(NewsNation) — The Centers for Disease Control and Prevention is warning Americans to avoid traveling to Mexico for surgery after reports of a series of fungal infections.

The agency has identified several travelers who went to Matamoros, Mexico, for surgery that involved anesthesia administered via injection near the spinal column who have developed fungal meningitis following their procedures.

Fungal meningitis occurs when a fungal infection spreads to the brain or spinal column. It can be severe and even fatal. At least four patients who recently had surgery in Matamoros are hospitalized in Texas and one has died from the illness.

Authorities are investigating the source of the infection, as fungal infections are typically spread from the environment and not person-to-person contact. In the meantime, they are advising anyone who had planned to travel to Mexico for surgery to postpone their trip until they have determined the cause of the infections.

Anyone who has had surgery in Mexico that included an epidural should be on the lookout for symptoms of fungal meningitis. Those include fever, headache, stiff neck, nausea, vomiting, confusion, or sensitivity to light.