The Denver Health Department is warning Coloradans of contaminated cocaine, tainted with a dangerous toxin that suppresses the immune system and can immediately lead to death.The toxin is Levamisole, a veterinary medication used to treat worm infestations in cattle, pigs and sheep, the health department said.Levamisole contamination of cocaine has been reported in other states. In mid-January, the New Mexico Department of Health reported 11 cases of levamisole poisoning in cocaine users, including at least one death.On Feb. 28, Colorado law enforcement officers were alerted to its presence here after a man stumbled into Denver Health with a high fever.Blood tests showed that his immune system was severely suppressed, doctors said. Physicians at Denver Health, who were aware of the New Mexico warning, suspected that the man might have levamisole poisoning.Levamisole poisoning suppresses the immune system, leaving people unable to fight off common infections. Levamisole poisoning can be fatal because people can die quickly from even minor infections, doctors said.Testing by a Denver police crime lab confirmed levamisole contamination in the cocaine the man had used."This gentleman is incredibly lucky to be alive," said Dr. Jennie Buchanan, a toxicology fellow at the Rocky Mountain Poison and Drug Center and an emergency room doctor at Denver Health who was one of the first physicians to recognize the situation."Just like a patient on chemotherapy, his body had no way to fight infection. He was smart to come to Denver Health for care as soon as he started feeling ill. As long as he stays off cocaine, he should be fine. Now, we want to do everything possible to prevent the same thing from happening to someone else," Buchanan said.In the past, levamisole has been used as a chemotherapy drug for colon cancer.The man remains hospitalized at Denver Health Medical Center and is expected to make a full recovery, hospital officials said. He has not been identified.The Denver Police Department is actively investigating the source of the cocaine."Obviously, cocaine itself is bad for your health, but having it cut with levamisole adds another whole layer of deadly danger to the addiction," said Dr. Chris Urbina, director of Denver Public Health.In addition to stopping cocaine use, Denver Health recommends that people who have used cocaine in the past month be aware of possible infections. If you, or someone you know, has used cocaine in the past month, has a fever, is not feeling well, or shows signs of an infection, see a doctor immediately, and tell the doctor about past cocaine use.Doctors who see patients with suspected levamisole poisoning should consider ordering a complete blood count.