Herpes Labialis, Chlamydophila pneumoniae, Helicobacter pylori, and Cytomegalovirus Infections and Risk of Dementia: The Framingham Heart Study

Background: An association between chronic infectious diseases and development of dementia has been suspected for decades, based on the finding of pathogens in postmortem brain tissue and on serological evidence. However, questions remain regarding confounders, reverse causality, and how accurate, reproducible and generalizable those findings are. Objective: Investigate whether exposure to Herpes simplex (manifested as herpes labialis), Chlamydophila pneumoniae (C. pneumoniae), Helicobacter pylori (H. pylori), and cytomegalovirus (CMV) modifies the risk of dementia in a populational cohort. Methods: Questionnaires regarding incidence of herpes infections were administered to Original Framingham Study participants (n = 2,632). Serologies for C. pneumoniae, H. pylori, and CMV were obtained in Original (n = 2,351) and Offspring cohort (n = 3,687) participants. Participants are under continuous dementia surveillance. Brain MRI and neuropsychological batteries were administered to Offspring participants from 1999–2005. The association between each infection and incident dementia was tested with Cox models. Linear models were used to investigate associations between MRI or neuropsychological parameters and serologies. Results: There was no association between infection serologies and dementia incidence, total brain volume, and white matter hyperintensities. Herpes labialis was associated with reduced 10-year dementia risk (HR 0.66, CI 0.46–0.97), but not for the duration of follow-up. H. pylori antibodies were associated with worse global cognition (β –0.14, CI –0.22, –0.05). Conclusion: We found no association between measures of chronic infection and incident dementia, except for a reduction in 10-year dementia risk for patients with herpes labialis. This unexpected result requires confirmation and further characterization, concerning antiviral treatment effects and capture of episodes.

Atypical pathogen infection of respiratory system

The frequency of respiratory infections, especially atypical pneumonia, is increasing significantly. Most often, atypical pneumonia is caused by Mycoplasma pneumoniae and Chlamydophila pneumoniae. Human is the only reservoir of these atypical bacteria. The infection occurs via droplets or direct contact with a sick person or convalescent. Pneumonia of the etiology of Mycoplasma pneumoniae and Chlamydophila pneumoniae most often affects children without comorbidities and is usually mild, while most patients with Legionella infection require intensive care treatment. Symptoms of mycoplasma infection can range from mild symptoms in the upper respiratory tract to pneumonia and extrapulmonary symptoms. The infection is often underdiagnosed, and patients usually do not seek medical attention and treatment. Chlamydial pneumonia is, in most cases, mild, similar to Mycoplasma pneumoniae, and tends to heal itself. The drugs of choice in the treatment of atypical pneumonia are macrolides, and because of the best compliance in children – azithromycin.

Mucosal Respiratory Syndrome: A Systematic Literature Review

<b><i>Background:</i></b> <i>Mycoplasma pneumoniae</i> atypical pneumonia is frequently associated with erythema multiforme. Occasionally, a mycoplasma infection does not trigger any cutaneous but exclusively mucosal lesions. The term mucosal respiratory syndrome is employed to denote the latter condition. Available reviews do not address the possible association of mucosal respiratory syndrome with further atypical bacterial pathogens such as <i>Chlamydophila pneumoniae</i>, <i>Chlamydophila psittaci</i>, <i>Coxiella burnetii</i>, <i>Francisella tularensis</i>, or <i>Legionella</i> species. We therefore performed a systematic review of the literature addressing this issue in the National Library of Medicine, Excerpta Medica, and Web of Science databases. <b><i>Summary:</i></b> We found 63 patients (≤18 years, <i>n</i> = 36; &#x3e;18 years, <i>n</i> = 27; 54 males and 9 females) affected by a mucosal respiratory syndrome. Fifty-three cases were temporally associated with a <i>M. pneumoniae</i> and 5 with a <i>C. pneumoniae</i> infection. No cases temporally associated with <i>C. psittaci</i>, <i>C. burnetii</i>, <i>F. tularensis</i>, or <i>Legionella</i> species infection were found. Two cases were temporally associated with Epstein-Barr virus or influenzavirus B, respectively.

Plasma Amyloid-β in Relation to Antibodies Against Herpes Simplex Virus, Cytomegalovirus, and Chlamydophila pneumoniae

Background: Amyloid-β (Aβ), the key constituent of Alzheimer’s disease (AD) plaques, has antimicrobial properties. Objective: To investigate the association between plasma Aβ and antibodies against the AD-related pathogens herpes simplex virus (HSV), cytomegalovirus (CMV), and C. pneumoniae. Methods: Plasma from 339 AD cases, obtained on average 9.4 years (±4.00) before diagnosis, and their matched controls were analyzed for Aβ40 and Aβ42 concentrations with Luminex xMAP technology and INNOBIA plasma Aβ-form assays. Enzyme-linked immunosorbent assays were utilized for analyses of anti-HSV immunoglobulin (Ig) G, anti-HSV1 IgG, anti-HSV2 IgG, anti-CMV IgG, and anti-C. pneumoniae IgG. Follow-up samples were available for 163 of the cases. Results: Presence and levels of anti-HSV1 IgG, anti-HSV2 IgG, anti-CMV IgG, and anti-C. pneumoniae IgG did not correlate with concentrations of Aβ42 or Aβ40 in cases or controls. Conclusion: Levels of plasma Aβ were not associated with antibodies against different AD-related Spathogens.

Acute Chlamydophila pneumoniae infection and its association with cardiovascular diseases.

Chronic infection with Chlamydophila pneumoniae (C pneumoniae) has been associated with cardiovascular disease (CVD). This study evaluates the association of acute C pneumoniae infection and CVD in adult patients. We conducted a cross-sectional study that included 397 patients with a diagnosis of CVD, and 127 without CVD, at the Hospital General de Zona del Instituto Mexicano del Seguro Social (IMSS) in the state of Morelos, Mexico; the diagnosis was established by the Department of Cardiology. Patients with CVD were divided into 4 groups: I) Cardiac arrhythmia, II) Ischemic heart disease, III) Hypertensive heart disease and, IV) Valvular heart disease. Exposure to C pneumoniae was measured by antibody determination (IgG, IgM e IgA) with the microimmunofluorescence (MIF) technique. Statistical analysis included the determination of prevalence, and multiple logistic regression analysis. Results showed that the prevalence of acute C pneumoniae infection in the study population was 21%, and was highest in the groups with CVD versus patients without CVD, and an association was established (OR, 13.93; 95% CI, 3.8-66.1). Likewise, when comparing the Ig titer geometric means, we found that an acute C pneumoniae infection increased the risk of presenting a cardiac arrhythmia and ischemic heart disease by a factor of 18, and increased 12-fold the risk of having hypertensive or valvular heart disease. The prevalence of acute infection + chronic infection was greater in the group with ischemic heart disease (18.4%). Our study reflects the great significance of seroprevalence of acute infection with C pneumoniae among patients with CVD. Further, the seroprevalence of acute infection + chronic infection was greater in patients with ischemic heart disease, suggesting that this combination may be associated with the mechanisms leading to atherosclerosis mediating coronary episodes. It appears that this is the first report on the subject.

Comparison of Molecular Method and Culture in Detection of Community Acquired Pneumonia in Under Five Year Children in Assam, India

Introduction: Pneumonia is the single largest infectious cause of death in children worldwide. Aetiology of pneumonia can be identified using multiple diagnostic tools including culture, serology and Polymerase Chain Reaction (PCR); common pathogens include Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, some atypical bacteria like Mycoplasma pneumoniae and Chlamydophila pneumoniae. Aim: To find out the bacteriological agents causing Community Acquired Pneumonia (CAP) in under five year children and to compare the conventional culture and PCR in identifying the pathogen. Materials and Methods: This cross-sectional study was undertaken in the Department of Microbiology and Department of Paediatrics in a tertiary care centre of Assam, India, between March 2016 to September 2018. The study was undertaken with 200 under five year old children who were clinically diagnosed as CAP. Oropharyngeal (OP) swabs and blood culture were processed for bacteriological culture. PCR assay of OP swabs for Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus etc., including atypical bacteria like Mycoplasma pneumoniae and Chlamydophila pneumoniae were performed. Data entry, database management and statistical analysis were performed using Epi-Info software version 7.0. Results: A total of 200 subjects were included in the present study with a male:female ratio of 1.63:1. Most of the study subjects were <11 months of age. Most common isolates were Streptococcus pneumoniae (26.5%) and Staphylococcus aureus (25%) from OP swabs; blood culture revealed mostly Staphylococcus aureus (59%) and Streptococcus pneumoniae (25%). PCR assay of OP swabs were found positive mostly for Staphylococcus aureus (47%), Streptococcus pneumoniae (21.5%) while two children were positive for Haemophilus influenzae; Bordetella pertussis was detected in one child. On evaluation, PCR assay in detecting the bacterial pathogen was found statistically more significant than conventional culture of OP swabs (p<0.05). Conclusion: Staphylococcus aureus and Streptococcus pneumoniae were the most common bacterial organisms in the study. PCR assay was found to be more useful in diagnosing the pathogen for bacterial pneumonia including those difficult to grow in conventional culture.