A significant association was observed between chronic infections caused by Chlamydia pneumoniae, Helicobacter pylori, and Mycobacterium tuberculosis bacteria and an increased risk for ischemic stroke, according to findings published in New Microbes and New Infections.
In this meta-analysis that included results from 50 case-control studies comprising 33,978 patients, researchers sought to determine the relationship between bacterial infections and the occurrence of ischemic stroke. The included studies were conducted between 1996 and 2017.
Among patients in the ischemic stroke (n=13,652) and control groups (n=20,326), the mean age was 61.7 and 59.8 years, around 62.6% and 56.1% were men, and 38% (95% CI, 37-39) and 26% (95% CI, 25-27) had bacterial infections, respectively.
The researchers found that infections caused by C pneumoniae, H pylori, Mycoplasma pneumoniae, and M tuberculosis were associated with a significantly increased risk for ischemic stroke (odds ratio [OR], 1.704; 95% CI, 1.57-1.84; P =.01; I2 =78.55).
Further analysis was conducted among studies that assessed the associative risk for ischemic stroke by specific bacteria. The researchers found that C pneumoniae infections were increased among patients in the ischemic stroke vs control groups (57% vs 36%), indicating a significant association between C pneumoniae bacteria and ischemic stroke occurrence (OR, 2.14; 95% CI, 1.91-2.38; P =.001; I2 =71). Analysis of H pylori infections among patients in the ischemic stroke vs control groups (63% vs 55%) showed that H pylori bacteria was also associated with an increased risk for ischemic stroke (OR, 1.64; 95% CI, 1.44-1.87; P =.001; I2 =72.88).
Despite a similar rate of M tuberculosis infections among patients in the ischemic stroke and control groups (4% vs 3%, respectively), M tuberculosis bacteria also was associated with an increased risk for ischemic stroke (OR, 1.15; 95% CI, 0.99-1.34; P =.05; I2 =94.73).
No significant association was found between M pneumonia bacteria and ischemic stroke occurrence (OR, 0.97; 95% CI, 0.12-7.69; P =.98; I2 =77.94).
This analysis was limited by the small number of included studies, significant heterogeneity, and potential publication bias.
According to the researchers, “[these] results indicate the need for additional longitudinal investigations to determine the impact of infectious disease on the risk [for] ischemic stroke.”
Keikha M, Karbalaei M. Potential association between bacterial infections and ischemic stroke based on fifty case-control studies: a systematic review and meta-analysis. Published online April 8, 2022. New Microbes New Infect. doi.10.1016/j.nmni.2022.100980