Search Results (227)

A systematic review was conducted to assess the effects of microgravity and space radiation on astronauts’ oral health. This review aimed to determine if these conditions increase the risk of dental and periodontal diseases, identify pre-mission dental care strategies, and specify relevant dental emergencies for astronauts to manage during missions. Following PRISMA guidelines, the review was registered on PROSPERO (CRD42023472765). Databases including PubMed, Scopus, Web of Science, Cochrane Library, and OVID Medline were searched. Of the 13 studies identified, 7 were eligible for qualitative synthesis. The included studies revealed that space conditions compromise oral health. Findings indicate changes in saliva composition, with a significant decline in salivary lysozyme levels during missions lasting 28 to 84 days. Salivary IgA levels also increased before and peaked after flights (microgravity alters fluid shear and protein folding). Viral reactivation was a key finding, with latent viruses such as Epstein–Barr virus (EBV), cytomegalovirus (CMV), and varicella zoster virus (VZV) being reactivated during missions (immune suppression and gene expression shifts under spaceflight stress). Data from a study found that 50% of crew members shed viruses in their saliva or urine, and 38% tested positive for herpesviruses. The included studies also documented alterations in the oral microbiome, including increased gastrointestinal and decreased nasal microbial diversity. This suggests alterations in salivary biomarkers, viral shedding, and microbiome changes in astronauts during long-duration missions. These changes appear associated with immune dysregulation and stress, but causality remains uncertain due to observational designs, small heterogeneous samples, and confounding factors. Although current evidence is indicative rather than definitive, these findings highlight the need for preventive dental measures prior to missions and preparedness for managing oral emergencies in-flight. Future studies should address the mechanistic separation of microgravity and radiation effects, with implications for upcoming Moon and Mars missions. Full article

Objectives: The varicella vaccine (VarV) produced by Sinovac (Dalian) obtained World Health Organization (WHO) prequalification in November 2022. However, no direct comparative studies have been conducted between VarV and other WHO-prequalified varicella vaccines. The study aimed to assess the immunogenicity and safety of Sinovac’s VarV compared with Merck Sharp & Dohme’s (MSD) VARIVAX^® (Moorgate, London, UK) following a single dose administration. Methods: This Phase III, randomized, double-blind, active-controlled, non-inferiority trial was conducted in the Philippines. Healthy children aged 12 to 15 months were enrolled. Eligible participants were randomly assigned (1:1) to receive a single dose of varicella vaccine either manufactured by Sinovac (Test group) or MSD (Active control group). Immunogenicity was evaluated 6 weeks after vaccination by enzyme-linked immunosorbent assay (ELISA). The primary immunogenicity endpoint was seroresponse rate 6 weeks after vaccination. Seroresponse rate was defined as varicella-zoster virus (VZV) antibody concentration ≥ 10 mIU/mL in participants who were seronegative (antibody concentration < 10 mIU/mL) at baseline. The secondary endpoint was the corresponding geometric mean concentration (GMC). Adverse events (AEs) and serious adverse events (SAEs) were monitored for 6 weeks after vaccination. Results: Among the 484 participants analyzed, the seroresponse rates 6 weeks after vaccination were 98.85% and 98.88% in the Test group and Active control group, respectively, with a difference of −0.03% (95% CI: −3.10%, 2.99%), which exceeded the predefined non-inferiority margin of −10%. The corresponding GMCs were 35.73 mIU/mL and 37.34 mIU/mL, respectively, with the ratio of 0.96 (95% CI: 0.86, 1.06), also exceeding the predefined non-inferiority margin of 0.67. Furthermore, the incidence of adverse reactions (ARs) in the Test group was lower than that in the Active control group (38.08% vs. 55.51%). Conclusions: Sinovac’s VarV demonstrated non-inferior immunogenicity to WHO-prequalified comparator vaccine (VARIVAX^®) and favorable safety profile. These findings indicated that VarV (Sinovac, Beijing, China) met WHO standards for varicella vaccine evaluation, supporting its global use consideration. Full article

Introduction: Hyponatremia is a common finding in hospitalized patients, especially the elderly. Symptoms of hyponatremia can vary depending on the concentration of sodium in serum as well as the dynamics of its escalation. Hyponatremia can have many etiologies, including medication, vomiting, or diarrhea, and central nervous system disorders, including tumors, trauma, and infections. Case report: In this case, we present a 74-year-old patient who was admitted to the Department of Internal Medicine with symptomatic, acute, and severe hyponatremia in the course of the syndrome of inappropriate antidiuretic hormone secretion due to varicella zoster virus meningoencephalitis. Clinical improvement and normalization of natremia occurred after the initiation of causal treatment. Conclusion: Given the complexity of the potential causes of hyponatremia and the variety of treatments available, it is essential to thoroughly consider the possible reasons for electrolyte abnormalities, including uncommon ones such as central nervous system infections. Full article

Visceral disseminated varicella-zoster virus infection (VD-VZV) involves the hematogenous spread of VZV from the skin to the internal organs. Though rare, it is potentially life-threatening, predominantly affecting immunocompromised individuals. Diagnosis is often delayed due to nonspecific symptoms mimicking other viral illnesses. While the vesicular rash is a hallmark sign, it is absent in approximately 5% of cases. Visceral involvement may precede cutaneous lesions, complicate early recognition, and increase the risk of severe complications. This scoping review screened 594 articles of which 153 met the inclusion criteria, yielding 156 individual cases. Patients were predominantly male (53.8%), with a mean age of 42.3 years. The overall mortality rate was 25.0%. Multiple organs were involved in 46.1% of cases. The most frequently affected were the lungs (56%), liver (44%), heart (16%), kidneys (11%), pancreas (11%), stomach (10%), and esophagus (6%). Antivirals were administered in 89.1% of cases, while corticosteroids were used in 22.4%, with no significant impact on outcomes. Early diagnosis, achieved in 65.4% of patients, was significantly associated with survival (p = 0.043). Mortality was significantly associated with underlying comorbidities (p = 0.004), especially autoimmune diseases requiring immunosuppression (p = 0.048). Septic shock or multi-organ dysfunction (MODS), hepatitis, acute kidney injury, and acute liver failure were linked to higher mortality in univariate analysis. Multivariate analysis identified comorbidities (p < 0.001), septic shock/MODS (p = 0.008), and acute liver failure (p = 0.039) as independent predictors of mortality. Patients with septic shock/MODS had over twice the risk of death (OR = 2.24; p = 0.008). This review underscores the diagnostic challenges and high mortality of VD-VZV. Early recognition and timely administration of antiviral treatment appear critical for survival. Greater clinical awareness and further research are needed to guide management. Full article

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disorder characterized by the destruction of insulin-producing pancreatic beta cells, resulting in lifelong insulin dependence. While genetic susceptibility—particularly human leukocyte antigen (HLA) class II alleles—is a major risk factor, accumulating evidence implicates viral infections as potential environmental triggers in disease onset and progression. This narrative review synthesizes current findings on the role of viral pathogens in T1DM pathogenesis. Enteroviruses, especially Coxsackie B strains, are the most extensively studied and show strong epidemiological and mechanistic associations with beta-cell autoimmunity. Large prospective studies—including Diabetes Virus Detection (DiViD), The environmental determinans of diabetes in the young (TEDDY), Miljøfaktorer i utvikling av type 1 diabetes (MIDIA), and Diabetes Autoimmunity Study in the Young (DAISY)—consistently demonstrate correlations between enteroviral presence and the initiation or acceleration of islet autoimmunity. Other viruses—such as mumps, rubella, rotavirus, influenza A (H1N1), and SARS-CoV-2—have been investigated for their potential involvement through direct cytotoxic effects, immune activation, or molecular mimicry. Interestingly, certain viruses like varicella-zoster virus (VZV) and cytomegalovirus (CMV) may exert modulatory or even protective influences on disease progression. Proposed mechanisms include direct beta-cell infection, molecular mimicry, bystander immune activation, and dysregulation of innate and adaptive immunity. Although definitive causality remains unconfirmed, the complex interplay between genetic predisposition, immune responses, and viral exposure underscores the need for further mechanistic research. Elucidating these pathways may inform future strategies for targeted prevention, early detection, and vaccine or antiviral development in at-risk populations. Full article

Schizophrenia is a challenging multifactorial neuropsychiatric disease that involves interactions between genetic susceptibility and environmental insults. Increasing evidence implicates viral infections as significant environmental contributors, particularly during sensitive neurodevelopmental periods. This review synthesises current findings on the viral hypothesis of schizophrenia, encompassing a wide array of neurotropic viruses, including influenza viruses, herpesviruses (HSV-1 and 2, CMV, VZV, EBV, HHV-6 and 8), hepatitis B and C viruses, HIV, HERVs, HTLV, Zika virus, BoDV, coronaviruses (including SARS-CoV-2), and others. These pathogens can contribute to schizophrenia through mechanisms such as direct microinvasion, persistent central nervous system infection, immune-mediated neuroinflammation, molecular mimicry, and the disturbance of the blood–brain barrier. Prenatal exposure to viral infections can trigger maternal immune activation, resulting in cytokine-mediated alterations in the neurological development of the foetus that persist into adulthood. Genetic studies highlight the role of immune-related loci, including major histocompatibility complex polymorphisms, in modulating susceptibility to infection and neurodevelopmental outcomes. Clinical data also support the “mild encephalitis” hypothesis, suggesting that a subset of schizophrenia cases involve low-grade chronic neuroinflammation. Although antipsychotics have some immunomodulatory effects, adjunctive anti-inflammatory therapies show promise, particularly in treatment-resistant cases. Despite compelling associations, pathogen-specific links remain inconsistent, emphasising the need for longitudinal studies and integrative approaches such as viromics to unravel causal relationships. This review supports a “multi-hit” model in which viral infections interfere with hereditary and immunological susceptibilities, enhancing schizophrenia risk. Elucidating these virus–immune–brain interactions may facilitate the discovery of biomarkers, targeted prevention, and novel therapeutic strategies for schizophrenia. Full article

Background/Objectives: The aetiology of Bell’s palsy remains unclear and is typically diagnosed by exclusion. This study investigated the potential role of neurotropic viruses and explored the relationship between facial nerve impairment and vestibular dysfunction to improve the understanding of the condition. Methods: Antibodies against herpes simplex virus (HSV) and varicella-zoster virus (VZV) were assessed using ELISA. Vestibular function was evaluated through computerised videonystagmography, rotatory chair, and clinical vestibulospinal assessments. Facial nerve lesion localisation was determined by stapedial reflex testing. Fisher’s exact test was used for statistical analysis. Results: Of 51 patients with Bell’s palsy, 62.7% exhibited vestibular dysfunction, and 70.6% were IgG-positive for at least one neurotropic virus. Vestibular impairment was significantly more common in seropositive patients. Statistically significant associations were observed between vestibular dysfunction and viral IgG seropositivity (p < 0.0001), the severity of vestibular dysfunction and facial paresis (p = 0.0126), and the side of vestibular impairment and the side of facial palsy (p < 0.0001), with 90.6% of cases showing ipsilateral involvement. Conclusions: These findings support the hypothesis that neurotropic viruses may act as a common pathological factor in both Bell’s palsy and associated vestibular dysfunction. Full article

The varicella-zoster virus is a human herpesvirus that causes varicella as the primary infection and HZ as the reactivation of a latent infection. Ten to twenty percent of cases of herpes zoster ophthalmicus (HZO) involve the ophthalmic branch of the fifth cranial nerve. Any area of the eye may be affected by the condition. HZ has a lifetime risk of more than 30%. Complications from herpes zoster can significantly lower quality of life. The goal of HZ vaccinations is to stop HZ activation and PHN formation. Despite the uncommon possibility of side effects such as eye problems, the majority of vaccines on the market now are safe. The purpose of this review is to discuss VZV infection and analyze and summarize the ocular complications following VZV vaccination. Full article

Rapid, safe, and field-deployable molecular diagnostics are crucial for the effective management of infectious disease outbreaks, particularly those involving highly infectious pathogens, which can produce clinical symptoms similar to less infectious pathogens, thus raising potential biosafety concerns. In this study, we evaluated DNA/RNA Defend Pro (DRDP) buffer, a novel viral-inactivating transport medium designed to stabilize nucleic acids and allow direct PCR without nucleic acid extraction. To ensure critical qPCR parameters were not compromised by using DRDP, we conducted serial dilution tests using herpes simplex viruses 1 and 2 (HSV-1, HSV-2) and varicella-zoster virus (VZV), comparing DRDP to standard universal transport medium (UTM). Detection sensitivity, determined by cycle quantification (Cq) values, favored DRDP, as UTM samples required a 2–3-fold dilution to mitigate PCR inhibition. DRDP maintained reliable PCR compatibility at reaction volumes containing up to 25% buffer. At higher DRDP concentrations (30–35%), PCR inhibition occurred due to EDTA content but was fully reversible by adding supplemental magnesium. Furthermore, DRDP samples did not require an initial 95 °C thermal lysis step, thus simplifying the procedure without reducing PCR sensitivity or efficiency. Full article

Background: Immunocompromised patients are at risk of severe varicella zoster virus (VZV) infection and reactivation. In VZV seronegative immunocompromised persons, live-attenuated VZV vaccination is contraindicated, thus the recombinant herpes zoster vaccine (rHZV) remains a safe alternative, although an off-label application. Yet, data on the induction of a VZV-specific immune response in immunocompromised individuals with VZV-specific IgG below the assay’s cut-off are only available for patients after solid-organ transplantation (SOT). Methods: We retrospectively analyzed the induction of VZV-specific IgG antibody levels after vaccination with rHZV in immunocompromised patients who previously tested anti-VZV-IgG negative between March 2018 and January 2024. Results: Of 952 vaccinees screened that received 2 or 3 doses rHZV, depending on the underlying disease, 33 patients (median age 53.0; 51.5% female) with either hematopoietic stem cell transplantation (82%) or high-grade immunosuppressive treatment (18%) fulfilled the inclusion criteria. Upon rHZV vaccination, 88% (29/33) individuals mounted a significant antibody response exceeding the assay’s cut-off level for seropositivity (p < 0.0001). We detected higher geometric mean antibody concentrations after three compared to two doses. However, 12% remained below the assay’s cut-off level and were therefore considered non-responsive. Conclusions: The rHZV is immunogenic in VZV-seronegative immunocompromised individuals and therefore presents a valid option to induce seroconversion. However, antibody testing in high-risk groups should be considered to identify humoral non- and low responders. Full article

Varicella-zoster virus (VZV) poses significant public health challenges as the etiological agent of varicella (chickenpox) and herpes zoster (HZ), given its high transmissibility and potential for severe complications. The introduction of VZV vaccines—particularly the vOka-based live attenuated and glycoprotein gE-based recombinant subunit vaccines—has substantially reduced the global incidence of these diseases. However, live attenuated vaccines raise concerns regarding safety and immunogenicity, especially in immunocompromised populations, while recombinant subunit vaccines, such as Shingrix, exhibit high efficacy but are associated with side effects and adjuvant limitations. Recent advancements in vaccine technology, including mRNA vaccines, viral vector vaccines, and virus-like particle (VLP) vaccines, offer promising alternatives with improved safety profiles and durable immunity. This review synthesizes current knowledge on VZV vaccine mechanisms, clinical applications, and immunization strategies, while also examining future directions in vaccine development. The findings underscore the pivotal role of VZV vaccines in disease prevention and highlight the need for continued research to enhance their public health impact. Full article

Purpose: Varicella zoster virus (VZV) vasculopathy can occur in patients with herpes zoster (HZ). Our aim was to evaluate the retinal microvascular vessel density (VD) in patients with trigeminal HZ measured by optical coherence tomography angiography (OCTA). Methods: 48 eyes of 24 patients with HZ and 48 eyes of 24 healthy age- and gender-matched controls were included in this study. All participants underwent an OCTA examination using RTVue XR Avanti with AngioVue. The VD data of the macular 3 × 3 mm OCT angiogram of the superficial capillary plexus (SCP), the deep capillary plexus (DCP), and the choriocapillaris (CC) as well as the VD data of the optic nerve head (ONH) were extracted and analyzed. Results: The VD in the SCP, DCP, and CC of patients with HZ was significantly lower compared with healthy controls (p < 0.05). Equally, there was a noticeable reduction in the inside disk area of the ONH. There was no statistically noticeable reduction in the FAZ area and central retinal thickness. Conclusions: In this study, HZ patients demonstrated a decrease in the retinal VD of the SCP, DCP, ONH, and the CC. Quantitative analysis of retinal perfusion using OCTA may therefore help in the diagnosis and monitoring of HZ. Further studies must show to what extent this may be an indication of VZV-related vasculopathy and whether OCTA data can be used as a biomarker in these patients in the future. Full article

Viral infections may vary from mild to severe, manifesting with a wide range of symptoms, including skin lesions, influenza-like symptoms, or meningitis/meningoencephalitis signs. Viruses that cause both skin lesions and meningitis comprise, e.g., Enteroviruses (EVs) and Herpes viruses (HV). EVs are responsible for approximately 90% of viral meningitis cases. They occur frequently among children under 3 years of age and are characterized by various types of rash. HV infections are responsible for up to 18% of viral meningitis, mostly among adults or older children. Most patients with viral meningitis recover entirely. However, the rates of serious complications and mortality may be as high as 74% and 10%, respectively, for particularly vulnerable neonatal or immunocompromised patients. Patients that present signs of encephalitis and/or are suspected to have HSV/VZV infection require immediate implementation of empiric acyclovir therapy before receiving the polymerase chain reaction (PCR) test results. The clinical picture of viral meningitis may differ depending on the virus, including the presence of both meningeal signs and skin lesions. Therefore, early identification of the etiological factor is necessary for early and proper treatment implementation. It is crucial to accurately differentiate between the causative agents, and this work focuses on answering the question of how skin lesions can assist in achieving a better and faster diagnosis. The aim of this review was to analyze the characteristics of skin lesions in the course of meningitis caused by various viral species. This can be helpful for physicians in the diagnostic process and subsequent treatment. Full article

Understanding the contribution of human herpesviruses to the aetiology of neurodegenerative diseases is an emerging field of interest. The association of Epstein–Barr virus with multiple sclerosis is the most researched example; however, the definitive proof of causation is still lacking. Alzheimer’s disease (AD) is the most common form of dementia and typically manifests in individuals aged over 65 years; however, it also occurs in a small number of individuals aged less than 65 years. A combination of environmental, genetic, and lifestyle factors is believed to contribute to the development of AD. There have been several reports describing potential associations of infections or reactivations of human alphaherpesviruses with AD. A particular characteristic of human alphaherpesviruses (herpes simplex viruses 1 and 2, varicella zoster virus) is that they are neurotropic and that lifelong infection (latency) is established mainly in the dorsal root and trigeminal ganglia. There have also been reports that suppression of alphaherpesvirus infections through either vaccination or the application of antiviral treatments may be protective against the development of AD. Zoster vaccines and acyclovir may prove to be effective interventions for preventing or limiting the progression of AD. This is particularly relevant as there are currently no available cheap and effective treatments for AD. In this review, the basic virology of human alphaherpesviruses is described followed by their epidemiology and associations with AD. Finally, the prevention and treatment of human alphaherpesviruses are considered in the context of potential applications for the prevention of AD. Full article

We aim to investigate the role of the Herpesviridae family (HHV) in the onset and progression of prostate cancer (PCa) and to profile the local PCa immunological status. A total of 116 “tru-cut” biopsies (58 PCa and 58 benign prostatic hyperplasia [BPH]) and 49 formalin-fixed paraffin-embedded (FFPE) instances of PCa were analysed using real-time qPCR and histological examination. Infection with CMV, EBV, HHV6, and HHV7 was detected in 11.5% of the “tru-cut” biopsies (25.9% in BPH and 6.9% in the PCa group). In the formalin-fixed paraffin-embedded (FFPE) samples, infection was detected in 69.4% of the patients, with individual rates of EBV (47%), HHV6 (38%), HHV7 (41%), CMV (2.9%), HSV2 (2.9%), and VZV (5.8%). In the HHV-infected PCa cases, the histopathological landscape included intratumor lymphocyte infiltration with fibrosis and necrosis, periductal chronic inflammatory reaction and granulomatous lesions with foci of abscesses and necrosis, as well as inflammatory infiltration, chronic lymphadenitis, prostatic intraepithelial atrophy (PIA), and high-grade prostatic intraepithelial neoplasia (HGPIN). The majority of HHV-infected PCa patients were predominantly classified as grade G3/G4/G5 tumours, exhibiting perineural, perivascular, and lymphovascular invasion, seminal vesicle invasion, senile vesicle amyloidosis, and lymph node metastasis. Statistical analysis demonstrated a significant association between HHV infection and PCa (χ² ≈ 20.3, df = 1, p < 0.0001; Fisher’s exact test, p < 0.0001) with an odds ratio of 6.50 (95% CI: 2.80–15.12). These findings suggest that long-term HHV infection could contribute to a complicated and potentially altered immune PCa tumour environment due to inflammation. This may serve as a predictor of aggressive disease progression. Full article