Don't rash it! The clinical significance of positive Varicella zoster virus PCR in cerebrospinal fluid of patients with neurological symptoms.

BACKGROUND: Varicella zoster virus (VZV) is among the leading pathogens causing meningitis and encephalitis. While VZV-PCR-positive CSF is considered a gold-standard for diagnosis, it is not-uncommon to detect VZV-DNA in CSF of patients with other acute or chronic illness. Our goal was to determine the clinical relevance of VZV-PCR-positive CSF when investigating patients with neurological symptoms. METHODS: In this retrospective cohort from the largest hospital in Israel, we collected demographic, clinical and laboratory data of patients with VZV-PCR-positive CSF, analyzing the significance of various parameters. RESULTS: During a 5-years study, 125 patient-unique VZV-PCR-positive CSFs were recorded, in which only 9 alternative diagnoses were noted. The commonest symptoms were headache (N = 104, 83 %) and rash (N = 96, 76 %). PCR-cycle-threshold (Ct), a surrogate of viral burden, did not significantly vary across the clinical manifestations; however, patients with rash and Ct<35 were prone to develop stroke in the following year (N = 6, 7 %). Empiric nucleoside-analogue treatment was not associated with a better outcome compared to treatment administered upon a positive-PCR result. DISCUSSION: Our findings suggest that in patients with neurological symptoms, detection of VZV-DNA in CSF renders VZV the probable culprit. Nevertheless, a systematic evaluation of treatment and follow-up algorithms of patients with suspected or proved VZV meningitis and encephalitis is needed. The benefits of a prompt treatment should be weighed against the potential complications of nucleoside-analogue. Conversely, the propensity for stroke in patients with higher viral-burden, necessitates further studies assessing VZV causal role, directing additional workup, treatment and monitoring policy.

Differentiation of highly pathogenic strains of human JC polyomavirus in neurological patients by next generation sequencing.

BACKGROUND: JC polyomavirus (JCPyV) persists asymptomatic in more than half of the human population. Immunocompromising conditions may cause reactivation and acquisition of neurotropic rearrangements in the viral genome, especially in the non-coding control region (NCCR). Such rearranged JCPyV strains are strongly associated with the development of progressive multifocal leukoencephalopathy (PML). METHODS: Using next-generation sequencing (NGS) and bioinformatics tools, the NCCR was characterized in cerebrospinal fluid (CSF; N = 21) and brain tissue (N = 16) samples from PML patients (N = 25), urine specimens from systemic lupus erythematosus patients (N = 2), brain tissue samples from control individuals (N = 2) and waste-water samples (N = 5). Quantitative PCR was run in parallel for diagnostic PML samples. RESULTS: Archetype NCCR (i.e. ABCDEF block structure) and archetype-like NCCR harboring minor mutations were detected in two CSF samples and in one CSF sample and in one tissue sample, respectively. Among samples from PML patients, rearranged NCCRs were found in 8 out of 21 CSF samples and in 14 out of 16 brain tissue samples. Complete or partial deletion of the C and D blocks was characteristic of most rearranged JCPyV strains. From ten CSF samples and one tissue sample NCCR could not be amplified. CONCLUSIONS: Rearranged NCCRs are predominant in brain tissue and common in CSF from PML patients. Extremely sensitive detection and identification of neurotropic viral populations in CSF or brain tissue by NGS may contribute to early and accurate diagnosis, timely intervention and improved patient care.

[A case of progressive multifocal leukoencephalopathy associated with daratumumab, bortezomib, and dexamethasone for multiple myeloma].

An 83-year-old man presented with visual disturbance and right hemiparalysis, one month after daratumumab, bortezomib, and dexamethasone administration for multiple myeloma (MM). Blood screens revealed a CD4+ T-lymphocyte count of 132/µl. Diffusion weighted and fluid-attenuated inversion-recovery MR imaging showed high intensity signals in the both occipital lobes and left precentral area. The patient had no history of human immunodeficiency virus infection. Cerebrospinal fluid (CSF) JC virus (JCV) was positive (83 copies/ml), as indicated by PCR. The patient was diagnosed with progressive multifocal leukoencephalopathy (PML). MM treatment was discontinued, and mefloquine and mirtazapine therapy was started. However, the CSF JCV-DNA PCR count did not improve (111 copies/ml) after 30 days from starting mefloquine and mirtazapine therapy. The patient died six months after symptom onset. Conclusively, patients with decreased CD4+ T lymphocyte counts following DBd therapy for MM, the possibility of PML should be considered.

Detection of human herpesviruses in cerebrospinal fluids collected from patients suspected of neuroinfectious diseases.

The full spectrum of human herpesviruses (HHV)-associated neuroinfectious diseases in immunocompetent adults remains unclear. Hence, we sought to elucidate the epidemiology and clinical features of these diseases. The study subjects were patients over 16 years old suspected of neuroinfectious diseases who underwent spinal tap performed by neurologists in our university hospital between April 2013 and March 2018. The presence of seven HHV DNAs in cerebrospinal fluid (CSF) was determined by real-time PCR. HHV DNAs were detected in 33 (10.2%) of the 322 patients. The most frequently detected herpesvirus was varicella zoster virus (VZV) (19 patients), followed by HHV-6 (four patients), herpes simplex virus (HSV)-1 (three patients), HSV-2 (three patients), and Epstein-Barr virus (two patients). HHV DNAs were detected in CSF collected from patients with various neuroinfectious diseases, including myelitis, peripheral neuritis, encephalitis, and meningitis. All patients with HSV-1 DNA had encephalitis, whereas all patients with HSV-2 DNA had meningitis. Eleven of the 19 patients with VZV DNA had meningitis. Patients with VZV-associated encephalitis (median age, 80 years) were significantly older than non-encephalitis patients (median age, 60.5 years) (P = 0.046). Although post-herpetic neuralgia was observed in seven (54%) of the 13 patients with VZV and without encephalitis, no such neurological sequela was observed in the four encephalitis patients. In conclusion, HHVs were associated with approximately 10% of neuroinfectious diseases in this cohort. VZV was the most common pathogen, probably due to the large number of VZV meningitis patients. In addition, patients with VZV-associated meningitis were significantly younger than patients with VZV-associated encephalitis.

Lessons from Epstein-Barr virus DNA detection in cerebrospinal fluid as a diagnostic tool for EBV-induced central nervous system dysfunction among HIV-positive patients.

Polymerase chain reaction (PCR) analysis of Epstein-Barr virus (EBV) DNA in cerebrospinal fluid (CSF) remains vital for evaluating active EBV infection involving the central nervous system (CNS). CSF EBV DNA was often found in conjunction with other microbial infection affecting the CNS among patients infected with human immunodeficiency virus (HIV). Sometimes CSF EBV DNA is detectable in patients without neurological symptoms. This review focused on the clinical and laboratory features of CNS EBV infection among patients with HIV, and discussed various types of EBV-associated CNS infections, and predominant neoplasms involving CNS such as primary central nervous system lymphoma (PCNSL), CNS-non-Hodgkin's lymphoma, smooth muscle tumors and leiomyosarcomas, EBV encephalitis or myelitis, EBV meningitis and EBV coinfection with other causative agents were also included. Furthermore, the metagenomic next-generation sequencing technique with high sensitivity for the detection of pathogenic coinfection in the CSF were also reviewed. We concluded that CSF EBV-DNA detection with high sensitivity and specificity could be a useful diagnostic tool for CNS lymphoma among HIV patients; however, it is still unknown for other CNS diseases. We further summarized and conclude that positive CSF EBV-DNA detection combined with specific brain focal lesions could be a minimally invasive method to diagnose PCNSL. The occurrence of positive CSF EBV-DNA was influenced by PCR detection limit, PCR methods, immunocompromised status, the possible influence of anti-herpetic therapy and anti-HIV therapy, and the size and location of a tumor mass. Uniform PCR methods as vital diagnostic tools and optimal EBV-DNA load threshold need to be established.

Cerebrospinal Fluid from Healthy Pregnant Women Does Not Harbor a Detectable Microbial Community.

Cerebrospinal fluid (CSF) circulating in the human central nervous system has long been considered aseptic in healthy individuals, because normally, the blood-brain barrier can protect against microbial invasions. However, this dogma has been called into question by several reports that microbes were identified in human brains, raising the question of whether there is a microbial community in the CSF of healthy individuals without neurological diseases. Here, we collected CSF samples and other samples, including one-to-one matched oral and skin swab samples (positive controls), from 23 pregnant women aged between 23 and 40 years. Normal saline samples (negative controls), sterile swabs, and extraction buffer samples (contamination controls) were also collected. Twelve of the CSF specimens were also used to evaluate the physiological activities of detected microbes. Metagenomic and metatranscriptomic sequencing was performed in these 116 specimens. A total of 620 nonredundant microbes were detected, which were dominated by bacteria (74.6%) and viruses (24.2%), while in CSF samples, metagenomic sequencing found only 26 nonredundant microbes, including one eukaryote, four bacteria, and 21 viruses (mostly bacteriophages). The beta diversity of microbes compared between CSF metagenomic samples and other types of samples (except negative controls) was significantly different from that of the CSF self-comparison. In addition, there was no active or viable microbe in the matched metagenomic and metatranscriptomic sequencing of CSF specimens after subtracting those also found in normal saline, DNA extraction buffer, and skin swab specimens. In conclusion, our results showed no strong evidence of a colonized microbial community present in the CSF of healthy individuals. IMPORTANCE The microbiome is prevalent throughout human bodies, with profound health implications. However, it remains unclear whether it is present and active in human CSF, which has been long considered aseptic due to the blood-brain barrier. Here, we applied unbiased metagenomic and metatranscriptomic sequencing to detect the presence of a microbiome in CSF collected from 23 pregnant women with matched controls. Analysis of 116 specimens found no strong evidence to support the presence of a colonized microbiome in CSF. Our findings will strengthen our understanding of the internal environment of the CSF in healthy people, which has strong implications for human health, especially for neurological infections and disorders, and will help further disease diagnostics, prevention, and therapeutics in clinical settings.

Progressive multifocal leukoencephalopathy with mild clinical conditions and detection of archetype-like JC virus in cerebrospinal fluid.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system with a poor prognosis and is primarily caused by JC virus (JCV) with a mutation called prototype. We encountered a case of PML with moderate progression and analyzed the mutational patterns of JCV in the cerebrospinal fluid (CSF). A 19-year-old Japanese woman with mild neurological symptoms was diagnosed with combined immunodeficiency following pneumocystis pneumonia. Brain magnetic resonance imaging scan showed multiple brain lesions, and real-time polymerase chain reaction testing detected JCV in the CSF, leading to the diagnosis of PML. The disease course of PML was stable after administration of mefloquine and mirtazapine with immunoglobulin replacement therapy. In the JCV genome cloned from the patient CSF, DNA sequences of the gene encoding the capsid protein (VP1) and the non-coding control region exhibited small mutations. However, they were quite similar to those of the archetype JCV, which persists asymptomatically in healthy individuals. These findings provide insight into the mutational characteristics of JCV in PML with mild symptoms and progression.

The Limitations of Cytomegalovirus DNA Detection in Cerebrospinal Fluid of Newborn Infants With Congenital CMV Infection: A Tertiary Care Neonatal Center Experience.

BACKGROUND: Congenital cytomegalovirus (cCMV) infection of the central nervous system (CNS) can cause ventriculomegaly, gliosis, calcifications and cortical defects. Detection of CMV DNA in cerebrospinal fluid by PCR (CSF-CMV-PCR) is a marker of CNS involvement. OBJECTIVE: To evaluate a diagnostic value of the positive CSF-CMV-PCR in cCMV. METHODS: Analysis of clinical, laboratory, neuroimaging and single-nucleotide polymorphisms (SNPs) data according to the results of CSF-CMV-PCR were performed in infants with cCMV. RESULTS: A total of 168 infants were included; 145 (86.3%) had negative and 23 (13.7%) had positive CSF-CMV-PCR results. Associations between the positive CSF-CMV-PCR results and prematurity (odds ratio [OR] = 3.24; 95% confidence interval [CI]: 1.30-8.07), microcephaly (OR = 5.67; 95% CI: 2.08-15.41), seizures (OR = 4.15; 95% CI: 1.10-15.67), sensorineural hearing loss (OR = 6.6; 95% CI: 2.49-17.46), splenomegaly (OR = 8.13; 95% CI: 3.12-21.16), hepatitis (OR = 10.51; 95% CI: 3.31-33.35), petechiae (OR = 10.21; 95% CI: 3.78-27.57) and heterozygous T/C genotype at TLR4rs4986791 (OR = 7.88; 95% CI: 1.55-40.12) were observed. When using a multivariate logistic regression analysis, only the presence of severe sensorineural hearing loss (OR = 7.18; 95% CI: 1.75-29.34, P = 0.006), cystic lesions on MRI (OR 5.29; 95% CI: 1.31-21.36, P = 0.02), and calcifications on MRI (OR = 7.19; 95% CI: 1.67-30.97, P = 0.008) remained as the significant independent predictors of the positive CSF-CMV-PCR results. CONCLUSIONS: The detection of CMV DNA in CSF is associated with a higher rate of CNS damage including abnormal MRI neuroimaging and severe hearing loss. Therefore, detection of CMV DNA in CSF may be considered as a marker of severe CNS injury in cCMV infection. However, the very low prevalence of the positive CSF-CMV-PCR results, even in infants with proven CNS involvement, may imply its limited role in clinical practice.

Varicella zoster virus infection in neurological patients in Bulgaria.

The clinical manifestations of neurological complications associated with varicella zoster virus (VZV) are non-specific and indistinguishable from those of other viral infections. Therefore, the definite diagnosis requires evidence of VZV infection in cerebrospinal fluid (CSF). The aim of this study was to determine the frequency of VZV DNA detection in CSF of patients with neurological diseases in order to obtain information concerning involvement of VZV infection in neuropathology in the country. This study is a retrospective survey of test results obtained from January 2015 to October 2019. During this period, 411 CSF specimens were tested for the presence of VZV DNA by nested PCR. Fisher's exact test was used to test for statistically significant difference in the frequency of VZV DNA positivity of CSF specimens from different groups. Of all 411 tested CSF samples, 11.2% were positive for VZV DNA. The highest VZV prevalence was detected in CFS from patients with meningitis-18.2%, followed by patients with cranial neuritis (15.4%), encephalitis (12.2%), Guillain-Barré syndrome (11.1%), myelitis (10%), and with other neurological syndromes (8.2%). The difference of VZV prevalence in CSF of patients according to the gender and age was not statistically significant. Our results indicated that VZV is a frequent causative agent of neurological diseases, suggesting an important role of VZV infection for neuropathology in the country. Therefore, efforts for wider application of VZV identification in CSF to facilitate faster onset of antiviral treatment and further strategies concerning varicella zoster virus vaccines in the country are needed.

Herpes Simplex Virus-1 and -2 Rapid Detection in Whole Blood.

BACKGROUND: Disseminated herpes simplex virus (HSV) infection has high morbidity and mortality, particularly in neonates, and requires rapid diagnosis for proper treatment. Currently, there are no US FDA-approved assays available to perform HSV testing on blood. OBJECTIVES: Our goal was to evaluate the analytical sensitivity and clinical performance of an available sample-to-answer real-time polymerase chain reaction (PCR) platform used as a laboratory-developed test (LDT) for the detection of HSV-1 and -2 in whole blood (WB). METHODS: A clinical comparison study comparing a real-time PCR reference assay to a LDT based on the DiaSorin Simplexa Direct assay kit was performed. Analytical sensitivity studies comparing WB to the FDA-approved specimen type, cerebrospinal fluid (CSF), were also conducted with contrived quantified HSV-1 and -2 samples in WB and CSF matrix. RESULTS: In total, 102 samples were tested using the LDT and reference assay for the clinical correlation study, with 91 negative and 10 positive results for HSV-1 (n = 7) and HSV-2 (n = 3), exhibiting 100% concordance with comparator results. The overall limit of detection (LoD) for HSV-1 and HSV-2 in WB was comparable to that seen in CSF, with the calculated 95% LoD for blood being 1489 ± 16 copies/ml for HSV-1 and 1187 ± 18 copies/ml for HSV-2 and for CSF being 1168 ± 17 copies/ml for HSV-1 and 953 ± 21 copies/ml for HSV-2. CONCLUSIONS: The performance of the LDT for detection of HSV-1 and HSV-2 in WB specimens is adequate for clinical use. The LoD for HSV-1 and HSV-2 is comparable to that in CSF, the FDA-approved specimen type.

Clinical significance of Epstein-Barr virus in the cerebrospinal fluid of immunocompetent patients.

INTRODUCTION: Polymerase chain reaction (PCR)-based testing of cerebrospinal fluid (CSF) samples has greatly facilitated the diagnosis of central nervous system (CNS) infections. However, the clinical significance of Epstein-Barr virus (EBV) DNA in CSF of individuals with suspected CNS infection remains unclear. We wanted to gain a better understanding of EBV as an infectious agent in immunocompetent patients with CNS disorders. METHODS: We identified cases of EBV-associated CNS infections and reviewed their clinical and laboratory characteristics. The study population was drawn from patients with EBV PCR positivity in CSF who visited Pusan National University Hospital between 2010 and 2019. RESULTS: Of the 780 CSF samples examined during the 10-year study period, 42 (5.4 %) were positive for EBV DNA; 9 of the patients (21.4 %) were diagnosed with non-CNS infectious diseases, such as optic neuritis, Guillain-Barré syndrome, and idiopathic intracranial hypotension, and the other 33 cases were classified as CNS infections (22 as encephalitis and 11 as meningitis). Intensive care unit admission (13/33 patients, 39.3 %) and presence of severe neurological sequelae at discharge (8/33 patients, 24.2 %) were relatively frequent. In 10 patients (30.3 %), the following pathogens were detected in CSF in addition to EBV: varicella-zoster virus (n = 3), cytomegalovirus (n = 2), herpes simplex virus 1 (n = 1), herpes simplex virus 2 (n = 1), Streptococcus pneumomiae (n = 2), and Enterococcus faecalis (n = 1). The EBV-only group (n = 23) and the co-infection group (n = 10) did not differ in age, gender, laboratory data, results of brain imaging studies, clinical manifestations, or prognosis; however, the co-infected patients had higher CSF protein levels. CONCLUSION: EBV DNA in CSF is occasionally found in the immunocompetent population; the virus was commonly associated with encephalitis and poor prognosis, and frequently found together with other microbes in CSF.

Cognitive impairment without altered levels of cerebrospinal fluid biomarkers in patients with encephalitis caused by varicella-zoster virus: a pilot study.

Varicella-zoster virus (VZV) is one of the most common agents causing viral infections of the central nervous system (CNS). VZV encephalitis is associated with severe neurological sequelae, despite antiviral treatment. Cognitive impairment has been reported and VZV has been associated with dementia. Our aim was to investigate the cognitive impairment and cerebrospinal fluid biomarkers in a follow-up study of patients with VZV encephalitis. Thirteen patients with VZV encephalitis, diagnosed by detection of VZV DNA in cerebrospinal fluid (CSF) by PCR and concomitant symptoms of encephalitis, were included. Neuropsychological assessment in parallel with a lumbar puncture to obtain CSF was performed 1.5-7 years after acute disease. The CSF biomarkers neurofilament light chain (NFL), S100B, glial fibrillary acidic protein (GFAP), amyloid-ß (Aß) 40 and Aß42, total tau (t-tau) and phosphorylated tau (p-tau) were analysed and compared to controls (n = 24). Cognitive impairment was shown in the domains of executive functions and speed/attention and to a minor degree in the domains of learning/memory and language, indicated by a significantly poorer performance on seven neuropsychological test variables. No convincing evidence of alterations in concentrations of biomarkers in the CSF were shown. Our results indicate that patients with VZV encephalitis suffer from cognitive impairment long time after acute disease. Importantly, these impairments do not seem to be accompanied by biomarker evidence of ongoing neuronal or astrocytic injury/activation or induction of dementia-related brain pathologies by the infection.

Atypical Multiple Sclerosis Lesions or Progressive Multifocal Leukoencephalopathy Lesions: That Is the Question.

Progressive multifocal leukoencephalopathy (PML) is a serious infective disease of the central nervous system that may occur in case of severe immunosuppression or after some treatment for multiple sclerosis (MS) with natalizumab, dimethyl fumarate, and fingolimod. In these case reports, we highlight the importance of differential diagnosis between PML and MS lesions in order to provide rapidly the best treatment option, by discussing the finding of brain (magnetic resonance imaging) MRI suggestive for PML in 2 MS patients, one treated with dimethyl fumarate and the other during natalizumab withdrawal. In both cases, although brain MRI was highly suggestive for PML, the detection of John Cunningham virus-DNA copies in cerebrospinal fluid resulted in negative result. These case reports illustrate the diagnostic process in case of suspected PML, as both patients were diagnosed with suspected PML during a routine brain MRI control, and highlights the importance of providing a strict brain MRI follow-up during dimethyl fumarate treatment, although only a few cases of PML during this therapy have been detected, and during natalizumab suspension phase. In clinical practice, in case of a radiologically suspected case of PML, although not confirmed by the cerebrospinal fluid analysis, the best approach could be to perform a close radiological and clinical monitoring before starting a new MS therapy.

Pseudorabies virus encephalitis in humans: a case series study.

Pseudorabies virus (PRV) is known to cause severe encephalitis in juvenile pigs and various non-native hosts; recent evidences suggest that PRV might cause encephalitis in humans. In a multicenter cohort study in China, next-generation sequencing of cerebrospinal fluid (CSF) was performed to detect pathogens in all patients with clinically suspected central nervous system infections. This study involved all the patients whose CSF samples were positive for PRV-DNA; their clinical features were evaluated, and species-specific PCR and serological tests were sequentially applied for validation. Among the 472 patients tested from June 1, 2016, to December 1, 2018, six were positive for PRV-DNA, which were partially validated by PCR and serological tests. Additionally, we retrospectively examined another case with similar clinical and neuroimaging appearance and detected the presence of PRV-DNA. These patients had similar clinical manifestations, including a rapid progression of panencephalitis, and similar neuroimaging features of symmetric lesions in the basal ganglia and bilateral hemispheres. Six of the patients were engaged in occupations connected with swine production. PRV infection should be suspected in patients with rapidly progressive panencephalitis and characteristic neuroimaging features, especially with exposure to swine.

Fatal Epstein-Barr virus infection in an immunocompetent host: a postmortem diagnosis.

Meningoencephalitis is the most common neurological complication related to Epstein-Barr virus (EBV), and in immunocompetent adults, it is most commonly self-limited. We describe a case of fatal EBV infection characterized by meningoencephalitis, foci of myocarditis and interstitial nephritis in an immunocompetent 74-year-old man. The postmortem diagnosis was made based on the presence of EBV DNA in the cerebrospinal fluid and by immunohistochemical assay that showed spots of intracellular positivity to anti-EBV antibody in brain tissue.

[Progressive Multifocal Leukoencephalopathy Associated with HIV Infection Diagnosed by Brain Biopsy with Repeated Negative PCR Testing of CSF JC Virus DNA].

A 36-year-old man with human immunodeficiency virus (HIV) infection was admitted to our hospital due to progressive ataxia. Brain MRI demonstrated high-signal intensity in the white matter of the right parietal lobe and left cerebellar hemisphere on T2-weighted images. Despite antiretroviral therapy, as his clinical symptoms worsened and MRI lesions gradually increased with the appearance of gadolinium-enhanced lesions, immune reconstitution inflammatory syndrome by progressive multifocal leukoencephalopathy (PML) associated with HIV infection was suspected. However, JC virus (JCV) in the cerebrospinal fluid (CSF) was undetectable by DNA PCR twice. Therefore, biopsy of the right parietal lobe was performed. JCV DNA was detected by PCR using the biopsy sample. JC viral protein was also identified by immunohistochemistry. Brain biopsy should be considered for the clinical diagnosis of PML when CSF JCV is negative on repeated DNA PCR. (Received September 20, 2019; Accepted January 14, 2020; Published May 1, 2020).

Epstein-Barr virus-related encephalitis in a young woman: A case report.

Although infectious mononucleosis due to Epstein-Barr virus (EBV) is a common disease among young individuals, central nervous system (CNS) complications are rare. In this report, we describe a case of CNS complications caused by EBV in a previously healthy young woman. She presented to our hospital with a 9-day history of headache and sore throat, followed by the development of fever and facial edema 6 days prior to admission. On Day 2 of admission, she was confused (Glasgow Coma Scale score: 10 points) and had fever, muscle weakness in her right arm and leg, stiff neck, and roving eye movement. We detected EBV in a cerebrospinal fluid (CSF) sample using a polymerase chain reaction (PCR) test. The magnetic resonance imaging of her brain revealed dural enhancement and right parietal and temporal lobe lesions. She was treated with acyclovir and high-dose steroid therapy. She responded well to treatment, recovered without neurologic sequelae, and was discharged home on Day 12. Our experience suggests that PCR detection of EBV DNA in CSF may be useful in diagnosing EBV encephalitis and that prognosis may be associated with an area of the brain that is affected and the time from symptom onset to starting treatment.

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.

Fulminant central nervous system varicella-zoster virus infection unexpectedly diagnosed by metagenomic next-generation sequencing in an HIV-infected patient: a case report.

BACKGROUND: Varicella-zoster virus (VZV) infection can be diagnosed clinically once classical rash occurs but the diagnosis is challenging when typical rash is absent. We reported a case of fulminant central nervous system (CNS) VZV infection in a human immunodeficiency virus (HIV)-infected patient without typical VZV-related rash. CNS VZV infection was unexpected identified by metagenomic next-generation sequencing (mNGS). CASE PRESENTATION: A 28-year-old HIV-infected patient presented with neurological symptoms for 3 days. The patient, who was not suspected of VZV infection at admission, quickly progressed to deep coma during the first 24 h of hospitalization. An unbiased mNGS was performed on DNA extract from 300 µL cerebrospinal fluid (CSF) with the BGISEQ-50 platform. The sequencing detection identified 97,248 (out of 38,561,967) sequence reads uniquely aligned to the VZV genome, and these reads covered a high percentage (99.91%) of the VZV. Presence of VZV DNA in CSF was further verified by VZV-specific polymerase chain reaction and Sanger sequencing. Altogether, those results confirmed CNS VZV infection. CONCLUSIONS: This study suggests that mNGS may be a useful diagnostic tool for CNS VZV infection. As mNGS could identify all pathogens directly from CSF sample in a single run, it has the promise of strengthening our ability to diagnose CNS infections in HIV-infected patients.

Human encephalitis caused by pseudorabies virus infection: a case report.

Pseudorabies virus (PRV) primarily infects swine but can infect cattle, dogs, and cats. Several studies have reported that PRV can cross the specie barrier and induce human encephalitis, but a definitive diagnosis of human PRV encephalitis is debatable due to the lack of PRV DNA detection. Here, we report a case of human PRV encephalitis diagnosed by the next-generation sequencing (NGS) of PRV sequences in the cerebrospinal fluid (CSF) of a patient. A male pork vendor developed fever and seizures for 6 days. NGS results showed PRV sequences in his CSF and blood. Sanger sequencing showed that PRV DNA in the CSF and PRV antibodies in both the CSF and blood were positive. MRI results revealed multiple inflammatory lesions in the bilateral hemisphere. Based on the clinical and laboratory data, we diagnosed the patient with PRV encephalitis. This case suggests that PRV can infect humans, causing severe viral encephalitis. People at risk of PRV infection should improve their self-protection awareness.