It sounds like something from Ridley Scott's Alien: an Australian couple has been infected with flesh-eating parasites and endured a traumatic exorcism of the bugs.

But no gruesome horror flick could have prepared Bryan Williams, an experienced traveller and avid adventurer from the Gold Coast, for the creepy episode he would endure in South America.

The 28-year-old is stuck in Bolivia, where his body served as a breeding ground for the human botfly that feasts on his flesh.

"I have travelled to nearly 50 countries over the past five years. This by far is the worst experience," Mr Williams said.

After trekking through knee-deep swamps populated by anacondas, catching piranhas for dinner and patting alligators, botflies were the least of Mr Williams's concerns.

He and his girlfriend Ally Vagg, from Sydney, returned to Bolivia after travelling across the Amazon basin late last year, only to learn what they thought were infected mosquito bites were in fact pockets of feasting botfly larvae.

In order to reproduce, the botfly, or dermatobia hominis, deposits up to 50 eggs on the faces of carrier insects such as mosquitoes.

The mosquitoes inject the soon-to-be-born larvae under the skin of unsuspecting humans.

"I think I saw it on National Geographic channel a few years back, labelled something like 'world's most disgusting bugs'," Mr Williams said. "Makes me sick thinking about the whole thing."

While Ms Vagg was volunteering at an animal refuge, she wrote to her boyfriend, who was staying with friends in the city, confirming the unimaginable.

"P.S: The bites on us actually have eggs in them. They pulled three worms from my back and one from my leg," Ms Vagg said via Facebook.

The diagnosis made Mr Williams even more queasy.

"It was feeding on my flesh, neutralising as it goes so I would not notice, and growing bigger every day," Mr Williams said.

Human flesh incubates botfly larvae until the maggots crawl out about five to eight weeks later.

After battling the language barrier and an apathetic doctor, the first attempt at removing the inch-long bug from the wound in Mr Williams' stomach failed.

"I see the little invader rise up out of the hole for one second; look like he took a big breath and maybe even wink at me, and then dive-bomb back down the hole of the infection not to be seen again," Mr Williams said.

Mr Williams was advised to cover the hole on his stomach with tape and wood glue for 24 hours to starve the botfly of oxygen.

When he peeled back the tape, the fly reared its head long enough for Mr Williams' friend to pull it out with tweezers.

"It was wiggling as it came out. It was nearly an inch long ... we all nearly puked. Repeatedly," Mr Williams said.

Mr Williams and Ms Vagg have to remain in Bolivia until they are fully healed, but expect to return home in late February.

• A botfly is removed from a man's ankle. Photo: Supplied