A second person has died from a severe lung illness after vaping, according to a lead investigator on the case in Oregon. The investigator said that the person had apparently become sick after vaping T.H.C. from a product purchased at a recreational marijuana shop in the state.

The investigator, Dr. Ann Thomas, a pediatrician and public health physician who is leading Oregon’s incident management team, said the person died in July after being hospitalized and put on a ventilator. Dr. Thomas declined to identify the person or disclose the age or gender, but said the patient was “otherwise healthy and quickly became very ill.”

Dr. Thomas said that the doctor who treated the patient recognized several weeks later that the patient’s lung infection was consistent with a syndrome thought to be connected to vaping that has affected more than 200 people around the country this summer, according to federal health officials.

So far, one other patient is known to have died, an adult in Illinois, and this second death — more than a thousand miles away — underscores what public health authorities say is a serious and deeply puzzling surge in vaping-related illnesses.