Anthropod parasites Flashcards
Arthropods
invertebrate animal that has an exoskeleton, a segmented body & jointed appendages
- can be a parasite themselves or act as a host or vector for other organisms
Ectoparasites vs vectors
ectoparasites : parasites that feed on humans ( lice, ticks, mosquitos)
vectors: transmit disease called by other microorganism)
Arthropod modes of transmission
mechanical transfer
- the insect is not required as part of a parasites lifecycle
- no further development or growth of the parasite occurs in the insect
Biological transfer
- the vector is required part of the parasites lifecycle
- growth & development of the parasite must occur inside the insect
bites & stings can cause
- hypersensitivities , allergic reactions, fatal anaphylaxis
- blood loss
- secondary bacterial infections
- injection of toxins & venoms
Myiasis
infestation of larvae in the body
- insect deposits eggs on the host ( wound)
- larvae hatch & invade the skin & feed on tissue
- larvae have been recovered from the ear, nose& urigenital tract
- ingestion of fly eggs or larvae may produce intestinal myiasis
Flies & mosquitos
greatest medical importance
- bloodsucking mosquitos & flies may transmit many viral, protozoan & helminthic diseases
- ectoparasites as adults
Lice
- Permanent ectoparasites that live on the host only
- Eggs ( nits) are deposited on hair shaft of the host
- usually transferred directly from host to host
- eggs from louse infected clothing & personal articles may be infection
sources - Body lice may be acquired from cloth covered seats
- Pubic lice may be transferred via sexual intercourse or in gyms & change
rooms
Lice symtoms, diseases & treatment
- symptoms include irritation at site of infestation
- saliva & fecal excretions cause local hypersensitivities & inflammation
- secondary bacterial infections may occur
- treatment requires removal/killing of eggs & motile stages
- many commercial & home remedies used as treatment options
- body lice may transmit RIckettsia spp. ( cause of endemic typhus & trench fever)
Fleas; symptoms, infections, treatment
Adult flea sucks blood from a temporary host & then lays eggs
Symptoms include irritation & possible allergic reaction
secondary bacterial infections may also occur
different flea species carry & transmit
- RIckettsia typhi ( causes murine typhus )
- Yersinia pestis ( bubonic “black” plague )
- tapeworms
treatment: eliminating flea from pets & in the household with continued use of commercial products
Prophylactic treatment of pets is common for prevention
Ticks & mites transmission & symptoms
ticks transport more vector borne diseases than any other arthropod
the tick feeds ( sucks blood) & transmits the disease into the bloodstream
tick paralysis ( toxicosis) can occur when a female tick remains attached for more than 4 days in susceptible hosts
bite wounds may become infected if parts of the tick are left behind after removal
symptoms: skin irritation, inflammation, edema & hemorrhage at bite site
Ticks & mite diseases
Babesiosis- Babesia spp. ( parasite) enters the bloodstream(tick bite) & infects the RBCs
Scabies- caused by Sarcoptes scabiei ( itch mite) diagnosed by finding eggs, nymphs or adult motes in skin scrapings of infected lesions
Dematophagoides spp. -( house dust mites) cause dust allergies - feed on sloughed skin cells, food particles & other organic matter
Ornithonyssus sylviarium- bird mite that migrate into the home from birds nests & can infect pets & humans
Borrelia burgdorferi- transmitted by ticks & cause lime disease
Ticks & mites treatment
Ticks
- remove tick (fully) & treat the irritation & potential disease
- pets can be treated prophylactically to prevent tick bites
Mites
- treat the irritation & allergic reaction
- prevent infestation with good cleaning regime
