Synthetic cannabinoids — often called Spice, K2 or fake weed — have been tied to 38 cases of severe bleeding, including one death, across Chicago and areas in central Illinois.
All of those cases required hospitalization related to coughing up blood, blood in the urine, bloody nose, bleeding gums and other symptoms. Three cases tested positive for brodifacoum, or rat poison, according to a statement from the Illinois Department of Public Health on Saturday.
Now, state officials are working to identify any common synthetic cannabinoid products related to those cases and to determine where the products were obtained.
There are still many questions about the outbreak that need answers.
"This is the first time we've seen an outbreak of this magnitude in the area," Melaney Arnold, a spokeswoman for the Illinois Department of Public Health, said Monday.
"We're working with numerous different partners across the city and state as we investigate this outbreak," she said.
Synthetic cannabinoids are sold in convenience stores, gas stations, drug paraphernalia shops, novelty stores and even online.
Health officials warn that anyone who has a reaction to synthetic cannabinoids immediately should call 911 or be taken to an emergency department.
'There could be additional deaths coming'
"Synthetic cannabinoids are unsafe," Dr. Nirav Shah, director of the Illinois Department of Public Health, said in the statement.
"They can contain a variety of chemicals, and users often don't know what those are, such as rat poison," he said. "Despite the perception that synthetic cannabinoids are a safe alternative to marijuana, they can cause very severe illness."
Though many of the recent cases were tied to synthetic cannabinoid products in the Chicago area, contaminated products could be in counties statewide, the Department of Public Health noted.
Ten of the cases were in Chicago, four were in Cook County, seven were in Peoria County, and 12 were in Tazewell County. The counties of DuPage, Kane, McLean and Will all had one each, and another county is under investigation for one case.
The death that had been reported was the first seen in Chicago related to fake weed, Arnold said.
"There could be additional deaths coming; it is difficult to say," she added. "We're doing whatever we can with regards to outreach to notify any who may be impacted by this outbreak."
What is fake weed?
This isn't the first time a region of the United States has seen an outbreak of health problems tied to synthetic cannabinoids.
Last year, 102 people in Lancaster County, Pennsylvania, overdosed on synthetic marijuana within three days. None of those cases was fatal.
In 2016, 33 people in Brooklyn were made ill from suspected overdoses of synthetic pot.
The number of acute poisonings from synthetic cannabinoids rose sharply between 2010 and 2015, according to a Morbidity and Mortality Weekly Report published by the US Centers for Disease Control and Prevention in 2016.
During that time, physicians treated 456 patients total for synthetic cannabinoid intoxications.
Synthetic cannabinoids, or fake weed, are human-made chemicals that can be sprinkled on dried, shredded plant material and smoked, or can be consumed as vaporized liquids inhaled through an e-cigarette or other device.
These mind-altering chemicals are called cannabinoids, since they are similar to the chemicals found in marijuana, though they can cause serious side effects that are different from those of marijuana.
One study of a synthetic cannabinoid found that it was 85 times as potent as tetrahydrocannabinol, or THC, the mind-altering chemical in marijuana. That study was published in the New England Journal of Medicine in 2016.
People who smoke synthetic cannabinoids can have rapid heart rate, vomiting, agitation, confusion and hallucinations, according to the CDC.
In the past few years, doctors have become familiar with the health outcomes people can face when they are exposed to synthetic cannabinoids, said Dr. Patrick Lank, an emergency physician and assistant professor of emergency medicine at the Northwestern University Feinberg School of Medicine in Illinois.
"They include things like seizures, heart attack, kidney failure," said Lank, who was not involved in the recent synthetic cannabinoid cases.
"What's happening in Illinois is different, and these are bleeding complications. Why they're happening? We're still uncertain," he said. "We don't know if the supply of synthetic cannabinoids in Illinois and the Chicago area have been tainted by someone with brodifacoum, or rat poison. Or if this is potentially a new side effect of a new synthetic cannabinoid."