More than 90 people have presented to emergency departments in Illinois and four other states since March 10 with serious unexplained bleeding, including two patients who died, the Centers for Disease Control and Prevention said yesterday in an alert to clinicians. All but five of the cases were in Illinois, including the two deaths, and the rest were in Indiana, Maryland, Missouri and Wisconsin. Laboratory investigation confirmed exposure to brodifacoum, a vitamin K antagonist anticoagulant, in at least 18 of the patients. All 63 patients interviewed by Illinois public health epidemiologists reported using synthetic cannabinoids, and at least three synthetic cannabinoid product samples related to the outbreak have tested positive for brodifacoum, CDC said. Health care providers should screen patients presenting with unexplained bleeding and a possible history of synthetic cannabinoid for vitamin K-dependent antagonist coagulopathy, and report suspected cases associated with synthetic cannabinoids to their local health department, the agency said.