Discussion
According to the Centers for Disease Control and Prevention in the United States, VRE accounts for approximately 30% of all types of enterococci compared to 0.8% by the Japan Nosocomial Infections Surveillance, Ministry of Health, Labour and Welfare in Japan in 2021; thus, VRE in Japan is rare1, 2).
In 2019, 80 patients were reported throughout Japan. The male-to-female ratio was 1:1, and the median age was 79 years. Of samples in which bacteria were detected, urine, blood, and ascites accounted for 38, 31, and 9%, respectively. Concerning clinical diagnosis, urinary tract infection was observed in 26 patients (33%), and bacteremia in 20 (25%)1). Although urologists are often responsible for the treatment of urinary tract infection, there have been few clinical reports on VRE from the field of urology.
The pathogenicity of VRE is low; however, surgical site infection, urinary tract infection, and bacteremia may occur in patients with underlying diseases; thus, caution is needed. A study showed that the admission period was 5 days longer than patients infected with vancomycin-susceptible enterococcus, and the mortality rate was 1.8 times higher3). For the treatment of VRE infection, daptomycin is the first-choice drug4). In our patient, combination therapy with daptomycin and a beta-lactam was started, and an adverse reaction to daptomycin was suspected; therefore, it was switched to linezolid.
VRE is highly transmissible, and readily causes contact infection. However, its onset is rare, and it may not be readily diagnosed. Therefore, nosocomial outbreaks may occur, and this type of bacteria is important for medical facilities involving a large number of high-risk patients from the viewpoint of infection control. Standard preventive measures alone are not sufficient; thus, contact prevention strategies should be adopted5).
Hayakawa et al.6) reported that 56.5% of patients with a history of hospitalization abroad had drug-resistant bacteria, including ESBL-producing bacteria and MRSA, and that these bacteria included highly resistant bacteria such as MDRA and VRE. When admitting patients with a history of medical exposure in other countries, caution is necessary, and private room isolation/contact infection control must be performed until the presence or absence of carriage is confirmed1).
Our patient was hospitalized in a private room from the time of admission, considering severe infection and potential for transmission of COVID-19. After VRE infection became clear, standard preventive measures were taken for in-hospital infection control. The inpatient ward was closed after consultation on effective pathogen management by the Department of Infection Control and a health center. A fecal culture test of all inpatients in the ward was conducted to confirm VRE-negative status. The ward closure period was 3 days.
In a urological ward, many patients are treated by catheter-insertion; furthermore, there are many cancer and elderly patients. The risk of nosocomial infection has been reported to be high7). Even in areas where VRE is rare, attention should be paid to patients who have received treatment in other countries.