Search for varicella zoster virus DNA in saliva of healthy individuals aged 20-59 years

Silent Reactivation of Varicella Zoster Virus in Pregnancy: Implications for Maintenance of Immunity to Varicella

We encountered two cases of varicella occurring in newborn infants. Because the time between birth and the onset of the illness was much shorter than the varicella incubation period, the cases suggested that the infection was maternally acquired, despite the fact that neither mother experienced clinical zoster. Thus, we tested the hypothesis that VZV frequently reactivates asymptomatically in late pregnancy. The appearance of DNA-encoding VZV genes in saliva was used as an indicator of reactivation. Saliva was collected from 5 women in the first and 14 women in the third trimesters of pregnancy and analyzed at two different sites, at one using nested PCR and at the other using quantitative PCR (qPCR). No VZV DNA was detected at either site in the saliva of women during the first trimester; however, VZV DNA was detected in the majority of samples of saliva (11/12 examined by nested PCR; 7/10 examined by qPCR) during the third trimester. These observations suggest that VZV reactivation occurs commonly during the third trimester of pregnancy. It is possible that this phenomenon, which remains in most patients below the clinical threshold, provides an endogenous boost to immunity and, thus, is beneficial.

Infectious ophthalmoplegias

Though infections account for a significant proportion of patients with ocular motor palsies, there is surprising paucity of literature on infectious ophthalmoplegias. Almost all types of infectious agents (bacteria, viruses, fungi and parasites) can lead to ocular motor palsies. The causative infectious agent can be diagnosed in most cases using an orderly stepwise approach. In this review we discuss how to approach a patient with ophthalmoplegia with main focus on infectious etiologies.

Neurological and Ophthalmological Manifestations of Varicella Zoster Virus

BACKGROUND

Approximately 1 million new cases of herpes zoster (HZ) occur in the United States annually, including 10%-20% with herpes zoster ophthalmicus (HZO). Postherpetic neuralgia, a debilitating pain syndrome occurs in 30% HZ, whereas 50% HZO develop ophthalmic complications. Diplopia from cranial nerve palsy occurs in less than 30% HZO, whereas optic neuropathy is seen in less than 1% HZO. We reviewed recent developments in the diagnosis, treatment, and prevention of HZ as well as neurological and ophthalmological complications of relevance to the neuro-ophthalmologist.

EVIDENCE ACQUISITION

We searched the English language literature on Pubmed and Google scholar for articles relevant to the various sections of this review.

RESULTS

Antiviral treatment should be initiated within 48-72 hours of onset of HZ and HZO to decrease pain and reduce complications. We recommend neuroimaging in all patients with neuro-ophthalmic manifestations such as diplopia and acute vision loss. Diagnostic confirmation using polymerase chain reaction and serology on paired serum and cerebrospinal fluid samples should be obtained in those with neurological signs and symptoms or abnormal imaging. Patients with neurological and/or retinal varicella zoster virus (VZV) infection should be treated promptly with intravenous acyclovir. Patients with isolated optic neuropathy or cranial nerve palsy can be managed with oral antivirals. The prognosis for visual recovery is good for patients with isolated optic neuropathy and excellent for patients with isolated ocular motor cranial nerve palsy.

CONCLUSIONS

HZ produces a spectrum of potentially blinding and life-threatening complications that adversely affect quality of life and increase health care costs. Individuals at risk for HZ, such as the elderly and immunocompromised, should be encouraged to receive the highly effective VZV vaccine to prevent HZ and its complications.

Relationships of varicella zoster virus (VZV)-specific cell-mediated immunity and persistence of VZV DNA in saliva and the development of postherpetic neuralgia in patients with herpes zoster

There are no surrogate markers for the development of postherpetic neuralgia (PHN) in patients with herpes zoster (HZ). All patients with HZ were prospectively enrolled to evaluate the associations of saliva varicella zoster virus (VZV) DNA persistence and VZV-specific cell-mediated immunity (CMI) with the development of PHN. Slow clearers were defined if salivary VZV DNA persisted after day 15. Salivary VZV was detected in 60 (85.7%) of a total of 70 patients with HZ on initial presentation. Of 38 patients for whom follow-up saliva samples were available, 26 (68.4%) were classified as rapid clearers and 12 (31.6%) as slow cleares. Initial VZV-specific CMI was lower in slow clearers than rapid clearers (median 45 vs 158 spot forming cells/10 ⁶ cells, P = .02). Of the 70 patients with HZ, 22 (31.4%) eventually developed PHN. Multivariate analysis showed that slow clearers (OR, 15.7, P = .01) and lower initial VZV-specific CMI (OR, 13.8, P = .04) were independent predictors of the development of PHN, after adjustment for age and immunocompromised status. Initial low VZV CMI response and persistence of VZV DNA in saliva may be associated with the development of PHN.

Diagnostic Usefulness of Varicella-Zoster Virus Real-Time Polymerase Chain Reaction Analysis of DNA in Saliva and Plasma Specimens From Patients With Herpes Zoster

Background

We evaluated the diagnostic usefulness of polymerase chain reaction (PCR) analysis for detecting varicella-zoster virus (VZV) infection and reactivation of VZV, using DNA extracted from saliva and plasma specimens obtained from subjects with suspected herpes zoster and from healthy volunteers during stressful and nonstressful conditions.

Methods

There were 52 patients with a diagnosis of herpes zoster (group 1), 30 with a diagnosis of zoster-mimicking disease (group 2), and 27 healthy volunteers (group 3). Saliva and plasma samples were evaluated for VZV DNA by real-time PCR analysis.

Results

Among patients with suspected herpes zoster (ie, patients in groups 1 and 2), the sensitivity of PCR analysis of salivary DNA for detecting VZV (88%; 95% confidence interval [CI], 74%-95%) was significantly higher than that of PCR analysis of plasma DNA (28%; 95% CI, 16%-44%; P < .001), whereas the specificity of PCR analysis of salivary DNA (100%; 95% CI, 88%-100%) was similar to that of PCR analysis of plasma DNA (100%; 95% CI, 78%-100%; P > .99). VZV DNA was not detected in saliva and plasma samples from group 3 (0%; 95% CI, 0%-14%).

Conclusions

Real-time PCR analysis of salivary DNA is more sensitive than that of plasma DNA for detecting VZV among patients with suspected herpes zoster. We found no subclinical reactivation of VZV in group 3 following exposure to common stressful conditions.

Varicella-Zoster Virus and the Enteric Nervous System

Varicella zoster virus (VZV) infects and becomes latent in sensory, enteric, and other autonomic neurons during the viremia of varicella. Reactivation of VZV in neurons that project to the skin causes the rash of zoster; however, reactivation of VZV in enteric neurons can cause a painful gastrointestinal disorder ("enteric zoster") without cutaneous manifestations. Detection of VZV DNA in saliva of patients with gastrointestinal symptoms may suggest enteric zoster. This diagnosis is reinforced by observing a response to antiviral therapy and can be confirmed by detecting VZV gene products in intestinal mucosal biopsies. We developed an in vivo guinea pig model that may be useful in studies of VZV latency and reactivation. VZV-infected lymphocytes are used to induce latent infection in sensory and enteric neurons; evidence suggests that exosomes and stimulator of interferon genes (STING) may, by preventing proliferation play roles in the establishment of neuronal latency.

Latent virus reactivation in astronauts on the international space station

Reactivation of latent herpes viruses was measured in 23 astronauts (18 male and 5 female) before, during, and after long-duration (up to 180 days) spaceflight onboard the international space station . Twenty age-matched and sex-matched healthy ground-based subjects were included as a control group. Blood, urine, and saliva samples were collected before, during, and after spaceflight. Saliva was analyzed for Epstein-Barr virus, varicella-zoster virus, and herpes simplex virus type 1. Urine was analyzed for cytomegalovirus. One astronaut did not shed any targeted virus in samples collected during the three mission phases. Shedding of Epstein-Barr virus, varicella-zoster virus, and cytomegalovirus was detected in 8 of the 23 astronauts. These viruses reactivated independently of each other. Reactivation of Epstein-Barr virus, varicella-zoster virus, and cytomegalovirus increased in frequency, duration, and amplitude (viral copy numbers) when compared to short duration (10 to 16 days) space shuttle missions. No evidence of reactivation of herpes simplex virus type 1, herpes simplex virus type 2, or human herpes virus 6 was found. The mean diurnal trajectory of salivary cortisol changed significantly during flight as compared to before flight (P = 0.010). There was no statistically significant difference in levels of plasma cortisol or dehydoepiandosterone concentrations among time points before, during, and after flight for these international space station crew members, although observed cortisol levels were lower at the mid and late-flight time points. The data confirm that astronauts undertaking long-duration spaceflight experience both increased latent viral reactivation and changes in diurnal trajectory of salivary cortisol concentrations.

THE JEREMIAH METZGER LECTURE VARICELLA ZOSTER VIRUS: FROM OUTSIDE TO INSIDE

Varicella zoster virus (VZV) gives rise to two diseases, a primary infection, varicella, and a secondary infection, zoster. Morbidity and mortality from VZV in the United States has decreased by 80% to 90% due to the effective use of attenuated live viral vaccines. Because latent VZV continues to reactivate, however, serious VZV-induced disease persists. Newly developed molecular analyses have revealed that zoster is more common than previously realized; moreover, the establishment of VZV latency in neurons, such as those of the enteric nervous system, which do not project to the skin, leads to unexpected, serious, and clandestine manifestations of disease, including perforating gastrointestinal ulcers and intestinal pseudo-obstruction. The development of the first animal model of zoster, in guinea pigs, now enables the pathophysiology of latency and reactivation to be analyzed.

Varicella zoster virus infection

Infection with varicella zoster virus (VZV) causes varicella (chickenpox), which can be severe in immunocompromised individuals, infants and adults. Primary infection is followed by latency in ganglionic neurons. During this period, no virus particles are produced and no obvious neuronal damage occurs. Reactivation of the virus leads to virus replication, which causes zoster (shingles) in tissues innervated by the involved neurons, inflammation and cell death - a process that can lead to persistent radicular pain (postherpetic neuralgia). The pathogenesis of postherpetic neuralgia is unknown and it is difficult to treat. Furthermore, other zoster complications can develop, including myelitis, cranial nerve palsies, meningitis, stroke (vasculopathy), retinitis, and gastroenterological infections such as ulcers, pancreatitis and hepatitis. VZV is the only human herpesvirus for which highly effective vaccines are available. After varicella or vaccination, both wild-type and vaccine-type VZV establish latency, and long-term immunity to varicella develops. However, immunity does not protect against reactivation. Thus, two vaccines are used: one to prevent varicella and one to prevent zoster. In this Primer we discuss the pathogenesis, diagnosis, treatment, and prevention of VZV infections, with an emphasis on the molecular events that regulate these diseases. For an illustrated summary of this Primer, visit: http://go.nature.com/14xVI1.

Use of Saliva to Identify Varicella Zoster Virus Infection of the Gut

BACKGROUND

Varicella zoster virus (VZV) establishes latency in dorsal root, cranial nerve, and enteric ganglia and can reactivate to cause zoster. Serious gastrointestinal dysfunction can result from VZV reactivation in enteric neurons (enteric zoster), but an absence of rash makes diagnosis difficult. We thus determined whether detecting VZV DNA in saliva facilitates identification of enteric zoster.

METHODS

Nested and real-time polymerase chain reaction were used to validate salivary VZV DNA as a surrogate marker of VZV reactivation and then to determine the utility of that marker for the identification of those individuals within a population defined by abdominal pain that might have enteric zoster.

RESULTS

Salivary VZV DNA was detected in 0 of 20 healthy negative controls, 11 of 16 positive controls with zoster or varicella (P < .0001), 2 of 2 patients with zoster sine herpete (P < .01), 6 of 11 patients with unexplained abdominal pain (P < .001), and 0 of 8 patients with unrelated gastrointestinal disorders. Salivary VZV DNA disappeared after recovery in 9 of 9 tested subjects with zoster, 2 of 2 with zoster sine herpete, and 5 of 5 with abdominal pain. One patient with abdominal pain and salivary VZV DNA had perforated gastric ulcers, necessitating a wedge gastrectomy. VZV DNA (vaccine type) was found in the resected stomach; immediate early (ORF63p) and late (gE) VZV proteins were immunocytochemically detected in gastric epithelium. After recovery, VZV DNA and proteins were not detected in gastric biopsies or saliva.

CONCLUSIONS

Detection of salivary VZV DNA in patients with abdominal pain helps to identify putative enteric zoster for investigation and treatment.

Lab in a tube: a fast-assembled colorimetric sensor for highly sensitive detection of oligonucleotides based on a hybridization chain reaction

Upon adding T_HBV, the self-assembly of T_HBV with H₁ allows the rest of the DNA sequence of H₁ to accelerate H₁–H₂ complex formation. The G-quadruplex at the end of the H₁–H₂ complex could catalyze TMB into a colored product.

Varicella-zoster virus and virus DNA in the blood and oropharynx of people with latent or active varicella-zoster virus infections

Varicella-zoster virus (VZV) can be detected in the blood from approximately 5 days before to 4 days after varicella. VZV DNA, primarily in T-lymphocytes, is detected as early as 8-10 days prior to rash and can persist for a week. The duration and magnitude of VZV DNAemia correlates with immune status and the efficacy of antiviral therapy. VZV DNA is also readily detected in the oropharynx just prior to rash and for 1-2 weeks thereafter. Detection of VZV DNA in blood and saliva has been useful for diagnosis and prognosis in atypical cases of varicella. Herpes zoster (HZ) is also characterized by VZV DNAemia at onset and for many weeks thereafter, and VZV DNA is present in the oropharynx shortly after HZ onset. Detection of VZV DNA in blood and saliva facilitates the diagnosis of zoster sine herpete and other atypical manifestations of VZV reactivation, such as neurologic syndromes when cerebrospinal fluid is not available, Bell's palsy, and atypical pain syndromes. VZV DNA is sometimes present in the blood and saliva of asymptomatic individuals. In total these observations extend understanding of the pathophysiology and epidemiology of VZV, and increasingly contribute to the clinical management of VZV infections.

Multiple latent viruses reactivate in astronauts during Space Shuttle missions

Latent virus reactivation and diurnal salivary cortisol and dehydroepiandrosterone were measured prospectively in 17 astronauts (16 male and 1 female) before, during, and after short-duration (12-16 days) Space Shuttle missions. Blood, urine, and saliva samples were collected during each of these phases. Antiviral antibodies and viral load (DNA) were measured for Epstein-Barr virus (EBV), varicella-zoster virus (VZV), and cytomegalovirus (CMV). Three astronauts did not shed any virus in any of their samples collected before, during, or after flight. EBV was shed in the saliva in all of the remaining 14 astronauts during all 3 phases of flight. Seven of the 14 EBV-shedding subjects also shed VZV during and after the flight in their saliva samples, and 8 of 14 EBV-shedders also shed CMV in their urine samples before, during, and after flight. In 6 of 14 crewmembers, all 3 target viruses were shed during one or more flight phases. Both EBV and VZV DNA copies were elevated during the flight phase relative to preflight or post-flight levels. EBV DNA in peripheral blood was increased preflight relative to post-flight. Eighteen healthy controls were also included in the study. Approximately 2-5% of controls shed EBV while none shed VZV or CMV. Salivary cortisol measured preflight and during flight were elevated relative to post-flight. In contrast DHEA decreased during the flight phase relative to both preflight and post-flight. As a consequence, the molar ratio of the area under the diurnal curve of cortisol to DHEA with respect to ground (AUCg) increased significantly during flight. This ratio was unrelated to viral shedding. In summary, three herpes viruses can reactivate individually or in combination during spaceflight.