Journal of Clinical Virology Plus

Background Reactivation of human herpesviruses (HHVs), particularly EBV, is associated with more severe acute SARS-CoV-2 infections and the development of Long COVID (LC). Observations of higher anti-EBV antibody levels in individuals with LC support the idea that chronic reactivation of HHVs could contribute to LC pathology. HHV shedding in saliva has also been previously associated with saliva hormone levels. This study aims to examine the relationship between salivary shedding of HHV DNA and LC symptoms, as well as cortisol, testosterone, and estradiol levels. Methods We enrolled 45 participants with LC, and 45 age-sex-matched controls. Surveys and validated health questionnaires were used to collect demographics, medical history, and symptom profiles. Saliva was self-collected at waking, 15, 30, and 45 minutes, and 8 and 16 hours after waking, across two consecutive days. Salivary cortisol, testosterone and estradiol were measured, and extracted nucleic acid was tested for EBV, HSV 1/2, HCMV and HHV-6 A/B using multiplex qPCR, plus SARS-CoV-2 and RNaseP using RT-qPCR. Findings Detection of salivary EBV and HHV-6 DNA was highest early in the morning. There were no significant differences in salivary cortisol, testosterone, or estradiol, or in EBV or HHV-6 shedding between the LC and control groups. However, salivary HHV-6 DNA levels were positively associated with a greater aggregated LC propensity score, as well as anxiety and depression scores. Interpretation The observed correlation between salivary HHV-6 shedding and symptom severity suggests HHV-6 may contribute to post-acute disease, though mechanisms remain unclear. While our study did not identify a relationship between salivary EBV shedding and LC, EBV may still play a role at earlier time points in the disease course, or in compartments not sampled here. These findings highlight the potential importance of HHV-6 in LC pathophysiology and underscore the need for longitudinal, multi-compartment studies of herpesvirus reactivation in LC.

Introduction: Hantavirus disease is an emerging and potentially severe zoonosis of global distribution. In Uruguay, it is transmitted by rodents inhabiting peridomestic, suburban, and rural areas. Global incidence is estimated at 150,000 to 200,000 cases per year, with up to 300 annual cases in the Americas. Since 1997, Uruguay's Ministry of Public Health (MPH) has monitored Hantavirus cardiopulmonary syndrome (HCPS), the most common clinical presentation in the region. By 2019, a total of 271 cases had been identified in the country, with an estimated mortality rate of nearly 50%. Objectives: To describe the clinical, epidemiological, and occupational characteristics of patients with Hantavirus disease in Uruguay during the pre-pandemic (2018-2019) and pandemic (2020-2021) periods. Methods: A descriptive, cross-sectional, observational study was conducted, including all serologically confirmed cases of Hantavirus infection reported to the MPH between 2018 and 2021. Clinical and demographic data were extracted from the mandatory reporting form for zoonotic diseases. Incidence and case fatality rates were calculated, and factors associated with fatal outcomes were analyzed. Results: A total of 58 confirmed cases were identified between 2018 and 2021. Most patients were male (62%), with a mean age of 36.5 years (SD 16). A decline in incidence was observed during 2020-2021, with no significant change in case fatality. Direct rodent exposure was the most frequently associated risk factor. Montevideo and Canelones were the most affected departments. Renal and pulmonary involvement were significantly associated with mortality. Conclusion: Hantavirus remains a relevant public health concern in Uruguay. Although a decrease in incidence was observed during the COVID-19 pandemic years, case fatality rates remained high. The findings underscore the need for sustained surveillance and early recognition, particularly in urbanizing regions.

Successive dengue virus (DENV) outbreaks can progressively reshape population immunity influencing disease expression and diagnostic performance. Objectives The aim was to evaluate the impact of secondary infections across sequential outbreaks on clinical severity, serotype dynamics and diagnostic concordance. Methods This retrospective study analyzed 976 febrile-stage samples from three sequential outbreaks in Misiones, Argentina. For serotyping and clinical analyses, 869 viremic samples confirmed by at least one direct method were included (2016: n=512; 2019: n=148; 2024: n=209). Additionally, 318 samples, including 107 non-viremic cases, were used to compare NS1 rapid diagnostic tests (NS1 Ag) and RT-PCR. Viral serotyping and clinical and laboratory markers of disease severity were evaluated. Results Secondary infections increased from 31.05% (2016) to 43.24% (2019) and 53.87% (2024) (p<0.0010). Serotype distribution shifted from DENV-1 predominance in 2016 (95.12%), DENV-1/DENV-4 co-circulation in 2019 (60.71%/39.29%), and DENV-2 predominance in 2024 (97.60%). Secondary infections were associated with more severe disease manifestations, particularly in 2024, with higher hematocrit (p=0.0120) and hemoglobin (p=0.0080), lower white blood cells (p=0.020) and platelet counts (p=0.0030), and elevated AST (p=0.0007) and ALT (p=0.0130). Concordance between NS1 Ag and RT-PCR was lower in secondary infections (k=0.457 vs k=0.759, p=0.0013). Conclusions The rising frequency of secondary infections may affect both clinical severity and diagnostic performance during outbreaks. The clinical impact was more evident in 2024, likely associated with the introduction of a new serotype. These findings highlight the need for optimized surveillance and diagnostic strategies to improve case detection and patient management during epidemics.

Background Oropouche virus (OROV) is an emerging vector-borne virus with rapidly expanding geographic range, increasing case counts, and growing evidence of severe outcomes including neuroinvasive disease and vertical transmission. Because OROV infection presents with nonspecific febrile illness that overlaps clinically with other viruses including dengue, zika, and chikungunya, accurate molecular diagnostics are essential for patient care and surveillance. Yet existing assays rely on single genomic targets and are vulnerable to detection failure as the virus evolves and reassorts. Methodology/Principal Findings To support diagnostic capacity, we developed and clinically validated a multiplexed qPCR assay targeting three regions of the OROV S segment, incorporating redundancy to preserve sensitivity across viral diversity while enabling robust clinical interpretation. The multiplex also includes an assay targeting RNaseP as an internal sample control to ensure adequate sample processing. We evaluated assay performance using both historical and contemporary OROV strains and validated the assay on contrived serum, plasma, and cerebrospinal fluid samples, assessing linearity, limit of detection (LOD), accuracy, specificity, precision, and sample stability. The assay met or exceeded all predefined acceptance criteria for clinical testing and achieved an LOD as low as 6 copies per reaction for contemporary outbreak strains. We further implemented a logic-based interpretation matrix that reduced false-positive risk while maintaining sensitivity near the analytical LOD. Conclusions/Significance Our assay sensitively and specifically detects OROV RNA in serum, plasma, and cerebrospinal fluid while incorporating safeguards against viral evolution and reassortment. The assay has been approved for use by CLIA at Nexus Medical Labs in 49 U.S. states, expanding access to timely OROV diagnostics in the United States and providing a durable framework for molecular detection of reassorting, rapidly evolving viruses as OROV continues to spread into new regions.

Using a commercially available H5 serology assay, we identified a 7.4% (n=5/68) anti-H5 seroreactivity rate among hunters in Northern Canada. All participants reported close contact with wild birds.

Nasopharyngeal (NP) swabs remain the dominant gold standard for respiratory infection diagnostics. While there has been increased use of alternative sample types since the COVID-19 pandemic, guidance on their use for detecting respiratory viruses is not yet definitive, especially for children. In this systematic review and meta-analysis, we aimed to compare the diagnostic accuracy and tolerability of multiple respiratory specimen types for detecting respiratory viruses in pediatric populations. Searches were conducted on July 17, 2025 in MEDLINE, Embase, Web of Science, and Scopus, with screening and data extraction performed in Covidence. English-language primary research articles published since 2000 comparing respiratory virus detection rates in children, using nucleic acid amplification tests between paired respiratory specimens, were included. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies criteria. We calculated pooled sensitivities and specificities of index specimens: nasopharyngeal aspirates (NPA), mid-turbinate swabs (MT), anterior nasal swabs (ANS), oropharyngeal swabs (OP), and bronchoalveolar lavage fluid (BAL), as compared to the reference, NP swabs, using random-effects modeling, firstly without discrimination by virus. Index specimens were then grouped by sample collection site as nasal, oral, and lower respiratory tract (LRT) specimens for virus-specific analyses. Overall performance and statistical validity were evaluated by hierarchical summary receiver operating characteristic (HSROC) analysis. Data regarding sampling tolerability was also assessed. We screened 2,448 studies and identified 36 publications (total N participants = 10,687) that reported diagnostic test accuracy using paired index-reference data in children. Of these, 18 (total N participants = 4,310) used NP specimens as the reference and were included in the diagnostic test accuracy analysis. Virus-agnostic pooled sensitivity estimates indicated that MT (0.92%) performed most similarly to NP, though sensitivities of ANS (0.79%) and OP (0.70%) were also moderately high for detection of any respiratory virus. BAL sensitivity was the lowest (0.37%). All sample types demonstrated high specificity (0.98%-0.99%). Group estimates and HSROC statistics found that nasal specimens, when grouped, had the highest sensitivity and accuracy for all examined viruses, including for influenza (92%) and RSV (90%). By comparison, oral and LRT specimens performed less well, with more variability, though both showed moderately high sensitivities for RSV (78%, 76%, respectively) and influenza (82%, 80%, respectively), and LRT samples showed high sensitivity for HMPV (82%). Analysis of sample tolerability found that NP swabs consistently ranked as the least comfortable and least preferred, while nasal swabs and saliva both performed well. Datasets for LRT and oral specimens were sparser than for nasal, and this contributed to greater variability, underscoring the need for further diagnostic accuracy studies on alternatives to NP sampling. These data support the viability of nasal and oral alternatives to NP swabs and affirm their application in pediatric care, particularly in outpatient settings. Such alternatives could greatly improve sampling tolerability and increase global access, including in resource-limited settings, to accurate diagnostic methods for respiratory infections.

Background Coeliac disease (CD) diagnosis on duodenal biopsies is limited by interobserver variability. We have previously demonstrated pathologist-level performance with our artificial intelligence (AI) model for the histopathological diagnosis of adult CD, but not in paediatric practice. As paediatric CD screening programmes expand internationally, accurate and scalable diagnostic tools are needed. We investigated whether an AI model trained exclusively on adult whole-slide images (WSIs) can generalise to paediatric CD diagnosis across independent centres. Methods A training and validation dataset of 9,958 WSIs from 8,421 adult patients (961 CD) from five centres was used to develop an ensemble of multiple-instance learning models using features from a foundation model. Testing was performed on 708 consecutive paediatric patients (86 CD) from two centres (Edinburgh and Southampton) not included in training. Model calibration was assessed, and probability outputs were grouped into clinically interpretable categories. Findings In adult cross-validation, the AI model achieved an area under the receiver operating characteristic curve (AUC) of 98.7%, sensitivity of 84.9%, specificity of 99.0%, and negative predictive value (NPV) of 98.1%. On testing (paediatric) datasets, performance remained high (AUC 98.8%, sensitivity 80.2%, specificity 98.4%, NPV 97.3%). Restricting analysis to predictions outside the intermediate-probability range (predicted CD probability <10% or [&ge;]65%; 85.3% of cases) improved sensitivity to 100% and specificity to 98.7%. No misclassifications were observed among high-confidence predictions (<2% or [&ge;]85%; 66.0% of cases). The expected calibration error was 0.03. Performance improved significantly when biopsies from both duodenal sites (bulb [D1] and descending [D2/3]) were considered. Interpretation Our AI model, trained on adult biopsies, generalises to paediatric CD diagnosis across centres and scanner platforms. Well-calibrated probability outputs provide clinically interpretable measures of diagnostic confidence and could support safe identification of CD-negative biopsies within defined thresholds. These findings demonstrate the feasibility of applying adult-derived AI models in paediatric populations and reinforce the importance of multi-site (D1 & D2) biopsy sampling.

Background. Women living in leishmaniasis-endemic zones are regularly exposed to the sandfly vector in their environments. While case series and laboratory evidence consistently suggest transplacental transmission of Leishmania parasites with deleterious maternal-fetal effects, this issue has received insufficient attention, particularly in areas where the predominant Leishmania species is mainly associated with cutaneous disease (CL). Methodology/Principal Findings. We conducted an exploratory cross-sectional study in a highly endemic zone of Tabasco, Mexico, enrolling 53 women with singleton term deliveries between April 2018 and April 2020. Placental PCR was positive in 18 (34%) participants. Buccal swabs were positive in 11 (21.2%) of 52 newborns. Immunofluorescence confirmed intracellular amastigotes within macrophages near the vascular endothelium of PCR-positive placentas, with no surrounding inflammatory infiltration. Sequencing revealed homology to Leishmania mexicana or L. amazonensis. Birthweight percentile was modestly lower in the PCR-positive group (predicted mean 53.8% vs. 56.5%, p = 0.76), while small for gestational age showed a non-significant trend toward higher prevalence among PCR-positive cases (prevalence ratio = 2.06, 95% CI: 0.32-13.39, p = 0.45). Conclusions/Significance. Subclinical, dynamic transmission of Leishmania parasites typically associated with cutaneous disease was detected in this endemic zone. The presence of L. mexicana in human placentas was confirmed by immunofluorescence and sequencing, without an associated inflammatory response. These findings highlight the potential of CL-associated Leishmania species to reach the placenta and buccal mucosa of newborns, warranting further epidemiological investigation into the consequences of vertical transmission in regions with endemic CL.

Background: In resource-limited settings, a critical bottleneck in cervical cancer prevention is the lack of practical strategies to triage high-risk human papillomavirus (HR-HPV)- positive women. Therefore, this study aimed to develop and internally validate a genotype-specific risk stratification model. Methods: A cross-sectional study enrolled 555 women in Cameroon. Data collection integrated cervical cytology and HPV genotyping using Abbott m2000rt and Sacace multiplex systems. An iterative modeling approach with bootstrap validation was used to develop the model and address model instability. HR-HPV genotypes were transformed into a hierarchical risk variable due to sparsity and integrated with significant predictors. The final model was translated into a scoring system, and the risk gradients and performances were evaluated at two thresholds. Data was analyzed using SPSS 27.0. Results: The mean age was 44.8 years, and the prevalence of HR-HPV was 26.5% (147/555). The final model, incorporating HPV categories, age, and tobacco, demonstrated moderate discriminative ability (AUC=0.702, 0.642-0.762) with a good calibration (Hosmer-Lemeshow {chi}{superscript 2}=4.05, p=0.399). The scoring system assigned women to risk groups based on their total scores which produced a clear monotonic risk gradient; the observed probability of high-grade lesions/cancer ranged from 15% (score 0) to >65% (score [&ge;]4). At a conservative threshold ([&ge;]4 points), 4.7% (26/555) of women were classified as high-risk, concentrating 46% (6/13) of cancers (positive predictive value[PPV]=58%) while a sensitive threshold ([&ge;]3 points) had 16.8% (93/555) high-risk, concentrating 77% (10/13) cancers (PPV=38%). Both thresholds maintained a high negative predictive value (>95%). Conclusion: This bootstrap-validated, risk-stratification tool is a proof-of-concept in resource limited settings that assigns HR-HPV-positive women to distinct management pathways using three variables. After refining through a longitudinal study and external validation, this scoring system can improve the efficiency of cervical cancer screening programs in low-resource settings.

Background Coeliac disease affects approximately 1% of the global population and remains substantially underdiagnosed. Histopathological assessment of duodenal biopsies is the diagnostic gold standard but is subject to approximately 20% inter-observer disagreement. While machine learning approaches show promise, most prior work relies on black-box models with limited interpretability, restricting clinical adoption. Methods We present an interpretable pipeline that follows established histopathological criteria by extracting clinically meaningful morphological features from H&E-stained whole-slide images. Five sequential stages perform pre-processing, semantic segmentation of villi, crypts, intraepithelial lymphocytes (IELs) and enterocytes, crypt morphometry, villus length estimation via a novel polyline-based keypoint model, and coeliac disease classification using three quantitative features: IEL-to-enterocyte ratio, villus-to-crypt area ratio, and villus-length-to-crypt-depth ratio. Training and validation used data from four institutions; independent testing used 1,357 WSIs from two further institutions including one with a previously unseen scanner manufacturer, spanning five diagnostic categories: coeliac disease, normal mucosa, chronic inflammation, gastric metaplasia, and gastric heterotopia. Results Semantic segmentation achieved villus and crypt precision and recall of 87-90%. Villus length estimation correlated strongly with expert annotations (Pearson's r=0.85, mean relative error 13.5% post-calibration). All three morphological features significantly separated coeliac disease from all non-coeliac diagnostic groups across internal and external datasets (p<0.01 in all comparisons). On the test set the diagnostic classifier achieved accuracy 94.5%, PPV 92.9%, NPV 94.7%, and AUC 0.982. Conclusions This interpretable framework achieves strong multi-centre diagnostic performance while producing quantitative morphological outputs, villus length, crypt depth, and IEL-to-enterocyte ratios, that directly reflect established histopathological criteria, representing a meaningful step towards standardised AI-assisted coeliac disease diagnosis.

Introduction: Synthetic oligopeptides provide a rapid and cost-efficient approach to developing antibodies and diagnostics for emerging viral variants. Methods: This study computationally and experimentally characterized a synthetic peptide analog of the SARS-CoV-2 spike subdomain 2 major disulfide loop (SD2MDL), designated S621 (CPVAIHADQLTPTWRVYSTC). Binding affinity was computationally estimated using the Heuristic Affinity Prediction Tool for Immune Complexes (HAPTIC), while experimental validation was performed using enzyme-linked immunosorbent assay (ELISA) with rabbit-derived antipeptide antibodies. Clinical diagnostic accuracy testing was done using plasma samples from RT-PCR-confirmed COVID-19 patients and pre-COVID-19 controls. Results: S621 demonstrated nanomolar binding affinity (Kdapp = 1.14 nM) and high avidity (3.67 nM), closely matching HAPTIC predictions (3.54 nM). Diagnostic evaluation yielded a sensitivity of 89.92% and specificity of 27.79%, corresponding to an overall accuracy of 71.79%. Discussion: These findings demonstrate that a single synthetic peptide derived from a conserved spike subdomain can function as a high-affinity surrogate for full-length antigens, supporting its potential application in rapid peptide-based immunodiagnostics.

Methicillin-resistant Staphylococcus (MRS) infections are a significant public health concern. Anterior nares serve as a major reservoir and source of spread of MRS ssp. People living with HIV (PLWHIV) tend to be at higher risk of colonisation with MRS organisms due to frequent healthcare exposure. We assessed the prevalence of MRS nasal carriage and associated factors among PLWHIV at the HIV clinic of Kiruddu National Referral Hospital, Kampala, Uganda, from May to July 2024. Nasal swabs from 256 PLWHIV were cultured, and microbiological isolation was performed at MBN Clinical Laboratories. Prevalence was calculated as proportions, and logistic regression identified associations with clinical and socio-demographic factors (p < 0.05). Of 256 participants, 163 (63.7%) carried Staphylococcus, with 82 (32%) identified as MRS carriers (8.9% MRSA, 23% MRCoNS). Frequent hospital visits ([&ge;]3) (adjusted incidence risk ratio [A-IRR] = 1.18 x 107, p < 0.001), second-line antiretroviral therapy (ART) (A-IRR = 3.82, p = 0.041), and unsuppressed viral load (>1000 copies/mL) (adjusted odds ratio [AOR] = 11.3, 95% CI: 2.11-60.58, p = 0.005) were significantly associated with MRS carriage. Mask-wearing was protective against MRCoNS (A-IRR = 1.66, 95% CI: 1.06-2.58, p = 0.026). MRS isolates exhibited high resistance to erythromycin (81.7%) and trimethoprim-sulfamethoxazole (79.3%), but susceptibility to linezolid (93.9%). MRS nasal carriage is prevalent among PLWHIV. Individuals with frequent health care contact and those on second-line ART regimens are more susceptible to MRS colonization, while individuals who wear face masks and those with an undetectable HIV viral load are less susceptible. Antimicrobial Resistance (AMR) surveillance within HIV programs, enhanced infection control, ART adherence, and targeted screening for high-risk groups are critical to mitigate colonization.

BackgroundHuntington disease (HD) is a neurological disorder caused by an aberrant CAG expansion in the HTT gene, producing a mutant protein (mHTT). Although HD is classically characterized by adult-onset cortical and striatal degeneration, accumulating evidence suggests that altered cortical development may also contribute to disease pathogenesis. ObjectiveWe sought to investigate the impact of mHTT on neocortical patterning, which is a largely unexplored aspect of HD. MethodsUsing the HdhQ140 HD knock-in mouse model, we performed immunofluorescence and in situ hybridization to analyze the patterning of the cortex from embryonic day 10 to postnatal day 7. ResultsDuring embryogenesis, HTT expression exhibited a high medial-to-low lateral gradient in the neocortex, like that observed for key transcription factors involved in cortical patterning. Notably, HTT expression was absent from the cortical hem, a critical patterning center. In HD, the protein gradient remained unchanged whereas the expression in medial pallium seemed increased. During the early development of the cerebral hemispheres, the expression of morphogens and signaling pathways, including Shh, Fgf8, and Wnt/BMP genes, were disrupted in organizing centers, leading to altered expression of major neocortical transcription factors. At postnatal stages, the motor and somatosensory cortical areas were misplaced. These developmental alterations were associated with postnatal sensorimotor deficits relevant to HD. ConclusionsOur findings demonstrate that HD-related neurodevelopmental alterations arise as early as embryonic day 10 in mice. This supports previous work suggesting that defects in brain development contribute to HD pathogenesis prior to clinical onset.

Objectives In Quebec, Canada, vaccination against human papillomavirus (HPV) has been publicly-funded since January 2016 for gay, bisexual, and other men who have sex with men (GBM) aged [&le;]26 years. The study aimed to analyze data collected in Greater Montreal (Engage study) to evaluate the HPV vaccination program for GBM in Quebec. Study Design Engage is a cohort of sexually active GBM aged [&ge;]16 recruited via respondent-driven-sampling (RDS) in Canada. Participants completed a questionnaire and tested for sexually transmitted infections. Methods RDS-II weights were applied to adjust for recruitment. Subgroups were compared using standardized mean differences. Odds ratios of HPV vaccination and prevalence ratios of anal HPV infection adjusted for potential confounders were estimated using robust regression models. Results Of 1179 participants, 309 were eligible for free HPV vaccination. Vaccine coverage among eligible GBM was 42%. Among those who disclosed same-sex sexual activity and discussed HPV vaccination with their healthcare provider, coverage reached 82%. Anal HPV prevalence among eligible GBM was 26.5% for [&ge;]1 HPV-6/11/16/18 genotypes without significant difference between vaccinated and unvaccinated individuals. Among unvaccinated GBM aged [&le;]26 who were aware of the vaccine, 60% intended to get vaccinated within the next year. Conclusions One to two years after GBM aged [&le;]26 were included in the Quebec HPV vaccination program, 42% of eligible GBM in Greater Montreal had been vaccinated. Anal HPV prevalence was high among GBM. Vaccinees were more likely to self-report a prior STI diagnosis. Offering vaccination to all preadolescents in schools appears essential to maximize vaccination benefits.

Background: The ongoing Bundibugyo virus disease (BDBV) outbreak in Central Africa highlights the absence of approved vaccines specifically targeting BDBV. Whether licensed Zaire ebolavirus (EBOV) vaccines induce cross-reactive immunity against BDBV remains largely unknown. Methods: We performed an immunogenicity analysis using serum samples from participants enrolled in the PREVAC randomized clinical trial evaluating licensed Ebola vaccine strategies in West Africa. Samples collected at day 28 (D28) and month 3 (M3) following vaccination with rVSV{Delta}G-ZEBOV-GP or Ad26.ZEBOV/MVA-BN-Filo were assessed using a multiplex Luminex assay against glycoproteins from multiple filoviruses, including EBOV Kikwit, EBOV Mayinga, BDBV, Sudan virus, Reston virus, and Marburg virus. Results: A total of 179 samples were analysed. Detectable cross-reactive antibody responses against BDBV were observed across vaccine groups, timepoints, and age categories. However, BDBV responses remained substantially lower than homologous EBOV responses. In rVSV recipients, median BDBV responses (net MFI) reached 282 (IQR 164-644) at D28 compared with 1788 (832-3311) against the homologous Kikwit antigen. Similar patterns were observed following rVSV booster vaccination and Ad26.ZEBOV/MVA-BN-Filo vaccination. The heterologous Ad26/MVA regimen demonstrated increasing BDBV responses between D28 and M3. Conclusions: Licensed EBOV vaccines induced detectable but quantitatively reduced cross-reactive antibody responses against BDBV. Although no direct assessment of vaccine efficacy against BDBV disease was possible, these findings support the plausibility of partial heterologous immunity following EBOV vaccination. In the absence of approved BDBV-specific vaccines, these data support the urgent evaluation of currently available Ebola vaccines during BDBV outbreaks and reinforce the importance of developing broadly protective pan-filovirus vaccines.

Powassan virus (POWV) is an emerging tick-borne flavivirus that can cause severe encephalitis in humans. Currently no vaccines or therapeutics are approved to treat POWV. POWV is spread by the deer tick, Ixodes scapularis, which is ubiquitous across the Northeastern United States. To better understand POWV prevalence in high-risk populations, we examined POWV seroprevalence in Cadets at United States Military Academy (USMA) in West Point, New York. Cadets at USMA, located in a heavily wooded area, are at high risk for tick exposure during outdoor military training. 1,051 serum samples from the Cadet class of 2017 were screened for POWV seropositivity using a POWV Envelope (E) DIII ELISA. A seropositivity rate of 1.3% was determined. Several ELISA-positive samples were also able to neutralize both reporter virus particles bearing the POWV E protein and authentic POWV. This study demonstrates populations at risk for tick exposure may have significant seroprevalence of POWV.

IntroductionPressure sores are a major health problem in people with spinal cord injury resulting in ischaemic tissue lesions caused by prolonged pressure against a bony surface. Conventional therapies are often defective and fundamental researches on the healing process of pressure sores must be enriched in order to understand any novel therapies that may be applied. We focalize on pressure sores fibroblasts as dermal fibroblasts perform a critic role in wound healing by populating the wound site to produce extracellular matrix. After characterizing morphological and the genetic profile of healthy fibroblasts and fibroblasts from pressure ulcers, we conducted an analysis of fibroblast proliferation, migration and myofibroblastic differentiation capacity. Materials and Methodsafter acquisition of dermal explants and fibroblasts culture, we conducted histological analysis, an evaluation of gene expression by RT-qPCR and an assessment of fibroblasts proliferation and migration capacity through IncuCyte. A study of the differentiation of fibroblasts into myofibroblasts through the detection of Alpha-Smooth Muscle Actin (-SMA) expression by immunofluorescence was also conducted. Resultshistological analysis showed histological analysis showed dermal disorganization in pressure sore compared with health skin, differences in morphological aspects and density of fibroblasts. Pressure sore fibroblasts express less genes coding for ECM proteins, metalloproteases, collagen III, Connective tissue growth factor (CTGF) and ACTA2 coding for -SMA. Pathological fibroblasts appear to proliferate less quickly than healthy fibroblasts but no differences in migration capacity were found. After stimulation under TGF-{beta}, pressure sore fibroblasts lose their ability to differentiate into myofibroblasts compared to healthy fibroblasts and this could be in relation with a less expression of ACTA2. ConclusionAll of our results highlight a morphological, genetic and functional difference between healthy and pathological fibroblasts which have a modified phenotype, less effective for skin repair. This suggests that new therapies for chronic wounds must take into account the environment in which they are applied and that pathological cells do not necessarily respond to treatments in the same way as healthy cells. Our results are not statistically significant, although several trends emerge. This is explained by the heterogeneity of the patients medical history and requires repetition of the experiments.

Ganciclovir (GCV), and its orally available pro-drug valganciclovir (VGCV), are preferred therapies for treating congenital cytomegalovirus (cCMV), however, their use carries a significant risk of neutropenia for the child. This risk limits dosing and effectiveness of VGCV, particularly in the treatment of infants with cCMV infection, who are at increased risk for sensorineural hearing loss (SNHL). We hypothesized that an improved understanding of the pharmacokinetics (PK) and pharmacodynamics (PD) of VGCV in cCMV-infected infants at risk for SNHL would inform strategies for optimizing safe and effective VGCV dosing. Participants were enrolled in one of two clinical studies interrogating the PK, safety, and efficacy of VGCV treatment in cCMV-infected infants at risk for SNHL. GCV exhibited a short median half-life of 2.02 h and the median (range) area under the 24 h concentration-time curve (AUC24) was 60.8 (26.8, 99.4) g*h/mL. An AUC24 > 70 g*h/mL was associated with an elevated risk of neutropenia (Fisher's Exact p = 0.029). No associations between GCV PK and hearing outcomes were observed. Taken together, these results indicate vast inter-individual variability in GCV PK that is associated with dose-related toxicity, supporting the need for individualized dosing in the cCMV-infected population.

People living with HIV (PLWH) are known to maintain a degree of immune deficiency despite efficient antiretroviral therapy and may exhibit diminished responses to vaccines. In this study, we assessed the immune response to SARS-CoV-2 infection and vaccines in two geographically distinct PLWH populations. PLWH and HIV-negative (HIV-) participants were recruited from Qu&bec City (QC), Canada, and Bobo-Dioulasso (BD), Burkina Faso, for two visits at 24-week intervals during the predominance of the Omicron variant, from May 2022 to September 2023. Blood samples were collected at each visit for the detection of antibodies against spike (anti-S) and nucleocapsid (anti-N) proteins of SARS-CoV-2 in platelet-free plasma. A total of 360 participants were enrolled. We detected anti-S antibodies in 99% of participants, indicating that nearly all had prior exposure to the SARS-CoV-2 spike antigen, either through vaccination or prior infection. Anti-S titers showed no difference between PLWH and HIV& participants in each location, while significantly higher titers were observed in participants from QC compared to BD. In contrast, anti-N antibodies, indicative of prior infection, were detected in 39% and 86% of the participants in QC and BD, respectively, suggesting that the virus circulated largely in the latter population. No difference in anti-N levels was observed between PLWH and HIV& participants in BD. However, participants in QC had significantly lower titers compared to HIV participants. Overall, this study shows that PLWH develop robust antibody responses to SARS-CoV-2 vaccination, comparable to those observed in HIV& participants. Significant geographic differences were observed in anti-S titers, irrespective of HIV status, with participants from QC displaying higher titers. In contrast, participants from BD had higher anti-N antibody prevalence and titers, reflecting more SARS-CoV-2 infections in BD than in QC. Finally, analysis of anti-S antibody titers against several circulating variants revealed significantly lower levels in unvaccinated participants and in those vaccinated with monovalent vaccines in BD. No significant difference was observed between monovalent and bivalent vaccines administered in QC. All authors have seen and approved the manuscript.

Animals facing threat must integrate multiple streams of information -- about danger, environment, and internal state -- into a time-pressured escape decision. In mice, this computation is performed by glutamatergic neurons of the dorsal periaqueductal grey (dPAG), but how their convergent long-range inputs combine to drive flexible decisions is unknown. Here we find that the functional weight of each input is set predominantly by the temporal statistics of its presynaptic activity, rather than by pathway identity or synaptic placement. We first used multi-region single unit recordings during naturalistic behaviour and generalised linear models to estimate the functional connectivity from midbrain, hypothalamic, and cortical inputs onto dPAG neurons. We then combined synapse-resolution circuit tracing, two-photon dendritic stimulation with whole-cell somatic and dendritic recordings, and biophysical modelling to identify the mechanisms setting these weights. We found that dPAG neurons are electrotonically compact, generating broadly uniform somatic responses to inputs across the dendritic tree. As a result, presynaptic firing dynamics -- burstiness within neurons and population synchrony -- are the dominant determinants of input efficacy. This temporal-statistics framework accounts for the measured differences in functional connectivity across input regions and predicts that input weights should change dynamically whenever presynaptic temporal structure shifts -- which we confirm by showing rapid, context-dependent reweighting of cortical input during motivational conflict. We propose that the subcellular specialisations of dPAG neurons allow them to integrate signals from distributed sources into a single decision, with input weights that can be flexibly adjusted on behavioural timescales -- a principle that may extend to other brain hubs that compute survival decisions.