The Wisconsin Department of Health Services (DHS) said it is investigating a cluster of people with severe lung disease who all reported recent vaping or dabbing vaping marijuana oils, extracts, or concentrates.
"As of August 15, 2019, we are aware of 15 confirmed cases. Fifteen other cases are under further investigation," it said.
While the department first saw cases among teenagers and young adults, cases in older age groups also emerged later.
According to a National Public Radio (NPR) report, the cluster was first detected by Children's Hospital of Wisconsin in Milwaukee where eight previously healthy teenagers were hospitalised with severe lung damage.
The patients showed respiratory symptoms including cough, shortness of breath and fatigue. The symptoms worsened over a period of days or weeks before admission to the hospital. Other symptoms reported by some patients included fever, anorexia, pleuritic chest pain, nausea and diarrohea, the Wisconsin Department of Health Services said.
Similar cases have also been reported from other states as well.
The Centers for Disease Control and Prevention (CDC) in the US is helping the health departments in Wisconsin, Illinois, Minnesota, Indiana and California to "investigate whether the illnesses may be linked to specific ingredients or contaminants in the devices or substances associated with e-cigarette use", a spokesperson for the CDC told NPR.
While state officials have confirmed at least 31 cases, the CDC said it is probing 94 possible cases in 14 states, according to a report in The Washington Post.
( With inputs from IANS )