Evaluation of Antimicrobial Drug Use and Concurrent Infections During Hospitalization of Patients With COVID-19 in Japan

A recent meta-analysis^1,2 and a prospective study³ reported that bacterial coinfection and secondary infection among patients with COVID-19 infection are uncommon. However, in these studies, antimicrobial drugs were prescribed for approximately 70% of patients with the disease.² Therefore, data are needed on patients with COVID-19 infection who do not routinely receive an antimicrobial drug prescription, to identify the true rate of concurrent infection in this patient population. At the National Hospital Organization Tochigi Medical Center in Utsunomiya, Tochigi, Japan, since the beginning of the COVID-19 pandemic, antimicrobial drugs have not been prescribed for patients with COVID-19 infection unless their symptoms are suggestive of another infectious disease. Therefore, we investigated the prevalence of antimicrobial drug use and concurrent infections among patients with COVID-19 during hospitalization.

This retrospective cross-sectional study obtained and analyzed data from electronic medical records. The institutional ethics committee of the National Hospital Organization Tochigi Medical Center approved this study and formally waived the informed consent requirement because deidentified data were collected without contacting the patients. We followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.

All symptomatic patients with laboratory-confirmed COVID-19 infection who were hospitalized at the National Hospital Organization Tochigi Medical Center from November 1, 2020, to October 9, 2021, were eligible. Excluding 47 patients who were transferred to other hospitals for intensive care, the final analysis included 1056 patients (eMethods in the Supplement). At the hospital, patients with COVID-19 infection were treated according to World Health Organization guidelines.⁴ The COVID-19 care team included 2 physicians on the antimicrobial stewardship team.

Information on demographic characteristics, microbial test results, and medication use during hospitalization was extracted from electronic medical records. The severity of COVID-19 was assessed using the World Health Organization classification.⁵ The primary outcomes were the prevalence of antimicrobial drug use and the proportion of patients with microbiologically confirmed concurrent infections during hospitalization. Descriptive statistics were used to report patient characteristics and outcomes. We used Stata, version 15 (LightStone).

Of the 1056 patients analyzed (median [IQR] age, 50 [36-61] years; 669 men [63.4%] and 387 women [36.7%]) (Table 1), 533 (50.5%) had mild, 313 (29.6%) had moderate, 203 (19.2%) had severe, and 7 (0.7%) had critical COVID-19 infection. During hospitalization, 9 patients (0.9%) died, 1046 patients (99.1%) recovered, and 1 patient was transferred to another hospital before recovery for social reasons. Although antimicrobial drugs were prescribed for 104 patients (9.9%) before admission, only 18 patients (1.7%) received any antimicrobial drugs during hospitalization (Table 2). Of these 18 patients, 15 used the drug as treatment, and 3 used it as a prophylaxis. Seven microbiologically confirmed infectious diseases other than COVID-19 were detected in 6 patients (0.6%) during hospitalization. Even if mild COVID-19 cases were excluded, they occurred in only 5 patients (0.9%).

The findings revealed that concurrent infectious diseases rarely occurred despite the infrequent use of antimicrobial drugs during hospitalization among patients with COVID-19 infection, most of whom had noncritical cases. This finding supports the results of recent studies showing that concurrent bacterial infections were uncommon in patients with COVID-19 infection.^1-3 Given that most patients with noncritical severity recovered without antimicrobial drugs, the use of most antimicrobial drugs to treat noncritical cases in many hospitals might be unnecessary. Antimicrobial drugs should be used cautiously to treat patients with COVID-19 infection.

The strengths and importance of this study were the assessment of the use of all antimicrobial drugs (regardless of the reason for use) and the finding of an extremely low rate of antimicrobial drug use compared with that in previous studies.² The limitations were the retrospective data collection, single-center design, short-term follow-up, and exclusion of patients who were transferred to other hospitals for intensive care. Moreover, a positive result on a microbial test did not necessarily indicate true infection. In addition, a few patients who had active cancer or were immunocompromised were included.

Accepted for Publication: December 30, 2021.

Published: February 18, 2022. doi:10.1001/jamanetworkopen.2022.0040

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2022 Komagamine J et al. JAMA Network Open.

Corresponding Author: Junpei Komagamine, MD, Department of Internal Medicine, National Hospital Organization Tochigi Medical Center, 1-10-37 Nakatomatsuri, Utsunomiya, Tochigi, Japan (junpei0919@yahoo.co.jp).

Author Contributions: Dr Komagamine had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Komagamine, Yabuki.

Acquisition, analysis, or interpretation of data: Komagamine, Matsumoto, Tanaka.

Drafting of the manuscript: Komagamine.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Komagamine.

Supervision: Komagamine, Yabuki.

Conflict of Interest Disclosures: None reported.

Meeting Presentation: Data from this study will be used at a poster presentation at the 119th Annual Meeting of the Japanese Society of Internal Medicine, April 15-17, 2022; virtual.