FILE PHOTO: A man uses a vape as he walks on Broadway in New York City, U.S., September 9, 2019. REUTERS/Andrew Kelly

CHICAGO (Reuters) - The number of cases reported in the epidemic of lung-related injuries from vaping appears to be leveling off or declining, the U.S. Centers for Disease Control and Prevention (CDC) said on Friday, but it is too early to say whether the outbreak has peaked.

“There may be less intensive investigation of possible cases by the health departments, fewer cases from earlier in the year reported into the public heath system, or lags in data reporting to the CDC,” Dr. Anne Schuchat, principal deputy director of the CDC, Schuchat said in a conference call with reporters.

On Thursday, the CDC reported an additional 125 cases of serious lung injuries related to vaping as of Oct. 22, compared with 180 additional cases a week earlier. The outbreak has now reached all but one U.S. state plus the District of Columbia and the U.S. Virgin Islands, and killed at least 34 people.

Brian King of CDC’s Office on Smoking and Health said in an email the decline likely reflects a delay in reporting, and said the agency “will continue to work with states to track confirmed and probable cases in the U.S. to understand how the outbreak is evolving.”

Overall, investigators do not appear to be closer to identifying a specific cause of the outbreak, but evidence still points to the use of THC - the high-producing component of marijuana - as a culprit.

So far, based on interviews with 860 patients who have gotten sick so far, about 85 percent reported a history of vaping THC and around 10 percent reported exclusive use of nicotine-containing products, Schuchat said.

(This story corrects number of patients from 160 to 860 in paragraph six)