Rapid diagnosis of herpes simplex encephalitis by nested polymerase chain reaction assay of cerebrospinal fluid

Clinical characteristics and outcomes of patients with Herpes Simplex Encephalitis in Vietnam: a retrospective study

BACKGROUND

Herpes simplex encephalitis (HSE) is an important central nervous infection with severe neurological sequelae. The aim of this study was to describe clinical characteristic and outcomes of patients with HSE in Vietnam.

METHODS

This was a retrospective study of 66 patients with herpes simplex encephalitis who admitted to the National Hospital for Tropical Diseases, Hanoi, Vietnam from 2018 to 2021. The detection of herpes simplex virus (HSV) in cerebrospinal fluid was made by the real-time PCR assay. We reported the clinical manifestation on admission and evaluated clinical outcomes at the hospital discharge by modified Rankin Scale (mRS). Multivariate logistic regression analysis was used to analyze the independent risk factors of severe outcomes.

RESULTS

Of the 66 patients with laboratory confirmed HSE, the median age was 53 years (IQR 38-60) and 44 patients (69.7%) were male. The most common manifestations included fever (100%), followed by the consciousness disorder (95.5%). Other neurological manifestation were seizures (36.4%), memory disorders (31.8%), language disorders (19.7%) and behavioral disorders (13.6%). Conventional magnetic resonance imaging (MRI) showed 93.8% patients with temporal lobe lesions, followed by abnormalities in insula (50%), frontal lobe (34.4%) and 48.4% of patients had bilateral lesions. At discharge, 19 patients (28.8%) completely recovered, 15 patients (22.7%) had mild sequelae, 28 patients (42.4%) had moderate to severe sequelae. Severe neurological sequelae were memory disorders (55.8%), movement disorders (53.5%), language disorders (30.2%). Multivariate logistic regression analysis showed that Glasgow score decrement at admission, seizures, and time duration from onset of symptoms to the start of Acyclovir treatment > 4 days were independent factors associated with severe outcomes in HSE patients.

CONCLUSION

Glasgow score decrement, seizures and delay treatment with Acyclovir were associated with the poor outcome of patients with HSE.

Herpes simplex encephalitis in France: incidence, 6-month rehospitalizations and mortality

BACKGROUND

Herpes simplex encephalitis (HSE) is a disease with unfavorable vital and functional prognoses. There are no recent epidemiological data on HSE at a national level using real-life databases, especially in France. This study aimed to report the incidence, the clinical characteristics and outcomes of the patients with HSE.

METHODS

We conducted a comprehensive retrospective cohort study on all patients hospitalized for HSE in France between 2015 and 2022 using national hospital discharge databases. Incidence, socio-demographic and clinical characteristics (including comorbidities, seizure, stays' features, intensive care supports) were described. The short- (first stay) and long-term (6-month) outcomes were reported, in terms of mortality and rehospitalizations.

RESULTS

1425 HSE patients were included (median age 67 [54-77] years old, M/F sex ratio 1.07), giving a mean yearly hospital incidence of 2.3 [2.1-2.5] per 1,000,000 inhabitants. 51.2% of the patients were admitted in ICU (n = 730), of whom 59.0% were mechanically ventilated. The overall mortality during the first stay was 14.3% (n = 204), up to 17.9% for ICU patients. Within 6 months, among the survivors, 10.1% had at least one rehospitalization related to HSE. At 6 months, 16.5% of all patients had died (n = 235), 20.8% for ICU patients.

CONCLUSION

In France, the incidence of hospitalizations for HSE was 2.3 per 1,000,000 inhabitants with more than half of the patients admitted in ICU and a 6-month in-hospital mortality about 16.5%. This real-life update on the characteristics and severe outcomes of the disease raises awareness among care practitioners, of the serious nature of the disease, and thus can lead to higher vigilance.

Molecular diagnostics of infectious disease: Detection and characterization of microbial agents in cytology samples

BACKGROUND

Cytology samples are widely used to diagnose various infectious diseases by detection and identification of causative infectious agents, including bacteria, fungi, and viruses. The role of cytopathology in infectious disease has expanded tremendously in the past decades with the advances in molecular techniques. Molecular diagnostic methods, compared to conventional methods, have shown improved patient outcome, reduction in cost, and shortened hospital stay times. The aim of this article is to review molecular testing in cytology samples for diagnosis of infectious diseases.

METHODS

The literature search for molecular testing in common cytology samples for diagnosis of infectious diseases was performed. The findings of the studies were summarized. The common cytology samples included in this article were gynecologic specimens, cerebrospinal fluid, bronchoalveolar lavage, and urine samples.

CONCLUSIONS

There are a number of molecular diagnostic tests that are available to be used in common cytology samples to detect infectious agents. Each test has its own advantages and limitations. It is our hope that upon reading this review article, the readers will have better understanding of molecular diagnostic testing of infectious diseases utilizing commonly sampled cytology specimens in daily practice.

Viral and Prion Infections Associated with Central Nervous System Syndromes in Brazil

Virus-induced infections of the central nervous system (CNS) are among the most serious problems in public health and can be associated with high rates of morbidity and mortality, mainly in low- and middle-income countries, where these manifestations have been neglected. Typically, herpes simplex virus 1 and 2, varicella-zoster, and enterovirus are responsible for a high number of cases in immunocompetent hosts, whereas other herpesviruses (for example, cytomegalovirus) are the most common in immunocompromised individuals. Arboviruses have also been associated with outbreaks with a high burden of neurological disorders, such as the Zika virus epidemic in Brazil. There is a current lack of understanding in Brazil about the most common viruses involved in CNS infections. In this review, we briefly summarize the most recent studies and findings associated with the CNS, in addition to epidemiological data that provide extensive information on the circulation and diversity of the most common neuro-invasive viruses in Brazil. We also highlight important aspects of the prion-associated diseases. This review provides readers with better knowledge of virus-associated CNS infections. A deeper understanding of these infections will support the improvement of the current surveillance strategies to allow the timely monitoring of the emergence/re-emergence of neurotropic viruses.

Meningoencefalitis por herpes simple: una visión de la infección viral que causa el mayor compromiso cerebral

La inflamación del sistema nervioso central secundaria a la infección por la familia herpesviridae puede generar un compromiso difuso del parénquima encefálico, la cual puede ser fatal en ausencia de un rápido diagnóstico y tratamiento. Objetivo: revisar las diferentes características biológicas, fisiopatológicas, clínicas, terapéuticas y pronóstico de la meningoencefalitis causada por VHS-1 y 2. Materiales y métodos: revisión de la literatura científica (revisión crítica), llevada a cabo mediante las bases de datos Medline y buscadores específicos IMBIOMED, PUBMEDE, SCIENCEDIRECT, SCIELO, con un total de 150 artículos, se priorizaron 67 los cuales fueron leídos a profundidad. Resultados y discusión: debido el neurotropismo del herpes virus simple puede causar neuroinvasividad, neurotoxicidad y latencia en el SNC. Por sus características semiológicas inespecíficas se requiere un estudio exhaustivo para lograr el diagnóstico acertado. Los métodos actuales tales como neuroimágenes y PCR han aportado al esclarecimiento del diagnóstico etiológico de esta patología. La detección temprana de la entidad y la instauración precoz del tratamiento, se asocian con un aumento en la tasa de supervivencia y a una disminución de las secuelas neurológicas. Conclusión: conocer la biología del virus, su comportamiento, las características clínicas y el tratamiento de la entidad es una estrategia eficaz para disminuir secuelas y desenlaces fatales.

Improving sensitivity of single tube nested PCR to detect fastidious microorganisms

Single Tube Nested PCR (ST-nPCR) is of value to clinical laboratories with limited settings for the detection of fastidious microorganisms. The detection sensitivity of ST-nPCR is dependent on ensuring minimal leftovers of outer primers during the second round of the reaction. In this work, we investigated various approaches to optimize the performance of outer primers, including decreasing outer primer concentrations; using antisense oligonucleotides to block outer primers; using chemically modified inner primers; and using Q5 Taq polymerase that lacks 5′-3′ exonuclease and strand displacement capabilities. These solutions were tested on C. abortus and C. psittaci, which are both fastidious intracellular bacteria that are difficult to diagnose.

The best obtained result was by using Q5 Taq polymerase. A detection limit with a range between 0.1 and 1 ag was achieved, which corresponds to a range between 0.2 and 2 copies of the plasmid positive control. This level of sensitivity is comparable or even better than the sensitivity achieved by TaqMan probe based real-time PCR assays. The assay was validated using 70 veterinary clinical samples from small ruminant abortions and 10% of these samples gave positive results.

In conclusion, sensitivity of ST-nPCR to detect fastidious microorganisms can be improved by using Taq polymerases that lacks 5′-3′ exonuclease. The proposed assay is affordable and applicable to a wide range of fastidious pathogens and can be suitable for laboratories with limited settings.

Herpes Simplex Virus Encephalitis: Patterns of Epidemiology and Outcomes of Patients Admitted to the Intensive Care Unit in Texas, 2008 - 2016

Background

Patients with herpes simplex virus encephalitis (HSVE) often require admission to the intensive care unit (ICU) and have considerably worse outcomes than those not critically ill. The short-term outcomes of critically ill patients in the general population have markedly improved over the past decades. However, the population-level patterns of demand for critical care services among patients with HSVE have not been examined, and it is unknown whether there were corresponding outcome gains among those admitted to the ICU.

Methods

The Texas Inpatient Public Use Data File was used to identify hospitalizations with HSVE aged ≥ 18 years during 2008 - 2016. ICU admissions were identified using unit-specific revenue codes. The patterns of ICU utilization and those of short-term outcomes (with short-term mortality defined as in-hospital death or discharge to hospice) were examined across demographic strata and over time.

Results

Among 1,964 hospitalizations with HSVE, 1,176 (59.9%) were admitted to ICU (45.8% aged ≥ 65 years; 53.1% female, among ICU admissions). ICU utilization increased with age (from 47.9% (age 18 - 44 years) through 61.2% (older adults (age ≥ 65 years)); P = 0.0003 for trend), and increased over time only among older adults (odds ratio: 1.06/year (95% confidence interval (CI): 1.01 - 1.12)). Among ICU admissions, routine home discharge, transfer to a post-acute care facility, and short-term mortality occurred in 26.8%, 39.5%, and 18.7%, respectively; the corresponding outcomes for older adults were 10.6%, 51.4%, and 26.2%, respectively. The outcomes for the whole cohort of ICU admissions remained unchanged over time.

Conclusions

Adults with HSVE had high demand for critical care services, and those admitted to ICU had high short-term mortality and substantial residual morbidity among survivors, which remained unchanged over time. These findings can inform clinicians’ decision-making and discussions about goals of care with affected patients and their surrogates.

Hyponatremia Is Predictive of HSV-1 Encephalitis among Patients with Viral Encephalitis

Encephalitis is an inflammatory process involving the brain parenchyma associated with neurologic dysfunction. The main causes of infectious encephalitis are viruses, including Herpes simplex virus type 1 (HSV-1). As the mortality rate of HSV-1 encephalitis could be reduced with early acyclovir treatment, it is imperative to distinguish HSV-1 encephalitis from other type of viral encephalitis as early as possible. However, sophisticated methods for definitive diagnosis of HSV-1 encephalitis are not readily available. We aimed to explore distinctive clinical and laboratory features of HSV-1 encephalitis. All of the adult patients with viral encephalitis hospitalized between 2011-2017 were enrolled, including 16 patients with HSV-1 encephalitis and 51 patients non-HSV-1 viral encephalitis. Determination of viruses in cerebrospinal fluid was performed by PCR tests. Female sex, hyponatremia, and abnormalities in MRI were independently associated with HSV-1 encephalitis (p < 0.05 for each). In particular, hyponatremia (< 135 mEq/L) was found in nine patients with HSV-1 encephalitis (56.3%) and 10 patients with non-HSV-1 viral encephalitis (19.6%) (p = 0.005). As serum sodium is determined easily and quickly in clinical practice, the presence of hyponatremia among patients with viral encephalitis could be helpful for the early diagnosis of HSV-1 encephalitis before cerebrospinal fluid PCR results were available. Moreover, the presence of positive finding in MRI could further support the diagnosis. This is the first study that compared the serum sodium levels among patients between HSV-1 and non-HSV-1 viral encephalitis. We thus propose the diagnostic value of hyponatremia for HSV-1 encephalitis.

Diagnostic Testing of Neurologic Infections

Neuroinfectious diseases continue to cause morbidity and mortality worldwide, with many emerging or reemerging infections resulting in neurologic sequelae. Careful clinical evaluation coupled with appropriate laboratory investigations still forms the bedrock for making the correct etiologic diagnosis and implementing appropriate management. The treating physician needs to understand the individual test characteristics of each of the many conventional candidate-based diagnostics: culture, pathogen-specific polymerase chain reaction, antigen, antibody tests, used to diagnose the whole array of neuroinvasive infections. In addition, there is a growing need for more comprehensive, agnostic testing modalities that can identify a diversity of infections with a single assay.

A 20-Month-Old Girl With Fever, Seizures, Hemiparesis, and Brain Lesions Requiring a Diagnostic Brain Biopsy

We report a case of a 20-month-old girl with atypical presentation of a fairly common condition. She presented with acute onset of fever, seizures, and hemiparesis. Her cerebrospinal fluid showed total nucleated cells 10/mm³ with lymphocyte dominance. Polymerase chain reaction was negative for herpes simplex virus. Computed tomography of head showed a cerebral hemorrhage of the left frontal lobe and small subarachnoid hemorrhage in the right frontal region. Brain magnetic resonance imaging revealed multiple foci of hyperintensity in bilateral parietal lobes and right basal ganglia. She remained clinically stable without a specific therapy. Her diagnosis was made after a brain biopsy.

Viral meningitis: current issues in diagnosis and treatment

PURPOSE OF REVIEW

The purpose of this review is to give an overview of viral meningitis and then focus in on some of the areas of uncertainty in diagnostics, treatment and outcome.

RECENT FINDINGS

Bacterial meningitis has been declining in incidence over recent years. Over a similar time period molecular diagnostics have increasingly been used. Because of both of these developments viral meningitis is becoming relatively more important. However, there are still many unanswered questions. Despite improvements in diagnostics many laboratories do not use molecular methods and even when they are used many cases still remain without a proven viral aetiology identified. There are also no established treatments for viral meningitis and the one potential treatment, aciclovir, which is effective in vitro for herpes simplex virus, has never been subjected to a clinical trial.

SUMMARY

Viruses are in increasingly important cause of meningitis in the era of declining bacterial disease. The exact viral aetiology varies according to age and country. Molecular diagnostics can not only improve the rate of pathogen detection but also reduce unnecessary antibiotics use and length of hospitalization. Further research is required into treatments for viral meningitis and the impact in terms of longer term sequelae.

Neurological Disorders Associated with Human Alphaherpesviruses

Herpes simplex virus (HSV) encephalitis is the most common cause of sporadic fatal encephalitis worldwide, and central nervous system (CNS) involvement is observed in approximately one-third of neonatal HSV infections . In recent years, single-gene inborn errors of innate immunity have been shown to be associated with susceptibility to HSV encephalitis . Temporal lobe abnormalities revealed by magnetic resonance imaging-the most sensitive imaging method for HSV encephalitis-are considered strong evidence for the disease. Detection of HSV DNA in the cerebrospinal fluid by polymerase chain reaction (PCR) is the gold standard for the diagnosis of HSV encephalitis and neonatal meningoencephalitis. Intravenous acyclovir for 14-21 days is the standard treatment in HSV encephalitis. Neurological outcomes in neonates are improved by intravenous high-dose acyclovir for 21 days followed by oral acyclovir suppressive therapy for 6 months. Varicella-zoster virus (VZV) causes a wide range of CNS manifestations. VZV encephalitis typically occurs after primary infection, and reactivation of VZV may cause encephalitis. On the other hand, VZV infection of cerebral arteries produces vasculopathy, which can manifest as ischemic stroke. Vasculopathy can occur after primary infection or reactivation of VZV. PCR detection of VZV DNA in the cerebrospinal fluid can be used for the diagnosis of encephalitis or vasculopathy. Although there are no controlled treatment trials to assess VZV treatments of encephalitis or vasculopathy, intravenous acyclovir is a common treatment.

Molecular Microbiology

Background

Nucleic acid (NA) amplification techniques are now commonly used to diagnose and manage patients with infectious diseases. The growth in the number of Food and Drug Administration–approved test kits and analyte-specific reagents has facilitated the use of this technology in clinical laboratories. Technological advances in NA amplification techniques, automation, NA sequencing, and multiplex analysis have reinvigorated the field and created new opportunities for growth. Simple, sample-in, answer-out molecular test systems are now widely available that can be deployed in a variety of laboratory and clinical settings. Molecular microbiology remains the leading area in molecular pathology in terms of both the numbers of tests performed and clinical relevance. NA-based tests have reduced the dependency of the clinical microbiology laboratory on more traditional antigen detection and culture methods and created new opportunities for the laboratory to impact patient care.

Content

This chapter reviews NA testing as it applies to specific pathogens or infectious disease syndromes, with a focus on those diseases for which NA testing is now considered the standard of care and highlights the unique challenges and opportunities that these tests present for clinical laboratories.

Experimental Oral Herpes Simplex Virus-1 (HSV-1) Co-infection in Simian Immunodeficiency Virus (SIV)-Infected Rhesus Macaques

Herpes simplex virus 1 and 2 (HSV-1/2) similarly initiate infection in mucosal epithelia and establish lifelong neuronal latency. Anogenital HSV-2 infection augments the risk for sexual human immunodeficiency virus (HIV) transmission and is associated with higher HIV viral loads. However, whether oral HSV-1 infection contributes to oral HIV susceptibility, viremia, or oral complications of HIV infection is unknown. Appropriate non-human primate (NHP) models would facilitate this investigation, yet there are no published studies of HSV-1/SIV co-infection in NHPs. Thus, we performed a pilot study for an oral HSV-1 infection model in SIV-infected rhesus macaques to describe the feasibility of the modeling and resultant immunological changes. Three SIV-infected, clinically healthy macaques became HSV-1-infected by inoculation with 4 × 108 pfu HSV-1 McKrae on buccal, tongue, gingiva, and tonsils after gentle abrasion. HSV-1 DNA was shed in oral swabs for up to 21 days, and shedding recurred in association with intra-oral lesions after periods of no shedding during 56 days of follow up. HSV-1 DNA was detected in explant cultures of trigeminal ganglia collected at euthanasia on day 56. In the macaque with lowest baseline SIV viremia, SIV plasma RNA increased following HSV-1 infection. One macaque exhibited an acute pro-inflammatory response, and all three animals experienced T cell activation and mobilization in blood. However, T cell and antibody responses to HSV-1 were low and atypical. Through rigorous assessesments, this study finds that the virulent HSV-1 strain McKrae resulted in a low level HSV-1 infection that elicited modest immune responses and transiently modulated SIV infection.

Radiotherapy-induced reactivation of neurotrophic human herpes viruses: Overview and management

PURPOSE

Infection by Human Herpes Viruses (HHV) types 1-3, are prevalent throughout the world. It is known that radiotherapy can reactivate HHVs, but it is unclear how and to what extent reactivations can interact with or affect radiotherapeutic efficacy, patient outcomes and mortality risk. Herein, we aim to summarize what is known about Herpes Simplex Virus (HSV)-1,2 and Varicella Zoster Virus (VZV) pathophysiology as it relates to tumor biology, radiotherapy, chemo-radiotherapy, diagnosis and management so as to optimize cancer treatment in the setting of active HHV infection. Our secondary aim is to emphasize the need for further research to elucidate the potential adverse effects of active HHV infection in irradiated tumor tissue and to design optimal management strategies to incorporate into cancer management guidelines.

MATERIALS AND METHODS

The literature regarding herpetic infection, herpetic reactivation, and recurrence occurring during radiotherapy and that regarding treatment guidelines for herpetic infections are reviewed. We aim to provide the oncologist with a reference for the infectious dangers of herpetic reactivation in patients under their care and well established methods for prevention, diagnosis, and treatment of such infections. Pain management is also considered.

CONCLUSIONS

In the radiotherapeutic setting, serologic assays for HSV-1 and HSV-2 are feasible and can alert the clinician to patients at risk for viral reactivation. RT-PCR is specific in identifying the exact viral culprit and is the preferred diagnostic method to measure interventional efficacy. It can also differentiate between herpetic infection and radionecrosis. The MicroTrak^® HSV1/HSV2/VZV staining kit has high sensitivity and specificity in acute lesions, is also the most rapid means to confirm diagnosis. Herpetic reactivation and recurrences during radiotherapy can cause interruptions, cessations, or prolongations of the radiotherapeutic course, thus decreasing the biologically effective dose, to sub-therapeutic levels. Active HHV infection within the treatment volume results in increased tumor radio-resistance and potentially sub-therapeutic care if left untreated. Visceral reactivations may result in fatality and therefore, a high index of suspicion is important to identify these active infections. The fact that such infections may be mistaken for acute and/or late radiation effects, leading to less than optimal treatment decisions, makes knowledge of this problem even more relevant. To minimize the risk of these sequelae, prompt anti-viral therapy is recommended, lasting the course of radiotherapy.

Prevalence of herpes simplex virus types 1 and 2 at maternal and fetal sides of the placenta in asymptomatic pregnant women

PROBLEM

Herpes simplex virus 1 (HSV-1) commonly causes orolabial infection, but can also infect the genital mucosa. In contrast, HSV-2 is usually genital. Genital herpes can transmit the virus vertically to the fetus during pregnancy. We sought to estimate the prevalence of HSV-1/2 on the maternal and fetal sides of the placenta.

METHOD OF STUDY

Placental tissues were collected from pregnant women seen at the Rio Grande University Hospital. HSV-1 and HSV-2 were detected by nested PCR.

RESULTS

The prevalence of HSV-1 and HSV-2 was, respectively, 28% and 12.6% (maternal side) and 29.9% and 8.3% (fetal side). All HSV-positive women were asymptomatic. Sexual behavior, vaginal delivery, and presence of HSVs on one side of the placenta were risk factors associated with HSV infection.

CONCLUSION

The occurrence of HSVs in placental tissue was high, especially for HSV-1. Novel strategies need to be implemented for the management of asymptomatic women who might transmit HSV to their newborns.

Varicella zoster virus vasculopathy: The expanding clinical spectrum and pathogenesis

Varicella zoster virus (VZV) is a ubiquitous, human alphaherpesvirus that produces varicella on primary infection then becomes latent in ganglionic neurons along the entire neuraxis. In elderly and immunocompromised individuals, VZV reactivates and travels along nerve fibers peripherally resulting in zoster. However, VZV can also spread centrally and infect cerebral and extracranial arteries (VZV vasculopathy) to produce transient ischemic attacks, stroke, aneurysm, sinus thrombosis and giant cell arteritis, as well as granulomatous aortitis. The mechanisms of virus-induced pathological vascular remodeling are not fully elucidated; however, recent studies suggest that inflammation and dysregulation of programmed death ligand-1 play a significant role.

Impact of a Rapid Herpes Simplex Virus PCR Assay on Duration of Acyclovir Therapy

Herpes simplex virus (HSV) infections of the central nervous system (CNS) are associated with significant morbidity and mortality rates in children. This study assessed the impact of a direct HSV (dHSV) PCR assay on the time to result reporting and the duration of acyclovir therapy for children with signs and symptoms of meningitis and encephalitis. A total of 363 patients with HSV PCR results from cerebrospinal fluid (CSF) samples were included in this retrospective analysis, divided into preimplementation and postimplementation groups. For the preimplementation group, CSF testing was performed using a laboratory-developed real-time PCR assay; for the postimplementation group, CSF samples were tested using a direct sample-to-answer assay. All CSF samples were negative for HSV. Over 60% of patients from both groups were prescribed acyclovir. The average HSV PCR test turnaround time for the postimplementation group was reduced by 14.5 h (23.6 h versus 9.1 h; P < 0.001). Furthermore, 79 patients (43.6%) in the postimplementation group had dHSV PCR results reported <4 h after specimen collection. The mean time from specimen collection to acyclovir discontinuation was 17.1 h shorter in the postimplementation group (31.1 h versus 14 h; P < 0.001). The median duration of acyclovir therapy was also significantly reduced in the postimplementation group (29.2 h versus 14.3 h; P = 0.01). Our investigation suggests that implementation of rapid HSV PCR testing can decrease turnaround times and the duration of unnecessary acyclovir therapy.

Herpes Simplex Encephalitis: an Update

PURPOSE OF REVIEW

The goal of this review is to provide an update on current thinking regarding herpes simplex encephalitis (HSE), emphasizing new information about pathogenesis, diagnosis, and immune responses. Specific questions to be addressed are the following: (1) Is there a genetic predisposition to HSE? (2) What clinical approaches have the greatest impact on improving the long-term outcomes in patients with HSE? And (3) are there immune-mediated mechanisms that may account for relapsing HSE?

RECENT FINDINGS

Toll-like receptor 3 (TLR 3) plays an important role in innate immune responses, including generation of interferons. Multiple single-gene errors in TLR 3 interferon pathways have recently been described in children that result in increased susceptibility to HSE. Conversely, studies in both animal models and humans indicate that both cytolytic viral replication and immune-mediated responses (including cytotoxic T lymphocytes and immune mechanisms mediated by TLR 2) contribute to the pathology of HSV, suggesting possible new therapeutic approaches. In terms of treatment, data clearly indicate that a longer duration between onset of symptoms and initiation of effective antiviral therapy correlates directly with less favorable clinical outcome. Recurrent or relapsing HSE may occasionally occur, but recent observations indicate that many instances of "relapsing HSE", especially in children, are more often anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis triggered by the antecedent HSV infection. Innate immune responses are critical for defense against HSV; genetic defects in this system may predispose patients to HSE. During acute HSE, exuberant immune responses may contribute to the CNS pathology, suggesting that selective immunosuppressive therapy, coupled with potent antiviral drugs, may eventually play a role in the therapeutic management of HSV. While overall clinical outcomes of HSE remain suboptimal, the initiation of high-dose acyclovir therapy as early as possible in the course of the illness provides the best chance for a patient to survive with minimal neurologic damage. Distinguishing relapsing HSE from autoimmune anti-NMDAR antibody encephalitis is critically important because therapeutic approaches will be very different.

The Case for Laboratory Developed Procedures: Quality and Positive Impact on Patient Care

An explosion of knowledge and technology is revolutionizing medicine and patient care. Novel testing must be brought to the clinic with safety and accuracy, but also in a timely and cost-effective manner, so that patients can benefit and laboratories can offer testing consistent with current guidelines. Under the oversight provided by the Clinical Laboratory Improvement Amendments, laboratories have been able to develop and optimize laboratory procedures for use in-house. Quality improvement programs, interlaboratory comparisons, and the ability of laboratories to adjust assays as needed to improve results, utilize new sample types, or incorporate new mutations, information, or technologies are positive aspects of Clinical Laboratory Improvement Amendments oversight of laboratory-developed procedures. Laboratories have a long history of successful service to patients operating under Clinical Laboratory Improvement Amendments. A series of detailed clinical examples illustrating the quality and positive impact of laboratory-developed procedures on patient care is provided. These examples also demonstrate how Clinical Laboratory Improvement Amendments oversight ensures accurate, reliable, and reproducible testing in clinical laboratories.

Review of Viral Encephalitis Cases Seen at a Tertiary Care Center in Turkey: Focus on Herpes Simplex Type 1

INTRODUCTION

The objective of this study was to determine the incidence of herpes simplex encephalitis (HSE), known as the most common, potentially mortal, and treatable cause of sporadic encephalitis, in a sample Turkish population.

METHODS

The demographic, clinical, laboratory, imaging, electrophysiology, and polymerase chain reaction (PCR) DNA results of patients examined with a pre-diagnosis of encephalitis were retrospectively examined.

RESULTS

A total of 68 patients were included in the study. The most common presenting symptom was altered behavior (67.6%), while temporal T2 hyperintensity was determined in the magnetic resonance imaging (MRI) of 27.9% of the patients and electroencephalography (EEG) abnormalities were determined in 66.2% of the patients. Lymphocytic pleocytosis was determined in the cerebrospinal fluid (CSF) in 35 patients. Fifty-seven patients had been diagnosed with viral encephalitis, 3 with bacterial meningitis, 3 with tuberculous meningitis, 2 with sporadic Creutzfeld-Jakob disease, 2 with acute disseminating encephalomyelitis, and 1 with Brucella encephalitis. Seven (10.2%) cases of viral encephalitis were found to be positive for herpes simplex virus (HSV) DNA by PCR.

CONCLUSION

Viral encephalitis is the most common cause of infectious encephalitis; however, other atypical causes should also be noted. Negative PCR results for HSV DNA should not exclude the need for antiviral therapy in patients with a strong pre-diagnosis of HSE because diagnostic modalities, including PCR, may fail in acute settings and HSE remains the sole treatable cause of infectious encephalitis.

Genomics Basics: DNA Structure, Gene Expression, Cloning, Genetic Mapping, and Molecular Tests

Genomics is the study of the structure and function of the human genome including genes and their surrounding DNA sequences. The over 3 billion base pairs of the human genome have now been sequenced and approximately 25 000 genes acknowledged. However, only 1% of the entire genome has been assigned to protein coding and decades more work is anticipated to define the functional relevance of noncoding DNA as well as the basis and consequences of sequence variations among individuals. For medical scientists, the focus remains on discovering both disease-causing and disease-susceptibility genes. For pharmaceutical companies, the opportunity to develop molecularly targeted therapy is not going unnoticed. For the practicing physician, the prospect of genomic medicine that incorporates molecular diagnosis and pathogenesis-targeted therapy requires basic understanding of terminology and concepts in molecular biology and the corresponding laboratory tests.

Clinical Trials in Neurovirology: Successes, Challenges, and Pitfalls

Clinical trials in neurovirology illustrate the special challenges confronting investigators planning to study these conditions, as well as the contributions of successful trials in establishing appropriate management for these devastating diseases. This article reviews key examples of progress in neurovirology that have been spurred by clinical trials, emphasizing human herpes virus encephalitis, HIV, and JC virus. Clinical trials in the setting of neurovirological diseases are characterized by specific challenges, which may include small sample sizes, clinical presentations from life-threatening conditions to chronic courses of disease, regional and temporally restricted outbreaks scenarios, and the unavailability of validated diagnostic tests that can be rapidly deployed at the bedside. This review aims to highlight these methodological challenges and pitfalls in designing and executing clinical neurovirology trials, as well as to outline innovative trial designs, which could be useful in addressing common challenges.

Detection of Herpes Simplex and Varicella-Zoster Viruses in Patients with Bell's Palsy by the Polymerase Chain Reaction Technique

Objectives:

Infectious causes of peripheral facial paralysis are well known. Bell's palsy, however, is an idiopathic facial paralysis, and the genesis is still unknown. Herpes simplex virus type 1 (HSV-1) and varicella-zoster virus (VZV) have been suggested as etiologic agents.

Methods:

Twenty consecutive adult patients with Bell's palsy were included in the study. Ten adult patients operated on for chronic otitis served as controls. A biopsy specimen from the posterior auricular muscle was resected within 72 hours after the onset of Bell's palsy and was analyzed together with cerebrospinal fluid (CSF) by nested polymerase chain reaction for HSV-1 and VZV DNA. Serum samples were analyzed for antibodies to HSV-1 and VZV.

Results:

HSV-1 DNA was found in the muscle biopsy specimen from 1 of the 20 patients, but was not found in any of the CSF samples. VZV DNA was detected in the muscle biopsy as well as the CSF from 1 other patient. All controls were negative. Seventeen of 19 patients had stationary serum antibody concentrations to HSV-1, and none displayed an antibody titer rise. A significant antibody titer rise to VZV was found in 1 of 19 patients, whereas 17 of 19 had stationary antibody levels.

Conclusions:

HSV-1 or VZV DNA was detected in 10% of patients with Bell's palsy in the present study. Viral replication might already have declined in many cases at the onset of the palsy. Use of an HSV-1/VZV polymerase chain reaction on a muscle biopsy specimen or CSF does not seem to be the method of choice for rapid etiologic diagnosis in the acute phase of Bell's palsy.

Genital Herpes: Management Issues for the Next Century

Genital herpes (GH) is caused by herpes simplex virus (HSV) types 1 and 2. HSV-2 is more commonly the causal agent, and is responsible for 98% of recurrences. A first episode may become clinically apparent within 2–21 days post-infection. Symptomatic recurrences present as vesiculo-ulcerative lesions, which typically resolve within 5 days. The overall recurrence rate for GH is 60–90%. Asymptomatic shedding occurs in both sexes on 1–5% of days. Aciclovir, famciclovir and valaciclovir are the approved drugs for GH, and one of these should be used in all first episodes. Episodic treatment is often used where recurrences are infrequent and easily recognized. Oral treatment with famciclovir, aciclovir or valaciclovir reduces the duration of lesions, viral shedding and uncomfortable symptoms. Patients with frequent or problematic recurrences are candidates for prophylaxis with antivirals which suppress both symptomatic and asymptomatic reactivation. A herpes diagnosis often leaves patients emotionally vulnerable, concerned about asymptomatic shedding and fearful of transmission to sexual partners. GH can be devastating, occasionally leading to clinical depression and/or suicidal ideation. Patients commonly fear discussing GH with their physician or partners, but doing so is vitally important for their psychological health. Counselling to assist in this process is helpful. In summary, good management of GH requires careful attention to proper diagnosis and therapy, with psychosocial intervention: all three provided in the context of accurate information.

Von Willebrand Factor Gene Variants Associate with Herpes simplex Encephalitis

Herpes simplex encephalitis (HSE) is a rare complication of Herpes simplex virus type-1 infection. It results in severe parenchymal damage in the brain. Although viral latency in neurons is very common in the population, it remains unclear why certain individuals develop HSE. Here we explore potential host genetic variants predisposing to HSE. In order to investigate this we used a rat HSE model comparing the HSE susceptible SHR (Spontaneously Hypertensive Rats) with the asymptomatic infection of BN (Brown Norway). Notably, both strains have HSV-1 spread to the CNS at four days after infection. A genome wide linkage analysis of 29 infected HXB/BXH RILs (recombinant inbred lines-generated from the prior two strains), displayed variable susceptibility to HSE enabling the definition of a significant QTL (quantitative trait locus) named Hse6 towards the end of chromosome 4 (160.89-174Mb) containing the Vwf (von Willebrand factor) gene. This was the only gene in the QTL with both cis-regulation in the brain and included several non-synonymous SNPs (single nucleotide polymorphism). Intriguingly, in human chromosome 12 several SNPs within the intronic region between exon 43 and 44 of the VWF gene were associated with human HSE pathogenesis. In particular, rs917859 is nominally associated with an odds ratio of 1.5 (95% CI 1.11-2.02; p-value = 0.008) after genotyping in 115 HSE cases and 428 controls. Although there are possibly several genetic and environmental factors involved in development of HSE, our study identifies variants of the VWF gene as candidates for susceptibility in experimental and human HSE.

Managing atypical and typical herpetic central nervous system infections: results of a multinational study

There have been many studies pertaining to the management of herpetic meningoencephalitis (HME), but the majority of them have focussed on virologically unconfirmed cases or included only small sample sizes. We have conducted a multicentre study aimed at providing management strategies for HME. Overall, 501 adult patients with PCR-proven HME were included retrospectively from 35 referral centres in 10 countries; 496 patients were found to be eligible for the analysis. Cerebrospinal fluid (CSF) analysis using a PCR assay yielded herpes simplex virus (HSV)-1 DNA in 351 patients (70.8%), HSV-2 DNA in 83 patients (16.7%) and undefined HSV DNA type in 62 patients (12.5%). A total of 379 patients (76.4%) had at least one of the specified characteristics of encephalitis, and we placed these patients into the encephalitis presentation group. The remaining 117 patients (23.6%) had none of these findings, and these patients were placed in the nonencephalitis presentation group. Abnormalities suggestive of encephalitis were detected in magnetic resonance imaging (MRI) in 83.9% of the patients and in electroencephalography (EEG) in 91.0% of patients in the encephalitis presentation group. In the nonencephalitis presentation group, MRI and EEG data were suggestive of encephalitis in 33.3 and 61.9% of patients, respectively. However, the concomitant use of MRI and EEG indicated encephalitis in 96.3 and 87.5% of the cases with and without encephalitic clinical presentation, respectively. Considering the subtle nature of HME, CSF HSV PCR, EEG and MRI data should be collected for all patients with a central nervous system infection.

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

Recurrent Herpes Simplex Virus Encephalitis After Neurologic Surgery

BACKGROUND

The herpes simplex virus (HSV) is the most common cause of sporadic encephalitis worldwide. Even with proper treatment, this infection is associated with a mortality rate of 19%-30% and with potential neurologic sequelae. Recurrences of encephalitis are rare and limited to a few cases in the literature. Although the mechanism of reactivation has not yet been clarified, in our patient, the surgery might have acted as a precipitating factor.

CASE DESCRIPTION

The case involved a female 10-year-old patient with a history of type 1 HSV encephalitis since 24 months of age. Secondarily, the patient developed postherpetic epilepsy in the following years. At 10 years old, she was referred to the epilepsy surgery service, and an elective right temporal lobectomy was performed. After surgery, the patient experienced severe clinical deterioration characterized by fever, severe headache, and altered state of consciousness. Encephalitis was diagnosed based on a positive polymerase chain reaction for HSV in the cerebrospinal fluid. The symptoms remitted after 8 weeks of treatment with acyclovir. The histopathologic diagnosis was a chronic encephalitic process with late secondary parenchymal changes without specific viral cytopathic findings. The only limitation that persisted was related to fine movements of the left hand. One year after surgery, the patient rejoined her school activities and is currently free of seizures.

CONCLUSIONS

HSV encephalitis is a rare but serious complication that should be suspected in cases of unexplained postoperative fever with altered consciousness, especially in patients with histories of encephalitic states.

Herpes Simplex Encephalitis: Lack of Clinical Benefit of Long-term Valacyclovir Therapy

BACKGROUND

Despite the proven efficacy of acyclovir (ACV) therapy, herpes simplex encephalitis (HSE) continues to cause substantial morbidity and mortality. Among patients with HSE treated with ACV, the mortality rate is approximately 14%-19%. Among survivors, 45%-60% have neuropsychological sequelae at 1 year. Thus, improving therapeutic approaches to HSE remains a high priority.

METHODS

Following completion of a standard course of intravenous ACV, 87 adult patients with HSE (confirmed by positive polymerase chain reaction [PCR] for herpes simplex virus DNA in cerebrospinal fluid) were randomized to receive either valacyclovir (VACV) 2 g thrice daily (n = 40) or placebo tablets (n = 47) for 90 days (12 tablets of study medication daily). The primary endpoint was survival with no or mild neuropsychological impairment at 12 months, as measured by the Mattis Dementia Rating Scale (MDRS). Logistic regression was utilized to assess factors related to the primary endpoint.

RESULTS

The demographic characteristics of the 2 randomization groups were statistically similar with no significant differences in age, sex, or race. At 12 months, there was no significant difference in the MDRS scoring for VACV-treated vs placebo recipients, with 85.7% and 90.2%, respectively, of patients demonstrating no or mild neuropsychological impairment (P = .72). No significant study-related adverse events were encountered in either treatment group.

CONCLUSIONS

Following standard treatment with intravenous ACV for PCR-confirmed HSE, an additional 3-month course of oral VACV therapy did not provide added benefit as measured by neuropsychological testing 12 months later in a population of relatively high-functioning survivors.

CLINICAL TRIALS REGISTRATION

NCT00031486.

Reactivation of herpes simplex type 1 in pneumococcal meningitis

BACKGROUND

Acute bacterial meningitis (ABM) and herpes simplex type 1 (HSV-1) encephalitis are two rare but serious infections affecting the central nervous system (CNS). Concurrent bacterial and viral CNS infection has occasionally been reported.

OBJECTIVES

To illustrate the possibility of intrathecal infection with both Streptococcus pneumonia and HSV-1 by presenting a case and to examine whether herpesvirus reactivation is common in ABM.

STUDY DESIGN

We report a case diagnosed with HSV-1 reactivation in the cerebrospinal fluid (CSF) during treatment for pneumococcal ABM. A retrospective analysis of CSF samples from 21 patients with ABM was performed, with analysis of DNA from HSV-1 and four other neurotropic herpesviruses.

RESULTS

All 21CSF samples were negative for HSV-1, HSV-2, varicella zoster-virus, Epstein-Barr virus and human herpesvirus 6 DNA by PCR.

CONCLUSIONS

Although herpesvirus infection does not seem to be a common phenomenon in ABM we suggest that HSV-1 reactivation could be kept in mind if patients with ABM show symptoms or signs compatible with encephalitis.

Microfluidic vapor-diffusion barrier for pressure reduction in fully closed PCR modules

Microfluidic systems for polymerase chain reaction (PCR) should be fully closed to avoid vapor loss and to exclude the risk of contaminating the laboratory environment. In closed systems however, the high temperatures of up to 95 °C associated with PCR cause high overpressures up to 100 kPa, dominated by the increase of vapor partial pressure upon evaporation. Such high overpressures pose challenges to the mechanical stability of microfluidic chips as well as to the liquid handling in integrated sample-to-answer systems. In this work, we drastically reduce the pressure increase in fully closed PCR systems by integrating a microchannel that serves as a vapor-diffusion barrier (VDB), separating the liquid-filled PCR chamber from an auxiliary air chamber. In such configurations, propagation of vapor from the PCR chamber into the auxiliary air chamber and as a consequence the increase of pressure is limited by the slow diffusion process of vapor through the VDB. At temperature increase from 23 °C to 95 °C, we demonstrate the reduction of overpressure from more than 80 kPa without the VDB to only 35 kPa with the VDB. We further demonstrate proper function of VDB and its easy integration with downstream processes for PCR based nucleic acid amplification within centrifugal microfluidics. Without integration of the VDB, malfunction due to pressure-induced delamination of the microfluidic chip occurred.

Rapid and fully automated bacterial pathogen detection on a centrifugal-microfluidic LabDisk using highly sensitive nested PCR with integrated sample preparation

Diagnosis of infectious diseases suffers from long turnaround times for gold standard culture-based identification of bacterial pathogens, therefore impeding timely specific antimicrobial treatment based on laboratory evidence. Rapid molecular diagnostics-based technologies enable detection of microorganisms within hours however cumbersome workflows and complex equipment still prevent their widespread use in the routine clinical microbiology setting. We developed a centrifugal-microfluidic "LabDisk" system for rapid and highly-sensitive pathogen detection on a point-of-care analyser. The unit-use LabDisk with pre-stored reagents features fully automated and integrated DNA extraction, consensus multiplex PCR pre-amplification and geometrically-multiplexed species-specific real-time PCR. Processing merely requires loading of the sample and DNA extraction reagents with minimal hands-on time of approximately 5 min. We demonstrate detection of as few as 3 colony-forming-units (cfu) of Staphylococcus warneri, 200 cfu of Streptococcus agalactiae, 5 cfu of Escherichia coli and 2 cfu of Haemophilus influenzae in a 200 μL serum sample. The turnaround time of the complete analysis from "sample-to-result" was 3 h and 45 min. The LabDisk consequently provides an easy-to-use molecular diagnostic platform for rapid and highly-sensitive detection of bacterial pathogens without requiring major hands-on time and complex laboratory instrumentation.

Herpes simplex encephalitis in Iceland 1987-2011

Herpes simplex encephalitis (HSE) is a serious disease with 10-20% mortality and high rate of neuropsychiatric sequelae. This study is a long-term, nationwide study in a single country, Iceland. Clinical data were obtained from patient records and from DNA PCR and antibody assays of CSF. Diagnosis of HSE was classified as definite, possible or rejected based on symptoms, as well as virological, laboratory and brain imaging criteria. A total of 30 definite cases of HSE were identified during the 25 year period 1987-2011 corresponding to incidence of 4.3 cases/106 inhabitants/year. Males were 57% of all patients, median age 50 years (range, 0-85). Fever (97%), cognitive deficits (79%), impaired consciousness (79% with GCS < 13), headache (55%) and seizures (55%) were the most common symptoms. Brain lesions were found in 24 patients (80%) by MRI or CT. All patients received intravenous acyclovir for a mean duration of 20 days. Three patients (10%) died within one year and 21/28 pts (75%) had a Karnofsky performance score of <70% with memory loss (59%), dysphasia (44%), frontal symptoms (44%) and seizures (30%) as the most frequent sequelae. Mean delay from onset of symptoms to treatment was 6 days; this was associated with adverse outcome. In conclusion, the incidence of `HSE is higher than recently reported in a national registry study from Sweden. Despite advances in rapid diagnosis and availability of treatment of HSE, approximately three of every four patients die or are left with serious neurological impairment.

Prevalence of herpes simplex virus type 2 and risk factors associated with this infection in women in southern Brazil

SUMMARY

The herpes simplex virus type 2 (HVS-2) is the most prevalent infection worldwide. It is a cofactor in the acquisition of human immunodeficiency virus (HIV) and the persistence of human papillomavirus (HPV). This study evaluated the prevalence of HSV-2, using the polymerase chain reaction (PCR), and associated factors in patients treated at the Federal University of Rio Grande (FURG) and Basic Health Units (BHU) in Rio Grande, Brazil. The observed prevalence of HSV-2 was 15.6%. Among the 302 women studied, 158 had received assistance in BHU and 144 were treated at FURG. The prevalence of HSV-2 in these groups was 10.8% and 20.8%, respectively, RR 1.9 and p = 0.012. Knowledge about the Pap smear, and the presence of lesions showed no association with HSV-2 infection. Multivariate analysis showed that the variable that most influenced the risk of HSV-2 infection was the presence of HIV infection, with a relative risk of 1.9 and p = 0.04. Discussion: Genital ulcers are an important entry point for HIV, and condom use is an important strategy to reduce transmission of HIV and HSV-2.

Characterization of neuronal populations in the human trigeminal ganglion and their association with latent herpes simplex virus-1 infection

Following primary infection Herpes simplex virus-1 (HSV-1) establishes lifelong latency in the neurons of human sensory ganglia. Upon reactivation HSV-1 can cause neurological diseases such as facial palsy, vestibular neuritis or encephalitis. Certain populations of sensory neurons have been shown to be more susceptible to latent infection in the animal model, but this has not been addressed in human tissue. In the present study, trigeminal ganglion (TG) neurons expressing six neuronal marker proteins were characterized, based on staining with antibodies against the GDNF family ligand receptor Ret, the high-affinity nerve growth factor receptor TrkA, neuronal nitric oxide synthase (nNOS), the antibody RT97 against 200kDa neurofilament, calcitonin gene-related peptide and peripherin. The frequencies of marker-positive neurons and their average neuronal sizes were assessed, with TrkA-positive (61.82%) neurons being the most abundant, and Ret-positive (26.93%) the least prevalent. Neurons positive with the antibody RT97 (1253 µm²) were the largest, and those stained against peripherin (884 µm²) were the smallest. Dual immunofluorescence revealed at least a 4.5% overlap for every tested marker combination, with overlap for the combinations TrkA/Ret, TrkA/RT97 and Ret/nNOS lower, and the overlap between Ret/CGRP being higher than would be expected by chance. With respect to latent HSV-1 infection, latency associated transcripts (LAT) were detected using in situ hybridization (ISH) in neurons expressing each of the marker proteins. In contrast to the mouse model, co-localization with neuronal markers Ret or CGRP mirrored the magnitude of these neuron populations, whereas for the other four neuronal markers fewer marker-positive cells were also LAT-ISH+. Ret and CGRP are both known to label neurons related to pain signaling.

Herpes simplex virus: prevalence in placental tissue and incidence in neonatal cord blood samples

Herpes simplex virus (HSV) infection is one of the most prevalent infectious diseases worldwide, with HSV-2 being primarily associated with genital infections. HSV-2 is believed to account for the majority of cases of neonatal herpes, which may cause diverse of complications in infected newborns. The present study sought to estimate the prevalence of HSV-2 in placental tissue samples and the incidence of HSV-2 in the umbilical cord blood of newborn infants. Placental tissue samples from 201 women (maternal-side and fetal-side = 402 specimens) and 184 neonatal cord blood samples, all collected at the obstetric ward of a University hospital were studied. HSV-2 was detected by means of nested PCR. The prevalence of HSV-2 in placental samples was 9.0% (n = 18), and the incidence of neonatal HSV-2 infection was 1.1% (n = 2). All HSV-2-positive patients were asymptomatic at the time of delivery and none reported genital herpes. Women with a time between rupture of membranes and delivery of ≥360 min had an approximately fourfold risk of HSV-2 infection in the placental tissue (95% CI 0.93-5.66, P = 0.01). These results suggest that HSV-2 is present in the placenta of asymptomatic women and that a risk of transmission to the neonate exists. New strategies must be implemented for the management of asymptomatic patients who are capable of transmitting the virus to the newborn.

Determination of viral load by quantitative real-time PCR in herpes simplex encephalitis patients

OBJECTIVE

Human herpesviruses cause various acute, subacute, and chronic disorders of the central nervous system and peripheral nervous systems in adults and children. The objective of the present study is to summarize the experience gained with the estimation of viral load in the central nervous system of children and adults with herpes simplex encephalitis (HSE) admitted to a neurological institute at Nagpur, India, by quantitative real-time PCR (qPCR) assay within the past 4 years.

METHODS

The qPCR assay was evaluated retrospectively in 242 cerebrospinal fluid (CSF) samples from patients. Evaluation of possible relationships was done between the herpes simplex virus (HSV) DNA concentration in CSF with that of patients' clinical and laboratory manifestations. The prevalence of the type of HSV in the study population was also determined using type-specific real-time PCR analysis.

RESULTS AND CONCLUSIONS

Real-time analysis using type-specific primers revealed the presence of predominantly HSV-1 genotype in the study population. The qPCR results show that in patients with higher viral loads in their CSF, a greater number of cases were associated with the presence of lesions in the brain as revealed by computed tomography/magnetic resonance imaging scan. They required acyclovir therapy for a longer duration and had a poorer clinical outcome than the patients with lower viral loads in their CSF.

Herpes simplex virus type 1 encephalitis and unusual retinitis in a patient with systemic lupus erythematosus

In this report we discuss a case of a patient with systemic lupus erythematosus who developed herpes simplex virus type 1(HSV-1) infection presenting with encephalitis as well as necrotic and non-necrotic retinitis. The patient presented with typical clinical symptoms and radiologic abnormalities consistent with HSV-1 encephalitis and HSV-1 retinitis in patients with HIV infection, but lacked cerebrospinal fluid pleocytosis and had bilateral retinitis with poor visual acuity. To the best of our knowledge, this is the first such case reported in the literature.