Seven people in Alberta have developed a form of immune system suppression after consuming cocaine laced with a chemical compound, public health officials said Friday.

The individuals developed agranulocytosis, a condition that makes the immune system incapable of fighting off infections.

It makes common infections become serious, even fatal, quite quickly.

"We are advising anyone who develops a fever or other signs of infection and has used cocaine to seek medical attention quickly," Dr. Gerry Predy, Alberta's Acting Chief Medical Officer of Health, said in a news release.

"Any skin abscess or lung infection that develops rapidly should also be treated immediately."

Officials have linked the cases to cocaine laced with levamisole, a chemical compound developed to treat intestinal worms in humans and animals.

The cases were reported in Edmonton, Red Deer, and in undisclosed locations in southern and northern Alberta.

Doctors in Alberta have been advised they should test and treat patients for this condition if they complain of a fever or other signs of infection after using cocaine.