Search Results (80)

Background: Lebanon adopted the World Health Organization (WHO)’s regional strategic plan (2012–2020) to achieve measles elimination. We aimed to analyze WHO measles surveillance performance indicators to identify areas for improvement. Methods: We reviewed suspected measles and rubella cases notified to the national epidemiological surveillance program between January 2013 and December 2024. A suspected case was defined as any patient with a febrile maculopapular rash or considered clinically compatible by physicians. We assessed notification rates of discarded non-measles/rubella suspected cases, timeliness of investigations within 48 h, completeness of case investigations (demographic and vaccination data), and proportion of cases tested for measles/rubella. Mean proportions and standard deviations were calculated across years and provinces. Results: A total of 6581 suspected cases were reported, predominantly from hospitals (66%). Outbreaks occurred in 2013 (n = 1760), 2018–2019 (n = 1984) and 2023–2024 (n = 346). Outside outbreak years, the notification rate ranged between 0.7 and 1.8 per 100,000 population. Timely investigation was achieved in 72% (±30%) of cases, while adequate investigation reached 52% (±19%). Laboratory testing was performed in 62% (±16%) of cases. Conclusions: Surveillance in Lebanon showed suboptimal sensitivity, a high proportion of hospitalized cases, and variability in completeness of epidemiological and laboratory investigations. Strengthening outpatient reporting and continuous training of healthcare professionals are essential to improve surveillance performance. 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

Parvovirus B19 is a DNA virus. Most parvoviruses infect animals; Parvovirus B19 infects humans. Parvovirus B19 is mainly transmitted through respiratory droplets during close contact, but additional routes such as transmission through contaminated blood products and vertical transmission from mother to fetus have also been documented. Infections occur throughout the year, with a seasonal increase between late winter and early summer. Clinical symptoms depend on age, and on patients’ immune status. Healthy, immunocompetent individuals experience asymptomatic or mild infections including a febrile rash; serious complications rarely appear, such as rheumatoid-like arthritis or acute myocarditis. Clusters of myocarditis cases following Parvovirus B19 infections appeared in a daycare in Thessaloniki in 2024. To molecularly and phylogenetically characterize Parvovirus B19 strains detected during a pediatric outbreak associated with elevated troponin levels and myocarditis in Northern Greece, and to compare these strains with isolates from adult cases with mild symptoms in order to explore potential associations between viral genetic variability and cardiac involvement. MinION sequencing protocol was performed for nine whole blood samples, seven belonging to children with myocarditis, and two to adults presenting mild symptoms. Statistical analysis was performed with QualiMap 2.3 and relevant tools. Phylogenetic analysis identified distinct viral groups originating from the samples investigated. A distinct branch was formed by the reference genome and the ones of the adults’ samples, while samples from children with myocarditis provided discrete branches differing from the reference one. The findings demonstrate a clear association between Parvovirus B19 infection and myocarditis in the pediatric cases analyzed. The detected viral strains, including variants identified in several samples, support the role of Parvovirus B19 as a contributing factor in post-infectious cardiac involvement. Although these results reinforce the clinical relevance of Parvovirus B19 in childhood myocarditis, expanding the sample size would allow for a more robust characterization of circulating strains and confirmation of the observed patterns. Full article

Oropouche virus (OROV) has emerged as a significant arboviral pathogen in South America, responsible for recurrent outbreaks of febrile illness. In the Loreto region of Peru, more than 600 cases were reported in 2024, markedly exceeding expected incidence rates. We conducted a retrospective observational study using clinical–epidemiological records of all RT-qPCR-confirmed cases of Oropouche fever from the Regional Health Directorate of Loreto between October 2024 and March 2025. A total of 100 confirmed cases were identified. The most frequent symptoms were fever (88%), headache (78%), and myalgia (72%). No atypical or neurological presentations were reported. No severe cases or deaths occurred. Eight patients required hospitalization, mainly due to severe abdominal pain, persistent vomiting, arthralgia, and pregnancy. Six pregnant women were identified; three experienced pregnancy complications, though no fetal malformations or miscarriages were observed. This outbreak represents a new OROV epidemic in the region, with fewer cases than in 2024 and predominantly mild clinical courses. Although outcomes were generally favorable, the occurrence of complications in pregnant women underscores the importance of continued molecular surveillance and targeted public health interventions. 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

African swine fever (ASF), caused by the African swine fever virus (ASFV), is an acute, febrile, highly contagious, and lethal disease that poses a severe threat to the global pig farming industry. Currently, no globally recognized, safe, and effective commercial ASF vaccine has been developed, making vaccination a crucial strategy for outbreak control. The ASFV structural proteins p72, p30, and p54 are key targets for vaccine development. In this study, we developed a novel baculovirus vector-based system for surface display of a recombinant protein comprising epitopes from p72, p30, and p54. Upon infection, the recombinant protein was expressed and anchored on the plasma membrane of Sf-9 cells. Purified virus analysis revealed that the Bac-recombinant protein enhanced gene delivery and transgene expression in mammalian cells compared to the Bac-Wild Type (Bac-WT). In a murine model, the Bac-recombinant protein induced significantly higher IFN-γ and IL-4 levels than Bac-p30 and the negative control. However, further evaluation in swine models is required to confirm its protective potential against ASFV. Furthermore, it also elicited a robust antibody response, generating high-titer Bac-recombinant protein-specific antibodies. Therefore, these findings suggest that the ASFV Bac-recombinant protein is a promising candidate for a vector-based vaccine. Full article

Oropouche virus (OROV) is an emerging arbovirus responsible for Oropouche fever, also known as sloth fever, a febrile illness that can lead to recurrent outbreaks in affected regions. Endemic to parts of South and Central America, OROV is primarily transmitted by biting midges (Culicoides paraensis), although mounting evidence implicates mosquitoes, particularly the Culex and Aedes species, as additional vectors. Recent ecological disturbances—such as deforestation, urbanization, and climate change—have driven significant shifts in vector population dynamics, contributing to the expanded geographic range and increased transmission of OROV. Notably, recent reports of OROV infections among American and European travelers to Cuba highlight the virus’s growing potential for international dissemination and underscore its significance as a global health concern. OROV is an enveloped orthobunyavirus within the Peribunyaviridae family, possessing a tripartite, single-stranded, negative-sense RNA genome composed of the S (small), M (medium), and L (large) segments. These segments encode the nucleocapsid (N) protein, glycoproteins (Gn and Gc), and RNA-dependent RNA polymerase, respectively. Despite increasing incidence and potential for global spread, no licensed vaccines or antiviral therapies currently exist, and effective diagnostic tools remain limited. Furthermore, although human-to-human transmission has not been observed, the absence of robust surveillance systems complicates timely outbreak detection and response. In this study, we present a comprehensive molecular characterization of OROV’s major structural proteins, with an emphasis on structural modeling and epitope prediction. By integrating bioinformatics approaches with available structural data, we identify key antigenic regions that could serve as targets for the development of serological diagnostics and vaccine candidates. Our findings contribute critical insights into the molecular virology of OROV and provide a foundational framework for future efforts aimed at the prevention, diagnosis, and control of this neglected tropical pathogen. These advancements are essential for mitigating the impact of OROV in endemic regions and reducing the risk of global emergence. 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

Rift Valley fever (RVF) is a re-emerging vector-borne zoonotic disease that causes outbreaks in humans and animals across Africa. To better understand RVF at human–animal interfaces, a prospective longitudinal survey of people, livestock, and mosquitoes was conducted from 2016 to 2018, in two regions of Tanzania, with distinct climatic zones (Iringa and Morogoro). Molecular and serological tools for testing (RT-qPCR and IgM/IgG ELISA) for RVF virus (RVFV) were used to assess infection and exposure in people and animals. Mosquitoes were collected quarterly from 10 sentinel locations. In total, 1385 acutely febrile humans, 4449 livestock, and 3463 mosquito pools were tested. In humans, IgM seroprevalence was 3.75% (n = 52/1385), and overall seroprevalence (IgM and/or IgG positive) was 8.30% (n = 115/1385). People from Iringa had a higher exposure risk than those from Morogoro (aOR 2.63), and livestock owners had an increased risk compared to non-owners (aOR 2.51). In livestock, IgM seroprevalence was 1.09%, while overall seroprevalence was 10.11%. A total of 68.4% of herds had at least one seropositive animal. Sentinel animal follow-up revealed that the probability of seroconversion was significantly higher in Morogoro. Low-level RVFV RNA was detected in 8 human and 22 mosquito pools. These findings indicate active transmission among vectors, livestock, and people during the study period, highlighting the need for One Health surveillance approaches for RVFV and other arboviruses. Full article

Background: Immunocompromised children with malignancies or after hematopoietic cell transplantation (HCT) often deteriorate before conventional cultures identify a pathogen. Next-generation sequencing (NGS) promises faster, broader detection, yet its clinical impact in pediatric oncology remains unclear. This review aimed to assess the diagnostic performance and clinical utility of NGS in this population. Methods: We searched PubMed, Embase, and Scopus from January 2010 to April 2025 for studies evaluating NGS (metagenomic, targeted, or whole-genome sequencing) in pediatric oncology or HCT patients meeting predefined eligibility criteria. Duplicate screening, data extraction, and Joanna Briggs Institute risk-of-bias appraisal were performed. Heterogeneity precluded formal meta-analysis; findings were synthesized using narrative synthesis complemented by limited quantitative analyses. The protocol was not registered. Results: Twenty-four studies (≥2700 children; 2019–2025) met inclusion criteria. Metagenomic NGS (mNGS) was the most common approach, applied to blood/plasma (46%), bronchoalveolar fluid (BALF) (21%), and other fluids. In culture-negative sepsis or persistent febrile neutropenia, mNGS detected pathogens in 69–86% of episodes versus 18–56% for culture/polymerase chain reaction (PCR). Described in limited studies, early (<48 h) testing shortened fever by ~1.5 days and cut antimicrobial costs by 25–30%. Across studies, treatment was escalated, de-escalated, or discontinued in a median of 63% of mNGS-positive cases. Whole-genome sequencing (WGS) identified 18 silent transmission clusters and resolved a multidrug-resistant Acinetobacter baumannii outbreak within hours. Conclusions: NGS benefits pediatric hemato-oncology by accelerating pathogen-directed therapy, supporting antimicrobial stewardship, and enhancing outbreak surveillance. Despite cost and standardization barriers, evidence supports its use in selected high-risk patients. 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

Dengue has been a serious public health concern in Nepal since the past few years, with concurrent big outbreaks occurring in 2022–2024. This cross-sectional study was conducted among febrile patients visiting hospitals in Mahottari district in southern Nepal. A total of 2141 dengue-suspected patients were investigated by routine laboratory assays and serological and molecular techniques, including real-time quantitative polymerase chain reaction (RT-qPCR). Among them, 455 (21.3%) were confirmed as dengue cases. The majority of dengue cases (435, 95.6%) had a primary dengue infection. The total bilirubin level was significantly higher in secondary dengue infection than in primary (p = 0.032). The major dengue virus (DENV) serotypes responsible for this outbreak were DENV-1 (45.5%) and DENV-2 (40.9%), while 13.6% patients had DENV-3 infection. DENV-3 infection showed a significantly higher viral load (median: 7.71 Log₁₀ copies/mL; range: 6.48–7.94) compared to DENV-1 (6.72 Log₁₀ copies/mL; 5.49–7.17) and DENV-2 (4.76 Log₁₀ copies/mL; 2.32–6.96). Adult patients exhibited a significantly higher viral load than children (p = 0.035). NS1- and IgM-positive as well as admitted patients had a higher viral load (p < 0.05). Co-circulation of multiple serotypes (DENV-1, -2, -3) was confirmed with the first introduction of DENV-1 and DENV-3 in Mahottari and surrounding areas in the 2023 outbreak. Identification of the circulating DENV serotypes is crucial to understanding the epidemiological trend and dynamics of population immunity. These findings underscore the need of nation-wide integrated surveillance, including genomic data generation, in Nepal for disease control, prevention, and potential vaccine implication. Full article

Outbreaks of infectious diseases contribute significantly to morbidity and mortality in resource-limited settings, yet the capacity to identify their etiology remains limited. We aimed to characterize microbes and antimicrobial resistance (AMR) genes in Tanzanian children affected by an acute febrile illness (AFI) outbreak using metagenomic next-generation sequencing (mNGS). A cross-sectional study was conducted on archived blood samples from children who presented with AFI between 2018 and 2019. Total nucleic acids were extracted from 200 µL of blood, and complementary DNA (cDNA), along with enriched pathogenic DNA, was sequenced using the Illumina MiSeq platform. mNGS data were analyzed using CZ-ID Illumina mNGS bioinformatics pipeline v7.0. Results were obtained from 25 participants (mean age: 11.6 years; SD ± 5), of whom 36% had a moderate to high-grade fever. The following five potential microbial causes of AFI were identified: Escherichia coli (n = 19), Paraclostridium bifermentans (n = 2), Pegivirus C (n = 2), Shigella flexneri (n = 1) and Pseudomonas fluorescens (n = 1), with E. coli being the most prevalent. Twelve AMR genes were detected, including mdtC, acrF, mdtF, and emrB. E. coli harbored most of the AMR genes previously associated with resistance to commonly used antibiotics. mNGS offers a promising complementary approach to conventional diagnostics for identifying pathogens and AMR profiles in vulnerable populations. Full article

An unprecedented outbreak of Oropouche virus (OROV) is occurring in the Americas, characterized by thousands of confirmed cases and a wide geographical spread, including areas outside the Amazon Basin. Little is known about this neglected arbovirus regarding its pathophysiological aspects and potentially different transmission modes. This study describes the clinical course of a man who returned from a trip to Cuba and presented to our hospital 4 days after the onset of febrile symptoms. The patient was diagnosed with Oropouche fever and was followed for 177 days after the onset of symptoms. We performed a longitudinal investigation of the samples collected from several body sites (whole blood, serum, urine, and semen) with the aim of providing further insights into OROV infection dynamics, using the detection of antigenomic RNA as a marker of active viral replication. Clinical samples that were longitudinally collected over the course of OROV infection showed consistently higher amounts of antigenomic RNA compared to genomic RNA, even after viral clearance from serum. Moreover, our case study showed the persistence of OROV RNA in serum of less than 15 days from the onset of symptoms, as compared to up to one month in urine, three months in semen, and four months in whole blood. Our study suggests that Oropouche virus may persist in an actively replicating state in different body sites for long periods of time, with important implications for transmission dynamics. Furthermore, our results provide a diagnostic indication, suggesting that serum is inferior to both urine and whole blood as preferred diagnostic samples. Further studies are needed to determine the pathogenetic implications of these findings, as they have been derived from a single case and must be confirmed using a larger number of cases. Full article