King County officials are investigating two incidents where heroin may have contaminated users with Botulism.

Two individuals were recently diagnosed with the illness after injecting themselves with black tar heroin.

“Botulism is a rare but serious illness caused by Clostridium botulinum bacteria,” according to the National Library of Medicine. The bacteria is most commonly found in soil and untreated water throughout the world.

According to Public Health -- Seattle & King County, four similar cases have been reported in Texas since last month.

"There is no way for a person on the street to tell if black tar heroin is contaminated, nor any way to clean it to make it safe," said Dr. Jeff Duchin, at Public Health -- Seattle & King County. "The best way for injection drug users to prevent getting the disease is not to use heroin, but for those who do, they need to be aware of the risk of Botulism and seek medical attention immediately if they develop symptoms."

The initial symptoms of wound Botulism may occur within days or weeks of exposure and include; blurred vision and difficulty speaking or swallowing.

The two King County residents suspected of being infected with Botulism showed up at the hospital exhibiting these symptoms—both of their conditions worsened and they were later admitted to the intensive care unit.

Botulism-producing bacteria can contaminate 'black-tar' heroin, and injection drug users can develop botulism after injecting even if infected wounds are not apparent. Botulism can also be transmitted by consuming food that is contaminated with toxin-producing bacteria or their spores,” Public Health said.

Some ways to reduce the risk of botulism are:

  • Ensure that all works and skin are clean.
  • Don't use "black tar" heroin, which cannot be cleaned. "Cooking" the drug does not kill Botulism bacteria.
  • Don't share needles, syringes, filters, cookers, or water.
  • Always use a new sterile syringe.
  • If reusing a syringe, clean it well with bleach.
  • Get a tetanus shot every five years.