Herpes Simplex Virus Type 2 as a Cause of Severe Meningitis in Immunocompromised Adults

CNS Viral Infections-What to Consider for Improving Drug Treatment: A Plea for Using Mathematical Modeling Approaches

Neurotropic viruses may cause meningitis, myelitis, encephalitis, or meningoencephalitis. These inflammatory conditions of the central nervous system (CNS) may have serious and devastating consequences if not treated adequately. In this review, we first summarize how neurotropic viruses can enter the CNS by (1) crossing the blood-brain barrier or blood-cerebrospinal fluid barrier; (2) invading the nose via the olfactory route; or (3) invading the peripheral nervous system. Neurotropic viruses may then enter the intracellular space of brain cells via endocytosis and/or membrane fusion. Antiviral drugs are currently used for different viral CNS infections, even though their use and dosing regimens within the CNS, with the exception of acyclovir, are minimally supported by clinical evidence. We therefore provide considerations to optimize drug treatment(s) for these neurotropic viruses. Antiviral drugs should cross the blood-brain barrier/blood cerebrospinal fluid barrier and pass the brain cellular membrane to inhibit these viruses inside the brain cells. Some antiviral drugs may also require intracellular conversion into their active metabolite(s). This illustrates the need to better understand these mechanisms because these processes dictate drug exposure within the CNS that ultimately determine the success of antiviral drugs for CNS infections. Finally, we discuss mathematical model-based approaches for optimizing antiviral treatments. Thereby emphasizing the potential of CNS physiologically based pharmacokinetic models because direct measurement of brain intracellular exposure in living humans faces ethical restrictions. Existing physiologically based pharmacokinetic models combined with in vitro pharmacokinetic/pharmacodynamic information can be used to predict drug exposure and evaluate efficacy of antiviral drugs within the CNS, to ultimately optimize the treatments of CNS viral infections.

Clinical features and prognostic factors in adults with viral meningitis

Clinical features applicable to the entire spectrum of viral meningitis are limited, and prognostic factors for adverse outcomes are undetermined. This nationwide population-based prospective cohort study included all adults with presumed and microbiologically confirmed viral meningitis in Denmark from 2015 until 2020. Prognostic factors for an unfavourable outcome (Glasgow Outcome Scale score of 1-4) 30 days after discharge were examined by modified Poisson regression. In total, 1066 episodes of viral meningitis were included, yielding a mean annual incidence of 4.7 episodes per 100 000 persons. Pathogens were enteroviruses in 419/1066 (39%), herpes simplex virus type 2 in 171/1066 (16%), varicella-zoster virus in 162/1066 (15%), miscellaneous viruses in 31/1066 (3%) and remained unidentified in 283/1066 (27%). The median age was 33 years (IQR 27-44), and 576/1066 (54%) were females. In herpes simplex virus type 2 meningitis, 131/171 (77%) were females. Immunosuppression [32/162 (20%)] and shingles [90/149 (60%)] were frequent in varicella-zoster virus meningitis. The triad of headache, neck stiffness and hyperacusis or photophobia was present in 264/960 (28%). The median time until lumbar puncture was 3.0 h (IQR 1.3-7.1), and the median CSF leucocyte count was 160 cells/µl (IQR 60-358). The outcome was unfavourable in 216/1055 (20%) 30 days after discharge. Using unidentified pathogen as the reference, the adjusted relative risk of an unfavourable outcome was 1.34 (95% CI 0.95-1.88) for enteroviruses, 1.55 (95% CI 1.00-2.41) for herpes simplex virus type 2, 1.51 (95% CI 0.98-2.33) for varicella-zoster virus and 1.37 (95% CI 0.61-3.05) for miscellaneous viruses. The adjusted relative risk of an unfavourable outcome was 1.34 (95% CI 1.03-1.75) for females. Timing of acyclovir or valacyclovir was not associated with the outcome in meningitis caused by herpes simplex virus type 2 or varicella-zoster virus. In summary, the outcome of viral meningitis was similar among patients with different aetiologies, including those with presumed viral meningitis but without an identified pathogen. Females had an increased risk of an unfavourable outcome. Early antiviral treatment was not associated with an improved outcome in meningitis caused by herpes simplex virus type 2 or varicella-zoster virus.

Treatment of Herpes Simplex Virus Type 2 Meningitis: A Survey Among Infectious Diseases Specialists in France, Sweden, Australia, and Denmark

Background

We aimed to describe attitudes toward treatment of herpes simplex virus type 2 (HSV-2) meningitis and prioritize future trials.

Methods

This was a self-administered online survey of HSV-2 meningitis treatment among infectious diseases (ID) specialists in France, Sweden, Australia, and Denmark.

Results

A total of 223 ID specialists (45% female) from France (36%), Denmark (24%), Sweden (21%), and Australia (19%) participated in the survey, primarily from university hospitals (64%). The estimated overall response rate was 11% and ranged from 6% (Australia) to 64% (Denmark). Intravenous (IV) acyclovir followed by oral valacyclovir was the favored treatment in 110 of 179 (61%), whereas monotherapy with either IV acyclovir or oral valacyclovir was used by 35 of 179 (20%) and 34 of 179 (19%), respectively. The median total duration was reported to be 7 days (interquartile range, 7-10 days) regardless of antiviral regimen. Immunocompromise influenced decisions on antiviral treatment in 110 of 189 (58%) of respondents, mainly by prolonged total duration of treatment (36/110 [33%]), prolonged IV administration (31/110 [28%]), and mandatory antiviral treatment (25/110 [23%]). Treatment with acyclovir/valacyclovir versus placebo and comparison of acyclovir versus valacyclovir were assigned the highest prioritization scores for future randomized controlled trials on HSV-2 meningitis.

Conclusions

Perceptions of indications for as well as type and duration of antiviral treatment varied substantially among ID specialists.

Herpes simplex virus 2 meningitis in adults: A prospective, nationwide, population-based cohort study

BACKGROUND

Data on the clinical presentation are scarce and prognostic factors of Herpes simplex virus type 2 (HSV-2) meningitis remain unknown.

METHODS

Prospective, nationwide, population-based database identifying all adults treated for HSV-2 meningitis at departments of infectious diseases in Denmark from 2015-2020. Unfavorable outcome was defined as Glasgow Outcome Scale (GOS) score of 1-4 and extended GOS score of 1-6. Modified Poisson regression was used to compute relative risks with 95% confidence intervals (RR, 95% CI) for unfavorable outcome.

RESULTS

HSV-2 meningitis was diagnosed in 205 cases (76% female, median age 35 [IQR 27-49]) yielding an incidence of 0.7/100,000/year. Common symptoms were headache 195/204 (95%), photo/phonophobia 143/188 (76%), and neck stiffness 106/196 (54%). Median time to lumbar puncture was 2.0 hours (IQR 1-4.8) and cerebrospinal fluid (CSF) leukocyte count was 360x10 6/L (IQR 166-670) with a mononuclear predominance of 97% (IQR 91-99). Lumbar puncture was preceded by brain imaging in 61/205 (30%). Acyclovir/valaciclovir was administered in 197/205 (96%) cases for a median of 10 days (IQR 7-14).Unfavorable outcome was observed in 64/205 (31%) at discharge and 19/181 (11%) after six months and was not associated with female sex (RR 1.08, 95% CI 0.65-1.79), age ≥35 years (1.28, 0.83-1.97), immuno-compromise (1.07, 0.57-2.03), or CSF leukocyte count >1,000x10 6/L (0.78, 0.33-1.84).

CONCLUSIONS

HSV-2 meningitis often presented as meningeal symptoms in younger females. Unfavorable outcome at discharge was common and was not associated with sex, age, immune-compromise, or CSF leukocyte count. Sequelae persisted beyond six months in one tenth of patients.

Fatal fulminant HSV-2 myocarditis: A complicated presentation

Herpes simplex virus type 2 (HSV-2) infection is the leading cause of genital lesions. Infrequently HSV-2 primary infection can spread and involve other tissue and organs, however in immunocompetent individuals extra-genital complications are rare findings. In this report we present a fatal case of fulminant myocarditis and terminal liver involvement, caused by HSV-2 infection, with a unique presentation. Diagnosis was made only post-mortem.

Clinical use of steroids in viral central nervous system (CNS) infections: three challenging cases

The role of adjunctive corticosteroids in reducing morbidity and mortality of viral CNS infections remains poorly defined. Clinicians are often left in a quagmire regarding steroid use in complex and rapidly evolving viral CNS infections. Limited studies have explored the underlying mechanisms behind the potential benefit of steroids. Here, we describe steroid use in three cases of viral CNS disease: varicella zoster virus (VZV), Powassan virus, and influenza A-associated acute necrotizing encephalopathy.

Atypical imaging presentation of herpes simplex virus encephalitis in paediatric immunocompromised oncology patients

INTRODUCTION

We aim to assess the imaging manifestations of brain involvement in paediatric immunocompromised patients with haematological malignancies on chemotherapy presenting with encephalitis and positive HSV CSF PCR. We also aim to determine whether our findings are similar or different to those described in literature for paediatric patients in general.

METHODS

A retrospective study was performed in paediatric ALL/lymphoma patients on chemotherapy, and cases with positive CSF HSV-PCR with at least one head MRI scan were included. On imaging, location(typical/atypical), post-contrast enhancement and haemorrhage/diffusivity/gliosis were evaluated.

RESULT

A total of 28 scans were included in study from 16 patients fulfilling inclusion criteria, 12 (75%) HSV-1 and 4 (25%) HSV-2. Of the 16 initial scans (CT n = 10, MRI n = 6), 11 were normal (CT = 7, MRI = 4). Fourteen patients had follow-up MRI, of which two had normal scans. On the abnormal initial scan (5/16), only 20% had typical medial temporal/inferomedial frontal/cingulate involvement. Most had frontal (80%), parietal (60%) and non-medial temporal (40%) lesions. Abnormal diffusivity/haemorrhage was absent in all, and postcontrast enhancement was seen in 20%. On follow-up, more patients (33%) had typical medial temporal/inferomedial frontal/cingulate involvement. Widespread atypical site involvement of frontoparietal (75%), thalamus (58%), non-medial temporal (50%), occipital/basal ganglia (33%) and cerebellum (8%) was noted. Most lesions were cortical (91%)/subcortical (75%) with few periventricular lesions (58%). Few showed abnormal diffusivity (16%), post-contrast parenchymal enhancement/haemorrhage (8%), post-contrast meningeal enhancement (25%) and gliosis (16%).

CONCLUSION

Immunocompromised paediatric patients with haematological malignancies have widespread atypical brain involvement in herpes simplex encephalitis with lack of diffusion restriction and post-contrast enhancement, likely due to haematogenous spread of HSV across the blood-brain barrier, lack of cellular immunity and limited inflammatory cytokine response.

Disseminated Herpes Simplex Virus in an Immunocompetent Patient Without Presence of Epidermal or Mucosal Lesions

ABSTRACT

Herpes simplex virus (HSV) is a disease usually characterized by lesions within the epidermis or mucosa of children and adults. However, this infection can also cause complications to many systems of the body, including the peripheral and central nervous system, respiratory system, and hepatobiliary system. In this case, we present a 43-year-old man with a history of substance abuse, who presented with fever, cough, and headache, and within days, progressed into fulminant hepatitis and hypoxic failure. Bacterial and fungal cultures were negative, as well as the workup for human immunodeficiency virus. However, the presence of HSV was detected in a bronchial lavage culture after the patients had expired. This result, along with the findings at autopsy, including viral cytopathic effect in the lung and liver, which were confirmed with immunohistochemical stains for HSV, strongly suggest that the cause of death is from disseminated herpes virus infection with hepatitis and viral pneumonitis. This disseminated infection occurred in an immunocompetent host without any evidence of mucocutaneous lesions.

Aseptic Viral Meningitis Secondary to Herpes Simplex Virus 2 Genital Infection

Aseptic viral meningitis is the most common cause of meningitis in the United States. Most cases of herpes simplex virus meningitis are caused by herpes simplex virus type 2 (HSV-2), with HSV-1 primarily causing viral encephalitis. In this report, we present a case of aseptic meningitis generated by the HSV-2 in an immunosuppressed 35-year-old female with a recent diagnosis of genital herpes that was left untreated due to reported side effects of medication. 

Viral meningitis: an overview

Meningitis is a serious condition that affects the central nervous system. It is an inflammation of the meninges, which is the membrane that surrounds both the brain and the spinal cord. Meningitis can be caused by bacterial, viral, or fungal infections. Many viruses, such as enteroviruses, herpesviruses, and influenza viruses, can cause this neurological disorder. However, enteroviruses have been found to be the underlying cause of most viral meningitis cases worldwide. With few exceptions, the clinical manifestations and symptoms associated with viral meningitis are similar for the different causative agents, which makes it difficult to diagnose the disease at early stages. The pathogenesis of viral meningitis is not clearly defined, and more studies are needed to improve the health care of patients in terms of early diagnosis and management. This review article discusses the most common causative agents, epidemiology, clinical features, diagnosis, and pathogenesis of viral meningitis.

Long-Term Survival, Morbidity, Social Functioning and Risk of Disability in Patients with a Herpes Simplex Virus Type 1 or Type 2 Central Nervous System Infection, Denmark, 2000-2016

Background

The long-term prognosis following herpes simplex virus (HSV) central nervous system (CNS) infection is still debated.

Patients and Methods

We examined outcomes in all Danish residents who, during 2000–2016, tested PCR positive for HSV-1 (n=208) or HSV-2 (n=283) in the cerebrospinal fluid, compared to comparison cohorts from the general population (n=2080 and n=2830).

Results

One-year mortality was increased among HSV-1 patients (difference 19.3%; 95% CI: 13.6% to 25.0%) and HSV-2 patients (difference 5.3%; 95% CI: 2.5% to 8.1%), but thereafter mortality was not increased. After exclusion of persons diagnosed with cancer prior to study inclusion, one-year mortality difference for HSV-2 patients was 1.7% (−0.1% to 3.5%). After five years, HSV-1 patients had lower employment (difference −19.8%; 95% CI: −34.7% to −4.8%) and higher disability pension rates (difference 22.2%; 95% CI: 8.4% to 36.0%) than the comparison cohort, but similar number of inpatient days, outpatient visits, and sick leave. HSV-2 patients had employment and disability pension rates comparable to the comparison cohort, but more inpatient days (difference 1.5/year; 95% CI: −0.2 to 3.2), outpatient visits (difference 1.3/year; 95% CI: 0.3 to 3.2), and sick leave days (difference 9.1/year; 95% CI: 7.9 to 10.4).

Conclusion

HSV-1 and HSV-2 CNS infections differ substantially with respect to prognosis. HSV-1 CNS infection is followed by increased short-term mortality and long-term risk of disability. HSV-2 CNS infection has no substantial impact on mortality or working capability but is associated with increased morbidity.

Epidemiology of herpes simplex and varicella zoster virus in cerebrospinal fluid of patients suffering from meningitis in Iran

From the early 18th century that “meningitis” outbreak was firstly recorded in Geneva, it is one of the alarming health problems worldwide. Different infectious risk factors may contribute to the progression of meningitis. Herpes simplex virus (HSV) and Varicella-zoster virus (VZV) are just some noticeable risk factors among many involved in the progression of this disease. In this study, 415 meningitis suspected patients were recruited with some symptoms, such as fever, headache, nausea or vomiting, seizure, rash, dizziness from four different hospitals of Iran and molecular examinations of samples were performed by using specific primers of HSV½ and VZV via real-time PCR. Out of 415 included patient 41 (9.8 %) were VZV and six (1.4 %) cases were HSV ½ positive. Fever was the most frequent symptom by 315 (76 %) of patients with median temperature of 38 °C in all included patients. The median WBS counts of CSF in VZV positive, HSV½ positive, and all included cases were 1567 × 10⁶ /L, 1257 × 10⁶ /L, and 766 × 10⁶ /L (range 0-21200), respectively. In conclusion, as the rate of VZV infection was high among children patients and it was associated with the absence of vaccination program for chickenpox in Iran, we suggested that VZV is one of the plausible hallmarks in meningitis.

Multivalent DNA vaccine protects against genital herpes by T-cell immune induction in vaginal mucosa

Genital herpes is one of the most common sexually transmitted infections (STIs), and it is mainly caused by the neurotropic herpes simplex virus (HSV-2). Not only does this infection cause ulcers, but HSV-2 can also stay in a latent state in the nervous system of the host throughout their lifespan. As a result, many people do not know that they harbor this infection. Moreover, HSV-2 serves as a major risk factor for human immunodeficiency virus (HIV) infection and can be transmitted to the fetus. Despite the high risk of infection and adverse effects, attempts at development of an effective vaccine for HSV-2 have not yet been successful. In this study, we developed a DNA vaccine for HSV-2 (SL-V20). This multivalent DNA vaccine effectively reduced the pathological symptoms of infection and induced efficient elimination of the virus in a mouse model. Intramuscular injection of SL-V20 led to induction of an HSV-2-specific T-cell response in the vagina, the major infection site, and in draining lymph organs. Dendritic cells (DCs), especially basic leucine zipper ATF-like transcription factor 3 (Baft3)⁺ DCs and partially interferon regulatory factor 4 (Irf4)⁺ DCs, were involved in this T-cell-mediated protective response, while B cells were dispensable for these prophylactic effects. This study demonstrates that SL-V20 offers a novel and effective vaccine against vaginal HSV-2 infection and may be applicable to patients, pending validation in clinical studies.

18F-FDG PET/CT Findings in Disseminated Genital Herpes in an Immunocompetent Patient With Anaplastic Lymphoma Kinase Rearranged Advanced Nonsmall Cell Lung Cancer

We present the PET/CT findings of extensive disseminated genital herpes simplex virus infection in a 29-year-old woman known with disseminated anaplastic lymphoma kinase-mutated nonsmall lung cancer. PET/CT revealed extensive involvement of the outer and inner genitalia, multiple lymph nodes extending from the porta hepatis to the groins, and involvement of the liver. Disseminated herpes simplex virus infection is well described in neonates and immunocompromised individuals but very rare in immunocompetent adults as was the case with this patient.

Prevalence of Enterovirus Meningitis in Children: Report from a Tertiary Center

Meningitis is the most frequent infection of the central nervous system and viruses aret he most common agents. Enteroviruses are among the most important causative agents. The goal of this study was to determine Coxsackievirus and echovirus infections in children referred to Bahrami Hospital with the diagnosis of meningitis. Forty children with the diagnosis of meningitis, who were referred betweeen January 2017 and February 2018, were evaluated. Forty cases were evaluated. Twenty two (55%) were males and 18 (45%) females (M/F=2.1). The most common age group was 0-4 years and the most cases were admitted in autumn and summer. Entroviruses are the causative agent of meningitis in 26 (65%) cases, including coxsackieviruse type B5 in 18(69%) and coxsackieviruse type B4 in 2(10%). Six meningitis cases were caused by echoviruses(30%). In both coxsackieviruus and echovirus groups, the most frequent age group was less than four year. Among the 26 cases with enterovirus infection, three were admitted in spring (11.5%), eight in summer (30.7%), 10 in autumn (38.4%) and fice (19.2%) in winter. The most common symptoms in cases with entroviruses infection were fever in 26 (100%) patients and nausea/vomiting in 18 (69.2%). Entroviruses are among the most common viral infections leading to meningitis in Iranian children. Rapid diagnosis will result in early and proper treatment.

Infections in Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become a widely used modality of therapy for a variety of malignant and nonmalignant diseases. Despite advances in pharmacotherapy and transplantation techniques, infection remains one of the most severe and frequently encountered complications of allo-HSCT.

This chapter will address the risk factors for development of infection following allo-HSCT, including those related to the host, the conditioning regimen, and the graft, as well as the timing of opportunistic infections after allo-HSCT. The most common bacterial, viral, fungal, and parasitic infections, as well as issues surrounding their diagnostics and treatment, will be discussed. Finally, this chapter will address vaccination and other preventative strategies to be utilized when caring for patients undergoing allo-HSCT.

Expression and characterization of the soluble form of recombinant mature HSV-2 glycoprotein G for use in anti-HSV-2 IgG serodiagnostic immunoassay

Herpes simplex virus type-2 (HSV-2) specific glycoprotein G (gG-2) is widely used as the antigen of choice for serodiagnosis of HSV-2. In order to develop an ELISA for serodetection of HSV-2 IgG in patient sera, the soluble form of the mature gG-2 antigen (mgG-2), gG283-649, was expressed using a baculovirus expression system. gG283-649 contains the complete extracellular domain of mgG-2 including the C-terminal region, which despite homology to gG-1, does not cross-react with HSV-1 antibodies present in HSV-1 positive patient sera. gG283-649 had increased performance compared to a previously described gG-2 fragment and showed high sensitivity and specificity in a method comparison with HerpeSelect 1 & 2 Immunoblot IgG, a commercially available FDA-cleared assay for serodetection of HSV-1 and 2 antibodies. A total of 234 clinical samples consisting of 134 high risk samples, including 45 samples from pregnant subjects, and a panel of 100 mixed diagnosis samples, spanning the measurable range were tested in the method comparison. Clinical sensitivity and specificity were determined to be 94.2% and 100%, respectively. We conclude that this soluble form of mgG-2 is a novel antigen of choice for developing an ELISA for type-specific serodiagnosis of HSV-2.

Herpes simplex virus type 1 (HSV-1) specific T-cell generation from HLA-A1- and HLA-A2-positive donors for adoptive immunotherapy

BACKGROUND AIMS

Herpes simplex virus (HSV) reactivation and infection is common in patients undergoing hematopoietic stem cell transplant (HSCT) and requires routine antiviral prophylaxis. Drug-resistant strains are increasingly common, and effective alternative therapy is currently unavailable. We generated and characterized HSV-1-specific T cells for use in adoptive cellular immunotherapy following allogeneic stem cell transplantation.

METHODS

Peripheral blood mononuclear cells from HLA-A1 and HLA-A2 HSV-seropositive hereditary hemochromatosis donors were used as the antigen source. Three HLA-A1 and four HLA-A2 specific epitopes were used for stimulation of T cells. Cells were stimulated with antigen-pulsed dendritic cells and cultured for 21 days in medium with interleukin (IL)-2. Cultured cells were phenotyped and tested for cytokine production, proliferation and cytotoxicity.

RESULTS

There was a 5.3-fold expansion in total cell numbers over 21 days of culture, with 35% of T cells being CD8 positive. Thirty-five percent, 21% and 5% of CD8 cells secreted interferon-γ, tumor necrosis factor-α and IL-2 upon HSV antigen re-stimulation. More than 50% of antigen-specific T cells secreted multiple cytokines. Cultured T cells proliferated upon antigen re-stimulation and lysed HSV-1 peptide and virus-infected targets.

CONCLUSIONS

It is feasible to generate functional HSV-1 specific T cells from the blood of HLA-A1 and HLA-A2 HSV-seropositive donors using specific peptides. The utility of these cells in preventing and treating HSV-1 reactivation in allogeneic HSCT will need to be tested clinically.

Etiologies and Management of Aseptic Meningitis in Patients Admitted to an Internal Medicine Department

Several studies have focused on the clinical and biological characteristics of meningitis in order to distinguish between bacterial and viral meningitis in the emergency setting. However, little is known about the etiologies and outcomes of aseptic meningitis in patients admitted to Internal Medicine.The aim of the study is to describe the etiologies, characteristics, and outcomes of aseptic meningitis with or without encephalitis in adults admitted to an Internal Medicine Department.A retrospective cohort study was conducted in the Internal Medicine Department of the Lariboisière Hospital in Paris, France, from January 2009 to December 2011. Clinical and biological characteristics of aseptic meningitis were recorded. These included cerebrospinal fluid analysis, results of polymerase chain reaction testing, final diagnoses, and therapeutic management.The cohort included 180 patients fulfilling the criteria for aseptic meningitis with (n = 56) or without (n = 124) encephalitis. A definitive etiological diagnosis was established in 83 of the 180 cases. Of the cases with a definitive diagnosis, 73 were due to infectious agents, mainly enteroviruses, Herpes Simplex Virus 2, and Varicella Zoster Virus (43.4%, 16.8%, and 14.5% respectively). Inflammatory diseases were diagnosed in 7 cases. Among the 97 cases without definitive diagnoses, 26 (26.8%) remained free of treatment throughout their management whereas antiviral or antibiotic therapy was initiated in the emergency department for the remaining 71 patients. The treatment was discontinued in only 10 patients deemed to have viral meningitis upon admission to Internal Medicine.The prevalence of inflammatory diseases among patients admitted to internal medicine for aseptic meningitis is not rare (4% of overall aseptic meningitis). The PCR upon admission to the emergency department is obviously of major importance for the prompt optimization of therapy and management. However, meningitis due to viral agents or inflammatory diseases could also be distinguished according to several clinical and biological characteristics highlighted in this retrospective study. As recommendations are now available concerning the prescriptions of antiviral agents in viral meningitis, better therapeutic management is expected in the future.

Herpes simplex and varicella zoster CNS infections: clinical presentations, treatments and outcomes

OBJECTIVES

To describe the clinical manifestations, cerebrospinal fluid (CSF) characteristics, imaging studies and prognostic factors of adverse clinical outcomes (ACO) among adults with herpes simplex virus (HSV) or varicella zoster virus (VZV) CNS infections.

METHODS

Retrospective review of adult patients with positive HSV or VZV polymerase chain reaction on CSF from an observational study of meningitis or encephalitis in Houston, TX (2004-2014), and New Orleans, LA (1999-2008).

RESULTS

Ninety-eight adults patients were identified; 25 had encephalitis [20 (20.4 %) HSV, 5 (5.1 %) VZV], and 73 had meningitis [60 (61.1 %) HSV and 13 (13.3 %) VZV]. HSV and VZV had similar presentations except for nausea (P < 0.01) and rash (P < 0.001). The CSF profile did not differ between HSV and VZV infection. Abnormal neuroimaging findings were found in 11.6 % (10/86) brain CTs and 21.3 % (16/75) brain MRIs. The EEG was abnormal in 57.9 % (11/19). Sixteen patients (16.3 %) had an ACO (10 HSV encephalitis, 3 VZV encephalitis and 3 VZV meningitis). Intravenous acyclovir administered within 48 h was protective against an ACO [OR 0.19 (0.04-0.80), P = 0.02). However, on logistic regression only Charlson comorbidity score >1 and an encephalitis presentation were independently associated with an ACO. The treatment for HSV meningitis was variable, and all patients had a good clinical outcome.

CONCLUSION

Alpha herpes CNS infections due to HSV and VZV infections have similar clinical and laboratory manifestations. ACO was observed more frequently in those patients with comorbidities and an encephalitis presentation.

Analysis of clinical information and reverse transcriptase-polymerase chain reaction for early diagnosis of enteroviral meningitis

Purpose

Meningitis is among the most common infections affecting the central nervous system. It can be difficult to determine the exact pathogen responsible for the infection and patients are often treated with empiric antibiotics. This study was conducted to identify the most common clinical characteristics of enteroviral meningitis in children and evaluate the diagnostic efficacy of reverse transcriptase-polymerase chain reaction (RT-PCR) for early detection of an enterovirus.

Methods

We analyzed the medical records of children admitted to Korea University Medical Center and diagnosed with meningitis on the basis of cerebrospinal fluid (CSF) analysis and RT-PCR from CSF and other samples from January 2010 to August 2013.

Results

A total of 333 patients were enrolled and classified into four groups based on diagnosis: enteroviral meningitis (n=110), bacterial meningitis (n=23), other viral meningitis (n=36), and unknown etiology (n=164). Patients with bacterial meningitis were younger than those in the other groups (P<0.001). Pleocytosis in CSF was similar across all groups. Of patients in the enteroviral meningitis group, 92.7% were diagnosed based on RT-PCR findings. Mean length of hospital stay for patients with enteroviral meningitis was 6.08 days, which was significantly shorter than that for patients with meningitis of bacterial etiology (19.73 days, P<0.001).

Conclusion

Diagnosis of enteroviral meningitis before viral culture results are available is possible using RT-PCR. Accurate diagnosis reduces the length of hospital stay and helps to avoid unnecessary empiric antibiotic treatment.

Study of the Frequency of Herpesvirus Infections Among Patients Suspected Aseptic Meningitis in the West of Iran

Background:

Aseptic meningitis is the most common type of meningitis and is characterized by meningeal inflammation that is not linked to identifiable bacterial pathogens in cerebrospinal fluid (CSF).

Objectives:

This study aimed to evaluate the frequency of aseptic meningitis caused by herpesviruses, namely herpes simplex types I and II (HSV-1, HSV-2), Epstein-Barr virus (EBV), cytomegalovirus (CMV) and varicella-zoster virus (VZV).

Patients and Methods:

A total of 196 CSF samples were collected from patients with suspected meningitis. All samples were smear- and culture-negative for bacterial pathogens. The biochemical and cytological findings of CSF samples were also recorded. DNA was extracted from samples and PCR with specific primers was carried out to detect viruses.

Results:

The 196 samples derived from 100 (52%) men and 96 (48%) women ranging in age from one day to 86 years with an average age of 32.3 ± 25.3 years. Of them, 8 (4.08%) samples yielded positive results, including 5 (2.55%) cases of VZV infection and 3 (1.53%) cases of HSV-1 infection. No cases of HSV-2, CMV or EBV infection were detected. CSF protein and glucose levels among positive cases were all in the normal range.

Conclusions:

The results indicate a considerable rate of herpesvirus infection in patients with aseptic meningitis, and that VZV is the most common herpesvirus to cause infection followed by HSV-1. Our results also showed that a moderate increase in the WBC count and predominance of lymphocytes can be valuable clues in diagnosing viral meningitis. Given the different approaches of drug therapy in bacterial and viral meningitis, use of molecular methods is necessary in hospitals to rapidly discriminate between them.

Clinical Presentation, Aetiology, and Outcomes of Meningitis in a Setting of High HIV and TB Prevalence

Meningitis causes significant morbidity and mortality globally. The aim of this study was to study the clinical presentation, aetiology, and outcomes of meningitis among adult patients admitted to Queen Mamohato Memorial Hospital in Maseru, Lesotho, with a diagnosis of meningitis. A cross-sectional study was conducted between February and April 2014; data collected included presenting signs and symptoms, laboratory results, and clinical outcomes. Descriptive statistics were used to summarise data; association between variables was analysed using Fisher's exact test. 56 patients were enrolled; the HIV coinfection rate was 79%. The most common presenting symptoms were altered mental status, neck stiffness, headache, and fever. TB meningitis was the most frequent diagnosis (39%), followed by bacterial (27%), viral (18%), and cryptococcal meningitis (16%). In-hospital mortality was 43% with case fatalities of 23%, 40%, 44%, and 90% for TB, bacterial, cryptococcal, and viral meningitis, respectively. Severe renal impairment was significantly associated with mortality. In conclusion, the causes of meningitis in this study reflect the high prevalence of HIV and TB in our setting. Strategies to reduce morbidity and mortality due to meningitis should include improving diagnostic services to facilitate early detection and treatment of meningitis and timely initiation of antiretroviral therapy in HIV-infected patients.

The yield of monitoring for HSV and VZV viremia in pediatric hematopoietic stem cell transplant patients

Reactivation of HSV and VZV is common following HSCT. Consensus guidelines do not support the use of routine screening for viremia following HSCT in adults, but no such clear guidelines exist in pediatrics. In our center, routine practice was to screen patients weekly for HSV and VZV viremia until engraftment in autologous transplant patients and up to day +100 in allogeneic transplant patients. We conducted a retrospective study of over 500 patients to establish whether this screening identified any patients with HSV or VZV viremia who would not have been identified by clinical signs or symptoms. Over a 4.5-yr period, routine screening identified three cases of HSV viremia and one case of VZV viremia. Two patients had persistent, unexplained fever and two patients had skin or mucosal lesions suggestive of HSV/VZV. We conclude that routine screening for HSV and VZV viremia in pediatric HSCT patients has a very low yield and that viremia can be reliably identified by targeted testing in patients with vesicular skin lesions, oral or genital ulceration, unexplained fever, neurological symptoms, or unexplained abnormal liver transaminases.

Disseminated Primary Herpes Simplex Virus Type 2 Infection in a 22-Year-Old male

We present a case of primary disseminated herpes simplex virus type 2 (HSV-2) cutaneous disease in a 22-year-old male. We discuss the immune response to HSV-2 infection as well as the extragenital manifestations of HSV-2 observed in immune-competent and immune-suppressed persons.

Houttuynia cordata targets the beginning stage of herpes simplex virus infection

Herpes simplex virus (HSV), a common latent virus in humans, causes certain severe diseases. Extensive use of acyclovir (ACV) results in the development of drug-resistant HSV strains, hence, there is an urgent need to develop new drugs to treat HSV infection. Houttuynia cordata (H. cordata), a natural herbal medicine, has been reported to exhibit anti-HSV effects which is partly NF-κB-dependent. However, the molecular mechanisms by which H. cordata inhibits HSV infection are not elucidated thoroughly. Here, we report that H. cordata water extracts (HCWEs) inhibit the infection of HSV-1, HSV-2, and acyclovir-resistant HSV-1 mainly via blocking viral binding and penetration in the beginning of infection. HCWEs also suppress HSV replication. Furthermore, HCWEs attenuate the first-wave of NF-κB activation, which is essential for viral gene expressions. Further analysis of six compounds in HCWEs revealed that quercetin and isoquercitrin inhibit NF-κB activation and additionally, quercetin also has an inhibitory effect on viral entry. These results indicate that HCWEs can inhibit HSV infection through multiple mechanisms and could be a potential lead for development of new drugs for treating HSV.

The role of antiviral therapy in immunocompromised patients with herpes simplex virus meningitis

BACKGROUND

Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) are important causes of acute neurologic illness. Although the role of acyclovir in treating HSV encephalitis is clear, the role of antiviral therapy in HSV meningitis remains controversial.

METHODS

In this retrospective observational study, we reviewed the charts of all patients with cerebrospinal fluid specimens positive for HSV-1 or HSV-2 by polymerase chain reaction between July 2000 and November 2012. Patients' charts were reviewed for demographic data, clinical presentation, treatment, and clinical outcomes.

RESULTS

Forty-two patient-episodes were clinically classified as meningitis. In 6 episodes (14.3%), patients with meningitis received no antivirals, whereas the remaining episodes were treated with an oral antiviral (n = 11 [26.2%]), combination intravenous and oral therapy (n = 22 [52.4%]), or intravenous acyclovir alone (n = 3 [7.1%]). Six patients had recurrent episodes of meningitis and all recovered without any neurologic sequelae. Neurologic outcomes were significantly improved with antiviral therapy in immunocompromised patients with herpes meningitis (P < .05), but not in the 27 patient-episodes among immunocompetent patients (P = 1.0), as no neurologic sequelae were noted in this group.

CONCLUSIONS

Most patients with HSV meningitis rapidly improve, but immunocompromised hosts have more neurologic sequelae and may benefit from antiviral therapy. Our data suggest symptomatic treatment alone for immunocompetent patients with HSV meningitis, avoiding the cost and side effects of prolonged intravenous acyclovir therapy; in contrast, immunocompromised patients had improved outcomes and would therefore benefit from antiviral therapy.

Herpes simplex virus 2 ICP34.5 confers neurovirulence by regulating the type I interferon response

The γ34.5 gene of herpes simplex virus (HSV) 2 encodes ICP34.5, which enhances HSV-2 neurovirulence by an unknown mechanism. We found that an HSV-2 γ34.5-null mutant (γ34.5(-/-)) replicated less robustly than its rescue virus (γ34.5R) in wild-type mouse embryo fibroblasts (MEFs), and in cells primed with IFNβ. Increased eIF2α phosphorylation correlated with γ34.5(-/-) attenuation. However, γ34.5(-/-) achieved titers equivalent to γ34.5R in MEFs lacking the type I IFN receptor (IFNα/βR(-/-)) or lacking protein kinase R. γ34.5(-/-) also replicated poorly in the vaginal mucosa of wild-type mice, caused little genital inflammation, and spread to the nervous system at lower levels compared to γ34.5R. In IFNα/βR(-/-) mice, however, γ34.5(-/-) regained the capacity to replicate and cause disease equivalent to γ34.5R after intravaginal infection or direct inoculation into the central nervous system. Thus, the capacity of HSV-2 ICP34.5 to interdict the type I IFN response in vivo largely determines its neurovirulence.

Comparison of clinical manifestations, outcomes and cerebrospinal fluid findings between herpes simplex type 1 and type 2 central nervous system infections in adults

In previous reports on the viral causes of central nervous system (CNS) infections, it has been generally recognized that HSV-1 is a major cause of encephalitis, while HSV-2 is the predominant cause of aseptic meningitis in adults. To examine this matter, the clinical characteristics in the two types of HSV CNS infections were investigated. In a retrospective cohort study which included all adult patients (≥16 years) between January 1999 and December 2013 in a 2,700-bed tertiary care hospital, all the patients in whom PCR of the CSF for HSV was positive were identified. Ninety-five patients with positive CSF PCR results for HSV were included, 21 with HSV-1 and 74 with HSV-2. Many patients with HSV-1 had encephalitis (13/21, 61.9%), whereas most patients with HSV-2 had meningitis (62/74, 83.8%). However, HSV-1 and HSV-2 accounted for similar proportion of patients with HSV encephalitis (13/25, 52.0% vs. 12/25, 48.0%). Neurological sequelae were more frequent among patients with HSV-1 (9/21, 42.9% vs. 6/74, 8.1%; P = 0.001). The present study suggests that HSV-2 is not only a major cause of aseptic meningitis, but also it may cause serious manifestation as HSV-1 encephalitis in adults.

Meningitis

Meningitis is defined as inflammation of the meninges, in almost all cases identified by an abnormal number of white blood cells in the cerebrospinal fluid and specific clinical signs/symptoms. Onset may be acute or chronic, and clinical symptoms of acute disease develop over hours to days. This article reviews the epidemiology, pathophysiology, clinical manifestations, diagnosis, and management of acute meningitis, and provides a list of key points for primary care practitioners. Aseptic and bacterial meningitis vary significantly and are discussed separately.

Herpes simplex virus 2 meningitis: a retrospective cohort study

Herpes simplex virus 2 is a leading cause of viral meningitis and the most commonly recognized infectious cause of benign, recurrent meningitis. We report a retrospective, observational cohort study of patients with herpes simplex virus type 2 (HSV-2) meningitis, confirmed by polymerase chain reaction (PCR) in the cerebrospinal fluid (CSF). The terms "herpes simplex," "meningitis," or "encephalitis" were searched in the medical records system of the Mayo Clinic in Rochester, Minnesota (1995-2008). Patients were included if they had a clinical diagnosis of meningitis and HSV-2 detected by PCR in the CSF. There were 28 patients with 33 episodes identified (83 % female; mean age at presentation of meningitis 36 years, range 17-53; mean time to HSV2 detection from symptom onset 3 days, range 0-6; history of genital herpes 23 %). No patient took oral antiviral treatment at the time of presentation. Episodes were most likely to include headache (100 %), photophobia (47 %), self-reported fever (45 %), meningismus (44 %), and nausea and/or vomiting (29 %). CSF at the time of meningitis was notable for elevated protein (mean 156 g/dL, range 60-258) and white cell count (mean 504 cells/μL, range 86-1,860) with normal glucose (mean 54 mg/dL, range 32-80). Mollaret cells were never detected. Neuroimaging was most often normal (83 %) when performed, although some cases showed nonspecific (14 %) or meningeal changes (3 %). There was no consistent relationship to genital herpes. The duration of treatment with intravenous acyclovir ranged from 3 to 14 days for the first meningitic episode (daily dose range from 500 to 1,000 mg and total dose range from 500 mg q8h for 3 days to 800 mg q8h for 14 days). For subsequent episodes, the duration of treatment of intravenous acyclovir ranged from less than 1 to 14 days (total dose range from 1,390 mg for 1 day to 900 mg q8h for 10 days). The dose of valacyclovir ranged from 500 mg once daily to 500 mg four times daily. The median duration of valacyclovir treatment following the first episode was 10 days (range 3 to 14 days, n = 13). The median duration of valacyclovir treatment following a subsequent meningitic episode was 9 days (range 7 days to indefinite period, n = 9). No patient was reported to have seizures, neurological disability, or death in extended follow-up (mean follow-up 3.4 years). Recurrence of meningitic symptoms was not universal.

Management of HSV, VZV and EBV infections in patients with hematological malignancies and after SCT: guidelines from the Second European Conference on Infections in Leukemia

These guidelines on the management of HSV, VZV and EBV infection in patients with hematological malignancies and after SCT were prepared by the European Conference on Infections in Leukemia following a predefined methodology. A PubMed search was conducted using the appropriate key words to identify studies pertinent to management of HSV, VZV and EBV infections. References of relevant articles and abstracts from recent hematology and SCT scientific meetings were also reviewed. Prospective and retrospective studies identified from the data sources were evaluated, and all data deemed relevant were included in this analysis. The clinical and scientific background was described and discussed, and the quality of evidence and level of recommendation were graded according to the Centers for Disease Control criteria.

Genotypic detection of acyclovir-resistant HSV-1: characterization of 67 ACV-sensitive and 14 ACV-resistant viruses

Infections due to herpes simplex virus (HSV) resistant to acyclovir (ACV) represent an important clinical concern in immunocompromised patients. In order to switch promptly to an appropriate treatment, rapid viral susceptibility assays are required. We developed herein a genotyping analysis focusing on thymidine kinase gene (TK) mutations in order to detect acyclovir-resistant HSV in clinical specimens. A total of 85 HSV-1 positive specimens collected from 69 patients were analyzed. TK gene could be sequenced directly for 81 clinical specimens (95%) and 68 HSV-1 specimens could be characterized as sensitive or resistant by genotyping (84%). Genetic characterization of 67 susceptible HSV-1 specimens revealed 10 polymorphisms never previously described. Genetic characterization of 14 resistant HSV-1 revealed 12 HSV-1 with either TK gene additions/deletions (8 strains) or substitutions (4 strains) and 2 HSV-1 with no mutation in the TK gene. DNA polymerase gene was afterwards explored. With this rapid PCR-based assay, ACV-resistant HSV could be detected directly in clinical specimens within 24 h.

Multiphasic encephalomyelitis in a patient with recurrent herpes simplex type 2 meningitis

We here describe a patient with a history of recurrent HSV-2 meningitis who had been free from symptoms for almost 20 y when he developed an acute encephalomyelitis. The clinical course laboratory and radiological findings support an acute multiphasic disseminated encephalomyelitis induced by a recurrent HSV-2 infection.

Herpes simplex virus infection, with particular reference to the progression and complications of primary herpetic gingivostomatitis

Primary herpetic gingivostomatitis (PHGS) represents the clinically apparent pattern of primary herpes simplex virus (HSV) infection, since the vast majority of other primary infections are symptomless. PHGS is caused predominantly by HSV-1 and affects mainly children. Prodromal symptoms, such as fever, anorexia, irritability, malaise and headache, may occur in advance of disease. The disease presents as numerous pin-head vesicles, which rupture rapidly to form painful irregular ulcerations covered by yellow-grey membranes. Sub-mandibular lymphadenitis, halitosis and refusal to drink are usual concomitant findings. Following resolution of the lesions, the virus travels through the nerve endings to the nerve cells serving the affected area, whereupon it enters a latent state. When the host becomes stressed, the virus replicates and migrates in skin, mucosae and, in rare instances, the central nervous system. A range of morbidities, or even mortality, may then occur, i.e., recurrent HSV infections, which are directly or indirectly associated with PHGS. These pathological entities range from the innocuous herpes labialis to life-threatening meningoencephalitis.

Viral meningitis

Viruses probably account for most cases of acute meningitis. Viral meningitis is often assumed to be a largely benign disease. For the commonest pathogens causing meningitis, enteroviruses, this is usually the case; however, for many of the other pathogens causing viral meningitis, and for common pathogens in the immunocompromised or infants, viral meningitis is frequently associated with substantial neurological complications and a significant mortality. Diagnostic methods for rapid and accurate identification of pathogens have improved over recent years, permitting more precise and earlier diagnoses. There have been fewer developments in therapies for viral meningitis, and there remain no effective therapies for most pathogens, emphasising the importance of prevention and early diagnosis. This review focuses on the presentation, diagnosis and management of viral meningitis and also covers the prevention of meningitis for pathogens where effective vaccines are available.

Construction of recombinant herpes simplex virus type I expressing green fluorescent protein without loss of any viral genes

For use in various applications in research on herpes simplex virus type 1, we attempted to generate recombinant HSV-1 expressing green fluorescent protein (GFP) without any loss of viral genes. Our results were as follows. (i) A recombinant HSV-1 (YK333), in which a GFP expression cassette driven by the Egr-1 promoter was inserted into the intergenic region between UL3 and UL4, was constructed. (ii) YK333 replicated as well as wild-type HSV-1 F strain in Vero cells. (iii) As one application of the recombinant YK333 for research on HSV-1, we developed a system to detect anti-herpetic activity, termed a fluorescence-based anti-viral assay. The 50% inhibitory concentration of ganciclovir for YK333 determined using our newly developed assay was comparable to that determined using a plaque reduction assay. YK333 will be a convenient tool for herpes simplex virus research, including such applications as monitoring of viral replication in vitro and in vivo, and rapid screening of potential anti-herpetic agents.