Fewer reports of vaping illnesses are coming in, but U.S. health officials say they are not sure what to make of it.
The Centers for Disease Control and Prevention said 125 additional cases were reported in the last week, bringing the total to 1,604 in this year's outbreak. That includes 34 deaths, one more than last week.
The outbreak is still happening, but the count of new cases has dropped for three straight weeks. A CDC spokeswoman said reporting delays could be one explanation.
The CDC reported the numbers Thursday.
The outbreak appears to have started in March. No single ingredient, electronic cigarette or vaping device has been linked to all the illnesses. Most who got sick said they vaped products containing THC, the high-inducing ingredient in marijuana.