EVALI, the vaping lung injury outbreak

In July 2019 the Wisconsin Department of Health Services and the Illinois Department of Public Health began receiving reports of lung injury in people who vaped, and opened a joint investigation. Their final report described 98 patients: 79 percent were male and the median age was 21. All had constitutional symptoms, 97 percent had respiratory symptoms and 77 percent had gastrointestinal ones, and every patient had infiltrates in both lungs on imaging. Ninety-five percent were admitted to hospital, 26 percent needed a ventilator, and two died. Eighty-nine percent had vaped products containing tetrahydrocannabinol, or THC.

Cases turned up across the country. Emergency department visits tied to vaping rose sharply in August 2019 and peaked in September, when weekly hospital admissions reported to CDC reached 215 in the week of 15 September. The syndrome was named e-cigarette, or vaping, product use-associated lung injury, or EVALI. By 14 January 2020 states had reported 2,668 hospitalized patients, aged 13 to 85 with a median of 24, and 66 percent male. Of those with information on what they had used, 82 percent reported THC products and 14 percent reported nicotine products only.

The chief suspect was found in the lungs. CDC scientists tested bronchoalveolar lavage fluid from 51 patients in 16 states and from 99 people without EVALI for vitamin E acetate, plant oils, medium-chain triglyceride oil, coconut oil, petroleum distillates and diluent terpenes. Vitamin E acetate, an additive in some THC vaping products, was present in 48 of the 51 patients and in none of the comparison group. Nothing else turned up except coconut oil and limonene, each in one patient. CDC said the evidence could not rule out other chemicals in some cases.

CDC and the FDA advised people not to use THC vaping products, especially from friends, family or dealers, and not to add vitamin E acetate to any product. By 18 February 2020, 2,807 hospitalized cases or deaths had been reported from all 50 states, the District of Columbia, Puerto Rico and the U.S. Virgin Islands, with 68 deaths in 29 states and the District. Cases had fallen steadily since September, and in February 2020 CDC stopped collecting case reports from states.