Chronic alcohol use does not protect against COVID-19 infection

Since the beginning of the coronavirus pandemic, there has been a concurrent global rise in misinformation about the prevention and treatment of coronavirus disease (COVID-19). Many of the proposed therapies, such as bathing in or ingesting bleach, can result in significant harm with no evidence of clinical efficacy. One of the earliest myths suggested that frequent consumption of concentrated ethanol could kill the COVID-19 virus in the oropharynx, thereby preventing airborne transmission or treating active infection [[1], [2], [3]]. Consequently, both the World Health Organization and the National Institute on Alcohol Abuse and Alcoholism have since released statements refuting these claims, but cite evidence only highlighting the adverse effects of chronic alcohol consumption [1,2]. Therefore, we sought to evaluate the association between COVID-19 infection and chronic alcohol use by comparing the incidence of COVID-19 infection in patients with chronic alcohol use versus the general population who presented to the emergency department.

We performed a retrospective, single center, cohort study examining the incidence of COVID-19 infection in patients who presented to an urban public hospital emergency department between May 1 and July 31, 2020 who received testing for COVID-19 when widespread testing was available. At this institution, COVID-19 testing was performed at clinician discretion based on patient risk factors, symptoms, or institutional disposition requirements (hospital admission, shelter placement, congregate living situation, psychiatric evaluation). We defined two cohorts: all patients who presented to the emergency department and patients who presented to the emergency department with a history of chronic alcohol use. Subjects were included in the chronic alcohol use cohort based on the presence of any positive serum ethanol level during the study period and if they had a documented history of alcohol withdrawal, alcohol use disorder, alcoholic cirrhosis, or more than three emergency department visits related to alcohol use in the prior calendar year based on retrospective chart review. Chart review was completed by two authors, JAL and AM, who were not blinded to the study hypothesis. All data abstracted by manual review were confirmed by both reviewers. Full consent between authors was required for inclusion. If consensus was not reached, the case was adjudicated by another reviewer. Nasopharyngeal swabs were tested for the presence of SARS-CoV-2 infection via polymerase chain reaction-based methods. We then compared the incidence of COVID-19 infection in all patients presenting to the emergency department and patients presenting to the emergency department with a history of chronic alcohol use. Institutional review board approval was obtained for all study procedures. Incidence rates were compared using χ² analysis.

Overall, a total of 5419 unique subjects received a COVID-19 test in the emergency department during the study period. Within this cohort, 161 subjects met criteria for chronic alcohol use. The incidence of COVID-19 in the general emergency department population was 5.66% (307/5419). The incidence of COVID-19 among subjects with a history of chronic alcohol use was 4.97% (8/161). There was no significant difference between cohorts (absolute difference 0.69%, χ² = 0.140, 95% CI -3.88-3.21). Demographic and clinical characteristics of the chronic alcohol use cohort are shown in Table 1 .

Table 1.

Summary of demographics and clinical characteristics of patients with chronic alcohol use (N = 161), May to July 2020.

Variable	Frequency, N (%)
Age (years, mean ± SD)	51.7 ± 12.2
Male Gender	135 (83.8)
Race Caucasian Hispanic African American Asian Not Specified/Other	67 (41.6) 48 (29.8) 34 (21.1) 5 (3.1) 7 (4.3)
Diagnosis Alcohol Use Disorder Alcohol Withdrawal Alcoholic Cirrhosis > 3 Alcohol-Related ED Visits in Prior Year	103 (63.9) 141 (87.5) 31 (19.3) 73 (45.3)
Blood Alcohol Level (mg/dL, mean ± SD)	262 ± 140
Number of alcohol related ED visits in the past year (mean ± SD)	5.44 ± 8.5

In this sample of emergency department subjects, chronic alcohol use was not associated with a decreased incidence of COVID-19 infection. To our knowledge, these are the first data to directly address this widespread myth and provide evidence to discredit the notion that frequent alcohol use can prevent COVID-19 infection.

The study limitations include the retrospective design at a single institution. The proportion of patients with a history of chronic alcohol use may be underestimated due to limitations of the electronic medical record used to define this cohort. Similarly, we were unable to account for other potential confounders, such as medical co-morbidities, housing status, or frequent contact with crowded indoor spaces. Testing thresholds evolved over the study period as institutional knowledge and protocols changed, although this would be present in both cohorts.

These data only address one myth in a sea of falsehoods. While public health entities have attempted to counter misinformation by disseminating evidence-based recommendations, the rapid proliferation of misinformation has undoubtedly resulted in additional harm to patients. It remains the responsibility of the medical community to continue working to counter potentially harmful remedies, myths, and fake news.