Ambispective epidemiological observational study of varicella-zoster virus infection: An 18 year-single-center Bulgarian experience

BACKGROUND Varicella(chickenpox)and herpes zoster(shingles)are outcomes of varicella-zoster virus(VZV)infection,and understanding their incidence trends is vital for public health planning.AIM To conduct an ambispective epidemiological study by analyzing the main epidemiological characteristics of VZV infection during an 18 year-period(2000-2018).METHODS We used descriptive and epidemiological methods to characterize chickenpox in Bulgaria,the city of Plovdiv and the region for a period of 18 years(2000-2018).RESULTS The average incidence of varicella-zoster infection for the period 2000–2018 in the Plovdiv region was estimated at 449.58‰.The highest relative share of the infection was assessed in the month of January at 13.6%,and the lowest in the months of August and September at 2.9%(both months).The age group most affected by the infection was 1-4 years,followed by 5-9 years.This corresponds to the so-called"pro-epidemic population"-a phenomenon typical for airborne infections,confirming their mass impact on the perpetuation of VZV infection.CONCLUSION Our findings reveal significant insights into VZV epidemiology,including age-specific incidence rates,clinical manifestations,and vaccination impact.This comprehensive analysis contributes to the broader understanding of VZV infec-tion dynamics and may inform evidence-based preventive measures.

Varicella-Zoster Virus Encephalitis with Hyponatremia in an Immunocompetent Elderly Patient:A Case Report

As a common cause of viral encephalitis,varicella-zoster virus(VZV)may invade the central nervous system of immunosuppressed patients during reactivation.Herein,we report a rare case of an immunocompetent patient with VZV encephalitis who developed severe hyponatremia and was considered to have a suspected primary infection.The patient was diagnosed with the support of second-generation sequencing and had persistent hyponatremia after being cured.Although rare,this case suggests that VZV encephalitis may occur in unexpected patients and present with unusual clinical manifestations,requiring advanced detection methods and clinical expertise for resolution.

Role of viruses in periodontitis:An extensive review of herpesviruses,human immunodeficiency virus,coronavirus-19,papillomavirus and hepatitis viruses

Periodontitis is the inflammation of the supporting structures around the dentition.Several microbial agents,mostly bacteria,have been identified as causative factors for periodontal disease.On the other hand,oral cavity is a rich reservoir for viruses since it contains a wide variety of cell types that can be targeted by viruses.Traditionally,the focus of research about the oral flora has been on bacteria because the most widespread oral diseases,like periodontitis and dental caries,are outcomes of bacterial infection.However,recently and especially after the emergence of coronavirus disease 2019,there is a growing tendency toward including viruses also into the scope of oral microbiome investigations.The global high prevalence of periodontitis and viral infections may point out to a concomitant or synergistic effect between the two.Although the exact nature of the mechanism still is not clearly understood,this could be speculated through the manipulation of the immune system by viruses;hence facilitating the furthermore colonization of the oral tissues by bacteria.This review provides an extensive and detailed update on the role of the most common viruses including herpes family(herpes simplex,varicella-zoster,Epstein-Barr,cytomegalovirus),Human papillomaviruses,Human immunodeficiency virus and severe acute respiratory syndrome coronavirus 2 in the initiation,progression and prognosis of periodontitis.

Identification of novel mammalian viruses in tree shrews(Tupaia belangeri chinensis)

The Chinese tree shrew(Tupaia belangeri chinensis),a member of the mammalian order Scandentia,exhibits considerable similarities with primates,including humans,in aspects of its nervous,immune,and metabolic systems.These similarities have established the tree shrew as a promising experimental model for biomedical research on cancer,infectious diseases,metabolic disorders,and mental health conditions.Herein,we used metatranscriptomic sequencing to analyze plasma,as well as oral and anal swab samples,from 105 healthy asymptomatic tree shrews to identify the presence of potential zoonotic viruses.In total,eight mammalian viruses with complete genomes were identified,belonging to six viral families,including Flaviviridae,Hepeviridae,Parvovirinae,Picornaviridae,Sedoreoviridae,and Spinareoviridae.Notably,the presence of rotavirus was recorded in tree shrews for the first time.Three viruses-hepacivirus 1,parvovirus,and picornavirus-exhibited low genetic similarity(<70%)with previously reported viruses at the whole-genome scale,indicating novelty.Conversely,three other viruses-hepacivirus 2,hepatovirus A and hepevirus-exhibited high similarity(>94%)to known viral strains.Phylogenetic analyses also revealed that the rotavirus and mammalian orthoreovirus identified in this study may be novel reassortants.These findings provide insights into the diverse viral spectrum present in captive Chinese tree shrews,highlighting the necessity for further research into their potential for crossspecies transmission.

Microbiology laboratory and the management of motherchild varicella-zoster virus infection

Varicella-zoster virus, which is responsible for varicella(chickenpox) and herpes zoster(shingles), is ubiquitous and causes an acute infection among children, especially those aged less than six years. As 90% of adults have had varicella in childhood, it is unusual to encounter an infected pregnant woman but, if the disease does appear, it can lead to complications for both the mother and fetus or newborn. The major maternal complications include pneumonia, which can lead to death if not treated. If the virus passes to the fetus, congenital varicella syndrome, neonatal varicella(particularly serious if maternal rash appears in the days immediately before or after childbirth) or herpes zoster in the early years of life may occur depending on the time of infection. A Microbiology laboratory can help in the diagnosis and management of mother-child infection at four main times:(1) when a pregnant woman has been exposed to varicella or herpes zoster, a prompt search for specific antibodies can determine whether she is susceptible to, or protected against infection;(2) when a pregnant woman develops clinical symptoms consistent with varicella, the diagnosis is usually clinical, but a laboratory can be crucial if the symptoms are doubtful or otherwise unclear(atypical patterns in immunocompromised subjects, patients with post-vaccination varicella, or subjects who have received immunoglobulins), or if there is a need for a differential diagnosis between varicella and other types of dermatoses with vesicle formation;(3) when a prenatal diagnosis of uterine infection is required in order to detect cases of congenital varicella syndrome after the onset of varicella in the mother; and(4) when the baby is born and it is necessary to confirm a diagnosis of varicella(and its complications), make a differential diagnosis between varicella and other diseases with similar symptoms, or confirm a causal relationship between maternal varicella and malformations in a newborn.

Varicella-zoster virus-associated meningitis,encephalitis,and myelitis with sporadic skin blisters:A case report

BACKGROUND Varicella-zoster virus(VZV)generally causes chickenpox at first infection in childhood and then establishes latent infection in the dorsal root ganglia of the spinal cord or other nerves.Virus reactivation owing to an impaired immune system causes inflammation along spinal nerves from the affected spinal segment,leading to skin manifestations(herpes zoster).Viremia and subsequent hematogenous transmission and nerve axonal transport of the virus may lead to meningitis,encephalitis,and myelitis.One such case is described in this study.CASE SUMMARY A 64-year-old man presented with dysuria,pyrexia,and progressive disturbance in consciousness.He had signs of meningeal irritation,and cerebrospinal fluid(CSF)analysis revealed marked pleocytosis with mononuclear predominance and a CSF/serum glucose ratio of 0.64.Head magnetic resonance imaging revealed hyperintense areas in the frontal lobes.He had four isolated blisters with papules and halos on his right chest,right lumbar region,and left scapular region.Infected giant cells were detected using the Tzanck test.Degenerated epidermal cells with intranuclear inclusion bodies and ballooning degeneration were present on skin biopsy.Serum VZV antibody titers suggested previous infection,and the CSF tested positive for VZV-DNA.He developed paraplegia,decreased temperature perception in the legs,urinary retention,and fecal incontinence.The patient was diagnosed with meningitis,encephalitis,and myelitis and was treated with acyclovir for 23 days and prednisolone for 14 days.Despite gradual improvement,the urinary retention and gait disturbances persisted as sequelae.CONCLUSION VZV reactivation should be considered in differential diagnoses of patients with sporadic blisters and unexplained central nervous system symptoms.

Review of varicella-zoster virus infections in pregnant women and neonates

Even though varicella is rare in pregnancy, the disease can lead occasionally to disastrous illnesses for both the mother and her neonate. By contrast, normal zoster is not associated with special problems during pregnancy and peri- natal period. Pregnant women, who contract varicella, are at risk of varicella pneumonia which must be regarded as medical emergency. At any stage during pregnancy, chickenpox may cause intrauterine infection. The consequences for the fetus depend on the time of maternal disease. During the first two trimesters, maternal varicella may result in congenital varicella syndrome which may occur in nearly 2%. Typical symptoms are skin lesions in dermatomal distribution, neurological defects, eye diseases, and skeletal anomalies. Maternal infection near term is associated with a substantial risk of intrauterine acquired neonatal chickenpox in the neonate. If the mother develops varicella rash between day 4 (5) ante partum and day 2 post partum, generalized neonatal varicella leading to death in about 20% of the cases has to be expected. The present paper reviews the clinical consequences and the currently available concepts of prevention, diagnosis, and therapy of varicella-zoster virus infections during pregnancy.

Varicella-zoster virus meningitis with hypoglycorrhachia: A case report

BACKGROUND Varicella-zoster virus(VZV)is a common viral infection,but meningitis is a rare complication of VZV infection.The cerebrospinal fluid glucose of viral meningitis is usually within the normal range,which is different from bacteria,fungi,and cancerous meningitis.This paper reports a case of VZV meningitis with hypoglycorrhachia and the relevant literature was reviewed.CASE SUMMARY We report a case of an immunocompetent 39-year-old male,presenting with severe headache and fevers,without meningeal signs or exanthem,found to have VZV meningitis by the metagenomic next-generation sequencing of cerebrospinal fluid.The cerebrospinal fluid analysis revealed hypoglycorrhachia(cerebrospinal fluid glucose of 2.16)and he was treated successfully with intravenous acyclovir.Our literature review identified only ten cases diagnosed with VZV meningitis with hypoglycorrhachia previously reported to date in the English literature whose cerebrospinal fluid glucose was from 1.6 to 2.7mmol/L,with a ratio of cerebrospinal fluid to serum glucose from 0.30 to 0.49.CONCLUSION Although rare,the cerebrospinal fluid of patients with VZV meningitis may have hypoglycorrhachia,which broadens the understanding of the disease.

Protocol for detection of pathogenic enteric RNA viruses by regular monitoring of environmental samples from wastewater treatment plants using droplet digital PCR

Background:The present comprehensive protocol is focused on the detection of pathogenic enteric RNA viruses,explicitly focusing on norovirus genogroup II(GII),astrovirus,rotavirus,Aichi virus,sapovirus,hepatitis A and E viruses in wastewater treatment plants through droplet digital PCR(ddPCR).Enteric viruses are of significant public health concern,as they are the leading cause of diseases like gastroenteritis.Regular monitoring of environmental samples,particularly from wastewater treatment plants,is crucial for early detection and control of these viruses.This research aims to improve the understanding of the prevalence and dynamics of enteric viruses in urban India and will serve as a model for similar studies in other regions.Our protocol's objective is to establish a novel ddPCRbased methodology for the detection and molecular characterization of enteric viruses present in wastewater samples sourced from Bhopal,India.Our assay is capable of accurately quantifying virus concentrations without standard curves,minimizing extensive optimization,and enhancing sensitivity and precision,especially for low-abundance targets.Methods:The study involves fortnightly collecting and analyzing samples from nine wastewater treatment plants over two years,ensuring comprehensive coverage and consistent data.Our study innovatively applies ddPCR to simultaneously detect and quantify enteric viruses in wastewater,a more advanced technique.Additionally,we will employ next-generation sequencing for detailed viral genome identification in samples tested positive for pathogenic viruses.Conclusion:This study will aid in understanding these viruses’genetic diversity and mutation rates,which is crucial for developing tailored intervention strategies.The findings will be instrumental in shaping public health responses and improving epidemiological surveillance,especially in localities heaving sewage networks.

Substitutions of stem-loop subdomains in internal ribosome entry site of Senecavirus A:Impacts on rescue of sequence-modifying viruses

Senecavirus A(SVA)has a positive-sense,single-stranded RNA genome.Its 5´untranslated region harbors an internal ribosome entry site(IRES),comprising 10 larger or smaller stem-loop structures(including a pseudoknot)that have been demonstrated to be well conserved.However,it is still unclear whether each stem-loop subdomain,such as a single stem or loop,is also highly conserved.To clarify this issue in the present study,a set of 29 SVA cDNA clones were constructed by site-directed mutagenesis(SDM)on the IRES.The SDM-modified scenarios included:(1)stem-formed complementary sequences exchanging with each other;(2)loop transversion;(3)loop transition;and(4)point mutations.All cDNA clones were separately transfected into cells for rescuing viable viruses,whereas only four SVAs of interest could be recovered,and were genetically stable during 20 passages.One progeny grew significantly slower than the other three did.The dual-luciferase reporter assay showed that none of the SDM-modified IRESes significantly inhibited the IRES activity.Our previous study indicated that a single motif from any of the ten stem structures,if completely mutated,would cause the failure of virus recovery.Interestingly,our present study revealed three stem structures,whose individual complementary sequences could exchange with each other to rescue sequence-modifying SVAs.Moreover,one apical loop was demonstrated to have the ability to tolerate its own full-length transition,also having no impact on the recovery of sequence-modifying SVA.The present study suggested that not every stem-loop structure was strictly conserved in its conformation,while the full-length IRES itself was well conserved.This provides a new research direction on interaction between the IRES and many factors.

Characterization of three African swine fever viruses from diferent clinical settings revealed a potential attenuation mechanism

African swine fever(ASF)is an acute and fatal hemorrhagic disease in domestic pigs and wild boars caused by African swine fever virus(ASFV)that currently threatens the pig industry worldwide.Since the 2018 ASF outbreak in China,ASFV has evolved and caused diverse clinical manifestations,such as chronic and asymptomatic infections.Therefore,it is important to understand the molecular mechanisms underlying ASFV attenuation in the feld.Here,we isolated three ASFVs from one diseased and two asymptomatic pigs by using primary porcine alveolar macrophages(PAMs)from both domestic pigs and Bama minipigs.The three ASFVs exhibited similar phenotypes in cell culture,includ‑ing cytopathic efects(CPEs),hemadsorptions(HADs),viral protein expressions and growth curves.Genome sequenc‑ing revealed that all three ASFVs were genotype II strains.Genomic comparisons suggested that the disruption of the viral genes MGF360 and MGF110,rather than EP402R and EP153R,is likely involved in the potential attenuation of ASFV via the upregulation of innate immune responses.

Genetic and biological properties of H10Nx influenza viruses in China

H10 subtype avian influenza viruses(AIV)have been circulating in China for 40 years.H10 AIVs in China have expanded their host range from wild birds to domestic poultry and mammals,even human.Most of the H10 subtype AIVs reported in China were isolate from the southeast part.We isolated an H10N3 AIV,A/Chicken/Liaoning/SY1080/2021(SY1080),from live poultry market(LPM)in Liaoning Province of the Northeast China.SY1080replicated efficiently in mice lungs and nasal turbinates without prior adaptation.We systematically compared SY1080 with other H10 subtype isolates in China.Phylogenetic analysis showed that SY1080 and most of the H10strains belonged to the Eurasian lineage.H10 AIVs in China have formed 63 genotypes.SY1080 as well as the H10N3 strains from human infections belonged to G60 genotype.H10Nx AIV acquired multiple mammalian adaptive and virulence related mutations during circulation and the recent reassortants derived internal genes from chicken H9N2 AIVs.The H10Nx subtypes AIVs posed potential threat to public health.These results suggested we should strengthen the surveillance and evaluation of H10 subtype strains.

Genetic and biological properties of H9N2 avian influenza viruses isolated in central China from2020 to 2022

The H9N2 subtype of avian influenza virus(AIV)is widely prevalent in poultry and wild birds globally,and has become the predominant subtype circulating in poultry in China.The H9N2 AIV can directly or indirectly(by serving as a"donor virus")infect humans,posing a significant threat to public health.Currently,there is a lack of in-depth research on the prevalence of H9N2 viruses in Shanxi Province,central China.In this study,we isolated 14 H9N2 AIVs from October 2020 to April 2022 in Shanxi Province,and genetic analysis revealed that these viruses belonged to 7 different genotypes.Our study on animals revealed that the H9N2 strains we identified displayed high transmission efficiency among chicken populations,and exhibited diverse replication abilities within these birds.These viruses could replicate efficiently in the lungs of mice,with one strain also demonstrating the capacity to reproduce in organs like the brain and kidneys.At the cellular level,the replication ability of different H9N2 strains was evaluated using plaque formation assays and multi-step growth curve assays,revealing significant differences in the replication and proliferation efficiency of the various H9N2 viruses at the cellular level.The antigenicity analysis suggested that these isolates could be classified into 2 separate antigenic clusters.Our research provides crucial data to help understand the prevalence and biological characteristics of H9N2 AIVs in central China.It also highlights the necessity of enhancing the surveillance of H9N2 AIVs.

Development and application of a SYBR Green I fuorescent PCR assay for the diferentiation of genotypes I and II African swine fever viruses

African swine fever(ASF)is a highly fatal hemorrhagic disease afecting domestic pigs caused by African swine fever virus(ASFV).Genetic analysis of ASFV isolates to date has identifed 24 geographically related genotypes with various subgroups,but only genotype I and II ASFVs have been reported outside Africa.ASFV genotype II and genotype I viruses were reported in China in 2018 and 2021,respectively.In this study,unique and highly conserved noncoding regions were found between MGF_505-9R and MGF_505-10R in the 188 genomes of ASFV genotypes I and II.A pair of primers was designed on the basis of this region.By optimizing the reaction system and conditions,a SYBR Green I fuorescence PCR assay that can distinguish between ASFV genotypes I and II was established,and the sensitivity,reproducibility and specifcity were evaluated.The detection limit was 1 TCID_(50)/0.1 mL for both genotypes,with no cross-reactivity observed with other common pig pathogens.The intra-and interbatch variation coefcients were both less than 1.2%.Clinical sample detection analysis revealed 47 positive cases out of 100,including 3 for genotype I and 44 for genotype II,aligning with results from the WOAH-recommended and national standard methods.The method developed in this study allows for the diferentiation of ASFV genotypes I and II without the need for genome sequencing,ofering a convenient and rapid approach for ASFV detection and genotype identifcation.

Advance of the Research on Testing of Animal Viruses by LAMP Technology in Abroad

Loop-mediated isothermal amplification（LAMP） is an amplification method developed by Notomi et al and has been applied successfully for the detection of many viruses.This paper introduced the current status of LAMP and recent developments,and the method applying in the diagnosis of animal viruses in abroad.

Varicella-zoster virus meningitis after spinal anesthesia:A case report

BACKGROUND Headache is a common complication of regional anesthesia.The treatment of post spinal anesthesia headache varies depending on the cause.Although meningitis is rare,it can cause significant harm to the patient.Post dural puncture headache and septic meningitis are the most commonly suspected causes of post spinal anesthesia headache;however,other causes should also be considered.CASE SUMMARY A 69-year-old woman was scheduled for varicose vein stripping surgery under spinal anesthesia.The procedure was performed aseptically,and surgery was completed without any complications.After 4 d,the patient visited the emergency room with complaints of headache,nausea,and anorexia.Clinical examination revealed that the patient was afebrile.Considering the history of spinal anesthesia,post dural puncture headache and septic meningitis was initially suspected,and the patient was treated with empirical antibiotics.Subsequently,varicella-zoster virus PCR test result was positive,and all other test results were negative.The patient was diagnosed with meningitis caused by varicella-zoster virus and was treated with acyclovir for 5 d.The headache improved,and the patient was discharged without any problems.CONCLUSION Viral meningitis due to virus reactivation may cause headache after regional anesthesia.Therefore,clinicians should consider multiple etiologies of headache.

Virion Proteomics of Large DNA Viruses

Large DNA viruses normally have complex structures with many of protein components derived from both viral and host origins. The development in proteomics, especially mass spectrometry identification techniques provide powerful tools for analyzing large viruses. In this review, we have summarized the recent achievements on proteomic studies of large DNA viruses, such as herpesvirus, poxvirus, nimavirus and baculoviruse. The proteomics of baculovirus occlusion-derived virions (ODV) were emphasized. Different mass spectrometry techniques used on various baculoviruses were introduced, and the identified structurally associated proteins of baculoviruses are summarized.

Molecular Characteristics of gp90 Gene of 14 Reticuloendotheliosis Viruses Isolated in China

[Objective] The paper was to study molecular characteristics of gp90 gene of 14 Reticuloendotheliosis viruses isolated in China.[Method] The surface envelop gene gp90 of 14 REV strains isolated from different commercial layer farms in China were amplified,and their nucleotide sequences were determined.[Result] Sequence analysis showes that 14 REV strains are more identical to the subtype 3 isolates than to the early Chinese REV isolates.In addition,14 REV strains have a high identity with some REV strains in US and Taiwan.[Conclusion] The study provided necessary information for further understanding the evolution of REV.

Laboratory biosafety for handling emerging viruses

Emerging viruses are viruses whose occurrence has risen within the past twenty years,or whose presence is likely to increase in the near future.Diseases caused by emerging viruses are a major threat to global public health.In spite of greater awareness of safety and containment procedures,the handling of pathogenic viruses remains a likely source of infection,and mortality,among laboratory workers.There is a steady increase in both the number of laboratories and scientist handling emerging viruses for diagnostics and research.The potential for harm associated to work with these infectious agents can be minimized through the application of sound biosafety concepts and practices.The main factors to the prevention of laboratory-acquired infection are well-trained personnel who are knowledgable and biohazard aware,who are perceptive of the various ways of transmission,and who are professional in safe laboratory practice management.In addition,we should emphasize that appropriate facilities,practices and procedures are to be used by the laboratory workers for the handling of emerging viruses in a safe and secure manner.This review is aimed at providing researchers and laboratory personnel with basic biosafety principles to protect themselves from exposure to emerging viruses while working in the laboratory.This paper focuses on what emerging viruses are,why emerging viruses can cause laboratory-acquired infection,how to assess the risk of working with emerging viruses,and how laboratory-acquired infection can be prevented.Control measures used in the laboratory designed as such that they protect workers from emerging viruses and safeguard the public through the safe disposal of infectious wastes are also addressed.

Could autophagy dysregulation link neurotropic viruses to Alzheimer’s disease?

Neurotropic herpesviruses have been associated with the onset and progression of Alzheimer’s disease,a common form of dementia that afflicts a large percentage of elderly individuals.Interestingly,among the neurotropic herpesviruses,herpes simplex virus-1,human herpesvirus-6A,and human herpesvirus-6B have been reported to infect several cell types present in the central nervous system and to dysregulate autophagy,a process required for homeostasis of cells,especially neurons.Indeed autophagosome accumulation,indicating an unbalance between autophagosome formation and autophagosome degradation,has been observed in neurons of Alzheimer’s disease patients and may play a role in the intracellular and extracellular accumulation of amyloidβand in the altered protein tau metabolism.Moreover,herpesvirus infection of central nervous system cells such as glia and microglia can increase the production of oxidant species through the alteration of mitochondrial dynamics and promote inflammation,another hallmark of Alzheimer’s disease.This evidence suggests that it is worth further investigating the role of neurotropic herpesviruses,particularly human herpesvirus-6A/B,in the etiopathogenesis of Alzheimer’s disease.