Seminar 6: Nematodes 2 (Dracunculus)

Question 1

Dracunculus are nematodes often called “___ ____”

Answer 1

guinea worms

Question 2

Neglected tropical diseases=

Answer 2

NTDs
= diverse group of tropical infections that typically infect low-income populations
- 20 are prioritized by WHO

Question 3

Give 3 prioritized NTDs

Answer 3

• chagas disease
• echinoccocus
• dracunculiasis or guinea worm disease

Question 4

What are 2 ways humans can become infected with guinea worm disease?

Answer 4

1. drinking unfiltered water containing copepods with L3 larvae
2. under/uncooked fish harboring infective larvae

Question 5

Give 2 groups of dracunculus spp:
- 1 that infects humans
- 1 that infects north american carnivores

Answer 5

• Dracunculus medinensis (infects humans)
• Dracunculus insignis (infects N. American carnivores- not zoonotic)

Question 6

Why is managing the guinea worm disease important?

Answer 6

• affects millions of people
• it’s debilitating: can’t go to school/work

Question 7

T/F
GWD usually shows no symptoms for the first year after infection

Answer 7

true

Question 8

What are the symptoms of GWD?

Answer 8

• slight fever, rash, nausea, dizziness
• blister on lower body

Question 9

is the death rate for GWD high?

Answer 9

no
low death rate but commonly leads to disability

Question 10

When is transmission of GWD the highest?

Answer 10

during times when stagnant water is available

• transmission has a seasonal pattern

Question 11

In 1986, there were __ cases of GWD in 21 countries. In 2018, there were __ cases in 5 countries

Answer 11

3.5 million
30

Question 12

Give 5 criteria that need to be met in order to eradicate a disease

Answer 12

• easily identifiable
• reservoir hosts
• geographically restricted
• vaccine possible
• benefits of eradicating are greater than the costs

Question 13

What’s being done to eradicate GWD?

Answer 13

block transmission to human host by
- increasing sanitation and access to clean water
- education: don’t go in water with a worm coming out of your leg
- report cases

Question 14

_____ ____ started the Carter Center: guinea worm eradication program

Answer 14

jimmy carter

Question 15

What’s the difference between disease elimination vs eradication?

Answer 15

Elimination= stopping the spread of a specific disease in a certain region as a result of deliberate, continued efforts. Efforts must continue in order to keep it in check

Eradication= complete wipeout of a specific disease worldwide. Intervention measures are no longer needed

Question 16

GWD has been eliminated in ___ countries. How many cases were there in 2021?

Answer 16

17
15

Question 17

T/F

GWD eradication efforts in the 90s were successful, but it was rediscovered in Chad in 2010

Answer 17

true

Question 18

What is the main challenge to eradication of GWD?

Answer 18

emergence of GWD infections in animals (mainly dogs in Chad)

–> dogs might somehow serve as a reservoir host human infection in this case. Could be a distinct spp of dracunculus that’s spilling over to people (worms from dogs vs humans are indistinguishable)

Question 19

What species serve as paratenic hosts for dogs with GWD?

Answer 19

fish and amphibians

= change in transmission