Arthropods Flashcards

Flashcards covering key vocabulary related to arthropods and their medical significance.

Sarcoptes scabiei

Parasitic arthropod that burrows into the skin, causing scabies in humans and animals.

Scabies

Common disease found worldwide, affecting people of all races and social classes.

Egg, Larva, Nymph, Adult

The stages in scabies life cycle

Larvae and Fertilized Females

Occur on the surface of the skin and drive new tunnels to infect new hosts.

Lifespan of a female Sarcoptes scabiei in human skin

Up to 4 weeks

Lifespan of Sarcoptes scabiei outside the host

Up to 10 days

How the scabies mite is transmitted from person to person

Direct contact

Where scabies mites burrow and produce tunnels in human skin

The horny layer (stratum corneum)

Main locations of scabies mites on the body

Between fingers and wrists

Approximate time for female mite to bury itself in the horny layer of skin

1 hour

Variable speed at which the scabies mite burrow is made

0.5 to 5.0 mm per day

How scabies spreads on different parts of the body

Scratching and manual transfer

Occurs due to the action of mites moving inside and on the skin

Intense itching sensations

Results from scratching scabies

Bleeding and secondary bacterial infections

Populations who are found to have Norwegian scabies (crusted scabies)

Elderly, immunosuppressed, and cognitive impaired populations

Unique pathological feature of Norweigian scabies

Thick crusts on the skin

Based on the diagnosis of scabies

Examination of infected skin and direct microscopic examination of skin scrapings

Common lotions used for scabies treatment

5% permethrin cream, 10% crotamiton lotion and cream, sulfur ointments

Prevention of Scabies

High social and personal hygiene, avoiding direct contact

Ixodes ricinus

Hard tick, ectoparasite infecting livestock, deer, dogs, and humans

Habitats of Ixodes ricinus

Cool, shrubby, or wooded areas

Where Ixodes ricinus is endemic

Most of Europe (excluding the Mediterranean region)

Ixodes ricinus

Three-host tick

Stages of Ixodes ricinus

Larvae, nymph, male, female

Location of the sensory Haller's organ on Ixodes ricinus

Tarsus of the first leg

critical functions of Haller's organ

Questing for hosts and mate seeking

Hypostome

Holdfast organ with large recurved teeth

Time required to complete the life cycle of Ixodes ricinus

Three years

Lifespan of Ixodes ricinus

Up to 15 years

Medical significance of Ixodes ricinus saliva and mouthpart action

Inflammation, ulceration, dermatosis, anemia, tick paralysis

Cause of tick paralysis

Neurotoxin produced by ticks

High-risk groups for Ixodes ricinus bites

Forest workers and tourists

Diseases transmitted by Ixodes ricinus

Viral tick-borne encephalitis, boreliosis (Lyme disease), tularemia, babesiosis

Based on the diagnosis of Ixodes ricinus

Detection of adult ticks in the folds of human skin and hairs

Prevention of Ixodes ricinus bites

Avoiding tick habitation, examination of body and clothes, using repellents

Pediculus humanus

Human louse

Geographic distribution of Pediculus humanus

Distributed worldwide

Parasitic type of Pediculus humanus

Permanent ectoparasite of humans

Two subspecies of Pediculus humanus

Pediculus humanus capitis (head louse) and Pediculus humanus corporis (body louse)

Where body lice (Pediculus humanus corporis) live

Seams of clothing

Stages of development of Pediculus humanus

Three larval stages

Time for life cycle of Pediculus humanus (egg to egg)

24 days

Number of eggs that a adult female Pediculus humanus deposit

300 eggs

Disease caused by Pediculus humanus

Pediculosis

How pediculosis is usually transmitted

Direct contact from person to person

Population usually affected by pediculosis

School children

Connected medical signficance of pediculosis

Intense pruritus, dermatitis, allergic reactions, secondary bacterial infections

Develops if the sympthoms of pediculosis persist for many years

Vagabond's disease

Changes known as plica in untreated pediculosis

Hairs become matted and gluted together by lymph exudate

Pediculus humanus corporis may transmit these diseases

Rickettsia provazeki, Borrellia recurrentis, Rochalimea (Rickettsia) quintana

Based on the diagnosis of Pediculus humanus

Detection of adult parasites and eggs on human hair and clothes

Treatment of Pediculus humanus

Medicated shampoos or creams containing pyrethrins or permethrin

Prevention of Pediculus humanus

Avoidance of contact with infected people and high personal hygiene

Pthirus pubis

Pubic (crab) louse

Parasitic type of Pthirus pubis

Cosmopolitan parasite

Location of Pthirus pubis on the human body

Pubic regions

Transmit of Pthirus pubis to new host infected person

Direct contact

Disease caused by Pthirus pubis

Pubic pediculosis or pthiriasis

Medical signficance of disease in Pthirus pubis

Very intense pruritus

Characteristic skin change at the feeding site of Pthirus pubis

Grey-blue pigmentation (maculae ceruleae)

Based on the diagnosis of Pthirus pubis

Typical location and direct detection of parasites

Affected patients report on clothing

Rust spots (louse excrement)

Prevention of Pthirus pubis

High personal hygiene and avoidance of sexual contact with infected people

Cimex lectularius

Bed bug

Daytime sites of bed bugs

Cracks in wall, mattresses, wallpapers, books, suitcases

Survival time for insects without food

18 months

Medical significance of bed bugs

Disturb sleep, cause allergic and inflammatory reactions, and reduce hemoglobin count

Based on the diagnosis of Cimex lectularius

Detection of adult forms of Cimex lectularius

Prevention of Cimex lectularius

High level of domestic cleanliness and insecticides

Glossina palpalis

Tsetse Fly

Response for disease of Glossina palpalis

Transmision of sleeping sickness

Inhabit of Glossina palpalis flies

Rural areas in the woodlands and thickets of East African savannah

Biting time Glossina palpalis flies

Daylight hours

Transmits infection of Glossina palpalis flies

Male and female

Anopheles maculipennis

Mosquito

Concentrated Geographic distribution of Anopheles maculipennis mosquitoes

Tropics and the subtropics

Anopheles maculipennis mosquitoes

Temporary extoparasites

Causative agent of malaria !!! in Anopheles maculipennis

Hosts of Plasmodium

May lead to various types of allergic reactions on the skin

Mosquitoes' saliva

Mosquito prevention of Anopheles maculipennis

Elimination of adult insects and use of repellents and insecticides

Culex pipiens

Common house mosquito

Culex pipiens Geographic location

Every continent except Antarctica

Single form Life cycle eggs of these mosquitoes are laid or sinlge or closely to each other as the raft

Culex Pipiens life cycle

Symptoms of Culex pipiens bites

Allergic reactions and hypersensitivity to mosquito bites

Pulex irritans

Human flea

Geographic Distribution of Pulex irritans

Worldwide

May all become infested by this human flea of Pulex irritans

Humans, canids, felids, pigs, badgers, rats

Site of infestation type of Pulex irritans

Pulex irritans attaches and feeds on the skin

Larvae Formpupae Diagnostic

Pulex irritans undergoing holometabolous Development

Causative agent of plague is vector of Vector isalso Pulex irritans

Black Death

Rickettsica Typhi causes typhus is vector of Pulex irritans vector

Mousedri

Bites of Pulex irritans can lead to medical infection

Restlessness and irritation of the skin

Diagnosis of Pulex irritans by accomplishing fleas on the host

Finding fleas on the host

Treatment for secondary pyoderma of all household and cat and dogs

Anti-inflammatory agents

Triatoma infestans bug as kissing bugs

Assassin bugs

Temporary Ectoparasite common in Triatoma infestans bug

South America

Triatoma Bug caused signficance medical infection

T. cruzi infection

Based on detection of adults, larvae and eggs in cracks

Domestical Cleanliness

Musca Domestica as known

Housesfly

Houseflies are believed to originated

Temperate regions