Infection occurs commonly in patients with acute ischemic stroke (AIS). This study aimed to investigate the association of infection with long- and short-term risk of recurrent stroke in patients with AIS.

The data for this study was obtained from AIS patients in 2 stroke registries:  CSCA and CNSR-III.

Associations of infection (urinary tract infection or pneumonia) during hospitalization with recurrent stroke in long and short term were analyzed. The long-term outcomes were analyzed with Cox models, whereas the short-term outcomes analysis was done with logistic models. In the CSCA program (n=789,596), the incidence of infection during hospitalization reached 9.6%. Patients with infection had a higher risk of stroke recurrence during hospitalization compared with patients without infection (10.4% vs. 5.2%). In the CNSR-III registry (n=13,549), the infection incidence during hospitalization was 6.5%. Infection during hospitalization was significantly associated with short-term risk of recurrent stroke (7.4% vs. 3.9%) but not with long-term risk of recurrent stroke (7.2% vs. 5.2%).

In conclusion, infection was a major risk factor for early stroke recurrence during the period of hospitalization. However, the sustained effect of infection on the long-term recurrence risk in patients with AIS is yet to be determined.