BOISE, Idaho (AP) — Public health officials confirmed Tuesday that two people in Idaho have developed a serious lung disease linked to vaping.

The Idaho Department of Health and Welfare announced the two patients, one a minor and the other a young adult, were hospitalized for a time but are now recovering at home. Three more suspected cases were being investigated, said department spokeswoman Niki Forbing-Orr, and said officials expected that number to increase.

“Last week we didn’t know about any cases,” said Forbing-Orr. “We’ve asked clinicians to be on the alert for signs of this respiratory illness, and I think as word gets out we will probably have more cases, unfortunately.”

The outbreak of vaping-related lung disease has sickened roughly 450 people in at least 33 states, according to the Centers for Disease Control and Prevention. The federal agency said five people had died nationwide as of Friday; a sixth death was reported in Kansas on Tuesday.

All of the suspected and confirmed cases in Idaho have been in people between the ages of 15 and 30, said Forbing-Orr.

State officials are asking health care providers to watch for any signs of respiratory illness in patients who use vaping products, and to report any possible cases to public health officials. Symptoms can include shortness of breath, chest pain, fever, fatigue, nausea, vomiting and diarrhea.

“We are investigating each report and looking for things that might be common among the patients as well as asking about the types of vaping products and devices people have used to try and pinpoint the source of these illnesses,” Deputy State Epidemiologist Dr. Kathryn Turner said in a statement.

Neighboring states have also reported cases, including one death in Oregon and illnesses in Utah and Montana.

The use of vapes and other e-cigarette devices has grown in popularity in recent years. The Centers for Disease Control and Prevention annual survey of risky behavior by youth found that a little more than 14% of Idaho high school students reported using an electronic vapor device at least once in the past 30 days in 2017, compared to a national rate of just over 13%.