Search Results (66)

Eastern, Venezuelan, and Western equine encephalitis viruses (EEEV, VEEV, and WEEV) are encephalitic alphaviruses transmitted by mosquitoes throughout the Americas. Infection by these viruses can present in humans as a febrile illness; however, it may progress into potentially life-threatening encephalitis. Currently, no publicly licensed vaccines are available, and at-risk individuals are restricted to superseded vaccines. Here, we will review recent advances in our understanding of how these viruses spread among animal populations and cause disease, and how we can manage their diagnosis and treatment. Additionally, we have summarised the recent developments in vaccines against these viruses in both pre-clinical and clinical stages. Overall, global climate change and ecological disruption drive a need for public access to safe and effective vaccines against EEEV, VEEV, and WEEV, which novel platforms, such as mRNA and viral vectors, may be able to achieve. Full article

Whole-genome sequencing (WGS) is central to outbreak response for high-consequence ribonucleic acid (RNA) viruses, but useful genomes depend on workflow design, sample quality, biosafety, diagnostic breadth, infrastructure, and bioinformatics as much as sequencing platform. The 2026 Bundibugyo virus disease outbreak in the Democratic Republic of the Congo and Uganda provides a case example. Bundibugyo virus (BDBV) was already known from the 2007–2008 Uganda and 2012 Democratic Republic of the Congo outbreaks, but sparse historical genome sampling, Ebola virus-centered diagnostic assumptions, non-specific febrile and viral hemorrhagic fever presentations, and difficult field conditions created a need for broad differential diagnosis, rapid species assignment, and representative genome generation. This review compares outbreak WGS strategies by the degree of prior viral sequence knowledge required, distinguishing direct RNA sequencing, random-primed complementary DNA (cDNA) sequencing, sequence-independent amplified cDNA sequencing, background-depleted or particle-enriched cDNA sequencing, probe-based hybrid capture, tiled amplicon sequencing, portable field sequencing, culture-derived sequencing, and associated bioinformatics workflows. For BDBV-like outbreaks, the most defensible strategy is staged and adaptive: broad viral hemorrhagic fever and febrile illness differential testing at recognition; Filoviridae-wide testing when filovirus disease remains plausible; divergence-tolerant first-genome recovery; quantification-cycle-informed sequencing prioritization without BDBV-only diagnostic narrowing; validated amplicon scale-up; and representative sequencing across locations and time. Full article

Viral hemorrhagic fevers (VHFs) are severe infectious diseases caused by RNA viruses of the families Arenaviridae, Filoviridae, Flaviviridae, and Hantaviridae, characterized by high morbidity, significant case fatality rates, and frequent diagnostic uncertainty in early disease stages. For military medical services, timely clinical recognition and laboratory confirmation are essential to guide patient management, prevent nosocomial transmission, and maintain operational continuity, particularly in endemic or resource-limited deployment settings. This review critically examines current diagnostic approaches to VHF-causative agents, emphasizing their use in clinical and field medical settings. The diagnostic process, from exposure through specimen collection, laboratory testing, and result interpretation is analyzed, including the use of molecular, serological, and antigen-based assays. Particular attention is given to deployable diagnostic platforms and their role in bridging the gap between frontline clinical suspicion and definitive laboratory confirmation. Biosafety requirements and infection prevention measures are discussed as integral components of clinical diagnostic workflows, aligned with guidance from the World Health Organization and the Centers for Disease Control and Prevention. Comparative analyses of virus-specific diagnostic timelines and laboratory requirements are presented to support differential diagnosis and clinical decision-making. Emerging technologies, including rapid molecular assays and genomic methods, are evaluated for their potential to improve early diagnosis and patient outcomes. This review highlights the central role of diagnostic readiness in clinical management of the VHFs and provides evidence-based considerations to support military clinicians facing high-risk febrile illnesses in operational environments. Full article

Measles resurgence threatens elimination achievements in the Americas. We conducted a nationwide analysis of Mexico’s 2025–2026 measles outbreak, integrating individual-level surveillance data from the Special Surveillance System for Febrile Exanthematous Diseases with municipal-level social determinants from eight national databases, complemented by molecular surveillance data. We analyzed 6892 confirmed cases using spatial autocorrelation (Moran’s I and LISA), effective reproduction number estimation, logistic regression models for municipal case presence, and multivariable logistic regression for risk factors for complications. Cases concentrated in Chihuahua (65.2%), with 47 LISA hot-spot municipalities containing 64.4% of cases. Molecular surveillance confirmed two independent introductions: D8/MVs/Ontario.CAN/47.24 (98.1%), linked to the North American outbreak, and B3 (1.9%) in Oaxaca. Transmission followed a three-stage pattern: introduction through seasonal agricultural worker networks, amplification in undervaccinated communities, and diffusion to marginalized indigenous populations. A dual-model analysis revealed that school non-attendance among children aged 6–14 years may have mediated the effect of very high marginalization on municipal case presence (OR 1.26; p < 0.001), identifying a potentially actionable vaccination pathway. Vaccine effectiveness was 98.1%, confirming susceptible accumulation rather than vaccine failure. Wave-stratified analysis showed late outbreak phase as an independent risk factor for complications (aOR 1.68, 95% CI: 1.42–2.00), converging with an age of <1 year (aOR 3.36), indigenous status (aOR 1.89), and unvaccinated status (aOR 1.96) in the most marginalized communities. Indigenous individuals comprised 29.1% of cases but 76% of the 25 deaths. This outbreak demonstrates that national vaccination thresholds are insufficient when municipal pockets of susceptibility remain systematically underserved. Full article

Viral hemorrhagic fevers (VHFs) are highly lethal diseases that often present non-specific, influenza-like symptoms in their early stages, making clinical recognition and differentiation from other febrile illnesses difficult. This overlap underscores the critical need for diagnostic tests that are both sensitive and specific. Point-of-care (POC) diagnostic tests are an invaluable tool for detecting and controlling the spread of pathogens that threaten public health, such as VHFs, as these require fast, accurate diagnostics to ensure biosafety and appropriate mobilization of resources during outbreaks. Current molecular and serological diagnostic tests, while efficient and effective, lack the characteristics required of a POC test (POCT) to quickly and easily respond to a VHF outbreak while maintaining a low cost. Clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostic tests have gained popularity as POCTs due to their inherent attractive qualities, including high sensitivity and specificity, adaptability, low cost, quick turnaround time, and ease of use. However, studies on the development of CRISPR-based POC diagnostic tests for VHFs are limited. This review summarizes the current CRISPR-based POCTs for VHFs, including Ebola virus (EBOV), Lassa virus (LASV), Dengue virus (DENV), and Crimean–Congo hemorrhagic fever virus (CCHF). The isothermal pre-amplification methods commonly paired with CRISPR-based tests, such as loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA), are also discussed. Full article

Background: Febrile neutropenia (FN) is a serious chemotherapy-related complication in patients with solid tumors. Identifying simple and accessible biomarkers that can predict prolonged hospitalization may support early risk stratification and clinical decision-making. Methods: This retrospective study included 169 adults hospitalized with FN between January 2023 and January 2025. Immunonutritional indices, including the Hemoglobin-Albumin-Lymphocyte-Platelet (HALP) score, the Prognostic Nutritional Index (PNI), and the C-reactive protein/albumin ratio (CAR), as well as the Clinical Index of Stable Febrile Neutropenia (CISNE) score were calculated. HALP and PNI were categorized using ROC-derived cut-offs based on the Youden Index. Prolonged hospital stay was defined as a binary variable based on the cohort median (>9 days). Spearman correlation, univariate and multivariate logistic regression were performed to identify predictors of prolonged hospitalization. Results: HALP showed a significant negative correlation with hospitalization duration (r = −0.469; p < 0.001), as did serum albumin (r = −0.184; p = 0.017) and PNI (r = −0.273; p < 0.001). CAR (p = 0.617) and neutrophil count (p = 0.955) demonstrated no correlation. In univariate logistic regression, low HALP (p < 0.001), low PNI (p = 0.001), intermediate CISNE (p = 0.002), high CISNE (p < 0.001), microbiological culture positivity (p < 0.001), and sex (p = 0.015) were significantly associated with prolonged hospitalization. Age, comorbidity status, metastatic stage, and CAR were not significant. In the multivariate model, low HALP (p < 0.001), intermediate CISNE (p = 0.007), high CISNE (p < 0.001), and culture positivity (p < 0.001) remained independent predictors. PNI (p = 0.400) and sex (p = 0.176) did not retain significance. Conclusions: A Low HALP score, higher CISNE risk categories, and microbiological culture positivity independently predicted prolonged hospitalization in FN. HALP, as a simple and inexpensive immunonutritional marker, may enhance early FN risk assessment when used alongside validated clinical tools such as CISNE or MASCC. Full article

Usutu virus (USUV) is an emerging arbovirus recently associated with outbreaks in Western Europe. Although USUV is typically associated with asymptomatic or nonspecific febrile disease, the occurrence of severe neuroinvasive forms of disease has raised concern. There is currently no antiviral treatment available for USUV infection; therefore, we sought to investigate the protective effects of the nucleoside analogue 7DMA against USUV. Adding to 7DMA’s activity against USUV in vitro reported by us and others, we found that 7DMA inhibits USUV replication at multiple stages in mammalian cell lines Vero CCL81 and SH-SY5Y. In vivo testing of 7DMA using the susceptible IFNAR^-/- mouse model indicated that 7DMA treatment significantly reduced USUV viremia and viral load in tissues and prolonged mice survival. The characterization of the protective effects of 7DMA indicated that treatment also altered immunological aspects of disease development, further increasing the expression of mediators such as CXCL10, IL-15, and IFN-γ, and increasing neutrophil recruitment to target organs. We did not observe significant tissue damage or pathology in USUV-infected mouse brains, suggesting that systemic infection and disease are the major components leading to mortality in this model. We conclude that 7DMA exerts protective effects against USUV infection in the IFNAR^-/- model. Full article

Perineal tears are common during vaginal delivery and are associated with significant maternal morbidity. While chorioamnionitis and intrapartum fever are known to affect labor dynamics and perineal tissue integrity, their relationship with perineal trauma in spontaneous vaginal deliveries has not been established. This study aimed to evaluate the prevalence of perineal tears among women with intrapartum fever who delivered spontaneously. This retrospective cohort study included women who underwent spontaneous vaginal delivery during 2013–2021 in Israel. The study group comprised women diagnosed with intrapartum fever (≥38 °C), while afebrile women served as controls in a 1:2 ratio matched by age (<35 or ≥35 years) and gestational age (preterm/term). Perineal tears were classified according to the Royal College of Obstetricians and Gynaecologists (RCOG) criteria. Multivariable logistic regression was performed to adjust for statistically significant variables including obesity, induction of labor, epidural analgesia, amniotomy, delivery week, gestational diabetes, birth number, duration of the second stage of labor, and episiotomy. The cohort included 373 women with intrapartum fever and 746 controls. The overall rate of perineal tears was similar between febrile and afebrile women (42% vs. 40%; adjusted odds ratio [aOR] 0.99, 95% confidence interval [CI] 0.72–1.36). However, the rate of obstetric anal sphincter injury (OASIS) was lower among women with intrapartum fever (0.5% vs. 2.0%; aOR 0.10, 95% CI 0.02–0.52). Intrapartum fever was associated with higher rates of postpartum hemorrhage, manual exploration of the uterus, endometritis, anemia, and blood transfusion. Bacterial cultures were positive in 31% of febrile women, predominantly Escherichia coli and Group B Streptococcus, without association with perineal trauma. Alltogether, Intrapartum fever did not increase the risk of perineal tears in spontaneous vaginal deliveries and was paradoxically associated with a lower rate of OASIS. Further studies are warranted to explore the underlying physiological mechanisms linking temperature and perineal tissue resilience. Full article

Background/Objectives: Henoch–Schönlein purpura (HSP), or IgA vasculitis, is the most common small-vessel vasculitis in children, yet Indian cohort data remain limited. We aimed to describe the clinical profile, renal involvement, treatment patterns, relapse, and outcomes of pediatric HSP at a tertiary centre in South India. Methods: We conducted a retrospective review of children <18 years diagnosed with HSP (January 2013–October 2018) using EULAR/PRINTO/PRES criteria. Demographics, clinical features, laboratory parameters, treatments, and outcomes were abstracted from records and analyzed in SPSS (descriptive statistics; Chi-square/Fisher’s exact and t/non-parametric tests as appropriate). Subgroup comparisons included renal vs. non-renal disease and age <6 vs. ≥6 years. An exploratory analysis examined predictors of nephritis. Results: Of 43 children identified, 2 were excluded (misclassified as systemic lupus erythematosus); 41 were analyzed. Mean age was 8.5 years (range 3–17), male: female 1.4:1. A preceding febrile illness or upper respiratory tract infection was noted in 41.4% and 17%, respectively. Palpable purpura was universal; joint involvement 73.1%, abdominal pain 61.0%, vomiting 41.5%. Renal involvement 17% occurred only in children ≥6 years; exploratory testing supported a strong age-linked signal for nephritis. Laboratory abnormalities included anemia (48.7%), thrombocytosis (19.5%), and elevated ESR (51.2%). Skin biopsy (n = 29) showed IgA and complement deposition; renal biopsy (n = 2) showed ISKDC grades II–III. Treatments included NSAIDs 71.6%, corticosteroids 31.7%, and dapsone 24.4% (used for severe systemic/persistent cutaneous disease). Rash relapse 7.3% clustered with joint plus abdominal symptoms and was not observed among children with nephritis. At a mean 18.9-month follow-up, one child required long-term antihypertensives; no child progressed to end-stage renal disease. Conclusions: Pediatric HSP in this South-Indian cohort followed a largely self-limited course with favourable renal outcomes. Age ≥6 years flagged higher renal risk, supporting age-targeted urine and blood-pressure surveillance, while relapse appeared to follow a non-renal trajectory (joint/abdominal clustering). Steroid and dapsone use reflected clinical severity rather than relapse risk. Findings align with Indian series and suggest lower renal morbidity than some East-Asian reports, adding region-specific evidence to guide monitoring and counselling. Full article

Over the past five decades, the emergence and re-emergence of multiple flaviviruses have triggered significant global outbreaks, posing serious threats to public health. Among them, West Nile virus (WNV) is a major cause of mosquito-borne illness, typically presenting as an acute systemic febrile disease and, in some cases, progressing to the central nervous system involvement. No specific antiviral therapies or effective vaccines are available for WNV infections. In this context, antimicrobial peptides (AMPs) with antiviral properties—known as antiviral peptides (AVPs)—have gained attention as potential therapeutic agents due to their ability to interfere with various stages of the viral life cycle. Two frog-derived melittin-like peptides, AR-23 and RV-23, were synthesized and purified, and their hemolytic activity was assessed on human erythrocytes. Antiviral activity against WNV was evaluated in Vero cells using cytopathic effect reduction assays and real-time PCR quantification of viral RNA. Time-of-addition experiments were conducted to explore the stage of viral inhibition. In silico molecular docking studies were performed to examine interactions between the peptides and the viral E glycoprotein. Both peptides displayed strong antiviral effects during the early phases of infection, likely through direct interaction with viral particles and disruption of virus–host interactions. Compared with melittin, AR-23 and RV-23 showed greater efficacy and lower cytotoxicity, highlighting their potential as promising therapeutic candidates for flavivirus infections. Full article

Sindbis virus (SINV), a prototype of the Alphavirus genus (family Togaviridae), is a globally distributed arbovirus causing febrile rash and debilitating arthritis in humans. Viral structural proteins—capsid (C), E1, and E2—are fundamental to the virion’s architecture, mediating all stages from assembly to host cell entry and pathogenesis, thus representing critical targets for study. This review consolidates the historical and current understanding of SINV structural biology, tracing progress from early microscopy to recent high-resolution cryo-electron microscopy (cryo-EM) and X-ray crystallography. We detail the virion’s precise T = 4 icosahedral architecture, composed of a nucleocapsid core and an outer glycoprotein shell. Key functional roles tied to protein structure are examined: the capsid’s dual capacity as a serine protease and an RNA-packaging scaffold that interacts with the E2 cytoplasmic tail; the E1 glycoprotein’s function as a class II fusion protein driving membrane fusion; and the E2 glycoprotein’s primary role in receptor binding, which dictates cellular tropism and serves as the main antigenic target. Furthermore, we connect these molecular structures to viral evolution and disease, analyzing how genetic variation among SINV genotypes, particularly in the E2 gene, influences host adaptation, immune evasion, and the clinical expression of arthritogenic and neurovirulent disease. In conclusion, the wealth of structural data on SINV offers a powerful paradigm for understanding alphavirus biology. However, critical gaps persist, including the high-resolution visualization of dynamic conformational states during viral entry and the specific molecular determinants of chronic disease. Addressing these challenges through integrative structural and functional studies is paramount. Such knowledge will be indispensable for the rational design of next-generation antiviral therapies and broadly protective vaccines against the ongoing threat posed by SINV and related pathogenic alphaviruses. Full article

Early biomarkers are needed to predict the long-term persistence of rheumatical symptoms in patients infected with Chikungunya virus (CHIKV). This nested case-control study aimed to assess immunological factors during the early phases of CHIKV infection to predict the risk of post-CHIK chronic rheumatism (pCHIK-CR) in adult patients of two prospective cohorts. We evaluated 46 febrile patients (median age: 33.5 years; IQR: 19 years; women: 50.0%) with CHIKV infection confirmed during the 2014–2015 outbreak in Santander, Colombia. The participants were classified by a rheumatologist as either cases (pCHIK-CR) or controls (WoRM, without rheumatical manifestations). We quantified serum levels of IL-4, IL-6, IL-8/CXCL-8, IL-27, CCL-2, CXCL-9, CXCL-10, and IgG using Luminex and ELISA assays during the acute and subacute phases of infection. Then, we evaluated the association of these immune factors with the case-control status using piecewise logistic regression adjusted for age and sex. There were non-linear associations between IL-8/CXCL-8, CXCL-9, and CXCL-10 with pCHIK-CR. Increases in the levels of IL-8/CXCL-8 (<35.7 pg/mL), CXCL-9 (≥6000 pg/mL), and CXCL-10 (≥36,800 pg/mL) were significantly associated with a reduced risk of pCHIK-CR (adjusted ORs: 0.85, 0.96, and 0.94, respectively). These results suggest that increases in IL-8/CXCL-8, CXCL-9, and CXCL-10 levels, measured in the early stages of CHIKV infection, may predict a chronic disease risk. This suggests the possibility that an early and strong immune response could contribute to enhancing CHIKV control and potentially reduce the risk of persistent joint symptoms. Given their expression patterns and timing, these three immune factors may be considered promising biomarker candidates for assessing the risk of chronic rheumatologic disease. These findings should be considered as exploratory and validated in additional cohort studies. Full article

Background: The anti-tumor response of the immune system is pivotal for treating triple-negative breast cancer (TNBC), particularly as targeted therapies are limited. However, the impact of immune-modulating factors such as the application of granulocyte-stimulating factors (G-CSFs) or infections, including febrile neutropenia, prophylactic or therapeutical application of oral antibiotics (OABs), and the need for intravenous antibiotics (IABs), on survival outcomes remains unclear. Methods: 1583 patients with early-stage TNBC enrolled in the SUCCESS A or C study underwent primary surgery, adjuvant chemotherapy, and radiotherapy if indicated. All patients had Eastern Cooperative Oncology Group (ECOG) status ≤ 2. The effects of G-CSF, OAB, and IAB application on overall survival (OS), invasive disease-free survival (iDFS), breast cancer-specific survival (BCSS), and distant disease-free survival (DDFS) were assessed. Results: Only IAB treatment was significantly associated with decreased survival in univariable analyses (OS: p = 0.003; iDFS: p = 0.036; BCSS: p = 0.011; DDFS: p = 0.044), while G-CSF and OAB administration were not. Adjusted multivariable Cox regressions including febrile neutropenia and dose reduction/shift, ECOG, age of patients, and other clinicopathological parameters confirmed a significant negative effect of IABs on OS (p = 0.020), BCSS (p = 0.018), and DDFS (p = 0.044). Conclusions: In summary, IABs during adjuvant chemotherapy seems to be a risk factor for inferior OS, BCSS, and DDFS in TNBC patients, possibly by affecting microbiome-related immune response modulation. Hence, preventive measures to avoid the need for IABs should be considered in these patients. Full article

The Chikungunya virus (CHIKV) is a priority endemic pathogen identified by the World Health Organization and its infection induces an acute febrile illness in humans that is often associated with arthritis and musculoskeletal pain. Therefore, specific vaccines and treatments are urgently needed to prevent or treat Chikungunya disease. Here, we identify a series of CHIKV-specific neutralizing nanobodies (Nbs) from an alpaca which exhibit distinct binding modes compared to those previously reported. Two representative anti-CHIKV Nbs, N033-Fc and N053-Fc, demonstrated significant antiviral activity in Ifnar^−/− mice against lethal challenge. Further studies elucidated the functional mechanisms of N033-Fc and N053-Fc in blocking CHIKV infection at multiple stages of the viral life cycle. This study identifies multiple candidate Nbs that may be suitable for next-generation antibody therapies to combat CHIKV infection. Full article

Background/Objectives: Cerebral folate transporter deficiency is characterized by pauses and regression in general development stages, with ataxia, choreoathetoid movements, and myoclonic epilepsy generally resistant to treatment. The aim of this study was to comprehensively evaluate cases followed up in two centres in Türkiye for a diagnosis of folate receptor-α deficiency. Methods: The study included nine cases from six different families. Results: The patients comprised 22.2% males and there was parental consanguinity in 88.9% of cases. The mean age at which complaints were first noticed was 3.7 years, and the age of definitive diagnosis was 10.4 years. The most frequently seen first complaints were febrile convulsions and attention deficit-hyperactivity-learning difficulties. The diagnosis most commonly made before the definitive diagnosis was epilepsy, and the first seizure occurred at a mean of 5.2 years. On cranial imaging, white matter involvement, cerebellar atrophy and cerebral atrophy were determined most often. Definitive diagnosis was established solely through clinical findings and genetic analysis. Three different variants in the FOLR1 gene were determined. Treatment with folinic acid at a dose of 5.2 mg/kg/day of PO was started at the age of 9.8 years on average, and intravenous folinate was started at different doses. Conclusions: This study stands out as one of the largest case series in the literature and identifies a previously unreported novel variant. Our study suggests that FOLR1-related CFD should be considered in cases with febrile convulsions, developmental delay, ataxia, autism spectrum disorder, acquired microcephaly, and MRI findings of white matter involvement and cerebellar atrophy. Due to an asymptomatic early period, CFD diagnosis may be delayed, and treatment after symptom onset may be less effective. Incorporating FOLR1 gene analysis into newborn screening programmes could facilitate early diagnosis and treatment. It is thought that the application of vagus nerve stimulation, in addition to folinic acid and anticonvulsant drug treatment, could be effective in seizure control. Full article