A novel mutation of varicella-zoster virus associated to fatal hepatitis

Fulminant varicella hepatitis: a rare but lethal cause of abdominal pain

An 81-year-old woman with no history of immunocompromise presented with 2 days of upper abdominal pain associated with nausea. On arrival, her physical examination was unremarkable apart from mild epigastric and right hypochondriac tenderness, and laboratory investigations were unremarkable apart from mild thrombocytopenia and transaminitis. A CT scan performed on the day of admission revealed a tiny 0.3 cm stone in the common bile duct, with no upstream dilatation. On day 2 of admission, she developed a vesicular rash and with acutely worsening transaminitis. She deteriorated rapidly and demised from complications of acute liver failure within the next 24 hours. The diagnosis of varicella was confirmed with antibody testing. Fulminant varicella hepatitis is an extremely rare and lethal condition with only a handful of reported cases in the current literature. We aim to share our clinical experience and summarise the salient points from existing case reports.

Rare presentation of primary varicella zoster as fatal fulminant hepatitis in adult on low-dose,short-term steroid: Case report

Background

Varicella zoster virus presents clinically as primary (chickenpox) or secondary (herpes zoster) infection. Cutaneous and extracutaneous dissemination may occur, usually in immunocompromised patients. VZV hepatitis that progresses to fulminant hepatic failure is very rare and fatal. To the best of our knowledge, 9 cases have been reported to date, of which 7 were in immunocompromised adults, and only one patient was on short duration steroid therapy.

Presentation of case

We present a 26-year old man who was admitted initially with acute abdomen as query persistent biliary colic. Later, he showed clinical and laboratory findings of VZV hepatitis that progressed rapidly despite maximal medical ICU support and he expired on day 3 of admission.

Conclusions

Acute VZV infection may present as fulminant hepatitis. The presentation may initially be challenging for the diagnosis and should be considered if the patient has been in contact with a sick case. Low dose corticosteroid could carry a risk for fatal VZV fulminant hepatitis and should be used very cautiously especially with VZV patients' contacts. Further causative relationships remain to be established.

Varicella-Zoster Virus-Induced Hepatitis in a Liver Transplant Recipient: A Case Report

Infections after solid organ transplantation are a major cause of mortality and morbidity. Varicella-zoster virus (VZV) infection after solid organ transplantation is rare. Here we present a case presenting with acute hepatitis and shingles after a liver transplantation (LT). A 36-year-old male patient underwent a liver transplantation; 7 months later his liver function tests increased. An examination and test results revealed that he had VZV-induced hepatitis. After VZV treatment, his test results returned to normal levels. Hepatic involvement of VZV infection is rare, but it may be fatal in immunocompromised individuals. Early diagnosis and early initiation of antiviral therapy is important in the control of hepatitis and rare hepatotropic viruses in immunocompromised individuals.

Acute Liver Failure due to Disseminated Varicella Zoster Infection

Acute liver failure (ALF) can be due to numerous causes and result in fatality or necessitate liver transplantation if left untreated. Possible etiologies of ALF include ischemia, venous obstruction, medications, toxins, autoimmune hepatitis, metabolic and infectious causes including hepatitis A-E, varicella-zoster virus (VZV), cytomegalovirus (CMV), herpes simplex virus (HSV), Epstein-Barr virus (EBV), and adenovirus with VZV being the most rarely reported. Pathognomonic skin lesions facilitate diagnosis of VZV hepatitis, but definitive diagnosis is secured with liver biopsy, tissue histopathology, culture, and specific VZV polymerase chain reaction (PCR). Antiviral treatment with intravenous acyclovir can be effective if initiated in a timely manner; however, comorbidities and complications frequently result in high mortality, especially in immunocompromised hosts as exemplified in this case presentation.

Fatal varicella in immigrants from tropical countries: Case reports and forensic perspectives

The primary Varicella Zoster Virus (VZV) infection results in varicella, a generally benign, self-limiting disease in immunocompetent children. Despite the usual course a possible fatal evolution of the primary infection is observed predominantly in immunocompromised subjects and in adults, especially emigrating from tropical regions. Two cases of fatal varicella have been investigated and discussed. Death occurred in two patients over 40 years of age, coming from South Asia and receiving chronic immunosuppressive therapy. The forensic expert must be cautious and consider all clinical records in managing fatal varicella cases, bearing in mind risk factors and pre-existing conditions such as age, geographical provenance and pathological comorbidity, which may lead to a bad prognosis irrespective of therapies. Based on the severe and fatal course observed in the reported cases, an extension of the immunization program appears advisable for immigrants from tropical countries, especially before scheduled immunotherapy.

A highly conserved epitope-vaccine candidate against varicella-zoster virus induces neutralizing antibodies in mice

Varicella-zoster virus (VZV) is a highly infectious agent of varicella and herpes zoster (HZ). Vaccination is by far the most effective way to prevent these diseases. More safe, stable and efficient vaccines, such as epitope-based vaccines, now have been increasingly investigated by many researchers. However, only a few VZV neutralizing epitopes have been identified to date. We have previously identified a linear epitope between amino acid residues 121 and 135 of gE. In this study, we validated that this epitope is highly conserved amongst different VZV strains that covered five existing phylogenetic clades with an identity of 100%. We evaluated the immunogenicity of the recombinant hepatitis B virus core (HBc) virus-like particles (VLPs) which included amino acids (121-135). VZV-gE-specific antibodies were detected in immunized mouse serum using ELISA. The anti-peptide antiserum positively detected VZV via Western blot and immunofluorescent staining assays. More importantly, these peptides could neutralize VZV, indicating that these peptides represented neutralizing epitopes. These findings have important implications for the development of epitope-based protective VZV vaccines.

Bioinformatics of varicella-zoster virus: single nucleotide polymorphisms define clades and attenuated vaccine genotypes

Varicella zoster virus (VZV) is one of the human herpesviruses. To date, over 40 complete VZV genomes have been sequenced and analyzed. The VZV genome contains around 125,000 base pairs including 70 open reading frames (ORFs). Enumeration of single nucleotide polymorphisms (SNPs) has determined that the following ORFs are the most variable (in descending order): 62, 22, 29, 28, 37, 21, 54, 31, 1 and 55. ORF 62 is the major immediate early regulatory VZV gene. Further SNP analysis across the entire genome has led to the observation that VZV strains can be broadly grouped into clades within a phylogenetic tree. VZV strains collected in Singapore provided important sequence data for construction of the phylogenetic tree. Currently five VZV clades are recognized; they have been designated clades 1 through 5. Clades 1 and 3 include European/North American strains; clade 2 includes Asian strains, especially from Japan; and clade 5 includes strains from India. Clade 4 includes some strains from Europe, but its geographic origins need further documentation. Within clade 1, five variant viruses have been isolated with a missense mutation in the gE (ORF 68) glycoprotein; these strains have an altered increased cell spread phenotype. Bioinformatics analyses of the attenuated vaccine strains have also been performed, with a subsequent discovery of a stop-codon SNP in ORFO as a likely attenuation determinant. Taken together, these VZV bioinformatics analyses have provided enormous insights into VZV phylogenetics as well as VZV SNPs associated with attenuation.

Pangaea and the Out-of-Africa Model of Varicella-Zoster Virus Evolution and Phylogeography

The goal of this minireview is to provide an overview of varicella-zoster virus (VZV) phylogenetics and phylogeography when placed in the broad context of geologic time. Planet Earth was formed over 4 billion years ago, and the supercontinent Pangaea coalesced around 400 million years ago (mya). Based on detailed tree-building models, the base of the phylogenetic tree of the Herpesviridae family has been estimated at 400 mya. Subsequently, Pangaea split into Laurasia and Gondwanaland; in turn, Africa rifted from Gondwanaland. Based on available data, the hypothesis of this minireview is that the ancestral alphaherpesvirus VZV coevolved in simians, apes, and hominins in Africa. When anatomically modern humans first crossed over the Red Sea 60,000 years ago, VZV was carried along in their dorsal root ganglia. Currently, there are five VZV clades, distinguishable by single nucleotide polymorphisms. These clades likely represent continued VZV coevolution, as humans with latent VZV infection left Arabia and dispersed into Asia (clades 2 and 5) and Europe (clades 1, 3, and 4). The prototype VZV sequence contains nearly 125,000 bp, divided into 70 open reading frames. Generally, isolates within a clade display >99.9% identity to one another, while members of one clade compared to a second clade show 99.8% identity to one another. Recently, four different VZV genotypes that do not segregate into the previously defined five clades have been identified, a result indicating a wider than anticipated diversity among newly collected VZV strains around the world.

Sequence analysis of the glycoprotein E gene of varicella-zoster virus strains of clades 1, 3 and 5

Eighty-six varicella-zoster virus (VZV) strains of clades 1, 3 and 5, isolated from varicella and zoster patients in Germany, were analyzed by sequencing the glycoprotein E gene. Four novel non-synonymous and 10 novel synonymous mutations were detected. Of these, two synonymous (C513T, C885T) and two non-synonymous mutations (T485G, C524T) were located within the coding regions of e1 and c1. The profile of single-nucleotide polymorphisms was found to be significantly associated with the VZV clades 1, 3 and 5.

Simultaneous cocirculation of both European varicella-zoster virus genotypes (E1 and E2) in Mexico city

Full-length genome analysis of varicella-zoster virus (VZV) has shown that viral strains can be classified into seven different genotypes: European (E), Mosaic (M), and Japanese (J), and the E and M genotypes can be further subclassified into E1, E2, and M1 through 4, respectively. The distribution of the main VZV genotypes in Mexico was described earlier, demonstrating the predominance of E genotype, although other genotypes (M1 and M4) were also identified. However, no information regarding the circulation of either E genotype in the country is available. In the present study, we confirm the presence of both E1 and E2 genotypes in the country and explore the possibility of coinfection as the triggering factor for increased virulence among severe cases. A total of 61 different European VZV isolates collected in the Mexico City metropolitan area from 2005 to 2006 were typed by using a PCR method based on genotype-specific primer amplification. Fifty isolates belonged to the E1 genotype, and the eleven remaining samples were classified as E2 genotypes. No coinfection with both E genotypes was identified among these specimens. We provide here new information on the distribution of VZV genotypes circulating in Mexico City.

VZV molecular epidemiology

The molecular epidemiology of varicella zoster virus (VZV) has led to an understanding of virus evolution, spread, and pathogenesis. The availability of over 20 full length genomes has confirmed the existence of at least five virus clades and generated estimates of VZV evolution, with evidence of recombination both past and ongoing. Genotyping by restriction enzyme analysis (REA) and single nucleotide polymorphisms (SNP) has proven that the virus causing varicella is identical to that which later reactivates as zoster in an individual. Moreover, these methods have shown that reinfection, which is mostly asymptomatic, may also occur and the second virus may establish latency and reactivate. VZV is the only human herpesvirus that is spread by the respiratory route. Genotyping methods, together with epidemiological data and modeling, have provided insights into global differences in the transmission patterns of this ubiquitous virus.

Fatal varicella in an immunocompromised adult associated with a European genotype E2 variant of varicella zoster virus

Varicella zoster virus (VZV) seronegative patients under immunosuppressive therapy are at risk for severe life-threatening varicella. A 25-year-old male patient presented with rash and hepatitis. He had been known to suffer from Crohn's disease and received immunosuppressive treatment with azathioprine. The patient showed dyspnoea, and presented with a generalized rash with vesicular lesions typical for herpesvirus infections. He was started immediately on acyclovir therapy. Varicella infection was determined in this VZV seronegative patient in rash vesicles, blood and tracheal secretions and a high VZV viral load was detected in these specimens. The causative agent was genotyped by sequencing of several genes as a variant of the European genotype E2 containing several unique single nucleotide polymorphisms. Despite all measures, there was progressive septic shock, and the patient died due to multi-organ failure. Immunocompromised adults without varicella history are at high risk to develop life-threatening complications of varicella. Antiviral therapy with acyclovir can only be successful when administered as early as possible on suspicion of varicella infection in this group of patients. The most effective method to prevent severe varicella in immunocompromised patients is active immunization prior to immunosuppressive therapy.

Chickenpox-associated fulminant hepatitis that led to liver transplantation in a 63-year-old woman

A 63-year-old woman treated with prednisone for sinusitis developed fulminant liver failure due to a clinically unsuspected primary varicella zoster virus infection. The diagnosis of herpetic hepatitis was made from a liver biopsy, and varicella zoster virus viremia was detected by polymerase chain reaction. She was treated successfully with transplantation and perioperative administration of acyclovir.

Comparative analyses of the 9 glycoprotein genes found in wild-type and vaccine strains of varicella-zoster virus

The complete DNA sequences of wild-type and vaccine strains of varicella-zoster virus have been published and listed in GenBank. In this comparative genomic analysis, the sequences of the 9 glycoprotein open reading frames (ORFs) were compared. They included gE (ORF68), gI (ORF 67), gC (ORF14), gH (ORF37), gL (ORF60), gB (ORF31), gK (ORF5), gM (ORF50), and gN (ORF8 or ORF9A). After realignment on the basis of newer data, the corrected gB sequence was lengthened to include 931 residues. The data showed that there were glycoprotein polymorphisms that differentiated North American/European strains from Japanese strains-for example, an additional ATG codon in the gL of all Oka strains. Also, there were a small number of coding single-nucleotide polymorphisms present only in glycoproteins of vaccine strains. Because these changes were highly conserved, the structure of the glycoprotein was unlikely to be altered.

Novel varicella-zoster virus glycoprotein E gene mutations associated with genotypes A and D

Here, we describe the association of certain varicella-zoster virus (VZV) genotypes with unique glycoprotein E (gE) gene mutations. Within 45 analyzed VZV wild-type strains of genotypes A and D, five novel gE mutations were discovered. A statistically significant (P < 0.0001) association of certain gE mutations with VZV genotype D was found.

An increasing incidence of chickenpox central nervous system complications in children: What's happening in Tuscany?

BACKGROUND

The most frequent noncutaneous site of involvement of chickenpox is the central nervous system (CNS) and complications include cerebellar ataxia, encephalitis, and meningitis.

OBJECTIVES

We have recently observed an unusually high number of children with chickenpox CNS complications in our university children's hospital. A study to evaluate the incidence of these complications over time in children living in Tuscany was carried out.

STUDY DESIGN

We evaluated all cases of chickenpox and chickenpox complications leading to hospitalization in children aged 1 month-14 years reported to the Tuscany public health centre between 1997 and 2004. The International Classification of Disease Ninth Revision-CM hospital discharge diagnostic codes and medical records were used.

RESULTS

The incidence (95% confidence interval) of CNS complications/1000 chickenpox cases was stable between 1997 and 2001 [1997: 0.80 (0.29-1.74); 1998: 0.73 (0.29-1.50); 1999: 0.67 (0.25-1.46); 2000: 0.56 (0.15-1.44); 2001: 0.59 (0.16-1.50)] but increased significantly (chi(2) for trend: 9.401; p=.0021) in 2002 [1.56 (0.83-2.66)], in 2003 [1.73 (0.95-2.90)] and in 2004 [1.51 (0.74-2.27)]. Non-CNS complications remained stable over time.

CONCLUSIONS

Possible factors biasing the result were taken into account. Reasons of increased CNS complications remain unknown, but the possible emergence of a particularly neurotropic strain of varicella-zoster virus should be further investigated.

Genomic cartography of varicella-zoster virus: a complete genome-based analysis of strain variability with implications for attenuation and phenotypic differences

In order to gain a better perspective on the true variability of varicella-zoster virus (VZV) and to catalogue the location and number of differences, 11 new complete genome sequences were compared with those previously in the public domain (18 complete genomes in total). Three of the newly sequenced genomes were derived from a single strain in order to assess variations that can occur during serial passage in cell culture. The analysis revealed that while VZV is relatively stable genetically it does posses a certain degree of variability. The reiteration regions, origins of replication and intergenic homopolymer regions were all found to be variable between strains as well as within a given strain. In addition, the terminal viral sequences were found to vary within and between strains specifically at the 3' end of the genome. Analysis of single nucleotide polymorphisms (SNPs) identified a total of 557 variable sites, 451 of which were found in coding regions and resulted in 187 different in amino acid substitutions. A comparison of the SNPs present in the two gE mutant strains, VZV-MSP and VZV-BC, suggested that the missense mutation in gE was primarily responsible for the accelerated cell spread phenotype. Some of the variations noted with high passage in cell culture are consistent with variations seen in the IE62 gene of the vaccine strains (S628G, R958G and I1260V) that may help in pinpointing variations essential for attenuation. Although VZV has been considered to be one of the most genetically stable human herpesviruses, this initial assessment of genomic VZV cartography provides insight into ORFs with previously unreported variations.