Acute viral infection of the central nervous system in children: an 8-year review.

Reliable information on acute viral infections of the central nervous system (CNS) in Canadian children has not been available. To investigation this disease in Halifax the medical records of 180 patients with presumed or definite acute viral CNS infection diagnosed at the Izaak Walton Killam Hospital for Children over an 8-year period were reviewed. The yearly incidence was estimated at 19.5/100 000 for children up to 16 years of age, and the peak incidence was in July, August and September. The cause was determined in 64 (36%) of the 180 patients; it was most commonly a known infectious disease -- mumps (in 24 patients) or varicella (in 9 patients). An enterovirus was responsible in nine cases, herpes simplex virus in eight and measles virus in six. The clinical manifestations were variable and included apnea in three infants who would otherwise have been considered to have nearly suffered the sudden infant death syndrome. Localizing features were present on the electroencephalograms of nine patients, including six with herpes simplex infection. Serologic study of paired serum samples obtained during the acute phase of the illness and during convalescence was the most useful laboratory method of establishing the diagnosis. As medical therapy for specific causes of acute viral CNS infection advances, greater attention should be placed on establishing the correct diagnosis.     

Deep Sequencing to Identify the Causes of Viral Encephalitis

Deep sequencing allows for a rapid, accurate characterization of microbial DNA and RNA sequences in many types of samples. Deep sequencing (also called next generation sequencing or NGS) is being developed to assist with the diagnosis of a wide variety of infectious diseases. In this study, seven frozen brain samples from deceased subjects with recent encephalitis were investigated. RNA from each sample was extracted, randomly reverse transcribed and sequenced. The sequence analysis was performed in a blinded fashion and confirmed with pathogen-specific PCR. This analysis successfully identified measles virus sequences in two brain samples and herpes simplex virus type-1 sequences in three brain samples. No pathogen was identified in the other two brain specimens. These results were concordant with pathogen-specific PCR and partially concordant with prior neuropathological examinations, demonstrating that deep sequencing can accurately identify viral infections in frozen brain tissue.     

可复制性单纯疱疹病毒在抗肿瘤方面的应用

单纯疱疹病毒是肿瘤生物治疗中常用的病毒载体之一,可复制性单纯疱疹病毒以其溶瘤效率高、特异性好、可行性强成为近年来研究的热点。其中对溶瘤性单纯疱疹病毒突变株G207的研究开展得早,其溶瘤效果、靶向性及安全性都得到了确认,这也带动了可复制性单疱病毒应用的发展,目前已研究出多种溶瘤单纯疱疹病毒突变株。本文就近几年可复制性单纯疱疹病毒在抗肿瘤方面的研究现状加以综述,以探讨其临床治疗肿瘤的潜在价值及可行性。     

Absence of idoxuridine and persistence of herpes simplex virus in brains of patients being treated for encephalitis.

Thirty-two specimens of brain from five patients with encephalitis suspected to be caused by herpes simplex virus, type 1 (HSV-1) were assayed for antiviral activity. Each patient received 60-80 mg/kg/day of idoxuridine (IDU) by intravenous infusion. The antiviral assay does not measure anti-HSV-1 antibodies. Biopsies of brain in every patient taken before IDU was used, and portions of several regions of the brain at autopsy were available during courses of treatment in four of the five patients. The last patient died 7 days after completing treatment. A significant concentration of IDU (833 mug/ml) was measured transiently in the cerebrospinal fluid of one patient. Meninges and brains showed inflammatory changes. Within the sensitivity of the test (larger than or equal to 6 mug/g) all specimens contained no IDU. As given, IDU does not achieve therapeutic concentrations in human brain. Further clinical use of IDU in therapy of herpes simplex virus encephalitis is not indicated.     

Acyclovir given as prophylaxis against oral ulcers in acute myeloid leukaemia: randomised,double blind,placebo controlled trial.

OBJECTIVES--To evaluate (a) the prophylactic effect of the antiherpetic drug acyclovir on oral ulcers in patients with acute myeloid leukaemia receiving remission induction chemotherapy and thus (b), indirectly, the role of herpes simplex virus in the aetiology of these ulcers. DESIGN--Randomised, double blind, placebo controlled trial. SUBJECTS--74 herpes simplex virus seropositive patients aged 18-84. Thirty seven patients received acyclovir (800 mg by mouth daily) and 37 placebo. The patients were examined daily for 28 days. MAIN OUTCOME MEASURES--Occurrence of herpes labialis, intraoral ulcers, and acute necrotising ulcerative gingivitis. RESULTS--The two populations were comparable in age, sex, type of antineoplastic treatment, and history of herpes labialis. Acute oral infections occurred in 25 of the acyclovir treated patients and 36 of the placebo treated patients (relative risk 0.69 (95% confidence interval 0.55 to 0.87)). This difference was due to a reduction in the incidence of herpes labialis (one case versus eight cases; relative risk 0.13 (0.02 to 0.95)), intraoral ulcers excluding the soft palate (one case versus 13 cases; relative risk 0.08 (0.01 to 0.56)), and acute necrotising ulcerative gingivitis (one case versus eight cases; relative risk 0.13 (0.02 to 0.95)). However, ulcers on the soft palate were diagnosed with similar frequency in the two groups. Isolation of herpes simplex virus type 1 in saliva was reduced from 15 cases in the placebo group to one case in the acyclovir group (relative risk 0.07 (0.01 to 0.48)). CONCLUSION--Intraoral ulcers excluding the soft palate are most often due to infection with herpes simplex virus, whereas ulcers on the soft palate have a non-herpetic aetiology. The findings suggest that acute necrotising ulcerative gingivitis may also be due to herpes simplex virus. Prophylaxis with acyclovir should be considered for patients with acute myeloid leukaemia during remission induction therapy.     

Detection of herpes simplex and varicella zoster viruses in clinical specimens using direct immunofluorescence and cell culture assays

Patients (33 in toto) with a clinical diagnosis of herpes infections (simplex, zoster or chickenpox) were investigated for the presence of herpes simplex virus (HSV) and varicella zoster virus (VZV) in skin samples, using direct immunofluorescence and cell culture assays. Five patients with nonherpetic vesiculobullous disorders were included as negative controls. Of the 33 patients, nineteen (57.6%) were positive for HSV or VZV and fourteen (42.4%) were negative. Five controls were all negative for HSV or VZV. Of the nineteen positive patients, HSV was isolated from eight (42.1%) patients, by both direct immunofluorescence and cell culture assays. VZV was isolated from eleven (57.9%) patients, eleven (100%) by direct immunofluorescence assay, and six (54.5%) by cell culture assays. HSV was isolated from one patient clinically diagnosed as chickenpox (VZV), but otherwise the positive laboratory results were concordant with the clinical diagnosis. For epidemiological studies, atypical cases and immunocompromised patients the clinical diagnosis should be confirmed in the laboratory.     

Herpes simplex encephalitis: treatment with surgical decompression and cytosine arabinoside.

Herpes simplex encephalitis in a 21-year-old man presented as a flu-like illness, followed by inappropriate behaviour, drowsiness and focal neurologic signs. Investigations indicated a lesion in the right temporal lobe. The diagnosis was confirmed by isolation of the virus from a cerebral biopsy. Pronounced clinical improvement was noted when cytosine arabinoside therapy was started in the postoperative period. This report supports the observation by some authors that cytosine arabinoside may be of value in the treatment of herpes simplex encephalitis.     

Cytodiagnosis of herpes simplex keratitis by means of an immunoperoxidase technique. A case report

Typical herpes simplex keratitis that developed in a 5-year-old boy was initially diagnosed cytologically in Papanicolaou-stained samples. Subsequently, an immunoperoxidase staining technique was used to identify the specific type of herpes simplex virus (HSV) in the destained cellular samples. The positive staining helped to establish the diagnosis of a type 1 HSV infection, permitting early treatment with acyclovir and subsequent complete recovery from the ocular herpetic infection. Emphasis is placed on the value of the immunoperoxidase technique for the rapid and specific diagnosis of cases of suspected HSV infection.     

Prevalence of Herpes Simplex Virus Type 1- and 2- Specific Antibodies among the Acute,Recurrent, and Provoked Types of Female Genital Herpes

Sixty-eight sera from the acute, recurrent, and provoked types of female genital herpes were compared for the seroprevalence of herpes simplex virus (HSV) types 1 and 2 by immunodot assay using HSV glycoprotein G. In the HSV-1-isolated patients, no HSV-2 antibodies were detected, whereas in the HSV-2-isolated patients, HSV-1 seroprevalence was 9% for the acute type, 89% for the provoked type (P< 0.005), and 55% for the recurrent type (P<0.05). The natural history of female genital herpes and the possible protective role of pre-existing antibodies in preventing the acquisition or clinical manifestation of a subsequent HSV infection are discussed.     

Antibody to herpes simplex virus type 2 as serological marker of sexual lifestyle in populations.

OBJECTIVES--To examine the epidemiology of antibody to herpes simplex virus type 2 and to assess its suitability as a serological marker of sexual behaviour in populations with high and low prevalences. DESIGN--Cross sectional survey. SETTING--Department of genitourinary medicine and blood donation centre in central London. SUBJECTS--Representative sample of 869 patients attending department between November 1990 and December 1991, and 1494 consecutive blood donors attending for donation between February and April 1992. METHOD--Participants had a blood sample taken for antibody testing with a novel type specific assay and completed a questionnaire. RESULTS--Prevalence of antibody differed significantly between the two groups (188/833 (22.7%) clinic attenders; 102/1347 (7.6%) blood donors). In both populations antibody was strongly associated with sex, sexual orientation, years of sexual activity, number of lifetime sexual partners, and past infection with sexually transmitted diseases after other factors were controlled for. Only 130 (45%) of all those with antibody had symptoms suggestive of genital herpes, and 79 (27.4%) had had genital herpes diagnosed. Of those without antibody to herpes simplex viruses type 1 and 2, 8.0% reported genital blisters or sores and 1.1% had had genital herpes diagnosed by a doctor. CONCLUSIONS--The strong relation between herpes simplex virus type 2 and sexual lifestyle suggests that the presence of antibody to the virus may be suitable for use as an objective, serological marker of patterns of sexual behaviour in different populations. These data show that only a minority of those infected with herpes simplex virus type 2 have a diagnosis of genital herpes or express clinical symptoms, making serological determinants of infection essential for epidemiological studies.     

Detection of herpes simplex virus-specific DNA sequences in latently infected mice and in humans.

Herpes simplex virus-specific DNA sequences have been detected by Southern hybridization analysis in both central and peripheral nervous system tissues of latently infected mice. We have detected virus-specific sequences corresponding to the junction fragment but not the genomic termini, an observation first made by Rock and Fraser (Nature [London] 302:523-525, 1983). This "endless" herpes simplex virus DNA is both qualitatively and quantitatively stable in mouse neural tissue analyzed over a 4-month period. In addition, examination of DNA extracted from human trigeminal ganglia has shown herpes simplex virus DNA to be present in an "endless" form similar to that found in the mouse model system. Further restriction enzyme analysis of latently infected mouse brainstem and human trigeminal DNA has shown that this "endless" herpes simplex virus DNA is present in all four isomeric configurations.     

Metabolism and mode of action of (R)-9-(3,4-dihydroxybutyl)guanine in herpes simplex virus-infected vero cells

The metabolism and mode of action of the anti-herpes compound buciclovir [R)-9-(3,4-dihydroxybutyl)-guanine, BCV) has been studied in herpes simplex virus-infected and uninfected Vero cells. In uninfected cells, a low and constant concentration of intracellular BCV was found, while in herpes simplex virus-infected cells, an increasing concentration of BCV phosphates was found due to metabolic trapping. The major phosphorylation product was BCV triphosphate (BCVTP) which was 92% of the total amount of BCV phosphates. BCV phosphates were accumulated to the same extent in cells infected with either a herpes simplex virus type 1 or a herpes simplex virus type 2 strain while thymidine kinase-deficient mutants of herpes simplex virus type 1 were 10 times less efficient in accumulating BCV phosphates. In uninfected Vero cells, the concentration of the phosphorylated forms of BCV was less than 1% of that found in herpes simplex virus-infected cells. The BCVTP formed in herpes simplex virus-infected cells was highly stable, as 80% of the amount of BCVTP was still present even 17 h after removal of extracellular BCV. BCV was a good substrate for herpes simplex virus type 1- and type 2-induced thymidine kinases but not for the cellular cytosol or mitochondrial thymidine kinases. BCV monophosphate could be phosphorylated by cellular guanylate kinase to BCV diphosphate. BCVTP was a selective and competitive inhibitor to deoxyguanosine triphosphate of the purified herpes simplex virus type 1- and type 2-induced DNA polymerases. BCVTP could neither act as an alternative substrate in the herpes simplex virus type 2 or cellular DNA polymerase reactions, nor could [3H]BCV monophosphate be detected in DNA formed by herpes simplex virus type 2 DNA polymerase, or be detected in nucleic acids extracted from herpes simplex virus type 1-infected cells. These data indicate that BCVTP may inhibit the herpes simplex virus-induced DNA polymerase without being incorporated into DNA.     

Prophylactic and therapeutic treatment with acyclovir of genital herpes in the guinea pig

The antiviral drug, acyclovir, was tested on experimentally infected guinea pigs with either of two herpes simplex virus type 1 (HSV-1) isolates following intravaginal inoculation. The drug was continuously infused subcutaneously utilizing an osmotic pump. Infusion was begun either prior to virus inoculation (prophylactic) or after virus inoculation at the time of first appearance of lesions (therapeutic). Prophylactic treatment markedly reduced the severity of the genital lesions, the appearance of acute neurologic sequellae, and the virus excretion in the genital tract of guinea pigs infected with either of the two strains tested. Therapeutic acyclovir treatment, however, did not decrease the incidence of acute neurologic sequellae with one of the two HSV-1 strains tested, nor did it reduce the severity of the genital lesions of either strain. These neurologic sequellae may be due to insufficient levels of ACV in the central nervous system as the concentration of ACV in the dorsal root ganglia was found to exceed that of the plasma, but only trace amounts of acyclovir were present in the brain and spinal cord. Continuous perfusion of ACV gave far higher tissue levels than intermittent injections. These findings suggest that prophylactic ACV is far more effective than therapeutic treatment for genital herpes in the guinea pig model.     

Detection of herpes simplex virus by DNA-DNA hybridization method]

Eight recombinant clones were obtained by insertion of BamHI fragments of herpes simplex type I viral DNA into a vector plasmid pUC19o. Of the obtained clones 5 were found to hybridize with herpes simplex type I and 2 viral DNA while 3 clones revealed a positive reaction with the Vero cells DNA. A constructed DNA-probe possessing the highest level of activity was selected for further studies. The probe is a BamHI fragment of herpes simplex type I viral DNA labelled with 32P dTTP. Probe sensitivity in blot hybridization is 10 pg for identification of type I viral DNA and 50 pg for type 2 viral DNA. The DNAs of cytomegalovirus and herpes zoster virus do not show positive signals with the probe. The increased sensitivity of the used dot hybridization as compared with biological or IEA antigen identification of the virus was confirmed with the clinical material from 59 patients with the different clinical manifestations of the herpes viral infection.     

Efficacy of 4'-thio-5-ethyl-2'-deoxyuridine (TEDU) and its derivatives in experimental infection in mice caused by herpes simplex virus]

It was demonstrated that several 5'-phosphonates of 4'-thio-5-ethyl-2'-deoxyuridine possessed antiviral activity in vitro and in the murine model of herpes simplex virus type 1 infection. It was shown that the derivatives after intraabdominal administration penetrated effectively into the brain tissue. The agents provided statistically significant increase of the average life span, lower virus titre in the brain and lower lethality when compared to the control group of the animals. It is emphasized that the derivatives were less toxic than the original compound.     

Subacute herpes simplex virus type 1 encephalitis as an initial presentation of chronic lymphocytic leukemia and multiple sclerosis: a case report

Introduction

Herpes simplex virus type 1 encephalitis presents acutely in patients who are immunocompetent. We report what we believe to be the first published case of a subacute course of herpes simplex virus type 1 encephalitis in a patient with asymptomatic chronic lymphocytic leukemia who subsequently developed multiple sclerosis.

Case presentation

A 49-year-old Caucasian woman with a history of fever blisters presented to the emergency department with a history of left temporal headache for four weeks, and numbness of the left face and leg for two weeks. A complete blood count revealed white blood cell count of 11,820 cells/mL, with an absolute lymphocyte count of 7304 cells/mL. The cerebrospinal fluid contained 6 white blood cells/μL, 63 red blood cells/μL, 54 mg glucose/dL, and 49 mg total protein/dL. Magnetic resonance imaging of the brain revealed meningoencephalitis and bilateral ventriculitis. Cerebrospinal fluid polymerase chain reaction for herpes simplex virus type 1 was positive, and the patient's symptoms resolved after ten days of treatment with parenteral aciclovir. Incidental findings on peripheral blood smear and flow cytometry testing confirmed chronic lymphocytic leukemia. One month later, she developed bilateral numbness of the hands and feet; a repeat cerebrospinal fluid polymerase chain reaction for herpes simplex virus type 1 at this time was negative. A repeat magnetic resonance imaging scan showed an expansion of the peri-ventricular lesions, and the cerebrospinal fluid contained elevated oligoclonal bands and myelin basic protein. A brain biopsy revealed gliosis consistent with multiple sclerosis, and the patient responded to treatment with high-dose parenteral steroids.

Conclusion

Herpes simplex virus type 1 encephalitis is a rare presentation of chronic lymphocytic leukemia. Our patient had an atypical, subacute course, presumably due to immunosuppression from chronic lymphocytic leukemia. This unusual case of herpes simplex virus type 1 encephalitis emphasizes the importance of T cell function in diseases of immune dysregulation and autoimmunity such as chronic lymphocytic leukemia and multiple sclerosis. It raises the question of whether atypical presentations of herpes simplex virus encephalitis warrant deliberations on immunocompetence. The development of multiple sclerosis in our patient so soon after she received treatment for herpes simplex virus type 1 encephalitis raises the possibility that herpes simplex virus type 1 encephalitis in an immunosuppressed patient may trigger multiple sclerosis.

     

Chromosomal organization of the herpes simplex virus genome during acute infection of the mouse central nervous system.

After corneal inoculation, herpes simplex virus type 1 replicates in the mouse eye, trigeminal ganglia, and brainstem, producing first an acute and then a latent infection. Previous work from this laboratory focused on the structure of the viral DNA in this system. We have now examined the structure of the viral genome at the chromosome level by using micrococcal nuclease digestion. Studies with disaggregated cell preparations made from the brainstems of acutely infected mice show that the majority of the viral DNA is in a nonnucleosomal form; however, a nucleosomelike fraction was also consistently detected. A similar result was obtained for viral DNA in herpes simplex virus type 1-infected C1300 (clone NA) neuroblastoma cells (a neuronal cell line).     

Sequential detection of different antigens induced by Epstein-Barr virus and herpes simplex virus in the same Western blot by using dual antibody probes

A dual antibody probing technique that permitted a color-coded identification of polypeptides representing different classes of Epstein-Barr virus (EBV) antigens as well as differentiation of the polypeptides induced by different herpesviruses in the same Western blot was developed. When the nitrocellulose sheet was probed first with monoclonal antibody against EBV early antigen diffuse component (EA-D) and then stained with 4-chloro-1-naphthol, four polypeptides specific for EA-D were identified by purple bands. Subsequently, the same nitrocellulose sheet was reprobed with human serum containing antibodies against EBV early antigen, viral capsid antigen, and nuclear antigen and stained with 3,3'-diaminobenzidine. Several brown bands corresponding to early, viral capsid, and nuclear antigen polypeptides were detected. The dual antibody probing technique was used in an analysis to differentiate polypeptides resulting from either EBV or herpes simplex virus infection, either in cells infected by individual virus or in a cell line dually infected by both viruses. On the basis of different colored bands in different lanes of the same gel, 20 polypeptides with molecular weights ranging from 31,000 to 165,000 were identified as herpes simplex virus-specific proteins. These results suggested that the dual antibody probing technique may be applicable in clinical diagnosis for detecting antigens and antibodies derived from different pathogens.     

Heterogeneity within an HSV-1 wild-type strain and its importance in pathogenesis

A herpes simplex virus-type 1 low passage, clinical eye isolate, E-43 at P2, was compared with its variant progeny, SLi-43 at P8, in terms of ocular disease, cytopathic effects, and genomic variation. In New Zealand White (NZW) rabbits, E-43 produced mild epithelial defects and punctate lesions with full recovery by Day 10 postinfection (pi). SLi-43 caused dendritic lesions, progressing to geographic ulceration and death from herpes simplex virus encephalitis in 10 days postinfection. In RK, Hep-2, and Vero cells, E-43 displayed the syn+ phenotype (aggregation and cell rounding); SLi-43 showed the syn phenotype (syncytium formation). DNA digestion profiles of E-43, SLi-43, and isolates from the brains of infected animals showed that the genomic differences map within the terminal repeat of the unique long segment and the internal joint region, specifically in bands B, E, N, and S (Bam HI) and bands M and N (Hind III). Analysis of the DNA of virus recovered from the brain stem of SLi-43-infected, encephalitic rabbits demonstrated that an in vivo selection for neurotropic virions had taken place. Plaque purification of 20 clones from the original E-43 strain showed that one of 20 was the syn phenotype, indicating that the SLi-43 variant was present in the original E-43 isolate and did not develop de novo by rapid mutation. The parent-progeny relationship between E-43 and SLi-43 forms an ideal model in which to compare differences in pathogenicity at the genomic level, and underscores the importance of heterogeneity within a single herpes simplex virus-type 1 wild-type population in terms of variations in ocular disease.     

Cytodiagnosis of herpes simplex virus infection in the newborn infant: report of a case

Typical herpetic stomatitis that developed in a premature 6-day-old infant was initially diagnosed cytologically. The cytomorphologic characteristics of herpes simplex virus (HSV) infection in smears of scrapings from the oral mucosa helped to establish the diagnosis of a neonatal HSV infection, permitting early treatment with cytosine arabinoside (ara-C) and subsequent complete recovery from the generalized infection. The diagnosis was later confirmed by rises in the serologic titer of complement-fixing antibodies for HSV type 2.