Where The Worms Are

I was reading a scary story about parasitic worms, when I came across this sentence:

After worming their way into people’s lives, particularly in developing countries, these suckers can lie undetected for months or even years.

What caught my eye was "developing countries." Euphemism alert!

Are they developing much at all?

They're mired in the ancient thrall
of  living with the things that crawl.