I have to say I agree with Soly047 that one should never ignore warning signs of parasites. I went to Guatemala in 2005 and definitely contracted something but never did anything about it. Almost 9 years later I'm still fighting something I believe I got there (h.pylori) which has mushroomed into a chain of other health problems.
And, when I went to go get a comprehensive parasite test from a lab, I only came up positive for one (h.pylori) but over the next month I did my own Humaworm cleanse and TONS of other critters came out that didn't show up on the test. So even the tests are not always accurate.