UTI, Other Infection Types Associated with Increased Stroke Risk

A recent study has found that a wide range of infection types are associated with a greater risk of acute ischemic stroke (AIS) and some infections are also associated with intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH).

After examining data from more than 175,000 patient admissions from New York, investigators found that the greatest association was between urinary tract infections and AIS.

“Healthcare providers need to be aware that stroke can be triggered by infections,” said Mandip Dhamoon, MD, senior study author and associate professor of neurology at the Icahn School of Medicine at Mount Sinai in New York City. “Probing into the previous weeks or months of a patient’s life before the stroke can sometimes help to illuminate the possible causes of stroke if there was an infection during that time.”

Using the State Inpatient and Emergency Department Databases from 2006 to 2013, investigators identified 152,356 index AIS admissions, 27,257 ICH admissions, and 11,853 SAH admissions. Investigators performed a case-crossover analysis for infections types — including skin, urinary tract infection (UTI), septicemia, abdominal, and respiratory infections — to assess associations between each infection type and stroke event type. Investigators considered records of hospitalization for infections for 7, 14, 30, 60, 90, and 120 days prior to stroke occurrence.

After analyses, using conditional logistical regression models with 95% confidence intervals, Investigators found that every infection type was associated with an increased likelihood of AIS. The association between AIS and UTI was greatest within a 7-day window before index AIS hospitalization (5.32 OR, 95% CI, P<0.0001). For all infection types, the stroke risk decreased as the time period before ischemic stroke occurred increased.

Investigators also found that UTI, septicemia, and respiratory infections were all associated with increased risk for ICH. Conversely, respiratory infection was the only infection type related to the occurrence of SAH — this association was greatest 14 days before index SAH hospitalization (3.67 OR, 95% CI, P=0.0048).

“Our study shows that we need to do more to understand why and how infections are associated with the occurrence of different kinds of stroke, and that will help us to determine what we can do to prevent these types of strokes,” Dhamoon said. “These findings suggest that there could be implications for vaccination, antibiotic regimens or intensive antithrombotic treatments not only to prevent the infections but to prevent stroke in those who are deemed high-risk.”

Study authors noted multiple limitations within their study. A lack of data on outpatient visits or medication use means more research is needed on potential interventions. They also noted their reliance on International Classifcaiton of Disease, Ninth Revision to identify conditions as a weakness.

This study, titled “Infection as a Stroke Trigger Associations Between Different Organ System Infection Admissions and Stroke Subtypes,” is published in the Journal of the American Heart Association.