Detection of human herpesvirus 6 and varicella-zoster virus in tear fluid of patients with Bell's palsy by PCR

Can COVID-19 Cause Peripheral Facial Nerve Palsy?

The aim of our study is to evaluate the relationship between peripheral facial paralysis and the patients who had a contact with a coronavirus disease 2019 (COVID-19) patient or had COVID-19. Patients with a history of contact with a COVID-19 patient or having COVID-19 disease, who were admitted to the emergency department for peripheral facial paralysis in the last 6 months, were included in the study. Facial paralysis grade at first presentation, treatment modality, treatment duration, post-treatment facial paralysis grade, and additional findings were analyzed. A total of 34 patients, 20 females and 14 males, were included into the study. Nasal-oropharyngeal reverse transcriptase-polymerase chain reaction (RT-PCR) was test taken from patients with a history of contact, and patients having COVID-19 disease were determined as positive in 5 and 3 patients, respectively. Peripheral facial paralysis was detected as an initial finding in 5 of these 8 patients, and paralysis developed in 7-12 days after the diagnosis of the COVID-19 disease in the remaining 3 patients. The grade of first admission paralysis did not change in one patient in the (+) group, while improvement was observed in all patients in the (−) group. Neuroinvasive potential of COVID-19 in the central and peripheral nervous system was reported in current literature. Our study indicates peripheral facial palsy can also be encountered during the clinical course of COVID-19 and should be considered a finding of this disease.

Bell's palsy in a pediatric patient with hyper IgM syndrome and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Bell's palsy is an acute facial paralysis with known association to viral infections. We describe a medically complex 6-year-old male with hyper IgM syndrome who presented with unilateral facial droop and positive SARS-CoV-2 RT-PCR. This is the first reported pediatric case of Bell's palsy in the setting of SARS-CoV-2 infection.

The Presence of Human Herpesvirus 6 in the Brain in Health and Disease

The human herpesvirus 6 (HHV-6) -A and -B are two dsDNA beta-herpesviruses infectingalmost the entire worldwide population. These viruses have been implicated in multipleneurological conditions in individuals of various ages and immunological status, includingencephalitis, epilepsy, and febrile seizures. HHV-6s have also been suggested as playing a role inthe etiology of neurodegenerative diseases such as multiple sclerosis and Alzheimer's disease. Theapparent robustness of these suggested associations is contingent on the accuracy of HHV-6detection in the nervous system. The effort of more than three decades of researching HHV-6 in thebrain has yielded numerous observations, albeit using variable technical approaches in terms oftissue preservation, detection techniques, sample sizes, brain regions, and comorbidities. In thisreview, we aimed to summarize current knowledge about the entry routes and direct presence ofHHV-6 in the brain parenchyma at the level of DNA, RNA, proteins, and specific cell types, inhealthy subjects and in those with neurological conditions. We also discuss recent findings relatedto the presence of HHV-6 in the brains of patients with Alzheimer's disease in light of availableevidence.

[Ramsay Hunt syndrome]

Ramsay Hunt syndrome is a complication of varicella-zoster virus infection, which manifests by geniculate ganglion involvement. Clinical presentation of Ramsay Hunt syndrome includes virus affecting external ear by vesicular rash on the ear, ear pain and peripheral facial nerve paralysis. The review presents an analysis of etiology, clinical picture and diagnosis of the disease. The clinical features of combined cranial nerve involvement, contemporary treatment and prophylaxis options are described. Early diagnosis and medical therapy is a crucial factor for positive prognosis to improve damaged nerves in Ramsay Hunt syndrome.

Revisión sistemática sobre la prevalencia de la serología infecciosa en la parálisis facial periférica

Introducción y objetivos. La parálisis facial periférica es una afección del Nervio Facial que suele cursar con dolor retroauricular, pródromos vitales y parálisis facial. Ante la falta de bibliografía sobre la etiología de dicha parálisis se propuso realizar una revisión sistemática orientada a conocer la prevalencia serológica de la parálisis facial periférica en los diferentes estudios publicados incluyendo el realizado en esta facultad el curso anterior. Materiales y métodos. Revisión sistemática y metanálisis de los estudios publicados sobre la confirmación de una parálisis facial periférica por serología positiva. Resultados. Un total de 628 pacientes fueron analizados, de los cuáles 76 tenían serología positiva (12,10%). El metanálisis muestra heterogeneidad entre los resultados y sesgo de publicación. Conclusiones. No se evidencia que haya una relación significativa entre una parálisis facial periférica y una serología positiva reciente por lo que no se obtendría beneficio con un tratamiento antiviral.

Contact lens-based lysozyme detection in tear using a mobile sensor

We report a method for sensing analytes in tear-fluid using commercial contact lenses (CLs) as sample collectors for subsequent analysis with a cost-effective and field-portable reader. In this study we quantify lysozyme, the most prevalent protein in tear fluid, non-specifically bound to CLs worn by human participants. Our mobile reader uses time-lapse imaging to capture an increasing fluorescent signal in a standard well-plate, the rate-of-change of which is used to indirectly infer lysozyme concentration through the use of a standard curve. We empirically determined the best-suited CL material for our sampling procedure and assay, and subsequently monitored the lysozyme levels of nine healthy human participants over a two-week period. Of these participants who were regular CL wearers (6 out of 9), we observed an increase in lysozyme levels from 6.89 ± 2.02 μg mL-1 to 10.72 ± 3.22 μg mL-1 (mean ± SD) when inducing an instance of digital eye-strain by asking them to play a game on their mobile-phones during the CL wear-duration. We also observed a lower mean lysozyme concentration (2.43 ± 1.66 μg mL-1) in a patient cohort with dry eye disease (DED) as compared to the average monitoring level of healthy (no DED) human participants (6.89 ± 2.02 μg mL-1). Taken together, this study demonstrates tear-fluid analysis with simple and non-invasive sampling steps along with a rapid, easy-to-use, and cost-effective measurement system, ultimately indicating physiological differences in human participants. We believe this method could be used in future tear-fluid studies, even supporting multiplexed detection of a panel of tear biomarkers toward improved diagnostics and prognostics as well as personalized mobile-health applications.

Does Herpes 6 Infection Have a Role in Bell's Palsy Among Children and Adolescents?

BACKGROUND

Bell's palsy is a peripheral paralysis of the seventh cranial nerve, whose etiology is unknown. Using polymerase chain reaction technology, it is possible to sample accessible body fluids and identify possible viral factors. The purpose of this research is to investigate its connection to the herpes virus family by testing for the presence of the virus in the saliva and tear fluid of Bell's palsy patients.

METHODS

Saliva and tears were collected from 42 children and adolescents suffering from idiopathic facial nerve paralysis. Polymerase chain reaction was used to test for the presence of the viruses Epstein-Barr virus, cytomegalovirus, herpes simplex virus 1 and 2, varicella zoster virus and human herpes virus 6 (HHV-6). Samples were also taken from a control group without paralysis. A second specimen was taken from patients who tested positive for HHV-6 several months after their recovery.

RESULTS

Of the 42 patients in the study group, 71% (30 patients) tested positive for HHV-6, compared with only 37% of the control group (P = 0.001). The prevalence of the other 5 viruses tested was low-herpes simplex virus 1: 9.5%, Epstein-Barr virus: 9.5%, cytomegalovirus: 4.8%, varicella zoster virus: 2.3% and herpes simplex virus 2: 0%. Twenty-four of the 30 patients who were HHV-6-positive during their illness were reexamined following recovery. Only 13 patients (54.2%) excreted the virus after recovery from the paralysis.

CONCLUSIONS

Herpes 6 virus appears to play some role in the etiology of facial nerve paralysis. The virus was detected in the saliva of children during acute illness and decreased with resolution. Our research opens new insights linking HHV-6 to the etiology of Bell's palsy in children.

Recurrent ocular surface inflammation associated with human herpesvirus 6 infection

OBJECTIVES

To report a case of atypical herpes keratitis and bilateral conjunctivitis associated with human herpesvirus 6 (HHV-6).

METHODS

An immunocompetent 34-year-old man was referred for herpetic epithelial keratitis in his left eye, which was non-responsive to topical acyclovir. Biomicroscopy revealed a central dendritic ulcer with a white stromal infiltrate beneath the ulcer.

RESULTS

The corneal scraping multiplex polymerase chain reaction (CLART ENTHERPEX, Genomica, Spain) was positive for HHV-6 and negative for herpes simplex virus, varicella zoster virus, cytomegalovirus, and Epstein-Barr virus. An improvement of the keratitis and visual acuity was achieved with topical fluorometholone and systemic valacyclovir. One year later, the patient complained of redness of the eyes. A slit-lamp examination disclosed bilateral follicular conjunctivitis, and HHV-6 DNA was once again detected in a conjunctival scraping of both eyes.

CONCLUSIONS

Human herpesvirus 6 may be another causative agent for corneal ulcers and conjunctivitis in isolation. Stromal necrosis is a rare manifestation of herpetic dendritic keratitis. In these cases, we should consider the presence of HHV-6 in the differential diagnosis, even in immunocompetent patients.

Herpes zoster epidemiology, management, and disease and economic burden in Europe: a multidisciplinary perspective

Herpes zoster (HZ) is primarily a disease of nerve tissue but the acute and longer-term manifestations require multidisciplinary knowledge and involvement in their management. Complications may be dermatological (e.g. secondary bacterial infection), neurological (e.g. long-term pain, segmental paresis, stroke), ophthalmological (e.g. keratitis, iridocyclitis, secondary glaucoma) or visceral (e.g. pneumonia, hepatitis). The age-related increased incidence of HZ and its complications is thought to be a result of the decline in cell-mediated immunity (immunosenescence), higher incidence of comorbidities with age and social-environmental changes. Individuals who are immunocompromised as a result of disease or therapy are also at increased risk, independent of age. HZ and its complications (particularly postherpetic neuralgia) create a significant burden for the patient, carers, healthcare systems and employers. Prevention and treatment of HZ complications remain a therapeutic challenge despite recent advances. This is an overview of the multidisciplinary implications and management of HZ in which the potential contribution of vaccination to reducing the incidence HZ and its complications are also discussed.

Bell's palsy: a summary of current evidence and referral algorithm

Spontaneous idiopathic facial nerve (Bell's) palsy leaves residual hemifacial weakness in 29% which is severe and disfiguring in over half of these cases. Acute medical management remains the best way to improve outcomes. Reconstructive surgery can improve long term disfigurement. However, acute and surgical options are time-dependent. As family practitioners see, on average, one case every 2 years, a summary of this condition based on common clinical questions may improve acute management and guide referral for those who need specialist input. We formulated a series of clinical questions likely to be of use to family practitioners on encountering this condition and sought evidence from the literature to answer them. The lifetime risk is 1 in 60, and is more common in pregnancy and diabetes mellitus. Patients often present with facial pain or paraesthesia, altered taste and intolerance to loud noise in addition to facial droop. It is probably caused by ischaemic compression of the facial nerve within the meatal segment of the facial canal probably as a result of viral inflammation. When given early, high dose corticosteroids can improve outcomes. Neither antiviral therapy nor other adjuvant therapies are supported by evidence. As the facial muscles remain viable re-innervation targets for up to 2 years, late referrals require more complex reconstructions. Early recognition, steroid therapy and early referral for facial reanimation (when the diagnosis is secure) are important features of good management when encountering these complex cases.

Herpes simplex virus 2 infection: molecular association with HIV and novel microbicides to prevent disease

Infection with herpes simplex viruses is one of the most ancient diseases described to affect humans. Infection with these viruses produces vexing effects to the host, which frequently recur. Infection with herpes simplex viruses is lifelong, and currently there is no vaccine or drug to prevent or cure infection. Prevalence of herpes simplex virus 2 (HSV-2) infection varies significantly depending on the geographical region and nears 20 % worldwide. Importantly, HSV-2 is the first cause of genital ulcers in the planet. HSV-2 affects approximately 500 million people around the globe and significantly increases the likelihood of acquiring the human immunodeficiency virus (HIV), as well as its shedding. Thus, controlling HSV-2 infection and spread is of public health concern. Here, we review the diseases produced by herpes simplex viruses, the factors that modulate HSV-2 infection, the relationship between HSV-2 and HIV and novel therapeutic and prophylactic microbicides/antivirals under development to prevent infection and pathological outcomes produced by this virus. We also review mutations associated with HSV-2 resistance to common antivirals.

Varicella-zoster virus keratitis with asymptomatic conjunctival viral shedding in the contralateral eye

Purpose

To report a case of varicella-zoster virus (VZV) keratitis with detection of VZV DNA in the tear fluid of not only the symptomatic eye but also the contralateral asymptomatic eye by polymerase chain reaction (PCR).

Methods

This is a case report. A 63-year-old otherwise healthy woman presented with circular corneal ulcer and stromal opacity with infiltration accompanied by mild conjunctival and ciliary injections in the left eye. Bacterial cultures of the corneal scrapings and virus PCR analyses of tear fluid from both eyes were performed.

Results

No pathogen was found by bacterial cultures. PCR was negative for Acanthamoeba, herpes simplex virus and cytomegalovirus, but positive for VZV. VZV DNA was also detected in the unaffected eye. Based on the diagnosis of VZV keratitis, oral valacyclovir and acyclovir eye ointment were administered to the corneal infected eye. The infected eye was healed and VZV DNA turned negative in the tear fluid of the treated eye after 6 months of treatment; however, VZV DNA was still positive in the tear fluid of the contralateral eye.

Conclusions

To our knowledge, this is the first case report of the detection of VZV DNA in the tear fluid of both affected and unaffected eyes in a patient with VZV keratitis. Asymptomatic conjunctival shedding of VZV may continue in the healthy unaffected eye in VZV keratitis patients.

Safety of zoster vaccine in adults from a large managed-care cohort: a Vaccine Safety Datalink study

OBJECTIVES

The aim of this study was to examine a large cohort of adults who received the zoster vaccine for evidence of an increased risk of prespecified adverse events requiring medical attention.

DESIGN

Two self-comparison approaches, including a case-centred approach and a self-controlled case series (SCCS) analysis were used.

SETTING

Eight managed-care organizations participating in the Vaccine Safety Datalink project in the United States.

SUBJECTS

A total of 193 083 adults aged 50 and older receiving a zoster vaccine from 1 January 2007 to 31 December 2008 were included.

MAIN OUTCOME MEASURES

Prespecified adverse events were identified by aggregated International Classification of Diseases, Ninth Revision (ICD-9) codes in automated health plan datasets.

RESULTS

The risk of allergic reaction was significantly increased within 1-7 days of vaccination [relative risk = 2.13, 95% confidence interval (CI): 1.87-2.40 by case-centred method and relative rate = 2.32, 95% CI: 1.85-2.91 by SCCS]. No increased risk was found for the following adverse event groupings: cerebrovascular events; cardiovascular events; meningitis; encephalitis; and encephalopathy; and Ramsay-Hunt syndrome and Bell's palsy.

CONCLUSIONS

The results of this study support the findings from the prelicensure clinical trials, providing reassurance that the zoster vaccine is generally safe and well-tolerated with a small increased risk of allergic reactions in 1-7 days after vaccination.

Hyperbaric oxygen therapy for Bell's palsy

BACKGROUND

Bell's palsy is an idiopathic, acute unilateral facial weakness that evolves rapidly and is maximal within two days. Moderate ear discomfort, sensitivity to sound and reduced tearing may occur.

OBJECTIVES

To assess the effects of hyperbaric oxygen therapy on recovery of facial function in adults with moderate to severe Bell's palsy.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (January 2012), CENTRAL (2011, Issue 4), MEDLINE (January 1966 to January 2012), EMBASE (January 1980 to January 2012), CINAHL (1937 to January 2012), AMED (1985 to January 2012), LILACS (January 1982 to January 2012). In addition we made a systematic search for relevant controlled trials in specific hyperbaric literature sources.

SELECTION CRITERIA

Randomised controlled trials or quasi-randomised controlled trials of adults (over 16 years of age) undergoing hyperbaric oxygen therapy for moderate to severe Bell's palsy. We considered studies to be of sufficient quality for inclusion in the review only if there was blinding in the assessment of the facial palsy grade. We planned to include studies of HBOT used as adjuvant therapy, or in addition to routine medical therapy (including corticosteroids or antivirals, or both). Both treatment and control groups were to receive the same baseline therapy. HBOT had to be delivered at concentrations greater than or equal to 1.2 ATA in a hyperbaric oxygen chamber as a series of dives of 30 to 120 minutes.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility and study quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Our searches found no randomised controlled trials or quasi-randomised controlled trials that met the eligibility criteria for this review.There is very low quality evidence from one randomised trial involving 79 participants with acute Bell's palsy, but this study was excluded as the outcome assessor was not blinded to treatment allocation and thus did not meet pre-defined eligibility criteria. The trial compared 42 people who received hyperbaric oxygen therapy (2.8 atmospheres for 60 minutes twice daily, five days per week until the facial palsy resolved; maximum 30 'dives') and placebo tablets with 37 people who received placebo hyperbaric oxygen therapy (achieving only a normal partial pressure of oxygen) and prednisone (40 mg twice daily, reducing over eight days). Facial function recovered in more participants treated with hyperbaric oxygen therapy than with prednisone (hyperbaric oxygen therapy, 40/42 (95%); prednisone, 28/37 (76%); risk ratio 1.26, 95% CI 1.04 to 1.53). There were no reported major complications and all participants completed the trial.

AUTHORS' CONCLUSIONS

Very low quality evidence from one trial suggests that hyperbaric oxygen therapy may be an effective treatment for moderate to severe Bell's palsy, but this study was excluded as the outcome assessor was not blinded to treatment allocation. Further randomised controlled trials are needed.

Differential diagnosis of acute central nervous system infections in children using modern microbiological methods

AIM

Except bacterial meningitis, the agents causing acute central nervous system (CNS) infections in children are disclosed in only approximately half of the cases, and even less in encephalitis. We studied the potential of modern microbiological assays to improve this poor situation.

METHODS

In a prospective study during 3 years, all children attending hospital with suspected CNS infection were examined using a wide collection of microbiological tests using samples from the cerebrospinal fluid, serum, nasal swabs and stool.

RESULTS

Among 213 patients, 66 (31%) cases suggested CNS infection and specific aetiology was identified in 56 patients. Of these microbiologically confirmed cases, viral meningitis/encephalitis was diagnosed in 25 (45%), bacterial meningitis in 21 (38%) and neuroborreliosis in 9 (16%) cases while 1 child had fungal infection. In meningitis patients, the causative agent was identified in 85% (35/41) cases and in encephalitis in 75% (12/16). The most common bacteria were Streptococcus agalactiae, Streptococcous pneumonie and Neisseria meningitidis, while the most frequently detected viruses were enteroviruses and varicella zoster virus.

CONCLUSION

In 75% to 85% of paediatric CNS infections, specific microbiological diagnosis was obtained with modern laboratory techniques. The results pose a basis for prudent approach to these potentially serious diseases.

Human herpesvirus-6 and -7 DNA in cerebrospinal fluid of facial palsy patients

CONCLUSIONS

Finding human herpesvirus (HHV)-7 and dual HHV-6A and -6B DNA in cerebrospinal fluid (CSF) of two facial palsy (FP) patients is intriguing but does not allow etiologic conclusions as such. HHV-6 or -7 DNA was revealed in 10% of the CSF samples tested from 70 immunocompetent adolescents and adults; a highly unusual result. How these findings are associated with the diseases they accompany remains to be defined.

OBJECTIVE

To determine whether herpes simplex virus (HSV)-1 and -2, varicella-zoster virus (VZV), HHV-6A, -6B, and -7, Epstein-Barr virus (EBV), and cytomegalovirus (CMV) DNA could be found in CSF of FP patients or controls.

SUBJECTS AND METHODS

In all, 33 peripheral FP patients (26 idiopathic, 5 with herpesvirus infection, 1 puerperal, 1 Melkersson-Rosenthal syndrome) (34 CSF samples) and 36 controls (16 nonidiopathic FP, 7 hearing loss, 6 vertigo, 5 headache, 2 other) previously tested for HSV-1, VZV, and HHV-6 DNA by polymerase chain reaction (PCR) were tested with highly sensitive multiplex-PCR and an oligonucleotide microarray method.

RESULTS

One FP patient had HHV-7 DNA and another had HHV-6A and -6B DNA simultaneously. In the control group, one HHV-7, one HHV-6A, and three HHV-6B DNA-positive specimens were found.

Tear lipocalin is the major endonuclease in tears

PURPOSE

Human endonucleases are integral to apoptosis in which unwanted or potentially harmful cells are eliminated. The rapid turnover of ocular surface epithelium and microbial colonization of the eyelids are continual sources of DNA in tears. Here, we determine the principal sources of endonuclease activity in tears.

METHODS

Endonucleases in human tears were identified after Sephadex G100 gel filtration. DNA hydrolyzing activity was measured by the conversion pUC19 plasmid DNA to its circular form in agarose gels. Fractions with endonuclease activity were further isolated using a combination ConA-Sepharose DNA, oligo (dT) cellulose, and anion exchange chromatographies. The molecular weights of the DNA hydrolyzing proteins were estimated in zymograms and by calibration of size exclusion chromatography. DNase activities were characterized for activity at a variety of pH and ion concentrations as well as in the presence of inhibitors including NiCl(2), ZnCl(2), G-actin, and aurintricarboxylic acid (ATA). To determine the mode of hydrolysis, the cleaved ends of the DNA digested by tear DNases were analyzed by 3' and 5' end labeling using either terminal deoxynucleotidyl transferase or polynucleotide kinase with or without pretreatment with alkaline phosphatase.

RESULTS

Tear lipocalin (TL) accounts for over 75% of the DNA catalytic activity in tears while a second endonuclease, approximately 34 kDa, is responsible for less than 24% of the activity. Both are Mg(2+) dependent enzyme endonucleases that are enhanced by Ca(2+), active at physiologic pH, inhibited by aurintricarboxylic acid, and catalyze hydrolysis of DNA to produce 3'-OH/5'P ends. However, the two enzymes can be distinguished by the inhibitory effect of NiCl(2) and the sizes of the cleaved DNA fragments.

CONCLUSIONS

Two magnesium dependent extracellular endonucleases were identified in tears that are different from other major human extracellular nucleases. TL is the principal endonuclease in human tear fluid. Tear endonucleases have unique characteristics that differ from other known human endonucleases.

Search for Herpesviruses in cerebrospinal fluid of facial palsy patients by PCR

CONCLUSIONS

Herpes simplex virus 1 (HSV-1) and varicella-zoster virus (VZV) DNA were not detected in the cerebrospinal fluid (CSF) of patients with acute idiopathic peripheral facial palsy (Bell's palsy). Our results indicate either the absence of these viruses or the presence of technical shortcomings. The role of human herpesvirus 6 (HHV-6) in this disorder and the significance of a positive HHV-6 DNA finding in the central nervous system need further investigation.

OBJECTIVE

Our goal was to determine whether DNA of HSV-1, VZV, or HHV-6 can be found by polymerase chain reaction (PCR) in the CSF of peripheral facial palsy patients.

MATERIALS AND METHODS

We used PCR to detect the presence of HSV-1, VZV, and HHV-6 DNA in CSF. This was a retrospective case control study with 33 peripheral facial palsy patients (34 CSF samples) in the study group (26 with Bell's palsy, 5 with simultaneously diagnosed herpesvirus infection, 1 with puerperal facial palsy, 1 with Melkersson-Rosenthal syndrome). The control group included 36 patients, most with diagnosed or suspected Borreliosis and facial palsy or sudden deafness.

RESULTS

One patient with Bell's palsy had HHV-6 DNA in CSF. Neither HSV-1 nor VZV DNA was detected in patients or controls.

Multiplex-PCR and oligonucleotide microarray for detection of eight different herpesviruses from clinical specimens

BACKGROUND

Human herpesviruses cause clinically important diseases, e.g. infections of the central nervous system. New diagnostic tools are required for rapid and reliable detection of these viruses.

OBJECTIVES

A microarray-based method was designed for detection of eight human herpesviruses in cerebrospinal fluid (CSF), whole blood, plasma, serum and proficiency-testing specimens.

STUDY DESIGN

Herpes simplex type 1 and 2, varicella-zoster, cytomegalo-, Epstein-Barr and human herpes viruses 6A, 6B and 7 were amplified from clinical specimens by two multiplex-PCRs and transcribed to single-stranded RNAs which were hybridized to oligonucleotides on microarray. The results were compared to those from conventional PCR. In total, 227 specimens were tested including 23 CSF, 10 whole blood, 73 plasma, 10 proficiency-testing samples and 111 negative control samples.

RESULTS

Concordant results were obtained in 214/227 (94%). Microarray detected 10 possible double and one triple infection. Negative control samples (70 serum, 30 CSF and 11 proficiency-testing samples) were all negative.

CONCLUSIONS

Microarray is suitable for detection of multiple herpesviruses in clinical samples.

Human herpesvirus-6 and -7 in pediatric stem cell transplantation

BACKGROUND

Human herpesvirus-6 (HHV-6) and -7 (HHV-7) may reactivate with immunosuppression and cause symptoms varying from subclinical to severe organ manifestations. The presence of HHV-6 and -7 and their possible association with clinical problems among pediatric recipients of stem cell grafts was studied in a single institution setting between November 1999 and December 2001.

PROCEDURE

A total of 60 patients, mean age 8.5 years, were transplanted: 2/3 received allogeneic grafts and 1/3 autologous stem cell rescue. The presence of HHV-6 and -7 was studied in blood by polymerase chain reaction (PCR) (HHV-6) and antigenemia (HHV-6 and -7).

RESULTS

Both HHV-6 and -7 were frequently present in the blood of stem cell graft recipients. No significant difference in the incidence of HHV-6 or -7 reactivations between the allogeneic and autologous patients nor recipients of sibling or unrelated donor (URD) grafts was observed. HHV-6 antigenemia was associated with fever, rash, and delayed engraftment. Among symptomatic patients two cases of encephalitis were encountered with both having HHV-6 detectable in their cerebrospinal fluid (CSF) by PCR.

CONCLUSIONS

HHV-6 and -7 seem to be common in blood both pre- and post-transplant among pediatric recipients of stem cell grafts. Prolonged reactivations appear to correlate with clinical symptoms such as fever, rash, and bone marrow suppression in the post-stem cell transplant setting (SCT), but severe complications are rare. Transient reactivations appear to be of very limited clinical significance.

Bell's Palsy and Herpes Simplex Virus: Fact or Mystery?

HYPOTHESIS AND BACKGROUND

In recent years, progress has been made in the understanding of Bell's palsy, the most common form of acute facial weakness. Herpes simplex virus (HSV) reactivation within the geniculate ganglion with subsequent inflammation and entrapment of the nerve at the meatal foramen has been proposed to be the pathogenetic mechanism. We challenged its accuracy by analyzing our own data on the presence of viral genomic DNA of HSV-1 and 2, human herpes virus (HHV)-6A/B, as well as varizella zoster virus (VZV) in patients with Bell's palsy and in control patients without the disease.

METHODS

Polymerase chain reaction was performed with primer sets specific for viral genomic DNA of HSV-1, HSV-2, and VZV in facial muscle biopsy specimens from patients with Bell's palsy. As control specimens, the Scarpa's ganglion of patients with Meniere's disease and the geniculate ganglion harvested at autopsy from patients without history of facial palsy. In a second study, we used polymerase chain reaction with primers specific for HSV-1, -2, and HHV-6A, -6B to analyze for the presence of these viruses in tear fluid samples from control patients and patients with acute Bell's palsy.

RESULTS

HSV-1 and VZV genomic DNA were detected in 86 and 43%, respectively, of geniculate ganglion preparations from control specimen. We were not able to detect the presence of HSV-1, HSV-2, or VZV genomic DNA in ganglion scarpae or muscle biopsy results in control and Bell's palsy patients. HHV-6A could be detected in tear fluid samples in 40% of control patients and 30% of Bell's palsy patients.

CONCLUSIONS

The sole presence of HSV genomic DNA within the sensory ganglion along the facial nerve does not explain the direct association with Bell's palsy. The missing link would be the identification of an active replicating virus, an investigation that has not yet been carried out.

The severe acute respiratory syndrome coronavirus in tears

BACKGROUND

Severe acute respiratory syndrome (SARS) is a new infectious disease that caused a global outbreak in 2003. Research has shown that it is caused by a novel coronavirus. A series of cases is reported where polymerase chain reaction (PCR) testing on tears had demonstrated the presence of the virus. Detection of ocular infection from tears using the PCR technique has been widely used by ophthalmologists to diagnose infections for other viruses.

METHODS

This is a case series report from cases classified as probable or suspect SARS cases. Tear samples were collected from 36 consecutive patients who were suspected of having SARS in Singapore over a period of 12 days (7-18 April 2003), and analysed by PCR using protocols developed by the WHO network of laboratories.

RESULTS

Three patients with probable SARS (one female and two male patients) had positive results from their tear samples. Tear samples were used to confirm SARS in the female patient, who was positive only from her tears. The positive specimens were found in cases sampled early in their course of infection.

CONCLUSIONS

This is the first case series reported with the detection of the SARS coronavirus from tears, and has important implications for the practice of ophthalmology and medicine. The ability to detect and isolate the virus in the early phase of the disease may be an important diagnostic tool for future patients and tear sampling is both simple and easily repeatable. Many healthcare workers are in close proximity to the eyes of patients and this may be a source of spread among healthcare workers and inoculating patients. Ophthalmic practices may need to change as more stringent barrier methods, appropriate quarantine, and isolation measures are vital when managing patients with SARS.

Facial nerve palsy after human herpesvirus 6 infection

Facial nerve palsy has long been considered to have an infectious etiology, either viruses, mainly herpesviruses, or bacteria, such as Borrelia burgdorferi. We report for the first time the association of human herpesvirus 6 and facial palsy in a previously healthy 1-year 9-month-old boy who developed left facial nerve palsy 7 days after exanthema subitum caused by human herpesvirus 6.

Human herpesvirus 6 (HHV6) infection

Human herpes virus-6 was first reported in 1986 and is the sixth member of the herpes virus family. HHV-6 consists of two closely related variants HHV-6A and HHV-6B. The majority of infections occur in healthy infants with most infections caused by HHV-6B. The virus preferentially infects CD4+T-lymphocytes and the surface marker CD46 acts as a co-receptor. Infection is followed by persistence and latency in different cells and organs including monocytes/macrophages, salivary glands, the brain and the kidneys. In this article we will discuss the clinical manifestations of HHV-6 infection in healthy children and the syndromes associated with HHV-6 reactivation in immunocompromised patients. Evidence of association between HHV-6 infection and different clinical entities such as multiple sclerosis, malignancy, infectious momononucleosis, drug hypersensitivity syndromes and skin eruptions is discussed. Published data on the use and efficacy of antiviral agents in complicated infections and infections in immunocompromised patients is presented.

Human herpesvirus 6: molecular biology and clinical features

Human herpesvirus 6 (HHV-6) exists as distinct variants HHV-6A and HHV-6B. The complete genomes of HHV-6A and HHV-6B have been sequenced. HHV-6B contains 97 unique genes. CD46 is the cell receptor for HHV-6, explaining its broad tissue tropism but its restricted host-species range. HHV-6 utilizes a number of strategies to down-regulate the host immune response, including molecular mimicry by production of a functional chemokine and chemokine receptors. Immunosuppression is enhanced by depletion of CD4 T lymphocytes via direct infection of intra-thymic progenitors and by apoptosis induction. Infection is widespread in infants between 6 months and 2 years of age. A minority of infants develop roseola infantum, but undifferentiated febrile illness is more common. Reactivation from latency occurs in immunocompromised hosts. Organ-specific clinical syndromes occasionally result, but indirect effects including interactions with other viruses such as human immunodeficiency virus type 1 and human cytomegalovirus or graft dysfunction in transplant recipients may be more significant complications in this population. Recent advances in quantitative PCR are providing additional insights into the natural history of infection in paediatric populations and immunocompromised hosts.

Detection of measles virus genomic RNA in tear samples from a patient with measles keratitis

PURPOSE

To report a case of measles keratitis, in which measles virus genomic RNA was detected in tear samples.

METHODS

Samples of tears and pharyngeal mucus were obtained from a 19-year-old man with active systemic measles on day 7 after illness onset. These specimens were then subjected to reverse-transcriptase polymerase chain reaction (RT-PCR), using measles-specific primers.

RESULTS

One week after systemic measles outbreak, the patient presented with a chief complaint of irritation in both eyes. Slit-lamp examination revealed bilateral superficial punctate keratopathy in the central cornea with small diffuse subepithelial infiltrations, and RT-PCR detected measles virus genomic RNA in tears and pharyngeal mucus. The patient was treated with topical 0.1% fluorometholone and 0.5% levofloxacin three times a day for 1 week, and the keratopathy resolved without sequelae.

CONCLUSION

This report demonstrates for the first time the presence of measles virus genomic RNA in the tears of a patient with measles keratitis. It also highlights the utility of RT-PCR for rapid detection of measles RNA in tear or mucus samples. Furthermore, the presence of virus in bodily fluids and secretions signifies the potential contagiousness of this type of keratopathy.

No evidence of acute Chlamydia pneumoniae infection in patients with Bell's palsy

The cause of Bell's palsy remains unknown even though available evidence suggests that infection could be a factor. In recent studies, Chlamydia pneumoniae has been associated with neurologic diseases such as multiple sclerosis. In the present study, the association of C pneumoniae with Bell's palsy was studied with the use of serology and polymerase chain reaction to test tear fluid and peripheral blood mononuclear cells from 21 patients with Bell's palsy and 21 control subjects. C pneumoniae DNA was detected from tear fluid samples in 1 patient with Bell's palsy and in 2 healthy control subjects. Whether this indicates earlier disease or subclinical infection remains to be studied. However, an association between Bell's palsy and acute C pneumoniae infection could not be shown.

Multiplex detection of herpesviruses in tear fluid using the "stair primers" PCR method: prospective study of 93 patients

Human herpesviruses can infect the eye and be excreted subsequently in tears. The aim of the present study was to use a multiplex PCR to detect herpesviruses (HSV-1, -2, VZV, CMV, EBV, HHV-6) in tears from normal subjects and from patients with pathological conditions (acute herpes, zoster, papillary conjunctivitis, and dry eye). Schirmer test strips were used to collect tear fluid from 93 patients, sampling both eyes. DNA was then extracted from the 186 samples by chromatography, and viral DNA amplified using a commercialised multiplex "stair primer" method. Thirty-four samples (18.3%) contained Taq inhibitors. The multiplex test gave positive results for HSV and VZV in tear fluid from patients with acute dendritic keratitis (3 patients) and acute ocular zoster (4 patients) and was, therefore, considered effective in testing samples from patients with acute lesions. HSV-1 and HSV-2 were found in two samples from patients with metaherpetic corneal scarring. Among 28 cases of dry eye, two were positive for HHV-6, the latter being associated with EBV in one patient. HHV-6 was also found in 4 out of 54 cases of papillary conjunctivitis. This raised occurrence of HHV-6 in dry eye or papillary conjunctivitis, suggests new clinical patterns for HHV-6 latency or reactivation. Detection of EBV in 1 out of 80 healthy eyes confirms previous evidence that lacrimal glands constitute potentially a site for latent-phase EBV.

Fifth (human parvovirus) and sixth (herpesvirus 6) diseases

Fifth (erythema infectiosum) and sixth (roseola infantum) diseases are common rash illnesses of childhood that have long been recognized in clinical medicine. The discovery of the viruses that cause these illnesses has revealed relationships with other syndromes. Primary infection with the agent of erythema infectiosum, human parvovirus B19, is associated with transient aplastic crisis in hemolytic anemia, arthropathy in adults, chronic anemia in immunocompromised patients, and nonimmune fetal hydrops in pregnant women. The only documented illness associated with primary infection with human herpesvirus 6 is roseola or exanthema subitum in young children. However, reactivated infections in adults and immunocompromised patients may be associated with serious illness such as encephalitis/encephalopathy, and bone marrow suppression leading to transplant failure or graft-versus-host disease. Diagnostic studies for both viruses have been limited, although reliable serologic tests for human parvovirus B19 have recently become available. Diagnosis of human herpesvirus 6 remains problematic, because current tests cannot differentiate primary from reactivated disease. This is more of an issue for the putative relationship of these viruses to more chronic conditions, such as rheumatologic disease for human parvovirus B19 and multiple sclerosis for human herpesvirus 6. The relationship between the viruses and these conditions remains controversial, and better diagnostic tests and further information on viral pathogenesis for both viruses are required in order to make a reliable judgment in this regard.

Human herpesvirus 6: its impact and influence on infectious diseases and their management

Human herpesvirus (HHV)-6 was discovered 15 years ago and was then grouped as a member of the family human herpesviridae. Its first clinical manifestation was identified 2 years later as the agent responsible for exanthem subitum. With the advent of newer molecular techniques, its diagnosis is easier and prospective studies have shown that it is the most common pathogen responsible for febrile illness in infants. In some infants, it is associated with febrile convulsions. Two subtypes, A and B, have been identified, B subtype commonly being responsible for primary infection in infants. Primary infection in healthy adults is rare. Most of the clinical manifestations are mild, self-limiting and rarely fatal. Reactivation of HHV-6 is frequently found in bone marrow as well as solid organ transplant recipients. HHV-6 has been shown to be an independent risk factor responsible for recurrence of cytomegalovirus infection, especially in solid organ transplants. In bone marrow transplant recipients, HHV-6 has been associated with various manifestations like marrow suppression and graft versus host disease, although most infections present as usually mild febrile illness with or without rash. It has been reported to cause encephalitis in transplant recipients. Although HHV-6 has been shown to be responsible for upregulation of HIV in vitro studies, its exact role in AIDS is yet to be defined. In addition to its neurotropic manifestation of febrile convulsion in infancy, it has been found in plaques in the brain of multiple sclerosis and progressive multifocal leukoencephalopathy. Further studies are needed before its role in the pathogenesis of these neurological illnesses can be established. Its lymphotropic feature was responsible for its discovery and now it has only been detected in some lesions of primary ocular mucosa associated lymphoid tissue lymphoma. As HHV-6 is found to be responsible for more and more illnesses, especially causing serious illnesses in the immunocompromised, it is becoming necessary to find effective treatment. Some agents, like cidofovir and phosphonoformic acid, are effective in in vitro studies and some have shown effectiveness in a clinical setting. Further studies are needed to identify its role in the pathogenesis of various neurological and malignant lesions and AIDS. Various treatment regimens should be tested in clinical scenario and especially in immunocompromised transplant recipients.