Association of herpesviruses and stroke: Systematic review and meta-analysis

Infection in Childhood Arterial Ischemic Stroke: Metagenomic Next-Generation Sequencing Results of the VIPS II Study

BACKGROUND

Acute respiratory infection transiently increases risk for childhood arterial ischemic stroke (AIS). We hypothesize that this paradox of a common exposure linked to a rare outcome could be explained by either (1) the infection hypothesis: unusual or multiple pathogens or (2) the host response hypothesis: heterogeneity in the inflammatory response to infection. We leverage metagenomic next-generation sequencing (mNGS), a comprehensive microbial detection tool, to test the first hypothesis.

METHODS

The VIPS II study (Vascular Effects of Infection in Pediatric Stroke II) prospectively enrolled children with AIS at 22 international sites over 5 years (December 2016 to January 2022). Sites measured prestroke clinical infection via standardized parental interviews and chart abstraction. To assess more broadly the background spectrum of pathogens, a central research laboratory performed mNGS on plasma and oropharyngeal swabs collected within 72 hours of stroke. mNGS was also performed on biological samples from stroke-free children (June 2017 to January 2022), both without (well) and with (ill) documentation of clinical infection.

RESULTS

VIPS II enrolled 205 patients with AIS, 95 stroke-free well children, and 47 stroke-free ill children. Clinical infection, most commonly upper respiratory tract infection, was detected in 81 of 205 (40%) of patients. Both plasma and oropharyngeal swab mNGS data were available for 190 of 205 patients with AIS, 91 of 95 stroke-free well children, and 27 of 47 stroke-free ill children. mNGS detected viruses in 27 of 190 (14%) patients with AIS, 9 of 91 stroke-free well children (10%), and 9 of 27 (33%) stroke-free ill children. Most were common upper respiratory viruses. Coinfections were rare. Similar viruses were found in patients with AIS and stroke-free children.

CONCLUSIONS

mNGS detected a variety of common childhood viruses in both patients with AIS and stroke-free children, suggesting that the type of infection does not explain AIS susceptibility. Rather, the alternative hypothesis regarding an unusual host immune response to common infections in the pathogenicity of AIS should be further explored.

Herpes zoster as risk factor for dementia: a matched cohort study over 20 years in a 10-million population in Italy

BACKGROUND

Herpes Zoster is caused by the reactivation of the Varicella-Zoster Virus. Zoster may influence the occurrence of dementia, but contradictory results about this association emerged from recent studies. These findings did not consider the severity of Zoster and observed individuals for limited follow-up time. Our study used a region-wide Italian registry to investigate the association between severe Zoster infection and dementia occurrence over a 23-year period.

METHODS

We included people aged ≥ 50 and hospitalised with Zoster, and two comparison cohorts from both the general population and the hospitalised population without Zoster. By random sampling, the matching 1:5 was based on sex, birth year, and entry date in the cohort. Dementia and Zoster were identified through validated algorithms. A Fine-Gray sub-distribution hazard model was used, accounting for competing risk of death.

RESULTS

We identified 132,968 individuals, of whom 12,088 with severe Zoster, 60,440 matched controls among the general population, and 60,440 matched controls among the hospitalised population. In severe cases of Herpes Zoster, the overall adjusted sub-distributed hazard ratio of dementia was 1.13 (95 % CI 1.07-1.19) compared to the general population, and 1.08 (95 % CI 1.03-1.14) compared to hospitalised population. Hazard ratios were still significant in different strata group, including by sex, age group (including in 50-65 younger adults) and at different follow-up period.

CONCLUSIONS

Our population-based study found an increased risk of developing dementia among severe Zoster cases. Those results support the importance of improving Zoster prevention and extending the vaccination recommendations to younger age groups.

The role of atherosclerosis in HIV-associated vasculopathy in young South African stroke patients

BACKGROUND

HIV-associated vasculopathy is known to cause stroke in people living with HIV (PLWH). The role of atherosclerosis is unclear. We assessed the aetiology of vasculopathy in PLWH and tested the utility of markers of subclinical atherosclerosis to distinguish atherosclerotic (AV) from non-atherosclerotic vasculopathy (NAV).

METHODS

This cross-sectional study recruited PLWH with stroke at a hospital in Johannesburg, South Africa, from 2014 to 2017. Patients with meningitis were excluded. Cerebrospinal fluid (CSF) was tested for multi-viral polymerase chain reaction, including varicella zoster virus (VZV). Once an aetiological category was assigned, carotid intima-media thickness (cIMT) and aortic pulse wave velocity (PWV) were compared in AV and NAV, and to predetermined thresholds for subclinical atherosclerosis (cIMT≥0.70 mm, PWV≥10.00 m/s).

RESULTS

Some 28/85 PLWH (32.9%) vs. 9/109 (8.3%, p < 0.0001) people-without-HIV had vasculopathy on computed tomography angiography. Only four PLWH had AV. Compared with NAV (n = 11), those with AV were older (50.0 ± 4.1 vs. 39.2 ± 9.2 years, p = 0.04) and had more cardiovascular risk factors (median 2.0 [IQR 1.5-2.5] vs. 0.0 [IQR 0.0-1.0], p = 0.02). cIMT in AV was higher than in NAV (1.01 ± 0.07 mm [n = 4] vs. 0.63 ± 0.04 mm [n = 9], p < 0.001). All with AV had cIMT and PWV above the predetermined thresholds, while all except one with NAV were below. We found evidence of VZV in eight PLWH and HIV-associated vasculitis in six.

CONCLUSIONS

Vasculopathy in PLWH in our region appears to be predominantly non-atherosclerotic. cIMT and PWV were useful adjuncts in distinguishing AV from NAV. Despite excluding meningitis, VZV was implicated in a large proportion, emphasizing the likely underdiagnosis of this treatable infection. We thus recommend CSF VZV testing in all PLWH with stroke.

The Regulation of Messenger RNAs and Biological Pathways by Long Non-Coding RNAs and Circular RNAs in Ischemic Stroke

Our aim was to evaluate the regulation of messenger RNAs (mRNAs) and biological pathways by long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in ischemic stroke. We employed weighted gene co-expression network analysis (WGCNA) to construct two co-expression networks for mRNAs with circRNAs and lncRNAs, respectively, to investigate their association with ischemic stroke. We compared the overlap of mRNAs and biological pathways in the stroke-associated modules of the two networks. Furthermore, we validated the association of key non-coding RNAs with the risk of ischemic stroke and poor prognosis using quantitative real-time polymerase chain reaction. Ischemic stroke patients exhibited lower eigengene expression in the turquoise module associated with lncRNAs and mRNAs, as well as in the turquoise, red, and greenyellow modules associated with circRNAs and mRNAs in ischemic stroke. In the lncRNA-mRNA network and circRNA-mRNA network, we observed a significant overlap of the 5126 mRNAs (P < 0.001) and 51 biological pathways (P < 0.001), respectively. Among the ten key non-coding RNAs, lnc-TPRG1-AS1, lnc-GUK1, and hsa_circ_RELL1 were significantly increased (P < 0.05), while hsa_circ_ZBTB20 and hsa_circ_ERBB2 were significantly decreased (P < 0.05) in ischemic stroke. Additionally, ischemic stroke patients with poor functional outcome had significantly lower levels of hsa_circ_ZBTB20 and hsa_circ_ERBB2 compared to those with favorable prognosis (P < 0.05). Our findings suggest lncRNAs and circRNAs display similar biological functions in ischemic stroke. Key non-coding RNAs may be associated with the risk and clinical prognosis of ischemic stroke. These results warrant further validation in the future studies.

Pediatric stroke: We need to look for it

PURPOSE

This review provides a comprehensive overview of the characteristics and diagnosis of pediatric stroke, emphasizing the importance of early recognition and accurate assessment. Pediatric stroke is a complex condition with diverse etiologies, and its timely diagnosis is critical for initiating appropriate interventions and improving clinical outcomes.

RECENT FINDINGS

Recent advances in neuroimaging techniques, including magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA), have significantly enhanced the diagnostic capabilities for pediatric stroke. Additionally, a better understanding of its underlying etiologies in specific cases, and of the importance of differential diagnosis have improved the outcome and prevention strategies in this vulnerable population. Despite these improvements, though, research still has a long way to go to optimize the management of this condition.

SUMMARY

Timely and accurate diagnosis of pediatric stroke remains a challenge due to its rarity and variability in clinical presentation, and to the presence of many mimic conditions. The integration of clinical evaluation, neuroimaging, and comorbidities analysis is crucial for achieving a precise diagnosis and guiding tailored treatment strategies for affected children.

Intersecting Pathways: The Role of Metabolic Dysregulation, Gastrointestinal Microbiome, and Inflammation in Acute Ischemic Stroke Pathogenesis and Outcomes

Acute ischemic stroke (AIS) remains a major cause of mortality and long-term disability worldwide, driven by complex and multifaceted etiological factors. Metabolic dysregulation, gastrointestinal microbiome alterations, and systemic inflammation are emerging as significant contributors to AIS pathogenesis. This review addresses the critical need to understand how these factors interact to influence AIS risk and outcomes. We aim to elucidate the roles of dysregulated adipokines in obesity, the impact of gut microbiota disruptions, and the neuroinflammatory cascade initiated by lipopolysaccharides (LPS) in AIS. Dysregulated adipokines in obesity exacerbate inflammatory responses, increasing AIS risk and severity. Disruptions in the gut microbiota and subsequent LPS-induced neuroinflammation further link systemic inflammation to AIS. Advances in neuroimaging and biomarker development have improved diagnostic precision. Here, we highlight the need for a multifaceted approach to AIS management, integrating metabolic, microbiota, and inflammatory insights. Potential therapeutic strategies targeting these pathways could significantly improve AIS prevention and treatment. Future research should focus on further elucidating these pathways and developing targeted interventions to mitigate the impacts of metabolic dysregulation, microbiome imbalances, and inflammation on AIS.

A comprehensive, updated systematic review and meta-analysis of epidemiologic evidence on the connection between herpes zoster infection and the risk of stroke

Stroke is a common worldwide cause of death and disability, resulting from an obstruction or reduction in blood flow to the brain. Research has demonstrated that systemic infection such as herpes zoster (HZ) / ophthalmicus herpes zoster (HZO) can potentially trigger stroke. This study includes an updated systematic review and meta-analysis of the epidemiologic data on the connection between HZ/HZO infection and the risk of stroke. A meticulous search of different database yielded 905 studies. Furthermore, an additional 14 studies from a previous meta-analysis were incorporated. Eligible studies underwent rigorous screening, resulting in 18 papers. Statistical analyses, including random/fixed effects models and subgroup analyses, were conducted to assess pooled relative risk (RR) and heterogeneity. The meta-analysis consisted of 5,505,885 participants and found a statistically significant association between HZ infection and the risk of stroke (pooled RR = 1.22, 95% confidence interval [CI] 1.12-1.34). The HZO infection showed a significantly higher overall pooled RR of 1.71 (95% CI 1.06-2.75), indicating a strong connection with the risk of stroke. Subgroup analysis revealed that the odds ratio might play a significant role in causing heterogeneity. Time since infection emerged as a crucial factor, with heightened stroke risk in the initial year post-HZ/HZO exposure, followed by a decline after the first year. Asian/Non-Asian studies demonstrated varied results in HZ/HZO patients. Meta-analysis reveals a significant HZ/HZO-stroke link. Subgroups highlight varied risks and warrant extended Asian/non-Asian patient investigation.

Herpes zoster associated with stroke incidence in people living with human immunodeficiency virus: a nested case-control study

BACKGROUND

The incidence of stroke is increasing among younger people with human immunodeficiency virus (HIV). The burden of stroke has shifted toward the young people living with HIV, particularly in low- and middle-income countries. People infected with herpes zoster (HZ) were more likely to suffer stroke than the general population. However, the association of HZ infection with the incidence of stroke among patients with HIV remains unclear.

METHODS

A nested case-control study was conducted with patients with HIV registered in the Taiwan National Health Insurance Research Database in 2000-2017. A total of 509 stroke cases were 1:10 matched to 5090 non-stroke controls on age, sex, and date of first stroke diagnosis. Logistic regression models were used to estimate the odds ratio and 95% confidence intervals (CI) of stroke incidence.

RESULTS

The odds ratio of stroke was significantly higher in the HIV-infected population with HZ (adjusted odds ratio [AOR]: 1.85, 95% CI: 1.42-2.41). A significantly increased AOR of stroke was associated with hypertension (AOR: 3.53, 95% CI: 2.86-4.34), heart disease (AOR: 2.32, 95% CI: 1.54-3.48), chronic kidney disease (AOR: 1.82, 95% CI: 1.16-2.85), hepatitis C virus infection (AOR: 1.49, 95% CI: 1.22-1.83), hyperlipidemia (OR: 1.41, 95% CI: 1.12-1.78), and treatment with protease inhibitors (AOR: 1.33, 95% CI: 1.05-1.69).

CONCLUSIONS

Our findings suggest that HZ concurrent with HIV may increase the risk of stroke. The incidence rates of stroke were independent of common risk factors, suggesting strategies for early prevention of HZ infection among people living with HIV.

Herpesvirus latent infection promotes stroke via activating the OTUD1/NF-κB signaling pathway

OBJECTIVE

Our study aimed to reveal the molecular mechanisms underlying the regulation of cerebral infarction by herpes virus latency infection via the OTUD1/NF-κB signaling pathway using evidence-based medicine Meta-analysis and bioinformatics analysis.

METHODS

We conducted a Meta-analysis by searching Pubmed, Embase, and Web of Science databases to evaluate the correlation between herpes virus infection and increased risk of cerebral infarction. We obtained wild-type or mutant herpes virus latent infection-related brain tissue datasets from the GEO database and performed differential analysis to identify differentially expressed genes (DEGs) in the brain tissue after herpes virus latent infection. We further conducted WGCNA co-expression analysis on the cerebral infarction-related datasets from the GEO database to obtain key module genes and intersect them with the DEGs. We used ROC curve analysis to identify the key gene OTUD1 for predicting the occurrence of cerebral infarction and combined correlation and pathway enrichment analyses to identify the downstream pathways regulated by OTUD1.

RESULTS

Our meta-analysis revealed that herpes virus infection is associated with an increased risk of cerebral infarction. By integrating the differential analysis and WGCNA co-expression analysis of GEO chip data, we identified three key genes mediating cerebral infarction after herpes virus latent infection. ROC curve analysis identified the key gene OTUD1, and the correlation and pathway enrichment analyses showed that OTUD1 regulates the NF-κB signaling pathway to mediate cerebral infarction.

CONCLUSION

Herpes virus latent infection promotes cerebral infarction by activating the OTUD1/NF-κB signaling pathway.

Effects of herpes zoster vaccination and antiviral treatment on the risk of stroke: a systematic review and meta-analysis

Background

Evidence suggests that there is an increased risk of stroke after herpes zoster (HZ). However, reports on the effects of HZ vaccination (HZV) and antiviral treatment on stroke risk are inconsistent. Thus, we examined these associations in a meta-analysis.

Methods

To identify relevant studies, we searched three databases for articles published up to January 2023. Random-effect models were examined to determine overall pooled estimates and 95% confidence intervals (CIs).

Results

This review included 12 observational studies (six on HZV and seven on antiviral treatment). When comparing vaccinated and unvaccinated patients, vaccination was found to be associated with a lower risk of stroke (OR, 0.78; 95% CI 0.68-0.9; P = 0.001). A meta-analysis of self-controlled case series (SCCS) revealed evidence of a reduced OR in individuals who received the vaccine (OR, 1.14; 95% CI 0.94-1.37; P = 0.181) compared with unvaccinated individuals (OR, 1.36; 95% CI 1.15-1.61; P < 0.001). Compared with untreated patients, antiviral therapy was not associated with a reduced risk of stroke (OR, 1.13; 95% CI 0.94-1.36; P = 0.201). The meta-analysis of the SCCS showed no evidence of a reduced OR in individuals who received antiviral therapy (OR, 1.33; 95% CI 1.17-1.51; P < 0.001) compared to untreated individuals (OR, 1.45; 95% CI 1.25-1.69; P < 0.001).

Conclusions

This meta-analysis suggests that the HZV, but not antiviral treatment, decreases the odds of developing stroke.

Advances in the Diagnosis and Treatment of Pediatric Arterial Ischemic Stroke

Though rare, stroke in infants and children is an important cause of mortality and chronic morbidity in the pediatric population. Neuroimaging advances and implementation of pediatric stroke care protocols have led to the ability to rapidly diagnose stroke and in many cases determine the stroke etiology. Though data on efficacy of hyperacute therapies, such as intravenous thrombolysis and mechanical thrombectomy, in pediatric stroke are limited, feasibility and safety data are mounting and support careful consideration of these treatments for childhood stroke. Recent therapeutic advances allow for targeted stroke prevention efforts in high-risk conditions, such as moyamoya, sickle cell disease, cardiac disease, and genetic disorders. Despite these exciting advances, important knowledge gaps persist, including optimal dosing and type of thrombolytic agents, inclusion criteria for mechanical thrombectomy, the role of immunomodulatory therapies for focal cerebral arteriopathy, optimal long-term antithrombotic strategies, the role of patent foramen ovale closure in pediatric stroke, and optimal rehabilitation strategies after stroke of the developing brain.

Neurological features related to influenza virus in the pediatric population: a 3-year monocentric retrospective study

Influenza virus is generally characterized by fever, myalgia, and respiratory symptoms. Neurological entities have already been described, such as acute necrotizing encephalitis (ANE). We aimed to highlight the non-exceptional nature and explore the clinical spectrum and evolution of neurological features related to influenza virus in children. This monocentric observational study included patients under 18 years old, positive for influenza virus, between January 2017 and April 2019 in a pediatric university hospital. Patients were classified into two groups: those with or without a previous significant neurological or metabolic disorder. Two hundred eighty-nine children were identified with influenza infection. Thirty seven had a neurological manifestation: 14 patients who had previous significant neurological or metabolic disorder and 23 patients with no medical history. We identified several clinical patterns: 22 patients had seizures, 7 behavior disorders, 5 disturbances of consciousness, and 3 motor deficits. Four were diagnosed with a known influenza-associated neurological syndrome: 1 ANE, 1 cytotoxic lesion of the corpus callosum, 1 hemiconvulsion-hemiplegia-epilepsia syndrome, and 1 recurrent encephalitis in the context of a RANBP2 mutation. The neurological outcome was favorable in most cases. None of the patients with previous significant disorder retained sequalae or had a recurrence. Two patients had a fatal outcome, and both had a predisposing disorder.

CONCLUSION

Various neurological manifestations can be associated with influenza virus. Certain entities led to a poor prognosis, but in most cases, symptoms improved within a few days. The severity of the neurological manifestations correlated with previous neurological or metabolic disorders.

WHAT IS KNOWN

• Influenza viruses are well known pathogens with a seasonal epidemic evolution, particularly affecting children. These viruses cause acute fever with respiratory symptoms, associated with myalgia and headaches. Neurological presentation in influenza-virus infection is a well-established possibility as influenza virus is considered to be responsible for 27 to 36% of childhood encephalitis. Some specific and severe entity as acute necrotizing encephalitis, cytotoxic lesion of the corpus callosum, or Hemiconvulsion-hemiplegia-epilepsy syndrome are well described.

WHAT IS NEW

• In a French monocentric cohort of 37 children with influenza-related neurologic manifestations, the majority of these manifestations, including seizure, drowsiness, motor deficiency, hallucination… are self limiting and do not lead to after-effects. In rare cases (4/37), they may reveal severe encephalitis requiring rapid and appropriate treatment. Otherwise, comparison of a group of 14 children with underlying neurological or metabolic disorder with a group of 23 children free of any significant disorder show that the severity of the neurological manifestations was largely related to previous neurological or metabolic disorders highlighting the importance of vaccination in this population.

Incident Herpes Zoster and Risk of Dementia: A Population-Based Danish Cohort Study

BACKGROUND AND OBJECTIVES

Herpes zoster (HZ) is caused by reactivation of the neurotrophic varicella-zoster virus (VZV). Zoster may contribute to development of dementia through neuroinflammation, cerebral vasculopathy, or direct neural damage, but epidemiologic evidence is limited. We used data from linked nationwide Danish registries to conduct a cohort study of the association between zoster and dementia during 1997-2017. As secondary aims, we examined whether associations were more pronounced for zoster involving cranial nerves (mainly ophthalmic zoster) or the CNS and Alzheimer disease as an outcome.

METHODS

We included people aged ≥40 years with zoster and a general population comparison cohort matched 5:1 by sex and birth year. We identified zoster and dementia in the registries using prescription records in the community and hospital diagnoses. We used Cox regression to compute confounder-adjusted hazard ratios (HRs) with 95% CIs for dementia associated with zoster during 0-1 year and 1-21 years of follow-up. We compared the cumulative incidence of dementia, inverse probability weighted for confounders.

RESULTS

The study included 247,305 people with zoster and 1,235,890 matched general population comparators (median age 64 years; 61% female). The HR of all-cause dementia was 0.98 (95% CI 0.92-1.04) during the first year and 0.93 (95% CI 0.90-0.95) thereafter in people with zoster vs matched comparators. Dementia was diagnosed in 9.7% of patients with zoster and 10.3% of matched comparators by the end of follow-up. We observed no increased long-term risk of dementia in subgroup analyses, except possibly in people with CNS infection (HR 1.94; 95% CI 0.78-4.80). Analyses of Alzheimer disease as a separate outcome showed similar results.

DISCUSSION

HZ is not associated with an increased risk of dementia, and contrary to expectation, we found a small decrease in the risk. The explanation for this finding is unclear, and systematic errors should be considered. Patients with CNS involvement had an almost 2-fold increased relative risk of dementia. The population attributable fraction of dementia due to this rare complication is estimated at 0.014%. Therefore, universal vaccination against VZV in the elderly is unlikely to reduce dementia risk.

Prompt antiviral therapy is associated with lower risk of cerebrovascular accident following herpes zoster ophthalmicus

PURPOSE

To examine risk factors associated with cerebrovascular accident (CVA) following herpes zoster ophthalmicus (HZO).

DESIGN

Retrospective cohort study METHODS: : Review of medical records of all subjects with HZO seen at the department of Ophthalmology, Auckland District Health Board, New Zealand, between 1^st January 2006 and 31^st December 2016.

MAIN OUTCOME MEASURES

Cerebrovascular accident within 12 months of diagnosis.

RESULTS

869 patients diagnosed with HZO were included in the study. The median age at onset of HZO was 65.5 (Interquartile range, IQR 52.9 - 75.4) and 52.5% (n=456) were male. Antiviral therapy was started in 765 participants (88.0%), not utilised in 95 (10.9%) and not documented in 9 participants (1.0%). Four hundred sixty-eight participants (54.9%) received prompt oral antiviral therapy (≤72 hours of rash onset). A CVA occurred in the 12 months following HZO in 14 subjects (1.6%) and was most common in older subjects, occurring in 2.5% aged ≥65 years, 0.7% aged 40-65 years and 0.9% aged <40 years. Hazard of CVA was highest immediately following HZO, with median time to CVA of 2.3 months (IQR 0.8 - 5.9 months). Subjects that received prompt acyclovir had a 76.2% lower hazard of CVA (0.9% vs 2.6%, p=0.022) on multivariate analysis.

CONCLUSIONS

Cerebrovascular accident occurs in a low proportion of individuals within one year following HZO. Antiviral treatment for HZO may reduce the risk of subsequent CVA when given within 72 hours of rash onset.

Antibodies to Human Herpesviruses and Rate of Incident Cardiovascular Events and All-Cause Mortality in the UK Biobank Infectious Disease Pilot Study

Background

Associations between human herpesviruses (HHVs) and cardiovascular disease/mortality have been reported, but evidence is inconsistent. We investigated associations between 3 common herpesviruses and (1) incident stroke or myocardial infarction (MI) and (2) all-cause mortality.

Methods

We included participants from the UK Biobank Infectious Disease pilot study with valid serum antibody (IgG) measurements taken at cohort entry (2006-2010) for herpes simplex virus type 1 (HSV1), varicella zoster virus (VZV), and cytomegalovirus (CMV). Linked hospital and mortality records up to December 30 2019 provided information on rates of (1) incident first stroke or MI and (2) all-cause mortality. Hazard ratios (HRs) from Cox proportional hazards regression models were used to assess relationships between (1) HHV seropositivity, (2) HHV titer and incident stroke/MI, and death outcomes. Fully adjusted models accounted for sociodemographic information (age, sex, ethnicity, education, deprivation quintile, birthplace, population density), baseline comorbidities (including diabetes and hypertension), smoking status, body mass index, and serum cholesterol.

Results

Of 9429 study participants (56% female, 95% White, median age 58 years), 41% were seropositive for all 3 HHVs. Human herpesvirus seropositivity was not associated with stroke/MI (fully adjusted HRs and 95% confidence intervals [CIs]: HSV1 = 0.93 [CI, 0.72-1.22], VZV = 0.78 [CI, 0.51-1.20], CMV = 0.91 [CI, 0.71-1.16]) or all-cause mortality (HSV1 = 1.21 [CI, 1.00-1.47], VZV = 0.79 [CI, 0.58-1.07], CMV = 0.90 [CI, 0.76-1.06]). Human herpesvirus titers were not associated with outcomes.

Conclusions

In this mostly White UK Biobank subset, neither HHV seropositivity nor titers were associated with stroke/MI or all-cause mortality.

Intracranial Large Artery Stenosis and Past Infectious Exposures: Results From the NOMAS Cohort

BACKGROUND

Intracranial large artery stenosis (ILAS) is an important contributor to ischemic stroke in the United States and worldwide. There is evidence to suggest that chronic exposure to certain infectious agents may also be associated with ILAS. We aimed to study this association further in an ethnically diverse, prospective, population-based sample of Northern Manhattan.

METHODS

We enrolled a random sample of stroke-free participants from an urban, racially, and ethnically diverse community in 1993. Participants have been followed prospectively and a subset underwent brain magnetic resonance angiograms from 2003 to 2008. Intracranial stenoses of the circle of Willis and vertebrobasilar arteries were scored as 0=no stenosis, 1≤50% (or luminal irregularities), 2=50% to 69%, 3≥70% stenosis, and 4=flow gap. We summed the individual score of each artery to produce a global ILAS score (possible range, 0-44). Past infectious exposure to Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, and herpes simplex virus 1 and 2 was determined using serum antibody titers.

RESULTS

Among 572 NOMAS (Northern Manhattan Study) participants (mean age 71.0±8.0 years, 60% women, 68% Hispanic) with available magnetic resonance angiogram and serological data, herpes simplex virus 2 (beta=0.051, P<0.001) and cytomegalovirus (beta=0.071, P<0.05) were associated with ILAS score after adjusting for demographics and vascular risk factors. Stratifying by anterior and posterior circulations, herpes simplex virus 2 remained associated with the anterior circulation (beta=0.055 P<0.01) but not with posterior circulation ILAS score.

CONCLUSIONS

Chronic infectious exposures, specifically herpes simplex virus 2 and cytomegalovirus were associated with asymptomatic ILAS as seen on magnetic resonance angiogram imaging. This may represent an additional target of intervention in the ongoing effort to stem the substantial global burden of strokes related to ILAS.

Human Cytomegalovirus and Risk of Incident Cardiovascular Disease in United Kingdom Biobank

BACKGROUND

Previous studies have yielded conflicting results on the association between human cytomegalovirus (HCMV) and cardiovascular disease (CVD). This study examined associations between HCMV and incident CVD, ischaemic heart disease (IHD) and stroke.

METHODS

This study included 8531 women and men of predominantly white ethnic background, aged 40-69 without prevalent CVD from the population-based UK Biobank study, recruited between 2006-2010 with HCMV antibody levels measured. CVD was ascertained via linkage to health administrative records collected until 2020. Multivariate Cox proportional-hazards models were used to determine associations between HCMV seropositivity and incident CVD, IHD and stroke. HCMV seropositive antibody levels in tertiles were used to assess dose-response associations.

RESULTS

Over a mean follow-up period of 10.2 years, HCMV seropositivity was not significantly associated with CVD (Cases = 626, Hazard Ratio [HR] =1.01, 95% confidence interval [CI], .86-1.20), IHD (Cases = 539, HR=1.03, 95% CI, .87-1.24) or stroke (Cases = 144, HR = 0.96, 95% CI, .68-1.36). There was no evidence of dose-response associations with any outcome.

CONCLUSIONS

We found no significant association between HCMV seropositivity and risk of CVD, IHD or stroke. Further research within understudied populations, such as those of non-white ethnicity, and CVD subtypes is warranted.

The Implications of Vaccines in Older Populations

Mean longevity is increasing worldwide, with major consequences for public health worldwide, as the global population of adults aged over 65 years now exceeds the number of children under 5 for the first time in history. The ageing process over the life course is extremely heterogeneous, and it will be important to promote and enhance healthy ageing worldwide. Vaccination is a key player in the healthy ageing process, both at the individual and the community level. We review here the contribution of vaccines to individual and community health. At an individual level, we highlight the prevention of infectious diseases, as well as other, less well-known benefits of vaccination, such as modulation of the inflammatory process. We then underline the importance of vaccination in achieving herd immunity and reducing the transmission of pathogens in the community. Finally, at a community level, another important benefit of vaccination is the reduction in antimicrobial resistance. Taken together, these effects contribute to ensuring the best health, for the greatest number, for the longest time possible.

No evidence that herpes zoster is associated with increased risk of dementia diagnosis

OBJECTIVE

To investigate whether herpes zoster (HZ) was associated with subsequent increased risk of dementia diagnosis.

METHODS

We conducted a historical cohort study using primary care electronic health records from the Clinical Practice Research Datalink in the United Kingdom. Individuals with incident HZ aged ≥40 years from 2000 to 2017 were matched with up to four individuals without HZ by age, sex, primary care practise and calendar time. The primary outcome was a new diagnosis of all-cause dementia. We used the Cox proportional hazards regression adjusting for demographic, lifestyle and clinical confounders to assess any association between HZ and dementia. We investigated interactions with sex, frailty index and antiviral treatment and conducted various sensitivity analyses.

RESULTS

The cohort comprised 177,144 individuals with HZ and 706,901 matched unexposed individuals (median age 65 years (IQR 55.1-75.0), 40% male) followed for a median duration of 4.6 years (IQR 2.0-8.1). In total, 26,585 (3%) patients had an incident dementia diagnosis recorded and 113,056 patients died (12.8%). HZ was associated with a small reduction in dementia diagnosis (adjusted HR 0.92 (95% CI 0.89-0.95)), occurring predominantly in frail individuals and females. For patients who were fit (578,115, 65%), no association was seen (adjusted HR 0.97, 95% CI 0.92-1.02). There was no association between HZ and a composite outcome of dementia or death (adjusted HR 1.00, 95% CI 0.99-1.02). Dementia risk did not vary by prescription of antiviral agents. Sensitivity analyses showed consistent results.

INTERPRETATION

HZ was not associated with increased dementia diagnosis in a UK primary care-based cohort.

Varicella-zoster virus reactivation is frequently detected in HIV-infected individuals presenting with stroke

Infections are an underappreciated cause of stroke, particularly in young and immunocompromised individuals. Varicella-zoster virus (VZV) reactivation, particularly ophthalmic zoster, has been linked to increased risk of stroke but diagnosing VZV-associated cerebral vasculopathy is challenging as neither a recent Zoster rash, nor detectable levels of VZV DNA are universally present at stroke presentation. Detection of VZV IgG in cerebrospinal fluid (CSF-VZVG) presents a promising alternative, but requires evaluation of individual blood-CSF dynamics, particularly in the setting of chronic inflammatory states such as HIV infection. Consequently, its use has not been broadly adopted as simple diagnostic algorithms are not available. In this study looking at young adults presenting with acute stroke, we used an algorithm that includes testing for both VZV nucleic acids and CSF-VZVG which was corrected for blood-CSF barrier dynamics and poly-specific immune activation. We found that 13 of 35 (37%), including 7 with a positive CSF VZV PCR, young HIV-infected adults presenting with stroke, 3 of 34 (9%) young HIV-uninfected adults presenting with stroke and 1 of 18 (6%) HIV-infected non-stroke controls demonstrated evidence of central nervous system reactivation of VZV. This article is protected by copyright. All rights reserved.

Infectious Causes of Stroke

Stroke is one of the primary causes of mortality and morbidity worldwide. It can be ischemic or hemorrhagic, and the former can be due to an in-situ thrombus or a distant embolus. Despite being a rare cause, stroke can also be caused in the setting of infection. Bacterial agents are the most common cause of stroke, among other infectious agents. Until the antibiotic era, rheumatic heart disease was a predisposing risk factor of infective endocarditis. VZV is the most common cause of strokes in pediatric and adult populations. Cryptococcus and Candida spp are the most common yeasts involved in CNS infections, especially in immunocompromised patients. In COVID-19 patients, ischemic strokes are more common than hemorrhagic strokes. In this review, we will discuss the most common infectious agents, with particular emphasis on COVID-19.

Vaccination as a preventative measure contributing to immune fitness

The primary goal of vaccination is the prevention of pathogen-specific infection. The indirect consequences may include maintenance of homeostasis through prevention of infection-induced complications; trained immunity that re-programs innate cells to respond more efficiently to later, unrelated threats; slowing or reversing immune senescence by altering the epigenetic clock, and leveraging the pool of memory B and T cells to improve responses to new infections. Vaccines may exploit the plasticity of the immune system to drive longer-term immune responses that promote health at a broader level than just the prevention of single, specific infections. In this perspective, we discuss the concept of “immune fitness” and how to potentially build a resilient immune system that could contribute to better health. We argue that vaccines may contribute positively to immune fitness in ways that are only beginning to be understood, and that life-course vaccination is a fundamental tool for achieving healthy aging.

Healthy Ageing and Vaccines: Application of the P4 Medicine Concept to Immunizations

In today's tormented world, it appears useful to take advantage of communication channels to promote life-course immunization and affirm its major role in healthy ageing. Instead of developing the argument of chronological age, we demonstrate the life-course principle here based on the P4 medicine concept. Are vaccines "preventive, personalized, predictive, and participatory?" Based on detailed analysis of research findings, we successively demonstrate the seminal role of vaccines on preventable infectious diseases, post-sepsis functional decline, non-communicable diseases (cardio-neuro-vascular, respiratory, and renal diseases), community protection, antimicrobial resistance, and perhaps even old-age dementia. Healthy ageing and the promotion of immunization are closely dependent on health literacy and provision of information by skilled health-care professionals. However, personal autonomy and individual freedom are influenced by psycho-cognitive hurdles (cultural approaches, beliefs, emotions, and behaviours), the opinions of the public/family/friends, and the increasing role of social media, which challenges scientific evidence. A similar phenomenon exists when dealing with the issue of healthy ageing, whose success depends greatly on life-course immunization.

Expanding the clinical and neuroimaging features of post-varicella arteriopathy of childhood

OBJECTIVE

Post-varicella arterial ischemic stroke (AIS) is considered an uncommon cause of pediatric stroke that is considered a self-limiting, monophasic disease. However, in a subset of patients, disease recurs; the prevalence of vasculopathy or AIS recurrence, severity of clinical outcomes, and standardized therapies have not been well characterized. Herein, we determined the clinical-neuroradiological features, long-term evolution, and relationship between acute phase treatment and vasculopathy recurrence in a pediatric population with post-varicella AIS.

METHODS

Clinical, laboratory, and neuroradiological features of 22 children with post-varicella AIS between 2010 and 2019 (16 males, mean age at stroke 4 years, range 1.7-10) were reviewed. Statistical analyses were performed using χ² and Fisher exact tests.

RESULTS

Of the 22 cases, mean time from varicella to stroke was 4.5 months with 3 cases presenting more than 12 months after rash; 21 (95%) were not vaccinated for varicella; 3 (13.6%) had posterior circulation involvement; and 5 (22.7%) had AIS or vasculopathy recurrence, of which 4 recurred 6.1 months to 2.8 years after initial clinical onset. Recurrence was associated with lack of antiviral treatment during the first episode (p = 0.02).

CONCLUSIONS

Post-varicella AIS can occur months after rash making diagnosis challenging. Because recurrent vasculopathy was seen predominantly in cases not treated with antiviral therapy during initial presentation, it is important to rapidly diagnose post-varicella AIS through clinical criteria and/or virological testing then treat with antivirals to prevent recurrence.

Association of recurrent common infections and subclinical cardiovascular disease in Mexican women

BACKGROUND

Acute and agent-specific chronic infections have been associated with increased cardiovascular risk, however data on the burden of common recurrent infections on cardiovascular disease is limited. We hypothesized women with greater exposure to uncomplicated common infectious events had an increased risk of subclinical cardiovascular disease (sCVD).

METHODS

In a cross-sectional study, we assessed the relation of recurrent infections and carotid artery intima-media thickness (IMT) in 1946 disease-free women from the Mexican Teachers' Cohort. Through 2012-2016, participants answered structured questions on respiratory, urinary and vaginal infections during the previous year and their IMT was measured using ultrasound by standardized neurologists. We defined sCVD as mean right and left IMT ≥0.8 mm or the presence of atheromatous plaque. Multivariable linear and logistic regression analyses were used to evaluate the association of infectious events with IMT and sCVD adjusting for age, sociodemographic, and cardiovascular risk factors.

RESULTS

Among participants (50±5 years) 13% reported no infections, 20% one infection and 67% three or more episodes. Overall prevalence of sCVD was 12%(n = 240). Adjusted models for logistic regression showed that women with 2 or more infections had 91% higher odds of sCVD (OR 1.91; 95%CI 1.16, 3.13) compared to women without infections (p-trend:0.015). Sub-analyses by type of infection resulted not significant. Linear regression analysis did not show a significant association between mean IMT and recurrent infections.

CONCLUSIONS

Recurrent infectious events in young adult women are associated with greater sCVD, which supports the hypothesis of low-grade chronic inflammation in the pathophysiology of cardiovascular disease.

Vitamin D Deficiency or Supplementation and the Risk of Human Herpesvirus Infections or Reactivation: A Systematic Review and Meta-analysis

BACKGROUND

Vitamin D may protect against respiratory virus infections, but any association with herpesviruses is unclear.

METHODS

We undertook a systematic review of vitamin D deficiency or supplementation and the risk of 8 human herpesviruses. Six databases and 4 gray literature databases were searched for relevant cohort studies, case-control studies, and clinical trials.

RESULTS

Ten studies were included, all conducted among immunosuppressed patients. There was no evidence that vitamin D deficiency is associated with cytomegalovirus (CMV) disease (pooled risk ratio, 1.06; 95% CI, 0.66-1.7), herpes zoster after transplantation (1 study), or HHV-8 among HIV patients (1 study). Vitamin D supplementation may decrease herpes zoster among hemodialysis patients (1 study) or CMV disease after renal transplantation (1 study), but supplementation was not associated with reduced EBV viral load among multiple sclerosis patients (1 study).

CONCLUSIONS

Any association between vitamin D and herpesviruses remains inconclusive. Further studies in the general population are needed.

Elevated serum substance P during simian varicella virus infection in rhesus macaques: implications for chronic inflammation and adverse cerebrovascular events

Varicella and zoster, produced by varicella-zoster virus (VZV), are associated with an increased risk of stroke that may be due to persistent inflammation and hypercoagulability. Because substance P is associated with inflammation, hypercoagulability, and atherosclerotic plaque rupture that may contribute to increased stroke risk after VZV infection, we measured serum substance P in simian varicella virus-infected rhesus macaques. We found significantly increased and persistent serum substance P concentrations during varicella and zoster compared with pre-inoculation, supporting the hypothesis that VZV-induced increases in serum substance P may contribute to increased stroke risk associated with VZV infection.

Infectious causes of stroke

PURPOSE OF REVIEW

Stroke continues to be a leading cause of debility in the world. Infections have been associated with stroke, but are not considered as directly causal, and so they are not often included in the traditional stroke workup and management. They are especially important in patients with stroke of undetermined etiology, and in certain patient populations, such as young patients without traditional risk factors, and immunocompromised patients.

RECENT FINDINGS

There has been strong evidence for infectious conditions, such as endocarditis, and pathogens, such as varicella zoster in stroke causation, and more supportive evidence is surfacing in recent years of several organisms increasing the stroke risk or being directly causal in stroke. The evidence also seems to be pointing to the role of inflammation in increasing the risk of stroke via accelerated atherosclerosis, vasculitis and vasculopathy.

SUMMARY

Infectious causes should be considered in the differential and work up of stroke in certain patient populations and appropriate treatments need to be initiated to minimize adverse stroke-related outcomes.

Disseminated herpes zoster with acute encephalitis in an immunocompetent elderly man

Varicella-zoster virus (VZV) encephalitis typically occurs in immunosuppressed populations such as in patients with HIV/AIDS, transplantation and autoimmune disease. However, it can also occur in healthy hosts. We present the case of an immunocompetent patient who presented with a clinical picture of VZV encephalitis with the sole precipitating factor of advanced age. We want to stress the importance of including VZV in the differential diagnosis for encephalitis in healthy elderly hosts. In patients with a clinical diagnosis of encephalitis, the presence of herpes zoster rash increases the likelihood of VZV encephalitis. However, the absence of a skin rash may not exclude the diagnosis. In general, there is an elevated risk of transient ischaemic attack and stroke associated with the diagnosis of herpes zoster infection. Early treatment is essential to prevent complications, including death.

Infections causing stroke or stroke-like syndromes

BACKGROUND

Stroke has relevant morbidity and mortality despite appropriate treatments and early diagnosis. Beside common risk factors such as diabetes and atrial fibrillation, infections can be involved in stroke pathogenesis, probably causing a systemic release of cytokines and other inflammatory mediators, triggering a latent pro-thrombotic state or damaging the vascular endothelium. In other cases, infections can occur as stroke-like syndromes, requiring a high grade of suspicion to avoid a delay in establishing a correct diagnosis.

RESULTS

Treatment of stroke or stroke-like syndromes of infectious origin can be difficult. When a previous infective event triggers stroke, Alteplase administration can be associated with a higher incidence of bleeding and the extension of the ischaemic area can be major than expected. On the other hand, when stroke is part of some infectious diseases' presentation as in endocarditis, bacterial or tuberculous meningitis and meningo-vascular syphilis, a correct diagnosis can be difficult. The management of these stroke-like syndromes is not standardised because common treatments proven to be effective for patients with stroke of vascular origin can worsen the prognosis, as it can be demonstrated after to be incorrect Alteplase administration to patients with endocarditis with septic embolism to the brain is associated with an increase of the risk of haemorrhage.

CONCLUSIONS

Stroke or stroke-like syndrome of infectious origin can be observed in an important proportion of case presenting with sensory-motor deficit of unknown origin; their accurate diagnosis has a considerable impact in terms of treatment choices and outcome.

Preventing Lethal Prostate Cancer with Diet, Supplements, and Rx: Heart Healthy Continues to Be Prostate Healthy and "First Do No Harm" Part III

PURPOSE OF REVIEW

To discuss the overall and latest observations of the effect of diet, lifestyle, supplements, preventive vaccinations, and some prescription heart healthy medications for prostate cancer prevention within a 3-part series of publications.

RECENT FINDINGS

The concept of maximizing heart health to prevent aggressive prostate cancer continues to be solidified with additional prospective observational and randomized controlled trial data. Heart healthy is prostate healthy, but heart unhealthy is prostate unhealthy. The primary goal for medical providers of reducing all-cause and cardiovascular disease (CVD) morbidity and mortality correlates with maximizing prostate cancer prevention. The obesity epidemic in children and adults along with research from multiple, diverse disciplines has only strengthened the nexus between heart and prostate health. Greater dietary adherence toward a variety of healthy foods is associated with a graded reduction in the probability of CVD and aggressive cancer. Preventing prostate cancer via dietary supplements should encourage a "first do no harm" or less-is-more approach until future evidence can reverse the concerning trend that more supplementation has resulted in either no impact or an increased risk of prostate cancer. Supplements to reduce side effects of some cancer treatments appear to have more encouraging data. A discussion of quality control (QC) before utilizing any pill also requires attention. Medications or interventions that potentially improve heart health including statins, aspirin, and metformin (S.A.M.), specific beta-blocker medications, and even preventive vaccines are in general generic, low cost, "natural," and should continue to garner research interest. A watershed moment in medical education has arrived where the past perception of a diverse number of trees seemingly separated by vast distances, in reality, now appears to exist within the same forest.

Reversible Cerebral Angiopathy after Viral Infection in a Pediatric Patient with Genetic Variant of RNF213

Ring finger protein (RNF) 213 is known as a susceptibility gene for moyamoya disease (MMD), which is characterized by bilateral carotid folk stenosis. Cerebral angiopathy after viral infection has been known to present angiographical appearance resembling MMD, however its pathogenesis and genetic background are not well known. We report a case of reversible cerebral angiopathy after viral infection in a pediatric patient with genetic variant of RNF213 mutation. The patient had developed a severe headache after hand, foot, and mouth disease. Magnetic resonance imaging and magnetic resonance angiography (MRA) performed 2-3 weeks after disease onset revealed bilateral carotid folk stenosis and an old cerebral infarction in the left putamen. The patient's headache spontaneously resolved and the follow-up MRA showed a complete spontaneous resolution of the arterial stenosis after 9 months. We were able to determine genetic predisposition to angiopathy by identifying the RNF213 c.14576G>A (rs112735431, p.R4859K) mutation. Based on the present case, we hypothesize that an RNF213 variant might play an important role for the onset of postviral cerebral angiopathy.

Precision Medicine and Vaccination of Older Adults: From Reactive to Proactive (A Mini-Review)

As populations age globally, the health of older adults is looming larger on the agendas of public health bodies. In particular, the priority is to ensure that older adults remain healthy, independent, and engaged in their communities. In other words, ensuring that increasing life spans are matched by increasing "health spans," meaning years spent in good health. Chronic conditions such as cancer or respiratory and cardiovascular diseases account for the bulk of the disease burden in older adults, and the consensus is that these can best be tackled by effective primary prevention. However, given the diverse nature of older populations, whose prior health experiences can be complicated by multi-morbidity and poly-pharmacy, effective primary prevention can be challenging. One approach that is gaining momentum is what is called "precision" or P4 medicine. The acronym stands for "predictive, personalized, preventive, participatory" medicine, and is based on the premise that preventing disease is better than treating it. However, effective prevention requires the ability to predict disease risk for a given patient, the tailoring of treatment to their circumstances, and their consent for or participation in the offered treatment. A P4 approach may seem counter-intuitive, given that vaccination is generally considered a public health intervention. However, in this article, we discuss the application of P4 medicine as a complement to planning the vaccination of older individuals, with a special focus on the important role that vaccine-preventable infections play in the burden of non-communicable disease.