Taco Bell 50K Organizers Standing By Race Despite Parasite Outbreak

The founders of the Taco Bell 50K aren't letting the fast-food chain's ongoing parasite outbreak derail their plans ... telling TMZ they're still expecting to hold the race this fall.

Race co-founder Dan Zolnikov tells TMZ the health of participants comes first, but he's optimistic the outbreak will be resolved and investigators will identify the source long before the October event.

He acknowledges the situation could leave some runners hesitant to sign up and may hurt Taco Bell's reputation, which TB just acknowledged on Instagram, in the short term, but says they're hoping for the best possible outcome.

And if anyone thought the outbreak would scare off die-hard Taco Bell fans ... think again.

Co-founder Jason Romero is currently hiking the Colorado Trail with one destination in mind -- the Taco Bell in Leadville, Colorado. Dan says Jason is expected to arrive in three or four days, and he still plans to celebrate the trek with a meal from the chain.

Jason and Dan founded the Taco Bell 50K in Denver as a tongue-in-cheek endurance race inspired by their love of Taco Bell ... and they even stopped by "TMZ Live" to taco-bout the run with Harvey and Charles.

As we've previously reported, the FDA is investigating whether iceberg lettuce supplied by Taylor Farms to some Taco Bell restaurants is the source of a multi-state cyclosporiasis outbreak. Taco Bell has said it removed the suspected ingredient from affected locations while the investigation continues.