin B
Preventing mosquito bite
_________ clothing
________ treated mosquito nets
Protective
Insecticide
In anopheles
Palpus is longer than proboscis
T/F
F
Equal length
Mention one specie of anopheles
Anopheles gambiae
Mention two specie of aedes
Aedes aegypti
Aedes albopictus
Mosquito borne diseases
•– Malaria parasite = _____ spp
•– __flies use mosquitoes as intermediate vectors
Helminthiasis
•–______ by different species of mosquito-
(Culex , Anopheles, Aedes , ______ mosquito)
anopheles
Bot
Filarial worms
Mansonia
Myiasis is the infection of a _____(____) in human tissue.
fly larva (maggot)
Mosquito borne diseases
Virus
Arboviruses like ____ fever, ____ fever, ____ fever and ______ are transmitted mostly by _______ mosquitoes.
___________(EEE) and ________(WEE) by __________
yellow; dengue; Zika ; chikungunya
Aedes aegypti
Eastern equine encephalitis; Western equine encephalitis
culex and Aedes
Lice
are (small or large?) (winged or wingless?) insects that feed on ______ or ________
Small
Wingless
Dead skin
Blood of hosts
Lice move by ______; they cannot _____ or ____
crawling
hop or fly
LICE
Phylum ______
Class _____
Order ______ ( ____lice) or Order _____ (______ lice)
Arthopoda
Insecta
Phthiraptera; sucking
Mallophaga; chewing
Chewing lice feed on mammals (except _______) and _____
humans
birds
Behaviour and Habitat
Sucking lice are found on _____ and mainly thrive by _______
Modes of Transmission: ______ and through ______ (clothes, combs and other beddings).
humans
sucking blood.
person to person
formites
Human lice
can be found on people’s ______ and _____, including the _____ area
survive by feeding on _______
heads, and bodies
Pubic
human blood.
Lice found on each area of the body are different from each other.
The three types of lice that live on humans are:
head lice (___________)
body lice (___________)
pubic lice (________, pubic lice)
Pediculus humanus capitis
Pediculus humanus corporis
Phthrus pubis
Life cycle of lice
consists of ____ stages
List them
three
nit; nymph ; Adult
LICE
The duration from egg to egg stage about ______
one month
Life cycle of a lice??
Eggs
First laval
Second laval
Third laval
Adult
Which stages of the life cycle of lice is diagnostic and which stage is infective
Eggs, First laval, Second laval, Third laval
= diagnostic
Adult= infective
Pediculus humanus capitis
Adult head lice are _________ in length.
Head lice infest the head and neck and attach their eggs to the ____________
Females can lay up to ____ per day.
2.1–3.3 mm
base of the hair shaft.
8 nits
Pubic lice = _____
Crab louse
Adult head lice
Which is larger, female or male
Female
Adult lice can live up to _____ on a person’s head.
30 days
To live, adult head lice need to feed on blood several times daily.
T/F
T
Without blood meals, the head louse will die within ________ off the host
1 to 2 days
Pediculus humanus corporis
Adult body lice are _____ mm in length.
Body lice live and lay eggs on ______ and only move to the ____ to feed spread most commonly by close person-to- person contact but are generally limited to persons who live under conditions of ________ and _______ (for example, the homeless, refugees, etc.).
2.3–3.6
clothing
skin
crowding and poor hygiene
Phthrus pubis
Adult pubic lice are ________ mm in length.
Pubic lice typically are found attached to ____ in the ____ area but sometimes are found on coarse hair elsewhere on the body (for example, _______,________,_____,_______ etc.
1.1–1.8
hair; pubic
eyebrows, eyelashes, beard, mustache, chest, armpits,
Phthrus pubis
Females will lay approximately ____ eggs during their _______ life span.
Eggs hatch after about a ___ and become _______, which look like (smaller or larger?) versions of the adults.
30; 3–4 week
week; nymphs
Smaller
Phthrus pubis
The nymphs undergo ______ molts before becoming adults.
Adults are _______ mm long and flattened.
three
1.5–2.0
Which is the widest
Head, body, or pubic lice
Pubic lice are much broader in comparison to head and body lice.
Pubic lice are transmitted from person to person most-commonly via _______, although ______ (bedding, clothing) may play a minor role in their transmission.
sexual contact
fomites
The majority of head lice infestations are (symptomatic or asymptomatic?)
asymptomatic
lice
When symptoms are noted they may include
a ____ feeling of something moving in the hair
______, caused by an allergic reaction to louse _____,
_______
tickling
itching; saliva
Irritability
lice infestation
Secondary ________ may be a complication.
Body lice can serve as vectors for ___________(epidemic ____), _________ (________), and __________ ( ____________ fever).
bacterial infection
Rickettsia prowazekii ; typhus
Bartonella quintana; trench fever
Borrelia recurrentis; louse-borne relapsing
Treatment of lice
_________ or ________
________
permethrin or pyrethrin
Ivermectin
Control of lice
Check all close contacts and treat
Wash clothes with ___ water or wash machine and dry using the ___ water and ___ air cycles because lice and eggs are killed by exposure for _______ to temperatures greater than ____°C (128.3°F).
hot; hot; hot; 5 minutes
53.5
TICKS
Ticks are small _____ that are also ____parasites that feed on _____ of mammals, birds and some on reptiles and amphibians.
arachnids; ecto ; blood
Ticks belong to the
Phylum _____
Class _____
Order ______.
There are over ____ species of ticks throughout the world, but only two families of ticks, ____ (hard ticks) and _____ (soft ticks), are known to transmit diseases or illness to humans.
Arthopoda
Arachnida
Acari
800
Ixodidae; Argasidae
Hard ticks have a ____, or ———, on their back while soft ticks do not.
scutum
hard plate
The life cycle of ticks consists of ____ stages:
Mention them
four
egg
larva (6 legs)
nymph (8 legs)
Adult (8 legs)
TICKS
It feeds on ____ different hosts during their life cycle which lasts for _____ and most will die because they don’t find a host for their next feeding
three
2 -3years
Life cycle of lice lasts ___ long
Life cycle of ticks lasts _____ long
One month
2-3 years
Ticks are commonly found near _____ and ____ and _____. They attach to a host’s body by inserting its _____ and ______ into the skin of the host (mainly dogs and cats).
trees and shrubs and water
mandibles
Feeding tube
Risk of greatest infection to human occurs in late ____ and _____
Late spring and summer
Egg- _____
Larva- _____
Nymph-_____
Adult-_____
Spring
Summer
Spring
Fall
The causative agent of Rocky Mountain spotted fever is??
Rickettsia rickettsi
From which stage of the tick life cycle can they infect humans
From nymph
Feeding and disease transmission of tick
Depending on the tick species and its stage of life, preparing to feed can take from ____ to _____.
When the tick finds a feeding spot, it _____ the skin and _________
The tick then __________
Many species also secrete a _______ substance that keeps them firmly attached during the meal.
10 minutes to 2 hours
grasps; cuts into the surface.
inserts its feeding tube.
cement-like
The feeding tube can have _____ which help keep the tick in place.
barbs
Ticks also can secrete small amounts of saliva with _______ properties so that _____________.
anesthetic
the animal or person can’t feel that the tick has attached itself
A tick will suck the blood (rapidly or slowly?) for _____.
Slowly
Several days
If the host animal has a blood borne infection, the tick will ____________.
Small amounts of _____ from the tick may also enter the skin of the host animal during the feeding process. If the tick contains a pathogen, ______________
After feeding, most ticks will ——- and prepare for the next life stage. At its next feeding, it can then ___________
ingest the pathogens with the blood
saliva
the organism may be transmitted to the host animal in this way.
drop off ; transmit an acquired disease to the new host
dog tick (_________ ________)
Transmits: _________ and ______
Comments: The highest risk of being bitten occurs during _____ and _____
Dermacentor variabilis
Tularemia and Rocky Mountain spotted fever.
spring and summer.
Dog ticks are sometimes called ——- ticks.
wood
Dog tick
________ are most likely to bite humans.
Adult females
Blacklegged tick (_____ _____)
Transmits: ________________________.
Comments: The greatest risk of being bitten exists in the ___,____,______. However, adults may be out searching for a host any time winter temperatures are above freezing. Stages most likely to bite humans are _________________
Ixodes scapularis
Lyme disease, anaplasmosis, ehrlichiosis , babesiosis, Borrelia miyamotoi, and Powassan disease
spring, summer, and fall
nymphs and adult females.
Brown dog tick (_____ ______)
Transmits: _____________
Comments: _____ are the primary host for the brown dog tick in each of its life stages, but the tick may also bite humans or other mammals.
Rhipicephalus sanguineus
Rocky Mountain spotted fever
Dogs
Gulf Coast tick (________ _______)
Transmits: ______ ______ _____, a form of spotted fever.
Comments:________ feed on birds and small rodents, while ____ ticks feed on deer and other wildlife. Adult ticks have been associated with transmission of R. parkeri to humans.
Amblyomma maculatum
Rickettsia parkeri rickettsiosis
Larvae and nymphs
adult
Lone star tick ( _______ _______)
Transmits: _______ and ________ (which cause human ehrlichiosis), _____ virus, ____, and ______
Amblyomma americanum
Ehrlichia chaffeensis and Ehrlichia ewingii
Heartland; tularemia; southern tick-associated rash illness (STARI).
Lone star tick is a very aggressive tick that bites humans.
T/F
T
Lone star tick
The adult female is distinguished by a ___________.
white dot or “lone star” on her back
Lone star tick saliva can be ______ leading to ______ and ______ but that
does not necessarily indicate an infection.
The ____________ most frequently bite humans and transmit disease.
irritating
redness and discomfort
nymph and adult females
Rocky Mountain wood tick (______________)
Transmits: __________ fever, _______ fever, and _______.
Comments: Adult ticks feed primarily on large mammals. Larvae and nymphs feed on small rodents. _____ ticks are primarily associated with pathogen transmission to humans.
Dermacentor andersoni
Rocky Mountain spotted
Colorado tick ; tularemia
Adult
Western blacklegged tick (______ _____)
Transmits: ______ and _____ disease.
Comments: Nymphs often feed on lizards, as well as other small animals. As a result, rates of infection are usually low (~1%) in adults. Stages most likely to bite humans are _______ females.
Ixodes pacificus
Anaplasmosis and Lyme
nymphs and adult
Soft ticks(________)
Ticks that are vectors of ————- fever.
Aragasidae
tick-borne relapsing
Argasid ticks Unlike the ixodid (hard) ticks, which stay attached to their hosts for up to ______ while feeding, most argasid ticks are adapted to _______ (for about an ____), then dropping off the host.
several days
feeding rapidly ; hour
Prevention of tick bites
Avoid _______ areas with high grass and leaf litter.
Walk in the _____ of trails.
Use repellent that contains ___ percent or more _____, ____, or IR3535 on exposed skin for protection that lasts several hour
Use products that contain _____ on clothing.
Treat clothing and gear, such as boots, pants, socks and tents with products containing ___% _______. It remains protective through several washings. Pre-treated clothing may be protective longer.
wooded and brushy; center
20 ; DEET; picaridin
permethrin
0.5; permethrin
How to remove a tick
Use _______ to grasp the tick as (far from or close to?) the skin’s surface as possible.
Pull ___ward with steady, even pressure. Don’t _______ the tick; this can cause ___________ , If this happens, remove them with ____. If you are unable to remove the mouth easily with clean tweezers, leave it alone and let the skin heal.
fine-tipped tweezers
Close to
up; twist or jerk
the mouth- parts to break off and remain in the skin.
tweezers
How to remove a tick
After removing the tick, thoroughly ____ the bite area and your hands with _____ rub, an _____ scrub, or ________
clean
alcohol; iodine; soap and water
Dispose of a live tick by _______________,__________,_______ or __________
Never ___________
submersing it in alcohol, placing it in a sealed bag/container, wrapping it tightly in tape, or flushing it down the toilet
crush a tick with your fingers
Fleas are (small or large?) , (winged or wingless?) bloodsucking insects with a characteristic _______ movement.
order __________
feed mainly on ——- but also on _____.
Small; wingless
jumping
Siphonaptera
mammals; birds
Fleas
The most important species are the _____,______,_ and _______
Their bites can cause ______, serious _______ and ________
rat flea, the human flea and the cat flea
irritation; discomfort
loss of blood.
Life cycle of fleas?
Egg
Larva
Pupa
Adult
Fleas move towards light
T/F
F
Fleas avoid light and are mostly found among the hairs or feathers of animals or in beds and in people’s clothing.
Heavy infestations with fleas are recognized by marks on ______ and bedding of _______ ejected by the fleas.
clothing
undigested blood
Most flea species feed on one or two host species, but in the absence of their normal host(______) they feed on humans or other animals.
Dogs
Adult fleas can survive _______ without food.
several months
Fleas move around by ______
some species can go as far as _______
Jumping
30cm
Diseases transmitted by fleas
The rat flea is important as a vector of _________ and ________
Cat fleas incidentally transmit _______.
bubonic plague; flea-borne typhus.
tapeworms
Dog and cat fleas transmit ______ caused by the ________________; and _________
tularaemia
bacillus Francisella tularensis
parasitic tapeworms
Flea control
Individual self-protection
An effective repellent, such as _____, applied to skin and clothing
DEET
Flea control
Heavy infestations can be controlled by spraying or dusting ______ into cracks and crevices, corners of rooms and areas where fleas and their larvae are likely to occur.
Insecticides can also be applied to clothing and the fur of animals
insecticides
Sand fleas or jigger fleas
The sand flea, ____ or jigger flea is unique among the fleas, it is a nuisance because the (males or females?) _________.
Specifically into the _______
chigoe
Females
burrow into the skin
Stratum granulosum
Diseases transmitted by jigger fleas
The sand flea, or jigger flea is not known to transmit disease to humans
Treatment of the aftermath of jigger fleas?
Skillfully remove the jigger and avoid rupturing of the egg sac
Dress the wound
MITES
Mites are tiny arthropods, related to ______.
ticks
The tropical ___ mite, ______________ , is one of the most common house invading species.
The tropical fowl mite, _________
northern fowl mite, ________, are also frequently encountered in homes.
rat; Ornithonyssus bacoti
Ornithonyssus bursa
Ornithonyssus sylviarum
The house mouse mite, ________________, may also be found in structures with house mouse infestations.
Liponyssoides sanguineus
Although none of these mite species are truly parasitic on _____, they ____ people readily, often producing ______ and ______
humans
bite
dermatitis and itching.
House dust mites
The house dust mite allergen is one of the most potent triggers of allergic reactions; it is a common trigger for _____,______, and ______
The main genus is identified as:
_____________
rhinitis, asthma and eczema
Dermatophagoides
Mention one non-biting mite
Clover mite(nonbiting)
Dust mites drown in water.
T/F
T
Bed bugs
parasitic insects of the ______ family that feed exclusively on blood.
cimicid
Blood
Two species of bedbug feed on humans: the ____ bedbug (____________), which occurs in most parts of the world, and the ______ bedbug (___________), which occurs mainly in tropical countries.
Common; Cimex lectularius
Tropical; Cimex hemipterus
Cimex ____, the common bed bug, is the best known as it prefers to ______
lectularius
feed on human blood
Bed bugs (Cimex lectularius)
Live in (cold or warm?) houses especially near or inside _____ and bedding or other sleep areas mainly active at ( day or night?) , but can bite during the ____ usually feed on their hosts without being noticed.
Warm; beds
Night
Day
A number of adverse health effects may results from bed bug bites, including _______, ________ effects, and ______ symptoms.
skin rashes
psychological; allergic
Bed bugs transmits _____ pathogens
no known
Bed bugs are regarded as disease vectors
T/F
F
They are not
Life cycle go bed bugs have ______ nymph life stages and a final sexually mature adult stage
five immature
Light bed bug infestations can be treated by ________ infested articles, pouring ______ water over them and exposing them to ____.
Aerosol spray cans can be used to spray household ______ on to mattresses, in crevices in walls, and in other possible hiding places
Long lasting insecticide treated bed net Indoor residual spray/ fumigation
thoroughly cleaning
boiling
Sunlight ; insecticides
scabies mite causes ____ which is _______ due to an _______ to the female mite’s trail of ____,_____, and _____
scabies; itchy skin rash
allergic reaction
debris, faeces and saliva.
Its most severe form(———- or ______ scabies) is highly transmissible in the _______ environment.
Crusted or Norwegian
hospital
Scabies transmission occurs when there is transfer of a fertilized female mite by (direct or indirect?) , prolonged (approximately ________) _______ contact with an infested person.
Direct
five minutes; skin-to-skin
Scabies Infection is easily spread to sexual partners and household members.
T/F
T
Transfer of scabies mite can also result from sharing clothing, towels and bedding as the mite can live for up to ________ away from the human body.
two to three days
Scabies completes its entire life cycle on its ______ hosts and, After mating the ___ dies , _____ burrow ________ to lay eggs (__/day)
larvae emerge and mature to reinfest the same or new hosts.
male; females; intradermally
2-3
Scabies
The entire incubation period from eggs to full-grown mites lasts ______ days.
The human incubation period from initial infestation to symptom development is _________ in initial infestations and as short as ________ in reinfestations as a result of sensitization to mite antigens.
14 to 15
3 to 6 weeks
1 to 3 days
Clinical features of scabies
intense itch, worse at ____ and after a (cold or hot?) shower/bath
______________ are usually seen on the wrists, interdigital spaces of fingers and toes, popliteal fosa flexor surfaces of wrists ,the axillae, genitalia, buttocks
Nonspecific secondary lesions occur commonly as the result of ______ and ______
night; hot
Rashes and burrows
scratching and secondary infection.
Myiasis is an ___parasitic infestation of _______ or ______ tissues larvae of _____
Ecto
viable or necrotic
higher flies.
________ myiasis is the most common clinical manifestation of myiasis and occurs when _________________, causing _______ lesions that resemble ____ or ____
Furuncular
one or more fly larvae penetrate the skin
pustular; boils; furuncles
dog tick (_________)
Blacklegged tick (______)
Dermacentor variabilis
Ixodes scapularis
Common bed bug(___________)
Tropical bed bug (_________)
Scabies mite (___________)
cimex lectularis
cimex Hemipterus
sarcoptes scabiei
Tropical rat mite (___________)
Tropical fowl mite (_____________)
Northern fowl mite (___________)
Ornithonyssus bacoti
Ornithonyssus bursa
Ornithonyssus sylviarum
Brown dog tick (_______________)
Gulf Coast tick (_____________)
Lone star tick (___________)
Rhipicephalus sanguineus
Amblyomma maculatum
Amblyomma americanum
Rocky Mountain wood tick (__________)
Western blacklegged tick (________)
Dermacentor andersoni
Ixodes pacificus
Fleas (_________)
rat flea (___________)
A cat flea (__________)
Ctenocephalides
Xenopsylla species
Ctenocephalides felis felis
Human fleas (___________)
Sand flea/jigger fleas (___________)
Pulex irritans
Tunga penetrans
House mouse mite(_____________)
Liponyssoides sanguineus
