Background and Purpose: Multiple studies have suggested an association between Chlamydia pneumoniae infection and atherosclerotic vascular disease. We investigated whether serological markers of C. pneumoniae infection were associated with acute stroke or transient ischaemic attack (TIA), exclusively in elderly patients. Methods: One-hundred white patients aged over 65 years admitted with acute stroke or TIA, and 87 control patients admitted with acute non-cardiopulmonary, non-infective disorders were recruited prospectively. Using an enzyme-linked immunosorbent assay kit, the presence of C. pneumoniae immunoglobulins IgA, IgG, IgM in patients’ sera was determined. Results: The seroprevalence of C. pneumoniae-specific IgA, IgG, IgM were 63, 71, and 14% in the stroke/TIA group (median age = 80), and 62, 65, and 17% in the control group (median age = 80), respectively. Using a logistic regression statistical model, adjusting for age and sex, history of hypertension, smoking, diabetes, ischaemic heart disease (IHD), ischaemic electrocardiogram (ECG), the odds ratios (ORs) of having a stroke/TIA in relation to C. pneumoniae-specific IgA, IgG, IgM were 1.04, 1.24, 0.79 (p = NS). Further analysis identified 43 acute stroke/TIA cases and 44 controls without history of IHD or ischaemic ECG or both. After adjusting for history of hypertension, smoking, diabetes, age and sex, the ORs in this subgroup were 1.40 for IgA [95% confidence interval (CI) 0.53–3.65; p = 0.49], 2.41 for IgG (95% CI 0.90–6.46; p = 0.08) and 1.55 for IgM (95% CI 0.45–5.40; p = 0.49). Conclusions: Although a high seroprevalence of C. pneumoniae in elderly patients was confirmed, no significant association between serological markers of C. pneumoniae infection and acute cerebrovascular events was found. There was, however, a weak trend towards increased ORs for acute cerebrovascular disease in a subgroup of C. pneumoniae seropositive elderly patients without any history of IHD or ischaemic ECG.

Background and Purpose-Multiple studies have suggested an association between Chlamydia pneumoniae andMycoplasma pneumoniae infection and cardiovascular disease. We investigated whether the risk of cerebrovascular disease is associated with Legionella pneumophila infection and the aggregate number/infectious burden of these atypical respiratory pathogens. Methods-One hundred patients aged Ͼ65 years admitted with acute stroke or transient ischemic attack (TIA) and 87 control patients admitted concurrently with acute noncardiopulmonary, noninfective conditions were recruited prospectively. Using enzyme-linked immunosorbent assay (ELISA) kits, we previously reported the seroprevalences of C pneumoniae and M pneumoniae in these patients. We have now determined the seroprevalences of L pneumophila IgG and IgM in this cohort of patients using ELISA. Results-The seroprevalences of L pneumophila IgG and IgM were 29% (nϭ91) and 12% (nϭ81) in the stroke/TIA group and 22% (nϭ86) and 10% (nϭ72) in the controls, respectively. Using logistic regression to adjust for age, sex, hypertension, smoking, diabetes, ischemic heart disease, and ischemic ECG, the odds ratios for stroke/TIA in relation to L pneumophila IgG and IgM were 1.52 (95% CI, 0.70 to 3.28; Pϭ0.29) and 1.49 (95% CI, 0.45 to 4.90; Pϭ0.51), respectively. The odds ratios in relation to IgG seropositivity for 1, 2, or 3 atypical respiratory pathogens after adjustment were 3.89 (95% CI, 1.13 to 13.33), 2.00 (95% CI, 0.64 to 6.21), and 6.67 (95% CI, 1.22 to 37.04), respectively (Pϭ0.06). Conclusions-L pneumophila seropositivity is not significantly associated with stroke/TIA. However, the risk of stroke/TIA appears to be associated with the aggregate number of chronic infectious burden of atypical respiratory pathogens such as C pneumoniae, M pneumoniae, and L pneumophila.

With use of an enzyme-linked immunosorbent assay (ELISA), Chlamydia pneumoniae immunoglobulins were detected in a consecutive series of patients' sera (n = 122 for IgA and IgG; n = 138 for IgM). When the ELISA tests were repeated, the percentage disagreements were 12%, 16% and 10% for C. pneumoniae IgA, IgG and IgM, respectively. The reproducibility of the ELISA, expressed as kappa values, for IgA, IgG and IgM was 0.73, 0.60 and 0.53, respectively (p < 0.001). It was concluded that the ELISA had good reproducibility for detecting C. pneumoniae IgA, and moderately good reproducibility for detecting C. pneumoniae IgG and IgM.

Background and Purpose: Previous studies have suggested certain infections as potential risk factors for stroke. Chlamydia pneumoniae, an atypical respiratory pathogen, has been linked to atherosclerotic vascular diseases. Mycoplasma pneumoniae, another atypical respiratory micro-organism, can rarely cause stroke. We investigated whether serological markers of M. pneumoniae infection were associated with acute stroke or transient ischaemic attack (TIA) in elderly patients. Methods: This case-control study was nested within the C-PEPS study – a case-control study on the seroprevalence of C. pneumoniae in elderly stroke and medical patients. Ninety-five incident cases of patients admitted consecutively with acute stroke or TIA, and 82 control subjects admitted concurrently with acute non-cardiopulmonary, non-infective disorders, were included in this study (both groups aged 65 years or older). Using commercial enzyme-linked immunosorbent assay (ELISA) kits, the presence of M. pneumoniae immunoglobulins IgA, IgG and IgM in patients’ sera was determined. Results: The seroprevalence of M. pneumoniae IgA, IgG and IgM in the stroke or TIA group (median age = 80) were 79, 61 and 6%, respectively. In the control group (median age = 80), the seroprevalence of respective M. pneumoniae IgA, IgG and IgM were 84, 50 and 11%. Using a logistic regression statistical model, adjusting for history of hypertension, smoking, diabetes mellitus, age and sex, history of ischaemic heart disease, and ischaemic electrocardiogram, the odds ratios of having a stroke or TIA in relation to M. pneumoniae IgA, IgG and IgM were 0.63 (95% confidence interval (CI) = 0.26–1.52, p = 0.31), 1.32 (95% CI = 0.66–2.64, p = 0.43) and 0.52 (95% CI = 0.14–1.92, p = 0.32), respectively. Conclusions: The study showed a high seroprevalence of M. pneumoniae in an elderly hospital population, using ELISA. Although the study ruled out M. pneumoniae seropositivity as a major risk factor for stroke in this elderly population, a smaller effect could not be excluded due to the small sample size. Future larger studies may be required to determine the precise role of M. pneumoniae infection in the pathogenesis of different subtypes of ischaemic stroke, in all age groups, and in different ethnic populations.