EVALI, or e-cigarette, or vaping, product use-associated lung injury, was documented across the United States during the 2019 outbreak. CDC reports counted cases and deaths at several points in time, while later analyses examined product use, sourcing, readmission, and laboratory findings. The numbers below are tied to their original dates, study groups, and geographic settings.
Contents
- Case counts and who was affected
- Products reported before illness
- Product sources and geographic variation
- Illinois risk-factor comparisons
- Readmission and post-discharge outcomes
- Vitamin E acetate findings
Case counts and who was affected
CDC’s October 2019 MMWR updates show how quickly the reported total changed as health departments identified and classified patients. As of October 8, 2019, CDC had received reports of 1,299 EVALI cases from 49 states, the District of Columbia, and one territorial health department. Twenty-six deaths had been reported from 21 states. By October 22, the reported total had reached 1,604 cases from 49 states, the District of Columbia, and the U.S. Virgin Islands, with 34 deaths reported in 24 states (CDC MMWR Oct. 2019).
The patient profile in the October 8 analysis was relatively young. Among 1,043 patients with age and sex information, the median age was 24 years, 70% were male, 80% were younger than 35, and 15% were younger than 18 (CDC MMWR Oct. 2019). In the October 22 update, 964 of 1,378 patients with available information were male, also representing 70% of the group. CDC reported no EVALI cases in pregnant women in that update (CDC MMWR Oct. 2019).
Deaths had a different age pattern. The median age at death was 49 years, with a range of 17 to 75 years (CDC MMWR Oct. 2019). That contrast matters when reading the overall median age: a young overall patient group does not mean severe or fatal outcomes were limited to young people.
Products reported before illness
The percentages for product use depend on the date and the patients who had usable substance-use information. In the October 8 CDC analysis, 573 patients had substance-use data. Among them, 76% reported using THC-containing products during the 90 days before symptom onset, while 58% reported using nicotine-containing products. Thirty-two percent reported exclusive THC-containing product use, and 13% reported exclusive nicotine-containing product use (CDC MMWR Oct. 2019).
The larger October 22 analysis included 867 patients with substance-use data. In that group, 749 patients, or 86%, reported any THC-containing product use; 552, or 64%, reported any nicotine-containing product use; and 455, or 52%, reported both THC- and nicotine-containing products. Exclusive THC use was reported by 294 patients, or 34%, while exclusive nicotine use was reported by 97 patients, or 11% (CDC MMWR Oct. 2019).
These figures should not be combined as though they were one survey. The denominators, reporting dates, and available records differ. They do show that CDC’s October analyses recorded both THC-containing and nicotine-containing product use among EVALI patients, with THC use reported more often in the available groups.
Among 19 patients who died and had substance-use data in the October 22 analysis, 84% reported any THC-containing product use. Sixty-three percent reported exclusive THC-containing product use, 37% reported any nicotine-containing product use, and 16% reported exclusive nicotine-containing product use (CDC MMWR Oct. 2019). This was a small subgroup, so the percentages describe those 19 deaths rather than all EVALI deaths.
Product sources and geographic variation
By January 7, 2020, 1,979 EVALI patients had available substance-use data, representing 76% of reported cases. Among these patients, 1,620, or 82%, reported any THC-containing product use; 665, or 34%, reported exclusive THC use; 1,128, or 57%, reported any nicotine-containing product use; and 264, or 13%, reported exclusive nicotine use (CDC MMWR Jan. 2020).
The January 2020 CDC analysis also separated commercial and informal sources. The categories below describe patients with source information for the relevant product type, not all reported EVALI patients.
| Product type and source | Patients with source data | Share |
|---|---|---|
| THC, commercial sources only | 131 of 809 | 16% |
| THC, informal sources only | 627 of 809 | 78% |
| THC, both commercial and informal sources | 51 of 809 | 6% |
| Nicotine, commercial sources only | 421 of 613 | 69% |
| Nicotine, informal sources only | 103 of 613 | 17% |
| Nicotine, both commercial and informal sources | 89 of 613 | 15% |
The geographic mix was not uniform. Nevada had the highest reported percentage of EVALI patients acquiring nicotine-containing products from informal sources, at 57%. For THC-containing products, Alaska, Hawaii, Idaho, Iowa, Mississippi, Montana, Oklahoma, Rhode Island, South Dakota, and Vermont were identified as states with informal-source shares of 50% to 100% (CDC MMWR Jan. 2020). The range is a state-level finding from that analysis, not a national estimate for every product user.
Illinois risk-factor comparisons
The Illinois analyses provide a more focused comparison between EVALI patients and adults surveyed in Illinois. The adult survey analyzed 4,631 respondents. In that survey, 94% reported any nicotine-containing e-cigarette or vaping-product use during the prior three months, 21% reported any THC-containing product use, and 11% reported using both THC-containing and nicotine-containing products (CDC MMWR Illinois risk factors).
Compared with the Illinois survey respondents, Illinois EVALI patients had adjusted odds of 2.0 for reporting exclusive THC use, with a 95% confidence interval of 1.1 to 3.6. The adjusted odds were 3.1 for frequent THC use more than five times per day, with a 95% confidence interval of 1.6 to 6.0. The adjusted odds of obtaining products from informal sources were 9.2, with a 95% confidence interval of 2.2 to 39.4 (CDC MMWR Illinois risk factors).
An odds ratio is a comparison measure, not a percentage of patients and not a probability that a particular person will develop EVALI. The confidence intervals also show the uncertainty around each estimate. These Illinois results should be read as findings from that state’s analysis rather than automatically generalized to every U.S. population.
The Illinois nicotine-only analysis used several small groups. Of 104 patients who reported using any THC-containing products, 46 were classified as confirmed EVALI, equal to 44%. Seventeen patients reported using only nicotine-containing products, and two of those patients were classified as confirmed EVALI, equal to 12%. Nine patients had no indication of any THC use, and none of those nine were classified as confirmed EVALI (CDC MMWR Illinois nicotine-only). The small denominators make these subgroup percentages especially sensitive to individual cases.
Readmission and post-discharge outcomes
As of December 10, 2019, CDC had received reports of 2,409 EVALI cases requiring hospitalization and 52 deaths (CDC MMWR Dec. 2019 rehospitalization). A follow-up analysis examined 1,139 hospitalized EVALI patients discharged on or before October 31, 2019. Thirty-one were rehospitalized after discharge, equal to 2.7%, and the median time from discharge to rehospitalization was four days (CDC MMWR Dec. 2019 rehospitalization).
Seven deaths occurred after discharge, equal to 13.5% of the EVALI deaths in that analysis. The median time from discharge to death was three days. The median age was 54 years among patients who died after discharge, compared with 27 years among rehospitalized patients and 23 years among patients with neither outcome (CDC MMWR Dec. 2019 rehospitalization).
The clinical characteristics of the two adverse-outcome groups were also reported:
| Measure | Rehospitalized patients | Patients who died after discharge |
|---|---|---|
| At least one chronic condition | 70.6% | 83.3% |
| Intensive-care-unit admission | 47.4% | 100% |
| Intubation and mechanical ventilation | 36.4% | 100% |
These percentages come from the December 2019 CDC follow-up analysis and describe the specified rehospitalized and post-discharge death groups. They are not the proportions for every hospitalized EVALI patient. The 100% figures in the death group reflect that analysis’s reported cases, not a forecast of outcomes for future patients.
Vitamin E acetate findings
Several findings in the supplied CDC and NEJM reports concern vitamin E acetate in THC-containing products or patient respiratory specimens. In Minnesota, 24 THC-containing products obtained from 11 of 12 EVALI patients contained vitamin E acetate. Separately, 20 THC-containing products seized during September 2019 contained vitamin E acetate, whereas 10 products seized during 2018, before the outbreak, did not (CDC MMWR Minnesota 2018–2019).
CDC testing of 29 bronchoalveolar-lavage specimens from EVALI patients found vitamin E acetate in all 29 specimens (CDC MMWR Minnesota 2018–2019). A New England Journal of Medicine bronchoalveolar-lavage study detected vitamin E acetate in 48 of 51 EVALI patient samples, equal to 94% (NEJM vitamin E acetate BAL study).
The product and specimen findings are measurements from the named investigations, with their own samples and collection settings. They should be kept distinct from the national case counts, Illinois comparisons, and post-discharge outcome data because each section uses a different population, date, and method.