Epidemiological features of healthcare-associated Acinetobacter baumannii infections in} Taiwan during 2008 − 2019

Background: Acinetobacter baumannii can reside in humans without causing infection or symptoms but can opportunistically cause community and nosocomial infections. Few studies from Taiwan have used national-level data to investigate antibiotic resistance rates of A. baumannii infections in the intensive care units (ICUs) of medical centers. Aim: This study determined the number of infection sites of A. baumannii and the resistance rates of carbapenem-resistant A. baumannii (CRAB) infections in ICUs in Taiwan, and identified trends over time, variations of infection site, and factors associated with resistance. Methods: This study used the database provided by Taiwan's Centers for Disease Control. Yearly, Taiwan Nosocomial Infections Surveillance System Surveys from 2008 to 2019 were analyzed, including data on the site of infection and resistance rates of A. baumannii and patient and hospital characteristics. Results: On average, 21 hospitals as medical center/year participated in the survey, and 6803 A. baumannii isolates were identified. All isolates were health care-related infections. The most frequent sites of infection were the urinary tract (50.6%), respiratory tract (19.6%), bloodstream (18.2%), surgical wounds (4.3%), and others (7.4%). Infection rates were the highest in the urinary tract in 2019 (63.6%; P < 0.001). On average, the rate of carbapenem resistance was 66.6% (95% confidence interval: 63.1–70.1) among ICU patients at medical centers. Considerable regional differences were observed, with the highest rates of resistance in the central regions. Higher resistance rates were observed between 2019 and 2020 COVID-19 pandemic (74.2%). Conclusion: This is the first report on the prevalence of health care-related A. baumannii infection in Taiwan in 2008–2019. Several invasive diseases, such as urinary tract infections, are associated with higher rates of carbapenem resistance. The resistance rate of CRAB in Taiwan is exceptionally high. The current big-data-derived findings may inform future surveillance and research efforts in Taiwan.