Prevalence and Factors Associated with Infections After Acute Ischemic Stroke: A Single-Center Retrospective Study over Five Years

Background/Objectives: Infections after stroke are a serious medical problem and have a significant impact on the outcome of stroke, but data regarding the Asian population are limited. This study aims to determine the bacterial and fungal profile of pathogenic organisms of infections after acute ischemic stroke (AIS). Methods: This is a retrospective study using the medical records of patients at least 18 years old who were hospitalized with AIS in a tertiary stroke hospital from 1 January 2018 to 31 December 2022. Demographic, patient-related, and other examination data were extracted from hospital medical records. Infections after AIS were defined as any infection that developed during the acute phase of ischemic stroke and was confirmed by microbiologic culture as the gold standard. Factors associated with infection were analyzed using multiple logistic regression. Results: Among 599 AIS patients with infection who underwent microbiologic culture, the prevalence of infection with an isolated pathogen was 21.4%, and most organisms were from sputum. Positive microbiologic culture revealed that bacteria such as K. pneumoniae, E. coli, A. baumannii, and S. aureus were the most common causes of infection, while fungi were rare. During the COVID-19 period, bacteria developed resistance to antimicrobials, including β-lactamase antibiotics for Gram-negative bacteria and methicillin for Gram-positive bacteria. Care in the intensive ward, including the stroke unit, reduced the risk of a positive microbiological culture in the COVID-19 and non-COVID-19 period. Urinary catheters promoted infections in the non-COVID-19 period, whereas steroids, total parenteral nutrition, and tracheostomy were negatively associated with infections after AIS in the COVID-19 period. Conclusions: The prevalence and factors associated with infection after stroke changed during the COVID-19 period. The risk of infection after stroke requires preventive measures such as early dysphagia screening.