Varicella Zoster Virus as a Potential Risk Factor in Stroke: A Pilot Case-Control PCR-Based Investigation

Purpose:To determine the presence of herpes simplex virus and varicella zoster virus (HSV 1 and 2, VZV) in the cornea of normal subjects by multiplex real time quantitative (qPCR) assay and evaluate its utility in the diagnosis of viral keratitis.Methods:Corneal epithelial cells from 33 eyes of 22 patients undergoing photorefractive keratectomy surgery (controls) and 50 corneal scrapings from 50 patients with suspected HSV keratitis were analyzed for the presence of HSV1 by conventional PCR and for presence of HSV1 and 2 and/or VZV by multiplex real-time PCR. Corneal scrapings of patients were also tested for HSV1 antigen by immunofluorescence assay (IFA). The results were compared and clinical records reviewed.Results:HSV1 and VZV DNA were detected in 8/33 controls (mean-14.3 ± 7.96, range: 3-29.1 copies/mL) and 2/33 controls (mean-10.7 ± 10.9, range 3-18.5 copies/ml) respectively. HSV2 was not detected in any of the controls. Copy numbers above the mean + 1SD of controls were considered significant for viral load in patient samples. Significantly higher number of corneal scrapings (39/50, 78%) from patients were positive for HSV1 (1.2 × 106 copies/mL ± 3.7 × 106 copies/mL) by real time qPCR compared to IFA (11/48, 23%, P value 0.0001) and conventional PCR (20/50, 40%, P value 0.0002). Double infection with HSV-1 (1.5 × 107 copies/ml) and HSV-2 (3.57 × 104 copies/ml) in one case and VZV infection (1.03 × 102 copies/ml) in another was also detected by the multiplex real-time PCR.Conclusion:Multiplex real-time PCR reliably detects HSV1 and 2 and VZV DNA and is ideal for the diagnosis of HSV and VZV keratitis in an ocular microbiology laboratory.

Stroke is a complex disease, with both genetic and environmental factors having a role in its pathogenesis. A review of past studies shows some evidence of genetic influences in the development of stroke. This is supported by studies of cardiovascular disease, which indicate major genetic influences at several levels including the development of risk factors. New approaches to phenotypic classifications, patient ascertainment, and genetic analysis will stimulate research into the role of genetics in cerebrovascular disease.

Since the routine use of polymerase chain reaction testing (PCR) in diagnosing herpes infections, varicella-zoster virus is increasingly recognized as a cause of varicella-zoster meningoencephalitis (VZV ME) among immunocompetent patients. We were interested to determine whether patients with VZV ME had VZV DNA in their saliva during the acute phase of the illness. Forty-five consecutive patients who underwent a lumbar puncture for diagnostic purposes were included in the study. The cerebrospinal fluid was examined for the presence of VZV DNA by PCR, and patients with positive findings were treated with acyclovir. The saliva was later analyzed in a blinded fashion for the presence of VZV DNA. VZV DNA was found in saliva in four of five (80%) patients with PCR confirmed VZV ME (sensitivity 0.8, specificity 0.84, and likelihood ratio 5). This was significantly more than in patients with non-zoster viral ME (0%, P = 0.009), parainfectious headache (12%, P = 0.03) and controls (9.5%, P = 0.007). In immunocompromised patients with systemic lymphoma and AIDS, VZV DNA was present at a similar rate (67%, P = 0.6). We have found VZV DNA in saliva of patients with PCR confirmed VZV ME at a higher proportion than in controls and patients with non-VZV viral ME. This finding might be of clinical importance, especially in immunocompetent individuals with suspected VZV ME where the results of genetic and immunological testing are not conclusive.

Incidence and Risk of Postherpetic Neuralgia after Varicella Zoster Virus Infection in Hematopoietic Cell Transplantation Recipients: Hokkaido Hematology Study Group

Human dorsal root ganglia from 14 randomly autopsied adults and 1 infant (all seropositive for both herpes simplex virus [HSV] and varicella zoster virus [VZV]) were examined for latent HSV-1 and VZV DNA by polymerase chain reaction. Thoracic ganglionic DNA from all subjects and trigeminal ganglionic DNA from 11 adults were analyzed. HSV-1 DNA was detected in trigeminal ganglia from 8 of 11 (73%) adults and in thoracic ganglia from 2 of 14 (14%) adults. VZV DNA was detected in trigeminal ganglia from 10 of 11 (91%) adults and in thoracic ganglia from 12 of 14 (86%) adults. None of the DNA samples were positive with primers specific for HSV-2. These findings indicate the presence of latent HSV-1 and VZV DNA in trigeminal ganglia and latent VZV DNA in thoracic ganglia of most seropositive adults. Furthermore, although HSV-1 latency most commonly develops in trigeminal ganglia, we also show for the first time the presence of HSV-1 latency in thoracic ganglia. Finally, both viruses can become latent in the same trigeminal ganglion.

Varicella-zoster virus (VZV) is a human neurotropic alphaherpesvirus and the etiological agent of varicella (chickenpox) and herpes zoster (HZ, shingles). Previously, inoculation of monkeys via the subcutaneous, intratracheal, intravenous, or oral-nasal-conjunctival routes did not recapitulate all the hallmarks of VZV infection, including varicella, immunity, latency, and reactivation. Intrabronchial inoculation of rhesus macaques (RMs) with simian varicella virus (SVV), a homolog of VZV, recapitulates virologic and immunologic hallmarks of VZV infection in humans. Given that VZV is acquired primarily via the respiratory route, we investigated whether intrabronchial inoculation of RMs with VZV would result in a robust model. Despite the lack of varicella and viral replication in either the lungs or whole blood, all four RMs generated an immune response characterized by the generation of VZV-specific antibodies and T cells. Two of 4 VZV-inoculated RMs were challenged with SVV to determine cross-protection. VZV-immune RMs displayed no varicella rash and had lower SVV viral loads and earlier and stronger humoral and cellular immune responses than controls. In contrast to the results for SVV DNA, no VZV DNA was detected in sensory ganglia at necropsy. In summary, following an abortive VZV infection, RMs developed an adaptive immune response that conferred partial protection against SVV challenge. These data suggest that a replication-incompetent VZV vaccine that does not establish latency may provide sufficient protection against VZV disease and that VZV vaccination of RMs followed by SVV challenge provides a model to evaluate new vaccines and therapeutics against VZV. Although VZV vaccine strain Oka is attenuated, it can cause mild varicella, establish latency, and in rare cases, reactivate to cause herpes zoster (HZ). Moreover, studies suggest that the HZ vaccine (Zostavax) only confers short-lived immunity. The development of more efficacious vaccines would be facilitated by a robust animal model of VZV infection. The data presented in this report show that intrabronchial inoculation of rhesus macaques (RMs) with VZV resulted in an abortive VZV infection. Nevertheless, all animals generated a humoral and cellular immune response that conferred partial cross-protection against simian varicella virus (SVV) challenge. Additionally, VZV DNA was not detected in the sensory ganglia, suggesting that viremia might be required for the establishment of latency. Therefore, VZV vaccination of RMs followed by SVV challenge is a model that will support the development of vaccines that boost protective T cell responses against VZV.

Risk of cerebrovascular accidents (CVAs) in patients with inflammatory bowel disease (IBD) remains inconclusive. In this systematic review and meta-analysis, we aimed to estimate the incidence of and identify the risk factors for CVA in patients with IBD. PubMed, EMBASE and Web of Science were searched for articles published up to January 13, 2023 to identify those reported the incidence of CVA in IBD patients, along with the total person-years or related data to calculate it. The main outcomes were the incidence of and risk factors for CVA in IBD. Based on the analysis of 10 studies, the pooled incidence of CVA in IBD patients was 2.74 per 1000 person-years (95% confidence interval [CI] 1.83-4.10 person-years; I2 = 99.2%), which was higher than that in the general population (incidence rate ratio [IRR] 1.21, 95% CI 1.09-1.34, P = 0.0002; I2 = 84.8%). Risk factors for CVA in IBD patients were age (significance in different definitions), ulcerative colitis (IRR 1.214, 95% CI 1.000-1.474, P = 0.0499; I2 = 81.9%), disease flares (IRR 1.699, 95% CI 1.359-2.122, P < 0.0001; I2 = 28.7%) and chronic activity (IRR 2.202, 95% CI 1.378-3.519, P = 0.0010; I2 = 83.0%). The risk of CVA modestly increased in IBD patients. Both the traditional and IBD-related risk factors should be managed to prevent CVA in these patients. Since the effects of risk factors were derived from pooled results of only 2-3 studies, further research is needed to confirm our results.

In general, IBD increases arteriovenous thromboembolic events, though the association between UC and cerebrovascular complications remains inconclusive. Some studies suggest young women with UC have an increased risk of cerebrovascular accidents (CVA). The focus of this study was to characterize the rates, anatomic distribution, and risk factors for CVA in patients with UC. We developed a retrospective cohort of patients with UC at a single health care system from June 2010 to June 2015. Neuroimaging was used to document presence, location and type of stroke and traditional risk factors were considered. Prevalence of CVAs in patients with UC was compared to that of the general population of Minnesota (MN) and the United States (U.S.). A total of 2,183 UC patients were identified (1088 females [f-UC], 1095 males [m-UC]). The prevalence of CVA in UC patients (4.7%, 95% CI 3.9–5.6) was higher than in the U.S. (2.5–2.7%, p < 0.0001) and in Minnesota (1.8% CI 1.5–2.2, p < 0.0001) . The prevalence increased in both sexes with a peak prevalence of 24.7% (95% CI 17.1–34.4) in women with UC over the age of 80. Older age, cancer and atrial fibrillation were risk factors for CVA in univariate analysis for both sexes. In multifactorial analysis, both age and atrial fibrillation were risk factors for CVA in the m-UC cohort, but only age was associated with CVA in f-UC. The most common type of CVA was ischemic stroke (77.7%). The most common locations for CVAs in UC patients were frontal and occipital lobes (19% and 18%, respectively). UC patients have an increased risk for CVA, with women over 80 demonstrating the highest risk. Providers should be aware of these risks in making treatment decisions for UC.

It is a pleasure for me to give the Willis Lecture. I am especially honored because at the 8th Conference in February 1983 I also gave the Keynote Address, before it became known as the Willis Lecture.1 I am going to discuss a few principles concerning the risk factors for stroke; some recent observations from the Rochester, Minnesota, population on modeling of stroke risk factors; and some new observations about modeling attributable risk for stroke risk factors in a multivariable analysis; and I shall discuss how we might consider the risk factors for stroke in regard to the pathologic substrates for stroke. The Rochester Epidemiology Project medical record linkage system2 provided the means to identify virtually all new cases of ischemic stroke in the Rochester population for a population-based, nested case-control study of risk factors for stroke. The controls for the study were selected from an enumeration of the population through the medical records of the Rochester Epidemiology Project. There were 1444 incidence cases of stroke in the population in the 25 years of the study from 1960 through 1984, with controls from the population matched one-to-one by age, sex, and duration of the medical record. About 80% of the cases were seen and evaluated by a neurologist. This study of risk factors for ischemic stroke provides a unique and powerful set of data because it includes such a large number of incident cases and population-based controls. The size of the data set allowed assessment of interactions that have not been assessed adequately. More details of this study were published in December 1996.3 The effect of a risk factor on the probability of stroke is determined by three considerations: (1) the relative risk of the factor, (2) the prevalence of the factor in the population, and (3) …

Establishing new approaches for the prevention and treatment of stroke relies on identifying modifiable risk factors that contribute to the development of this complex disease. Mendelian randomization (MR) studies, analogous to naturally occurring randomized trials, can assess causality of potentially modifiable biomarkers and offer new insights into biological pathways. Stroke is the second leading cause of death worldwide and the chief determinant of long-term disability. Stroke is a heterogeneous disease arising from several distinct underlying pathologies and is typically classified as ischemic or hemorrhagic, and further subclassified using imaging data. Ischemic stroke (IS), including its 3 main subtypes: small vessel disease, large vessel disease, and cardioembolic stroke, accounts for ≈80% of stroke and is the result of an interrupted blood supply, leading to localized areas of ischemia in the brain. Small vessel disease may be a consequence of nonatherosclerotic, as well as atherosclerotic, mechanisms that result in an occlusion of the small perforating arteries, whereas large vessel disease results from occlusions or emboli from plaque rupture in larger vessels, such as a carotid artery. Cardioembolic stroke arises typically from emboli from the heart. By contrast, hemorrhagic stroke is a consequence of intracerebral hemorrhage (bleeding into the brain) or subarachnoid hemorrhage (bleeding into the subarachnoid space). These diverse stroke subtypes have distinct underlying pathologies reflecting different risk factor distributions. MR studies, using genetic variants as instrumental variables, afford a powerful approach to assessing causality of risk factors and avoid biases inherent in observational studies, including confounding and reverse causation. This review considers the contribution of MR studies to stroke epidemiology and their relevance to understanding risk factors and new therapeutic targets for stroke. Meta-analyses of large prospective studies have enhanced our knowledge of classical and emerging risk factors for stroke.1–4 Classical risk factors for stroke include nonmodifiable characteristics, …

Background: Herpes simplex virus 1 and 2 (HSV-1 and HSV-2) and varicella zoster virus (VZV) are neurotropic herpesviruses that cause vesicular mucocutaneous eruptions. They both establish latency in peripheral ganglia and can reactivate to cause episodic outbreaks. HSV occurs more often in the young and may reactivate frequently. VZV reactivation is associated with advancing age due to a decline in the VZV-specific T cell population. While both viruses have been isolated from the same sensory ganglia, they rarely cause simultaneous disease. In most of these cases the viruses have been isolated at different body sites in immunocompromised hosts. However, clinical disease with concurrent detection of both HSV and VZV from the same anatomic location has been described. In a prior study of dual positive specimens, a lower PCR cycle threshold (Ct) was consistently observed for VZV, suggesting that zoster caused subsequent reactivation of HSV. Case presentation: Here we describe the case of a 64-year-old patient with uncontrolled diabetes who presented with painful penile ulcers and a dermatomal, crusted, left lower abdominal rash. His penile ulcers were positive for both HSV-2 and VZV by PCR. Ct data suggested that primary zoster led to secondary genital HSV-2. Hyperglycemia is known to cause reversible T cell dysfunction and was the likely precipitating factor for the patient’s illness, which responded to oral valacyclovir. Conclusion: To our knowledge this is the first report of diabetes-related concurrent herpesvirus reactivation. Clinicians should consider the possibility of simultaneous HSV and VZV infection in patients who present with dermatomal zosteriform lesions since higher antiviral doses are recommended for herpes zoster as compared to herpes simplex.

Varicella-Associated Stroke

Development and Clinical Validation of a Multiplex Real-time PCR Assay for Herpes Simplex and Varicella Zoster Virus

The cause of postherpetic neuralgia (PHN) is unknown. Besides PHN, two other qualitatively identical closely related forms of radicular pain without rash are associated with VZV infection. The first is prolonged radicular pain preceding zoster rash (preherpetic neuralgia). The second is chronic radicular pain associated with VZV infection without rash (zoster sine herpete). These collective clinical conditions alone suggest that PHN results from a smoldering VZV ganglionitis. There have been only two instances in which ganglia from PHN patients before death, corresponding to the area of pain during life, were analyzed pathologically. In both, an inflammatory response in ganglia of these subjects raised the possibility of prolonged viral infection. This chapter details cases of PHN in which VZV DNA and proteins were detected in the blood of many patients with PHN. Also, cases of zoster sine herpete that were studied virologically provide evidence of a productive VZV ganglionitis. Finally, a favorable response to antiviral treatment of patients with zoster sine herpete and some with PHN provides evidence that PHN is caused by chronic active VZV infection in ganglia. Because only a few studies have used antiviral therapy to treat PHN with conflicting results, larger, double-blinded studies, which give antiviral therapy intravenously, are needed.

Varicella zoster virus (VZV) is a neurotropic herpesvirus that infects nearly all humans. Primary infection usually causes chickenpox (varicella), after which virus becomes latent in cranial nerve ganglia, dorsal root ganglia and autonomic ganglia along the entire neuraxis. Although VZV cannot be isolated from human ganglia, nucleic acid hybridization and, later, polymerase chain reaction proved that VZV is latent in ganglia. Declining VZV-specific host immunity decades after primary infection allows virus to reactivate spontaneously, resulting in shingles (zoster) characterized by pain and rash restricted to one to three dermatomes. Multiple other serious neurological and ocular disorders also result from VZV reactivation. This review summarizes the current state of knowledge of the clinical and pathological complications of neurological and ocular disease produced by VZV reactivation, molecular aspects of VZV latency, VZV virology and VZV-specific immunity, the role of apoptosis in VZV-induced cell death and the development of an animal model provided by simian varicella virus infection of monkeys.