Chapter 1 Flashcards
A child dies of _____ every 30 seconds in Africa.
malaria
What is the annual human infections / death rates for all helminths?
4.465 billion infections / few deaths
What is the annual human infections/death rates for ascaris?
1472 million infected / 60 thousand deaths
What is the annual human infections/death rates for hookworms?
1298 million infected / 65 thousand deaths
What is the annual human infections/death rates for trichuris?
1049 million infected / 60 thousand deaths
What is the annual human infections/death rates for filarial worms?
657 million infected / 20-50+ thousand deaths
What is the annual human infections/death rates for schistosomes?
200 million infected / 0.5-1 million deaths
What is the annual human infections/death rates for malaria?
689 million infected / 1-2 million deaths
(150 million new cases per year)
What is the annual human infections/death rates for chagas disease?
18 million infected / 50+ thousand deaths
What is the annual human infections/death rates for entameoba histolytica?
50 million infected / 40 thousand deaths
What is the annual human infections/death rates for HIV/AIDS infection?
50-60 million infected / 8 million (estimated) deaths
What is the number of children in the US infected with worms?
about 55 million
What are the extremely successful organisms in the world today?
ticks and mosquitoes
What is the definition of parasitism?
symbiotic relationship in which the parasite is metabolically dependent on the host
what is the definition of symbiosis?
heterospecific organisms living together
Which species is the host in a symbiotic relationship?
the larger species
Which species is the symbiont in a symbiotic relationship?
the smaller species
what is phoresis?
symbiont carried by host
what is an example of phoresis?
pollen on bee leg
what is commensalism?
symbiont shares food
what is an example of commensalism?
anemone and clownfish
what is mutualism?
symbiont and host metabolically dependent on each other
what is an example of mutualism?
fungus and alga
what is a key feature of parasitism?
metabolic dependency
what are the general characteristics of parasites?
show degrees of host specificity based on:
1) physiological specificity
2) ecological specificity
What is the only insect host for the malaria parasite?
Anopheles mosquitoes
Why are Anopheles mosquitoes suitable hosts for malaria?
1) biochemically suitable (pH, nutrients, osmolarity)
2) immunologically tolerant
Some Anopheles are _______.
zoophilic
About how many species of Anopheles mosquitoes commonly transmit malaria to humans in nature?
30 - 40 species
When there is a protective antigen produced by the body, what is the fate of the parasite?
parasite killed
When there is a nonprotective antigen produced by the body, what is the fate of the parasite?
parasite lives
When there are immunodominant nonprotective antigens produced by the body, what is the fate of the parasite?
parasite lives
When there is an antigenic variation (expression of a new antigen), when the antibodies attack, what happens?
antibodies don’t recognize the new antigen
What is antigen mimicry?
parasite is viewed as “self” (good) antigen and able to be absorbed (or synthesized) from host
What is a major cause of harm?
immunopathology
what is hypersensitivity?
overstimulation of the immune system that leads to tissue damage (tissue damage often due to inflammation)
what are host proinflammatory molecules (given examples)?
cytokines
what is an example of occupation of privileged site?
blood cells (no MHC proteins on RBC)
what is occupation of privileged site?
antibody cannot cross membrane
what is immunosuppression?
may protect host from hypersensitivity (avoids clearance)
What is an example of a harmful effect on host for competition for nutrients?
megaloblastic anemia due to competition for vitamin B12 by tapeworm
what is an example of mechanical interference?
blockage of bile ducts by liver flukes
what is an example of hypersensitivity?
elephantiasis due to immune-mediated destruction of lymphatic vessels
what is an example of destruction/alteration of tissues?
destruction of nasal septum by Leishmania braziliensis
What does tremendous biotic potential do?
offsets the improbability of completing a complex life cycle
How do adult worms compensate for tremendous biotic potential?
lay 1000000 eggs/day
What do the “best parasites” do?
live in relative harmony w/host
what is the term for the offspring of parasites?
progeny
what is the definition of obligate?
host required for survival or life cycle
what is an example of obligate?
tapeworms + female mosquitoes
what is the definition of facultative?
free living organism (parasite)
what is an example of facultative?
Naegleria fowleri (brain eating amoeba)
what is the definition of accidental (referring to type of parasite)?
parasite in wrong host (usually dies)
what is an example of accidental parasite location?
dermatitis caused by avian schistosomes (usually carried by ducks + geese)
what is the definition of endoparasite?
live inside human
what is the definition of ectoparasite?
live on outside on body surface
what is an example of ectoparasite?
Anopheles mosquito
what is a hyperparasite?
parasite of a parasite
what is an example of a hyperparasite?
Anopheles mosquito bites human infected with plasmodium
What is a definitive host?
a host where sexual reproduction occurs
what is a reservoir host?
alternative (to human) definitive host
what is zoonosis?
infection of human by animal parasite
what is an intermediate host?
asexual reproduction or development
what is paratenic host?
transport only (no reproduction/development occurs)
What is usually the most important host in nature?
reservoir
what are the characteristics of protozoa?
- eukaryotes
- unicellular parasites
- absorb/ingest organic chemicals
- may be motile (via pseudopods, cilia or flagella) or non-motile
What is needed for diagnosis of malaria/plasmodium?
“O” trophozoite ring
what are parasitic flatworms and roundworms called?
helminths
What is an example of multicellular parasite?
flatworms + round worms
what are the 7 eukaryotic “lineages” or kingdoms?
- excavata
- amebozoa
- alveolata
- stramenopila
- rhizaria
- plantae
- opistholomta
what are the 3 domains of life?
bacteria, archaea, and eukarya
what are the kingdoms with human parasites?
- excavata
- amebozoa
- alveolata
- stramenopila
- opistholomta
what 4 kingdoms are protists (single celled)?
- excavata
- amebozoa
- alveolata
- stramenopila
What are the 3 major phyla of parasites of opisthokonts?
- platyhelminthes
- nematoda
- arthropoda
what is zoonotic spillover?
virus, bacteria, or protozoan spills over from its intended placement to another causing disease
what does sylvatic mean?
jungle
what is a vector? (definition)
a living organism that transmits an infectious agent from an infected animal to a human oranother animal
Vectors are frequently _______. (what phylum)
arthropods
There have been _____ totally novel new or reemerging diseases novel since 1980.
87
______ percent (or more) of all known infectious diseases in people can be spread from animals.
60%
_____ of every _____ new or emerging infectious diseases in people come from animals.
3 of every 4
What is an example of zoonosis?
lyme disease
What is the vector of Lyme disease?
lxodes scapularis
_____ serve as the amplifying host for Borrelia burgdorferi.
Humans
what is Borrelia?
bacteria that is in ticks that frequently lead to Lyme disease
The CDC already reports an estimated total ofabout ______ cases of Lyme disease per year.
476,000
AGS is associated with _______ _______.
tick bites
who is the Christian pioneer in parasitology?
Anton van Leeuwenhoek