The controversial natural history of oral herpes simplex virus type 1 infection

Management of oral herpes simplex virus infections: The problem of resistance. A narrative review

Herpes Simplex Virus (HSV) type 1 (HSV-1) and type 2 (HSV-2) are among the most common human viral pathogens, affecting several billion people worldwide. Although in healthy patients clinical signs and symptoms of HSV infection are usually mild and self-limiting, HSV-infections in immunocompromised patients are frequently more aggressive, persistent, and even life-threatening. Acyclovir and its derivatives are the gold standard antiviral drugs for the prevention and treatment of HSV infections. Although the development of acyclovir resistance is a rather uncommon condition, it may be associated with serious complications, especially in immunocompromised patients. In this review, we aim to address the problem of drug resistant HSV infection and discuss the available alternative therapeutic interventions. All relative studies concerning alternative treatment modalities of acyclovir resistant HSV infection published in PubMed between 1989 to 2022 were reviewed. Long-term treatment and prophylaxis with antiviral agents predisposes to drug resistance, especially in immunocompromised patients. Cidofovir and foscarnet could serve as alternative treatments in these cases. Although rare, acyclovir resistance may be associated with severe complications. Hopefully, in the future, novel antiviral drugs and vaccines will be available in order to avoid the existing drug resistance.

Herpes simplex virus type 1 in periapical pathoses: Systematic review and meta-analysis

OBJECTIVES

The objective of this systematic review and meta-analysis of observational studies was to assess whether herpes simplex virus type 1 (HSV-1) can infect endodontic periapical lesions.

MATERIALS AND METHODS

Studies with cross-sectional design investigating HSV-1 in periapical tissues of patients with symptomatic and asymptomatic acute and chronic apical periodontitis were searched through MEDLINE, Scopus, Embase, Web of Science, and Google Scholar. Pooled HSV-1 prevalence proportion with 95% confidence interval (95CI) in periapical lesions was assessed with both fixed-effect and random-effects models, with/without adjustment for study quality and publication bias. Result robustness was investigated through sensitivity and subgroup analyses.

RESULTS

Literature search, performed twice, provided 84 items, and eight remained for the meta-analysis; globally, there were 194 patients mostly adults. The pooled HSV-1 prevalence proportions, assessed with various methods, were 6.9% (95CI, 3.8-11.3%, fixed-effect); 6.8% (95CI, 3.6-11.0%, random-effects); 8.1% (95CI, 4.4-14.5%, quality-adjusted); and 4.8% (95CI, 2.0-11.4%; adjusted for small-study effect).

CONCLUSIONS

The results indicated that HSV-1 can colonize the periapical tissues of 3%-11% patients with periapical diseases. Such data do not imply a causative role of HSV-1 in disease development and advancement. Well-designed and large-sized prospective cohort studies should be added in the literature panorama.

The associations of herpes simplex virus and varicella zoster virus infection with dementia: a nationwide retrospective cohort study

BACKGROUND

In this study, the risk of dementia in patients with a history of herpes simplex virus (HSV) or varicella zoster virus (VZV) infection was evaluated.

METHODS

This nationwide cohort study used data from the Korean National Health Insurance Service collected between 2006 and 2017. A total of 752,205 subjects ≥ 45 years of age not diagnosed with dementia until 2006 were included. A multivariate Cox regression model, adjusted for age, sex, and other comorbidities, was used to assess the hazard ratio (HR) for dementia based on VZV or HSV infection. The interaction effects of both viral infections were analysed. Viral infections are classified into four categories: eye, central nervous system (CNS), simple, and complicated. The hazard ratio (HR) of viral infection was analysed based on the type of dementia.

RESULTS

In multivariable analysis, both HSV and VZV infection were associated with an increased risk of dementia (HR = 1.38, 95% confidence interval, CI:1.33-1.43) and (HR = 1.41, 95% CI:1.37-1.46), respectively. Patients who experienced both HSV and VZV infections were also at an increased risk of dementia (HR = 1.57, 95% CI:1.50-1.63). The co-infection group showed the shortest time from viral infection to dementia diagnosis (4.09 ± 3.02 years). In the subgroup analysis, all types of HSV and VZV infections were associated with an increased risk of dementia compared to the non-infection group. The eye, CNS, and complicated VZV infections were associated with a significantly higher risk than simple VZV infections. There were no significant differences between the subtypes of HSV infection. Furthermore, HSV, VSV, and co-infection were associated with an increased risk of all dementia types, including Alzheimer's disease (AD) and vascular dementia (VD).

CONCLUSIONS

Individual HSV and VZV infections were associated with an increased risk of all types of dementia, including AD and VD. Patients co-infected with HSV and VZV, VZV infection in the eye, CNS, or complicated type were more vulnerable to the development of dementia.

Flavonoids with Anti-Herpes Simplex Virus Properties: Deciphering Their Mechanisms in Disrupting the Viral Life Cycle

The herpes simplex virus (HSV) is a double-stranded DNA human virus that causes persistent infections with recurrent outbreaks. HSV exists in two forms: HSV-1, responsible for oral herpes, and HSV-2, primarily causing genital herpes. Both types can lead to significant complications, including neurological issues. Conventional treatment, involving acyclovir and its derivatives, faces challenges due to drug resistance. This underscores the imperative for continual research and development of new drugs, with a particular emphasis on exploring the potential of natural antivirals. Flavonoids have demonstrated promise in combating various viruses, including those within the herpesvirus family. This review, delving into recent studies, reveals the intricate mechanisms by which flavonoids decode their antiviral capabilities against HSV. By disrupting key stages of the viral life cycle, such as attachment to host cells, entry, DNA replication, latency, and reactivation, flavonoids emerge as formidable contenders in the ongoing battle against HSV infections.

The Role of DNA Viruses in Human Cancer

This review discusses the possible involvement of infections-associated cancers in humans, with virus infections contributing 15% to 20% of total cancer cases in humans. DNA virus encoded proteins interact with host cellular signaling pathways and control proliferation, cell death and genomic integrity viral oncoproteins are known to bind cellular Deubiquitinates (DUBs) such as cyclindromatosis tumor suppressor, ubiquitin-specific proteases 7, 11, 15 and 20, and A-20 to improve their intracellular stability and cellular signaling pathways and finally transformation. Human papillomaviruses (cervical carcinoma, oral cancer and laryngeal cancer); human polyomaviruses (mesotheliomas, brain tumors); Epstein-Barr virus (B-cell lymphoproliferative diseases and nasopharyngeal carcinoma); Kaposi's Sarcoma Herpesvirus (Kaposi's Sarcoma and primary effusion lymphomas); hepatitis B (hepatocellular carcinoma (HCC)) cause up to 20% of malignancies around the world.

Antiviral Potential of the Genus Panax: An updated review on their effects and underlying mechanism of action

Viral infections are known as one of the major factors causing death. Ginseng is a medicinal plant that demonstrated a wide range of antiviral potential, and saponins are the major bioactive ingredients in the genus Panax with vast therapeutic potential. Studies focusing on the antiviral activity of the genus Panax plant-derived agents (extracts and saponins) and their mechanisms were identified and summarized, including contributions mainly from January 2016 until January 2022. P. ginseng, P. notoginseng, and P. quinquefolius were included in the review as valuable medicinal herbs against infections with 14 types of viruses. Reports from 9 extracts and 12 bioactive saponins were included, with 6 types of protopanaxadiol (PPD) ginsenosides and 6 types of protopanaxatriol (PPT) ginsenosides. The mechanisms mainly involved the inhibition of viral attachment and replication, the modulation of immune response by regulating signaling pathways, including the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, cystathionine γ-lyase (CSE)/hydrogen sulfide (H₂S) pathway, phosphoinositide-dependent kinase-1 (PDK1)/ protein kinase B (Akt) signaling pathway, c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) pathway, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. This review includes detailed information about the mentioned antiviral effects of the genus Panax extracts and saponins in vitro and in vivo, and in human clinical trials, which provides a scientific basis for ginseng as an adjunctive therapeutic drug or nutraceutical.

A Comprehensive Overview of Epidemiology, Pathogenesis and the Management of Herpes Labialis

Herpes labialis remains exceedingly prevalent and is one of the most common human viral infections throughout the world. Recurrent herpes labialis evolves from the initial viral infection by herpes simplex virus type 1 (HSV-1) which subsequently presents with or without symptoms. Reactivation of this virus is triggered by psychosocial factors such as stress, febrile environment, ultraviolet light susceptibility, or specific dietary inadequacy. This virus infection is also characterized by uninterrupted transitions between chronic-latent and acute-recurrent phases, allowing the virus to opportunistically avoid immunity and warrant the transmission to other vulnerable hosts simultaneously. This review comprehensively evaluates the current evidence on epidemiology, pathogenesis, transmission modes, clinical manifestations, and current management options of herpes labialis infections.

Efficacy of Lazolex® Gel in the Treatment of Herpes Simplex Mucocutaneous Infections and the Prevention of Recurrences: A Pilot Study

Background. Previous in vitro and in vivo studies indicated that walnut extract has a therapeutic effect on herpes simplex infections. This study aimed to evaluate the efficacy and tolerance of Lazolex® Gel (Iveriapharma, Tbilisi, Georgia), an emollient gel to treat mucocutaneous lesions caused by herpes simplex virus. Methods. A single-center, single-arm, open-label, phase II clinical trial was conducted with 30 patients divided into two groups: 15 patients with herpes simplex virus type 1 (HSV-1) infections and 15 with herpes simplex virus type 2 (HSV-2). All received topical treatment with Lazolex® Gel four times a day for 10 days. The efficacy and tolerance of the treatment were evaluated on day 10 and day 20 of the study. Recurrence rates were also evaluated both prior to treatment with Lazolex® and over a 4-year follow-up period subsequent to treatment. Results. The median effective time to resolution of symptoms (itching, burning, and pain) was 1.97 days in the HSV-1 group and 3.11 days in the HSV-2 group. The median effective time for vesicles and erosion to disappear was 3.64 days in the HSV-1 group and 3.88 days for the HSV-2 group. Finally, the median effective time for inflammatory signs to disappear was 5.70 and 4.32 days, respectively. Following treatment with Lazolex® Gel, the frequency of outbreaks decreased from a median of 2.00 and 1.00 times per year in the HSV-1 and HSV-2 cohorts to 0.25 and 0.00 ( $p=0.001$ and $p=0.003$ ), respectively. Conclusions. Topical treatment with Lazolex® Gel applied to lesions four times a day for 10 days was shown to be effective and safe in the treatment of herpes simplex mucocutaneous infections and dramatically reduced the rate of recurrence. Clinical trial was approved by Drug Agency of Ministry of Labour, Health and Social Affairs of Georgia, registration # DA Nº CT-000032, date of approval 01.10.2007.

Oxidative stress and inflammation regulation of sirtuins: New insights into common oral diseases

Sirtuins are a family of nicotinamide adenine dinucleotide (NAD)⁺-dependent histone deacetylases, comprising seven members SIRT1-SIRT7. Sirtuins have been extensively studied in regulating ageing and age-related diseases. Sirtuins are also pivotal modulators in oxidative stress and inflammation, as they can regulate the expression and activation of downstream transcriptional factors (such as Forkhead box protein O3 (FOXO3a), nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB)) as well as antioxidant enzymes, through epigenetic modification and post-translational modification. Most importantly, studies have shown that aberrant sirtuins are involved in the pathogenesis of infectious and inflammatory oral diseases, and oral cancer. In this review, we provide a comprehensive overview of the regulatory patterns of sirtuins at multiple levels, and the essential roles of sirtuins in regulating inflammation, oxidative stress, and bone metabolism. We summarize the involvement of sirtuins in several oral diseases such as periodontitis, apical periodontitis, pulpitis, oral candidiasis, oral herpesvirus infections, dental fluorosis, and oral cancer. At last, we discuss the potential utilization of sirtuins as therapeutic targets in oral diseases.

The role of Herpes Simplex Virus type 1 in oral diseases in children

Relevance. Herpes virus infections are the most common and poorly controllable viral infections. There are many difficulties in herpetic lesion verification and treatment in dental practice.

Purpose. The study aimed to present the results of a foreign publication investigation on the role of herpes simplex virus type 1 in the development of oral diseases in children.

Material and methods. Foreign scientific articles about the oral HSV-1 infections published from 2018 to 2022 formed the basis for the study. The study searched the publications on PubMed and Google Scholar bases.

Results. The article presents the newest data on the prevalence, clinical characteristics and diagnosis of oral HSV infection in children. Primary herpetic gingivostomatitis (PHGS), chronic recurrent herpetic gingivostomatitis, chronic recurrent herpes labialis are the main clinical presentations of herpes infection diagnosed in a dental practice. Primary herpetic gingivostomatitis is very common in children aged six months to fve years and occurs in newborns from 2 to 43 days of life. Modern virology success can improve diagnosis and treatment of oral herpetic lesions.

Conclusion. Primary herpetic gingivostomatitis is an acute infectious disease that requires the joint attention of a general practitioner and a dentist to ensure comprehensive treatment.

The sampling strategy of oral microbiome

There are multiple habitats in the oral cavity with bacteria, fungi, viruses, and protozoa residing in, which together constitute the oral micro-ecosystem. These microflorae in the oral cavity primarily include saliva, supragingival dental plaque, subgingival dental plaque, submucosal plaque around implants, plaque in root canals, and plaque on the mucosal surface. The interest and knowledge of the microbiome have dynamically increased with the advancement of technology. Therefore, a reliable, feasible, and practical sampling strategy for the oral microbiome is required for the investigation. This paper introduced the sampling strategy of oral microorganisms, consisting of sample collection, transport, processing, and storage. The materials and devices involved in this study are all commonly used in clinical practice or laboratory. The feasibility and reliability of the sampling methods described in this paper have been verified by multiple studies.

Initial TK-deficient HSV-1 infection in the lip alters contralateral lip challenge immune dynamics

Primary infection with herpes simplex type 1 (HSV-1) occurring around the mouth and nose switches rapidly to lifelong latent infection in sensitive trigeminal ganglia (TG) neurons. Sporadic reactivation of these latent reservoirs later in life is the cause of acute infections of the corneal epithelium, which can cause potentially blinding herpes simplex keratitis (HSK). There is no effective vaccine to protect against HSK, and antiviral drugs provide only partial protection against recurrences. We previously engendered an acute disease-free, non-reactivating latent state in mice when challenged with virulent HSV-1 in orofacial mucosa, by priming with non-neurovirulent HSV-1 (TK_del) before the challenge. Herein, we define the local immune infiltration and inflammatory chemokine production changes after virulent HSV-1 challenge, which were elicited by TK_del prime. Heightened immunosurveillance before virulent challenge, and early enhanced lymphocyte-enriched infiltration of the challenged lip were induced, which corresponded to attenuation of inflammation in the TG and enhanced viral control. Furthermore, classical latent-phase T cell persistence around latent HSV-1 reservoirs were severely reduced. These findings identify the immune processes that are likely to be responsible for establishing non-reactivating latent HSV-1 reservoirs. Stopping reactivation is essential for development of efficient vaccine strategies against HSV-1.

SUN2 Modulates the Propagation of HSV-1

Herpesviruses assemble new viral particles in the nucleus. These nucleocapsids bud through the inner nuclear membrane to produce enveloped viral particles in the perinuclear space before fusing with the outer nuclear membrane to reach the cytoplasm. This unusual route is necessary since viral capsids are too large to pass through nuclear pores. However, the transient perinuclear nucleocapsids (250 nm in diameter) are also larger than the width of the perinuclear space (30 to 50 nm). Interestingly, linker of the nucleoskeleton and cytoskeleton (LINC) components SUN and KASH connect the inner and outer nuclear membranes and regulate their spacing. Previous work by others on the related pseudorabies virus and human cytomegalovirus showed that they functionally interact with SUN proteins. To clarify the role of SUN proteins, we explored their impact on herpes simplex virus 1 (HSV-1), another herpesvirus. Using dominant negative SUN mutants and RNA interference, we show that HSV-1 propagation is dependent on the LINC complex. In contrast to pseudorabies virus, SUN2 disruption by either approach led to increased HSV-1 extracellular viral yields. This SUN2 dependency may be linked to its greater impact on perinuclear spacing in infected cells compared to SUN1. Finally, the virus itself seems to modulate perinuclear spacing. IMPORTANCE The large size of herpesviruses prevents them from travelling across the nuclear pores, and they instead egress across the two nuclear membranes, generating short-lived enveloped perinuclear virions. This poses a challenge as the perinuclear space is smaller than the virions. This implies the separation (unzipping) of the two nuclear membranes to accommodate the viral particles. The LINC complex bridges the two nuclear membranes and is an important regulator of perinuclear spacing. Work by others hint at its functional implication during pseudorabies virus and cytomegalovirus propagation. The present study probes the importance for HSV-1 of the SUN proteins, the LINC components found in the inner nuclear membrane. Using dominant negative constructs and RNA interference (RNAi), the data reveal that SUN2 exhibits antiviral propriety toward HSV-1, as disrupting the protein leads to increased viral yields. This is in contrast with that reported for pseudorabies and suggests that differences among herpesviruses may, once again, prevail.

Low-dose Oral Thimerosal for the Treatment of Oral Herpes: Clinical Trial Results and Improved Outcome After Post-hoc Analysis

BACKGROUND

Thimerosal (TML) is an organomercury antimicrobial. Low doses (1/250^th of the amount in a typical vaccine dose) may promote an antiviral immune response. Low-dose TML (BTL-TML) was evaluated for safety and efficacy against herpes labialis in two FDA-approved, randomized, double blind, placebo-controlled clinical trials.

METHODS

BTL-TML was evaluated in a Phase IIa trial for its ability to block progression to lesion in subjects with recurrent oral herpes caused by dental trauma. Subjects were administered BTL-TML or a saline control over a 7-day period. In a Phase IIb trial, BTL-TML was evaluated for its ability to block progression to lesion over a 7-day period in subjects with herpes lip infections induced by exposure to ultraviolet (UV) radiation.

RESULTS

Progression to lesion post-dental procedure was prevented in 54.5% (12/22) TML subjects versus 22.2% (2/9) control subjects (p = 0.106). Progression to lesion post-UV irradiation was blocked in 47.8% (11/23) BTL-TML treatment subjects and 42.8% (6/14) control subjects. A post-hoc analysis yielded 52.2% (12/23) BTL-TML subjects with no progression to lesion versus 28.6% (6/21) control subjects with no progression (p = 0.099). There were no significant differences in adverse effects between treatment and control groups in either trial.

CONCLUSIONS

Neither clinical trial showed a statistically significant effect of BTL-TML on progression to lesion. However, the post-hoc analysis suggested there is a 48-hour period following UV radiation exposure during which the anti-herpes activity of antivirals such as BTL-TML is reduced. Accordingly, BTL-TML may have promise in subsequent, properly designed and powered clinical trials.

Herpes simplex virus type 1 in subgingival plaque and periodontal diseases. Meta-analysis of observational studies

BACKGROUND AND OBJECTIVES

This meta-analysis of observational studies (PROSPERO registration number CRD42021236054) sought to investigate strength and generalizability of the association of herpes simplex virus type 1 (HSV-1) in subjects with plaque-induced gingivitis and periodontitis, since the data from literature are contrasting.

MATERIAL AND METHODS

Case-control and cross-sectional studies, investigating HSV-1 in subgingival plaque/crevicular fluid and periodontal status, were searched through MEDLINE via PubMed, Scopus, Web of Science and Google Scholar. From each study the crude odds ratio (OR) with 95% confidence interval (95CI) was extracted, and the pooled OR was assessed for periodontitis, chronic and aggressive, and gingivitis. The meta-analytic method was chosen based on the level of heterogeneity. The generalizability of results, determined by the meta-analysis bias, was investigated through secondary analyses including sensitivity analyses for study quality, publication bias, and study inclusion, and subgroup analyses for quality of scientific journals that published the primary studies, world Region, subgingival plaque sampling method and study design.

RESULTS

Twelve studies were included (738 cases, 551 controls). The pooled ORs were 4.4 (95CI, 1.9-10.2) for any periodontitis; specifically, 2.8 (95CI, 1.0-8.3) for chronic periodontitis, 11.8 (95CI, 5.4-25.8) for aggressive periodontitis and 4.8 (95CI, 2.1-11.0) for gingivitis. These estimates were statistically significant, excluding for chronic periodontitis, resulting marginally significant (p = .05). Secondary analyses on any and aggressive periodontitis, and, partly, chronic periodontitis corroborated the results, while the material was insufficient for secondary analyses on gingivitis.

CONCLUSIONS

The results obtained indicated that HSV-1 is associated with periodontitis, while data about gingivitis are inconclusive. HSV-1 investigation in subgingival plaque could help assess periodontitis risk and severity and, if causal association were confirmed, could contribute to its control.

Release of HSV-1 Cell-Free Virions: Mechanisms, Regulation, and Likely Role in Human-Human Transmission

Herpes simplex virus type 1, or HSV-1, is a widespread human pathogen that replicates in epithelial cells of the body surface and then establishes latent infection in peripheral neurons. When HSV-1 replicates, viral progeny must be efficiently released to spread infection to new target cells. Viral spread occurs via two major routes. In cell-cell spread, progeny virions are delivered directly to cellular junctions, where they infect adjacent cells. In cell-free release, progeny virions are released into the extracellular milieu, potentially allowing the infection of distant cells. Cell-cell spread of HSV-1 has been well studied and is known to be important for in vivo infection and pathogenesis. In contrast, HSV-1 cell-free release has received less attention, and its significance to viral biology is unclear. Here, I review the mechanisms and regulation of HSV-1 cell-free virion release. Based on knowledge accrued in other herpesviral systems, I argue that HSV-1 cell-free release is likely to be tightly regulated in vivo. Specifically, I hypothesize that this process is generally suppressed as the virus replicates within the body, but activated to high levels at sites of viral reactivation, such as the oral mucosa and skin, in order to promote efficient transmission of HSV-1 to new human hosts.

Current vaccine approaches and emerging strategies against herpes simplex virus (HSV)

Introduction: Vaccine development for the disease caused by the herpes simplex virus (HSV) has been challenging over the years and is always in dire need of novel approaches for prevention and cure. To date, the HSV disease remains incurable and challenging to prevent. The disease is extremely widespread due to its high infection rate, resulting in millions of infection cases worldwide.Areas covered: This review first explains the diverse forms of HSV-related disease presentations and reports past vaccine history for the disease. Next, this review examines current and novel HSV vaccine approaches being studied and tested for efficacy and safety as well as vaccines in clinical trial phases I to III. Modern approaches to vaccine design using bioinformatics are described. Finally, we discuss measures to enhance new vaccine development pipelines for HSV.Expert opinion: Modernized approaches using in silico analysis and bioinformatics are emerging methods that exhibit potential for producing vaccines with enhanced targets and formulations. Although not yet fully established for HSV disease, we describe current studies using these approaches for HSV vaccine design to shed light on these methods. In addition, we provide up-to-date requirements of immunogenicity, adjuvant selection, and routes of administration.

Adolescents and primary herpetic gingivostomatitis: an Italian overview

Aim

The aim of this study was to investigate the therapies administered to Italian adolescents with primary herpetic gingivostomatitis (PHGS)

Methods

The medical records of 74 adolescents with PHSG were reviewed. The following data were recorded: age, gender, day of onset, type of treatment, lesions’ severity, pain scoring, eating, and drinking ability. The oral examination was performed at the first evaluation (T0) and after one week (T1).

Results

All patients showed up at the first visit at least 48 h after the onset of symptoms. No patient was prescribed an antiviral therapy. An antibiotic therapy was prescribed in order to prevent secondary bacterial infections. Fifteen patients had been treated with non alcoholic chlorhexidine rinses (group A), 29 patients with non alcoholic chlorhexidine rinses plus hyaluronic acid gel (group B); 30 patients with non alcoholic chlorhexidine rinses plus Mucosyte® (group C). A significant improvement of the pain scoring and lesions’ severity was noted in group C.

Conclusion

In Italian adolescents, PHGS is diagnosed at least 48 h after onset and the antibiotic therapy is widely prescribed in order to prevent overinfections. Among topical therapies, an association of verbascoside and sodium hyaluronhate seems to favour a faster healing.

Clinical Manifestations and Epigenetic Regulation of Oral Herpesvirus Infections

The oral cavity is often the first site where viruses interact with the human body. The oral epithelium is a major site of viral entry, replication and spread to other cell types, where chronic infection can be established. In addition, saliva has been shown as a primary route of person-to-person transmission for many viruses. From a clinical perspective, viral infection can lead to several oral manifestations, ranging from common intraoral lesions to tumors. Despite the clinical and biological relevance of initial oral infection, little is known about the mechanism of regulation of the viral life cycle in the oral cavity. Several viruses utilize host epigenetic machinery to promote their own life cycle. Importantly, viral hijacking of host chromatin-modifying enzymes can also lead to the dysregulation of host factors and in the case of oncogenic viruses may ultimately play a role in promoting tumorigenesis. Given the known roles of epigenetic regulation of viral infection, epigenetic-targeted antiviral therapy has been recently explored as a therapeutic option for chronic viral infection. In this review, we highlight three herpesviruses with known roles in oral infection, including herpes simplex virus type 1, Epstein–Barr virus and Kaposi’s sarcoma-associated herpesvirus. We focus on the respective oral clinical manifestations of these viruses and their epigenetic regulation, with a specific emphasis on the viral life cycle in the oral epithelium.

Online consultation and emergency management in paediatric dentistry during the COVID-19 epidemic in Wuhan: A retrospective study

BACKGROUND

The COVID-19 pandemic posed a great challenge to paediatric dentistry, which confronted with the restriction of service and resource shortage.

AIM

To retrospectively analyse the information of children's dental online health consultation during the COVID-19 pandemic in China, and to provide methods to distinguish between dental emergencies and non-emergencies as well as their management.

DESIGN

We collected all the online consultation information in Dept. of Paediatric dentistry, School & Hospital of Stomatology, Wuhan University, from 2 February to 31 March 2020, and extracted the information of age, gender, reason for consultation, description of symptom, and preliminary diagnosis of the children.

RESULTS

A total of 474 online consultations of paediatric dentistry were included within 59 days during lockdown, and 190 (40.1%) were dental emergencies and 284 (59.9%) non-emergencies. Of 190 emergency consultations, 186 (97.9%) showed swelling, pain, and trauma with or without systemic symptoms. Among 284 non-emergency consultations, retained primary teeth (n = 126) and orthodontic consultation (n = 53) were the most common reasons for consultation.

CONCLUSION

The paediatric emergency and non-emergency problems should be clearly distinguished and sufficient instructions provided in the special period of COVID-19. Priorities also should be set to deal with urgent conditions after the release of lockdown.

Herpes Labialis, Chlamydophila pneumoniae, Helicobacter pylori, and Cytomegalovirus Infections and Risk of Dementia: The Framingham Heart Study

BACKGROUND

An association between chronic infectious diseases and development of dementia has been suspected for decades, based on the finding of pathogens in postmortem brain tissue and on serological evidence. However, questions remain regarding confounders, reverse causality, and how accurate, reproducible and generalizable those findings are.

OBJECTIVE

Investigate whether exposure to Herpes simplex (manifested as herpes labialis), Chlamydophila pneumoniae (C. pneumoniae), Helicobacter pylori (H. pylori), and cytomegalovirus (CMV) modifies the risk of dementia in a populational cohort.

METHODS

Questionnaires regarding incidence of herpes infections were administered to Original Framingham Study participants (n = 2,632). Serologies for C. pneumoniae, H. pylori, and CMV were obtained in Original (n = 2,351) and Offspring cohort (n = 3,687) participants. Participants are under continuous dementia surveillance. Brain MRI and neuropsychological batteries were administered to Offspring participants from 1999-2005. The association between each infection and incident dementia was tested with Cox models. Linear models were used to investigate associations between MRI or neuropsychological parameters and serologies.

RESULTS

There was no association between infection serologies and dementia incidence, total brain volume, and white matter hyperintensities. Herpes labialis was associated with reduced 10-year dementia risk (HR 0.66, CI 0.46-0.97), but not for the duration of follow-up. H. pylori antibodies were associated with worse global cognition (β -0.14, CI -0.22, -0.05).

CONCLUSION

We found no association between measures of chronic infection and incident dementia, except for a reduction in 10-year dementia risk for patients with herpes labialis. This unexpected result requires confirmation and further characterization, concerning antiviral treatment effects and capture of episodes.

Antiviral potential of natural products from marine microbes

Humans have been suffered from viral infections over the centuries, such as influenza, HSV, and HIV, which have killed millions of people worldwide. However, the availability of effective treatments for infectious diseases remains limited until now, as most of the viral pathogens resisted to many medical treatments. Marine microbes are currently one of the most copious sources of pharmacologically active natural products, which have constantly provided promising antivirus agents. To date, a large number of marine microbial secondary metabolites with antiviral activities have been widely reported. In this review, we have summarized the potential antivirus compounds from marine microorganisms over the last decade. In addition, the structures, bioactivities, and origins of these compounds were discussed as well.

Clinical Study on the Effectiveness of Three Products in the Treatment of Herpes Simplex Labialis

Herpes simplex labialis (HSL) is a viral disease that affects the perioral region. No guidelines recommending an effective treatment exist. The treatment of HSL with three different products was examined. Herpatch Serum, a film-forming patch, was compared to Compeed Patches, a set of semiocclusive hydrocolloid patches, and Zovirax Cream (ingredient: 5% acyclovir). In this prospective, randomized, examiner-blind study, 180 patients with recurrent HSL were split into three groups (Compeed: n = 60, Herpatch: n = 60, Zovirax: n = 60) and examined within 24 hours of HSL outbreak (DRKS Registration No.: DRKS00007786). The primary endpoint was healing time. The secondary endpoints were the reaction rate and quality of therapy evaluated by the Clinician’s Global Assessment of Therapy (CGAT) and the Subject’s Global Assessment of Therapy (SGAT) (0 = no response; 10 = excellent response), respectively. There was no significant difference among the healing times for the different products. The mean (95% confidence interval) was 9.67 days (9.11–10.22) for Compeed, 9.30 days (8.75–9.85) for Herpatch, and 9.80 days (9.30–10.30) for Zovirax. The reaction rate and quality of therapy (CGAT and SGAT) of Herpatch were significantly higher than those of Compeed and Zovirax. Within the study limitations, Herpatch proved to be an effective, non-antiviral alternative in the treatment of HSL.

Prevalence of ulcerative stomatitis in arbovirus infections in a Brazilian Northeast population

BACKGROUND

Although there are no population-based studies that support an association, there are reports in the literature of mucocutaneous, vesiculobullous and ulcerated lesions in the oral mucosa in cases of arbovirus infection. The aim of this study is to analyze the prevalence of ulcerative stomatitis in individuals affected by arboviruses in a population of the municipality of Arcoverde, Pernambuco, Brazil.

MATERIAL AND METHODS

1,003 people living in an area assigned to a Primary Health Care Unit were interviewed. A structured questionnaire was used for data collection, with questions about sociodemographic variables, residence conditions, general health information, as well as information about the general signs and symptoms of arboviruses and specifically about oral lesions.

RESULTS

Of the 1,003 individuals interviewed, 815 (81.25%) were infected by one or more arboviruses. Of these, 147 (18%) reported ulcerated oral lesions during arbovirus infections. The association between arbovirus infections and the presence of ulcerated oral lesions was statistically significant (p = 0.000).

CONCLUSIONS

In these cases, the ulcerated lesions on the oral mucosa appear to be associated with arbovirus infection, especially Chikungunya, although the pathophysiological mechanisms are not defined, and the studies are not sufficient to confirm this association.

Human virus detection with graphene-based materials

Our recent experience of the COVID-19 pandemic has highlighted the importance of easy-to-use, quick, cheap, sensitive and selective detection of virus pathogens for the efficient monitoring and treatment of virus diseases. Early detection of viruses provides essential information about possible efficient and targeted treatments, prolongs the therapeutic window and hence reduces morbidity. Graphene is a lightweight, chemically stable and conductive material that can be successfully utilized for the detection of various virus strains. The sensitivity and selectivity of graphene can be enhanced by its functionalization or combination with other materials. Introducing suitable functional groups and/or counterparts in the hybrid structure enables tuning of the optical and electrical properties, which is particularly attractive for rapid and easy-to-use virus detection. In this review, we cover all the different types of graphene-based sensors available for virus detection, including, e.g., photoluminescence and colorimetric sensors, and surface plasmon resonance biosensors. Various strategies of electrochemical detection of viruses based on, e.g., DNA hybridization or antigen-antibody interactions, are also discussed. We summarize the current state-of-the-art applications of graphene-based systems for sensing a variety of viruses, e.g., SARS-CoV-2, influenza, dengue fever, hepatitis C virus, HIV, rotavirus and Zika virus. General principles, mechanisms of action, advantages and drawbacks are presented to provide useful information for the further development and construction of advanced virus biosensors. We highlight that the unique and tunable physicochemical properties of graphene-based nanomaterials make them ideal candidates for engineering and miniaturization of biosensors.

Ancient RNA virus epidemics through the lens of recent adaptation in human genomes

Over the course of the last several million years of evolution, humans probably have been plagued by hundreds or perhaps thousands of epidemics. Little is known about such ancient epidemics and a deep evolutionary perspective on current pathogenic threats is lacking. The study of past epidemics has typically been limited in temporal scope to recorded history, and in physical scope to pathogens that left sufficient DNA behind, such as Yersinia pestis during the Great Plague. Host genomes, however, offer an indirect way to detect ancient epidemics beyond the current temporal and physical limits. Arms races with pathogens have shaped the genomes of the hosts by driving a large number of adaptations at many genes, and these signals can be used to detect and further characterize ancient epidemics. Here, we detect the genomic footprints left by ancient viral epidemics that took place in the past approximately 50 000 years in the 26 human populations represented in the 1000 Genomes Project. By using the enrichment in signals of adaptation at approximately 4500 host loci that interact with specific types of viruses, we provide evidence that RNA viruses have driven a particularly large number of adaptive events across diverse human populations. These results suggest that different types of viruses may have exerted different selective pressures during human evolution. Knowledge of these past selective pressures will provide a deeper evolutionary perspective on current pathogenic threats.

This article is part of the theme issue ‘Insights into health and disease from ancient biomolecules’.