3 ms·

I still don't understand how getting rid of the last human case will resolve the issue. Presumably these crustaceans & worms still exist in the wild? Isn't ther

I still don't understand how getting rid of the last human case will resolve the issue. Presumably these crustaceans & worms still exist in the wild? Isn't there always a chance for a new flareup to occur?

ianburrell 4y ago
The parasite only effects humans and dogs. I guess that the worms in the water go away after a while. Prevention breaks the cycle.
- duskwuff 4y ago
  The worms themselves don't live in the water at all. Its larvae are released into the water, and can only grow to maturity and reproduce if they're consumed by a host.
  - b112 4y ago
    And, then consume some of the host (I guess?)
jvanderbot 4y ago
From wikipedia, "In 2020, Guinea worm was found in 1507 domestic dogs in Chad, 15 in Ethiopia, and eight in Mali, as well as in 61 domestic cats in Chad and three in Ethiopia. Small numbers have also been found in wildcats and baboons.[9] These findings are a potential problem for the eradication program. " Now I'm making things up, but it may be that eradication from human water sources is enough to break the cycle, if maybe the other mammals in the area are more migratory and cannot provide a consistent reservoir.
capableweb 4y ago
As I understand it, they rely on human hosts, so if no humans get infected for a while, the rest will die out. After that, there is none of them left, so no one can get infected again.
- beardog 4y ago
  It appears to not be known for sure as of 2019 if dogs are a main host or not. https://www.nature.com/articles/d41586-019-02921-w https://www.nature.com/articles/d41586-019-02921-w
maxerickson 4y ago
The parasite has a life cycle that passes through several stages. One of the stages involves infecting a mammal (and apparently mostly human) host. If you disrupt that stage, you disrupt the life cycle of the parasite. If you disrupt that stage completely, no parasite continues to the next cycle and after a bit of time there isn't any more parasite.
Someone 4y ago
The larvae don’t live forever and need a human or dog to procreate. Also, we’ll only be reasonably sure no human or dog cases exist over a year after the last human was infected because that’s how long it takes for symptoms to become obvious. I expect the life expectancy of the larvae to be much shorter, but can’t find that online (https://en.wikipedia.org/wiki/Dracunculus_medinensis#Life_cycle https://en.wikipedia.org/wiki/Dracunculus_medinensis#Life_cy... says* “Within the copepod, the D. medinensis larvae develop to an infective stage within 14 days”*, but doesn’t mention how long they stay infective or how long they can spend in the water before being eaten by the copepod) They probably also will be careful of declaring victory too early because of the existence of animal reservoirs (https://en.wikipedia.org/wiki/Dracunculus_medinensis#Animal_reservoirs https://en.wikipedia.org/wiki/Dracunculus_medinensis#Animal_...)
sinoue 4y ago
It is a cultural thing of educating fisherman to stop feeding fish entrails to dogs, and keeping infected dogs and people from entering the waterways once infected to break the reproductive cycle. We have an American version of the Guinea work that affects raccoons and other wildlife, but hasn’t crossed over. https://www.michigan.gov/dnr/managing-resources/wildlife/wildlife-disease/north-american-guinea-worm https://www.michigan.gov/dnr/managing-resources/wildlife/wil...

ianburrell 4y ago

The parasite only effects humans and dogs. I guess that the worms in the water go away after a while. Prevention breaks the cycle.

duskwuff 4y ago
The worms themselves don't live in the water at all. Its larvae are released into the water, and can only grow to maturity and reproduce if they're consumed by a host.
- b112 4y ago
  And, then consume some of the host (I guess?)

jvanderbot 4y ago

From wikipedia, "In 2020, Guinea worm was found in 1507 domestic dogs in Chad, 15 in Ethiopia, and eight in Mali, as well as in 61 domestic cats in Chad and three in Ethiopia. Small numbers have also been found in wildcats and baboons.[9] These findings are a potential problem for the eradication program. " Now I'm making things up, but it may be that eradication from human water sources is enough to break the cycle, if maybe the other mammals in the area are more migratory and cannot provide a consistent reservoir.

capableweb 4y ago

As I understand it, they rely on human hosts, so if no humans get infected for a while, the rest will die out. After that, there is none of them left, so no one can get infected again.

beardog 4y ago
It appears to not be known for sure as of 2019 if dogs are a main host or not. https://www.nature.com/articles/d41586-019-02921-w https://www.nature.com/articles/d41586-019-02921-w

maxerickson 4y ago

The parasite has a life cycle that passes through several stages. One of the stages involves infecting a mammal (and apparently mostly human) host. If you disrupt that stage, you disrupt the life cycle of the parasite. If you disrupt that stage completely, no parasite continues to the next cycle and after a bit of time there isn't any more parasite.

Someone 4y ago

The larvae don’t live forever and need a human or dog to procreate. Also, we’ll only be reasonably sure no human or dog cases exist over a year after the last human was infected because that’s how long it takes for symptoms to become obvious. I expect the life expectancy of the larvae to be much shorter, but can’t find that online (https://en.wikipedia.org/wiki/Dracunculus_medinensis#Life_cycle https://en.wikipedia.org/wiki/Dracunculus_medinensis#Life_cy... says* “Within the copepod, the D. medinensis larvae develop to an infective stage within 14 days”*, but doesn’t mention how long they stay infective or how long they can spend in the water before being eaten by the copepod) They probably also will be careful of declaring victory too early because of the existence of animal reservoirs (https://en.wikipedia.org/wiki/Dracunculus_medinensis#Animal_reservoirs https://en.wikipedia.org/wiki/Dracunculus_medinensis#Animal_...)

sinoue 4y ago

It is a cultural thing of educating fisherman to stop feeding fish entrails to dogs, and keeping infected dogs and people from entering the waterways once infected to break the reproductive cycle. We have an American version of the Guinea work that affects raccoons and other wildlife, but hasn’t crossed over. https://www.michigan.gov/dnr/managing-resources/wildlife/wildlife-disease/north-american-guinea-worm https://www.michigan.gov/dnr/managing-resources/wildlife/wil...