Parasitology II

Arthropods that parasitize humans fall into 2 groups. These are:

• diptera and lice

• fleas and lice

• ticks and mites

• mosquitoes and flies

• arachnids and insects

A key difference between arachnids and insects is:

• arachnids feed on the hosts blood, insects dont

• arachnids have an exposed hypostome, insects dont

• insects have 2 body segments, whereas arachnids have 3

• insects have antennae, arachnids have palps

Leishmania spp. are what kind of protozoan?

• flagellate

• apicomplexan

• sporozoan

• cilliate

• amoebic

T or F. Mite larvae develop in the environment and then find a host to burrow in their skin

Scabies is a disease that can:

• occur in people who are immunocompromised but also in those with weaker immune systems

• cause thick crusts on the skin that can harbour thousands of mites

• occur in over-crowded environments

• all are true

• none are true

Infection with Group A Streptococcus (GAS) bacteria during scabies is facilitated by:

• burrowing of the mite into the skin

• scratching to relieve itchiness

• dampening of the host immune system by scabies

• all of the answers are true

• none of the answers are true

Two bacterial infections that commonly co-occur with scabies infection are:

• E. coli, Staphylococcus epidermidis

• Streptococcus pyogenes, E. coli

• Streptococcus pyogenes, Staphylococcus epidermidis

• MRSA, Staphylococcus epidermidis

• Streptococcus pyogenes, MRSA

Which group of protozoans has species that are solely parasitic?

• flagellates

• ciliates

• apicomplexa

• amoebae

• none of these, all groups include species that are free-living

A classic diagnostic feature of Giardia spp. in the trophozoite stage is?

• presence in the blood

• rash on skin where cercaria have breached the epithelium

• presence of four visible nuclei

• presence of two visible nuclei

• the cell has a light right around it

Shortly after Taxoplasma gondii invades the host, it differentiates into a form called

• bradyzoite

• tachyzoite

• oocyst

• cyst

• none of these