Near-native state imaging by cryo-soft-X-ray tomography reveals remodelling of multiple cellular organelles during HSV-1 infection.

Herpes simplex virus-1 (HSV-1) is a large, enveloped DNA virus and its assembly in the cell is a complex multi-step process during which viral particles interact with numerous cellular compartments such as the nucleus and organelles of the secretory pathway. Transmission electron microscopy and fluorescence microscopy are commonly used to study HSV-1 infection. However, 2D imaging limits our understanding of the 3D geometric changes to cellular compartments that accompany infection and sample processing can introduce morphological artefacts that complicate interpretation. In this study, we used soft X-ray tomography to observe differences in whole-cell architecture between HSV-1 infected and uninfected cells. To protect the near-native structure of cellular compartments we used a non-disruptive sample preparation technique involving rapid cryopreservation, and a fluorescent reporter virus was used to facilitate correlation of structural changes with the stage of infection in individual cells. We observed viral capsids and assembly intermediates interacting with nuclear and cytoplasmic membranes. Additionally, we observed differences in the morphology of specific organelles between uninfected and infected cells. The local concentration of cytoplasmic vesicles at the juxtanuclear compartment increased and their mean width decreased as infection proceeded, and lipid droplets transiently increased in size. Furthermore, mitochondria in infected cells were elongated and highly branched, suggesting that HSV-1 infection alters the dynamics of mitochondrial fission/fusion. Our results demonstrate that high-resolution 3D images of cellular compartments can be captured in a near-native state using soft X-ray tomography and have revealed that infection causes striking changes to the morphology of intracellular organelles.

Cranial ultrasound in neonatal herpes simplex encephalitis.

Neonatal infection with herpes simplex virus (HSV) is associated with significant morbidity, high mortality, and long-term neurological sequelae. We report the clinical case of an infant with HSV encephalitis, where the initial diagnosis was established based on cranial ultrasound (CUS) findings. These findings revealed localized, asymmetrically distributed hyperechoic areas in the parenchyma and signs of brain swelling. CUS dynamics on days 7 and 14 after the onset of clinical symptoms demonstrated multiple subcortical and perivascular zones of encephalomalacia in the right hemisphere, accompanied by ex vacuo ventricular dilatation. The cerebellum, left basal ganglia, and left hemisphere appeared to be less affected by the pathological process.

Opsoclonus-myoclonus syndrome associated with herpes simplex virus infection: a case report.

Purpose: Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disease that can be associated with autoimmunity, paraneoplastic tumour, infection or unknown aetiology.Methods: We describe a 54-year-old woman who developed severe OMS, with the clinical onset occurring 2 months and 15 days after she experienced dizziness, vomiting and fever related to a herpes simplex virus infection. The patient was treated with hormones and clonazepam, and the symptoms of myoclonus and ataxia disappeared.Results: The patient was followed up for 1 year with no recurrence of symptoms.Conclusions: The case suggests that herpes simplex virus infection is a possible cause of OMS.

Uncommon acute neuroimaging findings in severe neonatal herpes simplex virus 2 and consequences of delayed diagnosis.

Neonatal herpes simplex virus (HSV) infection of the central nervous system (CNS) is an emergency that can have devastating structural consequences and clinical outcomes. As it presents non-specifically in neonates, it is difficult to rapidly diagnose without neuroimaging. Although once thought to cause widespread parenchymal destruction, neonatal CNS HSV infection may present with more focal parenchymal injury on neuroimaging, not involving the medial temporal lobes as in adults. We report a case of a three-week-old girl with herpes simplex virus type 2 (HSV-2) encephalitis with exclusive bilateral corticospinal and frontal opercular involvement, which remained undiagnosed and untreated until three months of age. Neuroimaging upon presentation to the emergency room demonstrates a highly suggestive pattern of severe neonatal CNS HSV-2 infection which followed the natural history on subsequent imaging, highlighting the importance of emergency neuroimaging as well as having a high index of suspicion for making the diagnosis.

Herpes simplex virus 2 vasculitis as cause of ischemic stroke in a young immunocompromised patient.

Herpes simplex virus 2 (HSV-2) is a very rare cause of central nervous system (CNS) infections. We report a case of a young woman with a left middle cerebral artery (MCA) ischemic stroke. The patient had history of HIV-1 infection, with periods of therapeutic non-compliance. Initial computed tomography (CT) imaging studies showed stenosis of the M1 segment of the left MCA, and magnetic resonance imaging (MRI) confirmed infarction of the MCA territory. Serial transcranial Doppler ultrasound revealed progressive occlusion of the MCA and stenosis of the left anterior cerebral artery. Systemic investigation for other causes of stroke was normal. Lumbar puncture revealed a mildly inflammatory cerebrospinal fluid, and HSV-2 DNA was identified by PCR, with a positive viral load in favor of active replication. No other viral or microbiological infections were identified. MRI angiography confirmed a vasculitic process involving the left carotid artery, and a HSV-2 vasculitis diagnosis was assumed. The patient started acyclovir with improvement of clinical features and imaging abnormalities. In the HIV-infected patient, stroke is a multifactorial common cause of morbidity. The physician should take into account a broad differential diagnosis including rare causes and atypical presentations of common etiologies, including HSV-1 and HSV-2 CNS infection.

Travel-associated neurological disease terminated in a postmortem diagnosed atypical HSV-1 encephalitis after high-dose steroid therapy - a case report.

BACKGROUND: Human encephalitis can originate from a variety of different aetiologies, of which infection is the most common one. The diagnostic work-up is specifically challenging in patients with travel history since a broader spectrum of unfamiliar additional infectious agents, e. g. tropical disease pathogens, needs to be considered. Here we present a case of encephalitis of unclear aetiology in a female traveller returning from Africa, who in addition developed an atypical herpes simplex virus (HSV) encephalitis in close temporal relation with high-dose steroid treatment. CASE PRESENTATION: A previously healthy 48-year-old female presented with confusion syndrome and impaired vigilance which had developed during a six-day trip to The Gambia. The condition rapidly worsened to a comatose state. Extensive search for infectious agents including a variety of tropical disease pathogens was unsuccessful. As encephalitic signs persisted despite of calculated antimicrobial and antiviral therapy, high-dose corticosteroids were applied intravenously based on the working diagnosis of an autoimmune encephalitis. The treatment did, however, not improve the patient's condition. Four days later, bihemispheric signal amplification in the insular and frontobasal cortex was observed on magnetic resonance imaging (MRI). The intracranial pressure rapidly increased and could not be controlled by conservative treatment. The patient died due to tonsillar herniation 21 days after onset of symptoms. Histological examination of postmortem brain tissue demonstrated a generalized lymphocytic meningoencephalitis. Immunohistochemical reactions against HSV-1/2 indicated an atypical manifestation of herpesviral encephalitis in brain tissue. Moreover, HSV-1 DNA was detected by a next-generation sequencing (NGS) metagenomics approach. Retrospective analysis of cerebrospinal fluid (CSF) and serum samples revealed HSV-1 DNA only in specimens one day ante mortem. CONCLUSIONS: This case shows that standard high-dose steroid therapy can contribute to or possibly even trigger fulminant cerebral HSV reactivation in a critically ill patient. Thus, even if extensive laboratory diagnostics including wide-ranging search for infectious pathogens has been performed before and remained without results, continuous re-evaluation of potential differential diagnoses especially regarding opportunistic infections or reactivation of latent infections is of utmost importance, particularly if new symptoms occur.

Fetal and neonatal abnormalities due to congenital herpes simplex virus infection: a literature review.

OBJECTIVE: Herpes simplex virus (HSV) infection during pregnancy can cause severe neonatal infections. It is also a rare cause of congenital infections. We aimed to describe fetal and neonatal abnormalities of congenital HSV infection in order to define the features that are accessible to prenatal diagnosis during ultrasound screening and/or during a work-up for congenital malformations. METHODS: We analysed all cases of congenital HSV infection (CHI) described before and/or after birth and identified in Pubed and classified the findings as accessible or not to prenatal diagnosis. RESULTS: Thirty-six cases of congenital herpes infection were reported, of which 15 were described prenatally and 21 postnatally. The most frequently reported malformations accessible to prenatal diagnosis were cerebral anomalies. The most common abnormalities described after birth were skin lesions and keratitis, which are not considered amenable to prenatal ultrasound detection. CHI can due to either HSV1 or HSV2 infection, whether primary or non-primary infection, with or without the presence of maternal symptoms. CONCLUSION: Prenatal ultrasound abnormalities due to CHI are rare, varied and non-specific. There is no clear role for fetal ultrasound in the routine management of women with primary or non-primary HSV infection in pregnancy. However, in fetuses with ultrasound abnormalities suggestive of congenital infection, HSV should still be considered as a differential diagnosis after the more common in utero infections, such as cytomegalovirus, are excluded.

Infectious causes and outcomes in patients presenting with cerebral spinal fluid pleocytosis.

To evaluate the infectious etiologies, clinical features, and outcomes of patients with CNS infections at a tertiary care center. Patients that present with a pleocytosis in the cerebral spinal fluid (CSF), defined as a CSF WBC count > 5 cells/mm3, from July 2015 to June 2016 at a tertiary care hospital were analyzed for this report. Data from patients with confirmed (n = 43) and presumed (n = 51) CNS infections were analyzed. CNS infection was the leading known cause of CSF pleocytosis (n = 43, 18% of all patients with a pleocytosis in the CSF), and HSV-2 was identified as the leading causative pathogen (n = 10) followed by varicella zoster virus (n = 5). Fifty-three percent of patients with a pleocytosis in the CSF did not receive a diagnosis. In the patients that did not receive a diagnosis, CNS infection was presumed to be the cause in 51 patients (21% of patients with CSF pleocytosis). The mean time to diagnosis for patients with confirmed CNS infection was 16 days, but time to diagnosis was highly variable depending on the causative pathogen. There was a significant overlap in CSF parameters and peripheral white blood cell counts in patients diagnosed with a viral, bacterial, or fungal infection. Neuroimaging changes were present in only 44% of CNS infections. The overall mortality was 7% for CNS infections, and 17% of patients with a CNS infection had a severe neurologic deficit at presentation while only 3% had a severe deficit at the last neurologic assessment. This study provides new insights into the infectious causes of disease in a cohort of patients with pleocytosis in the CSF. The study provides new insights into the time to diagnosis and outcomes in patients that present with pleocytosis in the CSF.

Imaging of congenital central nervous system infections.

Congenital central nervous system (CNS) infections are a cause of significant morbidity and mortality. The recent Zika virus outbreak raised awareness of congenital CNS infections. Imaging can be effective in diagnosing the presence and severity of infection. In this paper we review the clinical presentations and imaging characteristics of several common and less common congenital CNS infections.

Acyclovir resistance in herpes simplex virus type I encephalitis: a case report.

Acyclovir resistance is rarely seen in herpes simplex virus (HSV) type I encephalitis. Prevalence rates vary between 0.5 % in immunocompetent patients (Christophers et al. 1998; Fife et al. 1994) and 3.5-10 % in immunocompromised patients (Stranska et al. 2005). We report a 45-year-old, immunocompetent (negative HIV antigen/antibody testing), female patient, without previous illness who developed-after a febrile prodromal stage-aphasia and psychomotor slowing. Cerebral magnetic resonance imaging (cMRI) showed right temporal and insular T2-hyperintense lesions with spreading to the contralateral temporal lobe. Cerebrospinal fluid (CSF) analysis yielded lymphocytic pleocytosis and elevated protein level. Polymerase chain reaction testing for HSV type I showed a positive result in repeat lumbar puncture. HSV type I encephalitis was diagnosed and intravenous acyclovir treatment was initiated (750 mg t.i.d.). Acyclovir treatment was intensified to 1000 mg t.i.d., due to clinical deterioration, ongoing pleocytosis and progression on cMRI 5 days after initiation of antiviral therapy. In parallel, acyclovir resistance testing showed mutation of thymidine kinase gene at position A156V prompting foscarnet therapy (60 mg t.i.d.). Patient's condition improved dramatically over 2 weeks. Acyclovir resistance is rare but should be considered in case of clinical worsening of patient's condition. To our knowledge, this is the first report of acyclovir resistance in HSV type I encephalitis of an immunocompetent and previously healthy patient in Austria.

Human in vivo evidence of associations between herpes simplex virus and cerebral amyloid-beta load in normal aging.

BACKGROUND: Mounting data suggests that herpes simplex virus type 1 (HSV-1) is involved in the pathogenesis of AD, possibly instigating amyloid-beta (Aß) accumulation decades before the onset of clinical symptoms. However, human in vivo evidence linking HSV-1 infection to AD pathology is lacking in normal aging, which may contribute to the elucidation of the role of HSV-1 infection as a potential AD risk factor. METHODS: To shed light into this question, serum anti-HSV IgG levels were correlated with 18F-Florbetaben-PET binding to Aß deposits and blood markers of neurodegeneration (pTau181 and neurofilament light chain) in cognitively normal older adults. Additionally, we investigated whether associations between anti-HSV IgG and AD markers were more evident in APOE4 carriers. RESULTS: We showed that increased anti-HSV IgG levels are associated with higher Aß load in fronto-temporal regions of cognitively normal older adults. Remarkably, these cortical regions exhibited abnormal patterns of resting state-functional connectivity (rs-FC) only in those individuals showing the highest levels of anti-HSV IgG. We further found that positive relationships between anti-HSV IgG levels and Aß load, particularly in the anterior cingulate cortex, are moderated by the APOE4 genotype, the strongest genetic risk factor for AD. Importantly, anti-HSV IgG levels were unrelated to either subclinical cognitive deficits or to blood markers of neurodegeneration. CONCLUSIONS: All together, these results suggest that HSV infection is selectively related to cortical Aß deposition in normal aging, supporting the inclusion of cognitively normal older adults in prospective trials of antimicrobial therapy aimed at decreasing the AD risk in the aging population.

Spontaneous regression of fetal pleural effusion in pregnancy complicated with Herpes simplex infection: Clinical presentation and literature review.

Fetal primary hydrothorax is a rare congenital anomaly with an estimated incidence of 1:10,000-15,000 pregnancies, with an unpredictable clinical course, ranging from spontaneous resolution to fetal death. A case of unilateral fetal pleural effusion was diagnosed at 35th week of gestation during a routine ultrasonographic fetal assessment in an uncomplicated pregnancy. A large echogenic collection of fluid was revealed in the right pleural cavity, together with atelectasis of the right lung, as well as displacement of heart and mediastinal structures to the left side of thorax. The patient was also diagnosed with polyhydramnios and there was a disproportion of heart ventricles volume. No other fetal structural abnormalities were detected and there were no symptoms of edema. Fetal biometrics was consistent with the gestational age. In echocardiography, fetal heart was structurally and functionally normal. Screening tests for congenital infections of the fetus were negative. Autoimmune fetal hydrops was excluded after laboratory tests. There was no parents' consent for the analysis of the karyotype. The patient presented clinical symptoms and was diagnosed with Herpes simplex virus infection and was treated with oral acyclovir. Serial fetal ultrasound exams showed gradual decrease in pleural fluid volume up to complete resolution in 38th week of pregnancy. Pregnancy was ended in the 38th week of gestation with a cesarean delivery of a healthy neonate. It is yet to be determined if there is a direct association between Herpes simplex virus infection in pregnancy and the risk of fetal pleural effusion. The incidence of fetal pleural effusion is low and the neonatal outcome difficult to be predicted. The optimum management of fetal pleural effusion should be subject to further studies to determine the best clinical practice.

Detection of the inflammatory process in a Behçet's disease-like mouse model using 18F-fluorodeoxyglucose positron emission tomography.

OBJECTIVES: The major role of herpes simplex virus (HSV) type 1 infection in Behçet's disease (BD) immunopathogenesis has been demonstrated and inoculating the earlobes of ICR mice with HSV produced a BD-like mouse model. (18)Ffluorodeoxyglucose positron emission tomography (FDG PET) is widely used for diagnosing numerous human diseases other than malignancies. The aim of our study was to evaluate the inflammatory activities of BD-like symptoms in a HSV type 1-induced BD-like mouse model by small-animal FDG PET. METHODS: Five HSV-infected ICR mice with BD-like lesions, two asymptomatic HSV-infected mice, and two untreated mice were scanned with microPET, and autopsy specimens were histopathologically assessed to evaluate for infiltration by mixed inflammatory cells. RESULTS: The histopathological evaluation of the inflammatory process in knee and elbow joints significantly correlated with the quantitative assessment of FDG accumulation in the same joints in BD-like ICR mice, HSV-infected asymptomatic mice, and untreated control mice. Small-animal FDG PET clearly detected asymptomatic joint inflammatory processes in both BD-like mice and HSV-infected asymptomatic mice. In addition, genital ulcers and skin ulcers with associated perilesional lymphadenopathies in BD-like models were detected by microPET. However, biodistributed PET-positive images from the stasis of secreted FDG into the bowel lumen could not be distinguished from the inflammatory bowel lesions of BD when compared to FDG uptake in control mice. CONCLUSIONS: Our data indicate that FDG PET can non-invasively and quantitatively detect the inflammatory process in an HSV-induced BD-like mouse model.

Herpes Simplex Virus 1 infection: misleading findings in an infant with disseminated disease.

Neonatal Herpes Simplex Virus (HSV) infection is a serious illness with significant mortality and morbidity for disseminated disease. Clinical diagnosis of neonatal HSV infection is often difficult without evidence of HSV exposure, for example, absence of a rash or the presence of non-specified manifestations in an infant. Early recognition and treatment with high-dose Acyclovir may dramatically improve the short and long-term outcomes. We describe an infant with disseminated disease due to HSV-1 infection, who first presented clinical and radiologic features of pneumonia. The diagnosis was performed post-mortem by Real-Time Polymerase Chain Reaction (PCR) analysis of blood, cerebrospinal fluid and pleural liquid of the infant. Tissue PCR revealed a disseminated HSV-1 infection, with a high viral load detected in liver, lungs, brain, heart, striated muscle, kidneys, and thymus tissues. This case report highlights the need for neonatologists to raise awareness about the different clinical manifestations of disseminated neonatal HSV infection. HSV infections should be prominent in the differential diagnosis of an infant under four weeks of age with fever, pneumonia, unexplained seizures or sepsis-like disease, particularly if unresponsive to antibiotics. Early initiation of appropriate antiviral therapy for high-risk infants undergoing testing for HSV infection can be essential to prevent significant morbidity and mortality.

C-5 hydroxyethyl and hydroxypropyl acyclonucleosides as substrates for thymidine kinase of herpes simplex virus type 1 (HSV-1 TK): syntheses and biological evaluation.

The efficient syntheses of 5-(2-hydroxyethyl)- and 5-(3-hydroxypropyl)-substituted pyrimidine derivatives bearing 2,3-dihydroxypropyl, acyclovir-, ganciclovir- and penciclovir-like side chains are reported. A synthetic approach that included the alkylation of an N-anionic-5-substituted pyrimidine intermediate (method A) provided the target acyclonucleosides in significantly higher overall yields in comparison to those obtained by method B using sylilation reaction. The phosphorylation assays of novel compounds as potential substrates for thymidine kinase of herpes simplex virus type 1 (HSV-1 TK) showed that solely pyrimidine 5-substituted acyclonucleosides with a penciclovir-like side chain acted as a fraudulent substrates of HSV-1 TK. Moreover, the uracil derivative with penciclovir-like side chain with less bulky 2-hydroxyethyl substituent at C-5 proved to be a better substrate than the corresponding one with a 3-hydroxypropyl substituent. Therefore, this acyclonucleoside was selected as a lead compound for the development of a positron emission tomography HSV-1 TK activity imaging agent.

Herpes simplex virus 2 serology is associated with thinner whole-brain cortex in community-dwelling older adults.

Prior work in the Northern Manhattan Study (NOMAS) identified impaired cognition in cross-sectional analyses and more rapid memory decline in individuals with evidence of prior common infectious disease exposures. In this study, we sought to determine the cross-sectional relationship between prior exposure to cytomegalovirus, herpes simplex viruses 1 and 2, Chlamydia pneumoniae, and Helicobacter pylori and three magnetic resonance imaging (MRI) signatures (whole-brain cortical thickness, a previously validated AD signature, and hippocampal volume) in 455 NOMAS participants. We performed confounder-adjusted linear regression analyses between neuroimaging scores and both continuous serologies and categorical seropositivity of each pathogen, as well as a combined infectious burden index (IBI). We identified that increased serologic titers of herpes simplex virus 2 were associated with reduced whole-brain cortical thickness, and a combined score of HSV-2 and C. pneumoniae displayed an additive effect on reduced cortical thickness. Our findings suggest herpes simplex virus 2 seropositivity may contribute to accelerated brain aging, possibly resulting in an increased vulnerability to cognitive impairment and neurodegenerative disease in aging populations.

Extracorporeal membrane oxygenation for refractory, life-threatening, and herpes simplex virus 1-induced acute respiratory distress syndrome. Our experience and literature review.

We report our first experience of treating an immunocompetent adult patient with acute respiratory distress syndrome (ARDS) due to type 1 herpes simplex (HSV1) pneumonitis, using extracorporeal membrane oxygenation (ECMO). Similar cases reported in literature are reviewed as well. The therapeutic options for this particular complication are discussed. Pneumonia caused by HSV1 is a rare finding in immunocompetent individuals; it occurs more often in immunosuppressed and ventilated patients. It is a severe illness; therefore, early diagnosis and initiation of treatment are imperative. Diagnosis is based on cytologic and histologic findings, viral cultures, or serologic methods. This condition can be reversible; however, often, it can progress into refractory ARDS with limited therapeutic options available. We demonstrate the causative role of HSV1 in refractory ARDS of a previously healthy 18-year-old man who presented to the intensive care unit with acute respiratory distress after a week of flulike syndrome. Due to severe hypoxemia and hypercarbia, the patient required mechanical ventilation and later emergent blood oxygenation with extracorporeal support. For the first time in this condition, we used venovenous ECMO management, to rest the lung, sustain blood oxygenation and end-organ oxygen delivery, and promote potential lung recovery. During ECMO and after our etiologic diagnosis, specific therapy was introduced. After viral negativization, corticosteroid therapy (Meduri protocol) was initiated. Extracorporeal membrane oxygenation allowed us to initiate therapy while maintaining end-organ oxygenation and support the patient until lung recovery. After 18 days of ECMO, our patient recovered completely. Near-normal lung structures and functions were documented on a chest x-ray/computed tomography, thoracic ultrasonography, and pulmonary functional tests at hospital discharge and at a 1-year follow-up. Data suggest that severe pulmonary involvement in HVS1 infection associated with septicemia/shock is a rare but often fatal in immunocompetent adult as well. We suggest that ECMO might be the selected treatment for severe refractory ARDS in this clinical scenario. It seems to be an effective and useful ultimate therapeutic strategy for preventing death and furthermore permitting near-full pulmonary function recovery.

Case report: computed tomography scan-guided Gasserian ganglion injection of dexamethasone and lidocaine for the treatment of recalcitrant pain associated with herpes simplex type 1 infection of the ophthalmic division of the trigeminal nerve.

We describe the case of a 17-year-old boy with dermatologic herpes simplex virus-1 outbreaks with incapacitating facial pain requiring multiple hospitalizations. He failed to respond to aggressive treatments including antiviral drugs, opioid analgesics, stellate ganglion, and supraorbital and supratrochlear nerve blocks. The patient elected to undergo dexamethasone and lidocaine Gasserian ganglion block under computed tomography-scan guidance. He had immediate and complete relief of his pain for the first time in almost 2 years. The patient remained pain free during 6-month follow-up visits. This is the first reported use of Gasserian ganglion block for treatment of herpes simplex virus-1 infection of the trigeminal nerve.