Useless creatures. Fuck em

First of all it's debatable if viruses are lifeforms, but even if they were, in the examples you listed I think their eradication would be ok (or at lest fair) because it happened by using the means of evolution. Developing an immunity towards these viruses would have happened by random mutation sooner or later anyways. Then it would have taken years to spread among the human race, wich by that point would probably have been dramatically decimated. But the end result, the need for the virus to mutate and evolve in turn to be able to continue spreading is the same. We just spead that process up because we discovered vaccination.

And its not like the virus suffers horribly under bad living conditions in some zoo. It's for all intends inpurposes dead DNA. And if someone wanted to, they could set it free and it would start spreading again among the unvaccinated as if nothing ever happened.

The question about the mosqitos is more tricky. Fucking with the natural eco - balance that has evolved in a certain region over thousands of years can have devastating results and I've never heard of and experiment where introducing a new species or removing one entirely from a habitat didn't fuck things up even more. It balances out over the next few thousand years again, but it still might not be the effect you're looking for. For example how do these mosquitos influence the food chain? Is there an animal dependant on these? That animal would starve. And so on.
A better solution imo would be to genetically modify (e.g. random mutation) these types of mosqitos so that they become unsuitable to carry the illness. Let that spread though the species.
As for the ethics, I don't have a problem with "killing off" viruses, after all I don't mourn peoples cancer cells either, but tinkering with the animal kingdom via planned extinction is not a good idea imo. There's too many factor we don't really understand, and even then effective medicine or vaccines would be much preferrable.

Mosquitoes do indeed constitute  a food source for many species. Their aquatic larvae are a staple diet among freshwater fish. The adults are eaten by bats, birds, spiders, other insects, etc.

How do you feel about the guinea worm, an animal that can only reproduce by infecting humans and causing debilitating illness?

No, it should be isolated and showed in a museum.

It is specialized to humans? That seems like a promising ecological niche.

To be honest I can't comfortably pass judgement/offer a solution on that one because I'm not familiar with it. I'm reasonably well informed about Malaria, but I've never heard of the guniea worm. I don't know wich invironments it typically lives in (aside from Human bodys) and what it does. Or how you would go about planned extinction in it's case.

I mean in the case of malaria the Idea is not to wipe out the parasite itself, but to remove one of the hosts from the reproduction cicle. Is there a similar thing with the gunea worm? Or is it passed human to human?

I'd have to research this, and I'm frankly too lazy. :P

If I assume that this worm and humans lived in a vacuum and nothing else but these two species are involved, it falls back on what I said about viruses and vaccination. If we find a way to protect ourselves from getting infected by the worm, and as consequence the worm goes extinct because it fails to adapt, thats evolution.

(As an aside the thought of having fucking worms living inside me makes my skin crawl....*shudder*)

Edit: Ok, had a quick look at the Wiki and it seems that, these are contracted by accidently drinking infected waterflee larvas. In that case my answer would be simple. Make sure suffcient infrastuckture is built to give the people accsess to clean water. Wich we should be doing anyways.

Depends how you look at it.
You can also call in the Darwinism argument.

In my opinion.. yes.

But it's way more complicated than just saying yes or no.

Damn, the poll is exactly even.

It is ethically 100% OK in my eyes. Survival of the fittest.

Other species have developed different techniques to survive. Teeth, claws, whatever. Humans have tools and collaboration. It's also OK for us to secure our survival.

And by the way, humans are the only species that has developed empathy... even towards other species. Those mosquitoes wouldn't hesitate for a secod to kill us all if that meant more mosquitoes.

Now, species that we kill "by accident" and where doing so doesn't benefit us in any way, I can have issues with.

Exactly. They have sex inside you. I say to hell with them

It seems that they only interact with humans and water fleas (and water fleas only carry them), so I doubt their eradication would alter the ecosystem significantly.

doubtful

ofcourse we have dogs and dolphins that show behaviour similar to empathy, even for humans (a different species)

and then there also are reports of hunchback whales saving a lonely gray whale calf from a group of orcas and a hunchback whale swimming on it's back and balancing a seal with it's belly/fin for 30 minutes to shield it from an orca attack