STUDY SHEET FOR VT 0440,"CONQUEST OF THE PARASITES"
(from 1984, but most of it still valid--no major changes on the parasite front!)
Fill in the blanks as you watch the video and then use this as a study guide for parasites and possible approaches to parasite control.
- The intestines of ____________________________ of the world's population contains parasitic worms.
- Parasites try to _____________________ a body's defenses.
- Parasites get food and shelter from their ________________________.
- Parasitic diseases tend to be ________________________, debilitating conditions.
- Most parasites tend to be found in what general part of the world? ___________________________
- Ascaris
worms living in the gut can be up to ____________________ long.
- Hookworms cause a debilitating ____________________ because of their cutting plates biting into the intestinal wall.
- Life cycles that include other organisms besides _____________________ make parasites very difficult to control.
- Blood sucking insects are known as _________________________ and carry parasites to new hosts.
- The filarial worm Wuchereria bancroftii creates the lymphatic blockage disease known as
____________________________________.
- A major cause of blindness in the world is the filarial disease _________________________________.
- In summary, river blindness is caused by (circle one):
living female filarial worms living microfilariae dying microfilariae
- Spraying rivers with insecticides has lead to ______________________________ in the vector black flies (Simulium spp). (1999 update: rotation of different insecticides and single dose ivermectin drug treatment has made onchocerciasis a smaller problem than portrayed here, at least in areas where resources have been concentrated).
- People are infected by the blood fluke (Schistosoma, bilharzia worm) by ___________________________.
- Schistosoma
can live upwards of ____________ years inside of their human hosts.
- The real damage of the schistosome comes from its _________________, which squeeze through the bladder and intestinal walls.
- The schistosome life cycle includes what two organisms as hosts? __________________ and
____________________.
- What are two major approaches to dealing with schistosomiasis?
_____________________________________________
_____________________________________________
- The trypanosome parasite causes _______________________________. This infects humans and
___________________. As a result, Africa does not raise a lot of meat for consumption or export.
- The vector for the trypanosome is the _______________________. In addition to feeding on humans, this
vector also feeds on ______________________, which means there is a large resevior for the parasites.
- The most common and biggest killer of the parasitic diseases is ____________________. This parasite consumes and destroys red blood cells in part of its life cycle.
- The Anopheles mosquito that carries the malaria parasite can be potentially controlled since it rests in
peoples' houses at _______________ after feeding. Although subtropical areas are now mostly free of malaria, many of the mosquitoes are now resistant to DDT, the traditional pesticide.
- A major form of preventing infectious disease is __________________________, requiring the least compliance among the population.
- An example of a viral disease totally eliminated by vaccination is ______________________________.
In the video, scientists are gathering to use modern techniques to create vaccines. Note: 1984 was the beginning of the explosion in the use of molecular biology techniques. 1999 update: trials to date of malaria vaccines disappointing, so the excitement mentioned in this video still hasn't panned out!
- The principle behind vaccination is to prime the immune system, so that the next time a parasite arrives
_____________________________________________________________________
- Surface _____________________ molecules are what trigger immune responses, and the body responds to
them by sending _________________________ molecules to bind to them.
- One needs the technology of _________________________________ to find antigen genes.
- Genetic engineering uses ___________________________, because they grow rapidly and will express their own and the introduced genes.
- Schistosomes can disguise themselves by coating their surfaces with ____________________________.
- Trypanosomes can vary their __________________________________, to avoid the host's immune system. (1999 update: development of successful in vitro systems to grow trypanosomes in laboratories allows efforts to genetically address this"switching" process.)
- True false Conventional vaccines will work on trypanosomes.
- How have parasites learned all these techniques to avoid the immune system of their
hosts?______________________________________
- Of the major parasitic diseases, __________________________ seems to be the best chance for a vaccine.
- Malaria has three major stages in its life cycle: ________________________injection stage; rbc destroying
___________________________ stage; and the sexually mature ____________________________ stage picked up by the mosquito.
- Many scientists are working on the sporozoite stage of the malaria parasite, but the body has only
____________________________ before these hide from the immune system.
- True False Tropical diseases will be a big money maker for international drug companies.
- Who will pay for vaccines for tropical parasitic diseases? ______________________________
- Dictol is a veterinary vaccine to prevent ______________________________ in cattle. This helps to show that livestock are worth the investment, and that frankly, humans in developing countries do not figure to be as profitable for drug and vaccine development.
- One final discouraging factor is the distribution for vaccines. Polio and measles vaccines exist, yet these
are still major diseases in places like _____________________. A malaria vaccine might require multiple followups for boosters, hence putting additional strain on local health systems.
- Will parasitic diseases be here to stay? ____________________________________
|main page| |background| |03028: Physiology| |03048: Anatomy|
|03050: Invertebrate Zoology| |03051: Vertebrate Zoology| |03074: Economic Botany|
Please send comments and questions to: cronewil@hvcc.edu
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Copyright 1999 by Wilson Crone
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This page updated on October 8, 1999
