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Journal of Medical Virology

Wiley

Preprints posted in the last 90 days, ranked by how well they match Journal of Medical Virology's content profile, based on 137 papers previously published here. The average preprint has a 0.15% match score for this journal, so anything above that is already an above-average fit.

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Are Nutritional Aspects And Body Composition Associated With The Can Do, Do Do Concept In People With COPD In Latin America? An Observational Study

Borges, P.; Freire, A. P. F.; Pedroso, M. A.; Spolador de Alencar Silva, B.; Lima, F. F.; Uzeloto, J. S.; Gobbo, L. A.; Grigoletto, I.; Cipulo Ramos, E. M.

2026-04-15 rehabilitation medicine and physical therapy 10.64898/2026.04.13.26350788 medRxiv
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IntroductionIndividuals with COPD can be classified according to their levels of physical activity (PA) and physical capacity (PC). The relationship between nutrition and body composition within these classifications remains unclear. ObjectivesTo compare the body composition and food intake of people with COPD and verify the associations. MethodsCross-sectional exploratory analysis study in which body composition and food intake were assessed in individuals with COPD. Classification was based on six-minute walk test (PC) and accelerometry(PA): Quadrant "can do, dont do" (I-preserved PC, low PA); quadrant "can do, do do" (II-preserved PC, preserved PA). Results72 individuals with COPD, 39 in quadrant I and 33 in quadrant II, with mean ages of (69 {+/-} 6) (67 {+/-} 7), respectively. Group I had a higher proportion of males, whereas group II had a higher proportion of females. A positive trend in skeletal muscle mass (p=0.011) (B= 2.883) and a negative trend in basal metabolic rate (p=0.010) (B=-0.092) for group I. ConclusionBrazilians with COPD classified in quadrants I and II showed similar results in terms of body composition and food intake. A positive trend in skeletal muscle mass was observed for the group I. These findings align with the pathophysiological model of COPD, in which the preservation of muscle mass and adequate protein intake support functional capacity and the maintenance of higher physical activity levels.

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Genetic diversity of dengue virus serotype 1 associated with rare dengue ophthalmic syndrome in Reunion Island, Southwestern Indian Ocean, 2020-2022

Fourie, T.; Wilkinson, D. A.; Al Halabi, D.; Hoarau, J.-J.; Deparis, X.; Bertolotti, A.; Mavingui, P.

2026-02-22 infectious diseases 10.64898/2026.02.15.26346346 medRxiv
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In the past decade, dengue fever has emerged as a major public health on Reunion Island in the Southwest Indian Ocean. During the 2018-2022 outbreak, an unusual increase in ocular complications was reported in some patients. To investigate a potential viral cause, we analysed 447 blood samples from hospitalized patients with and without ophthalmic symptoms. Genetic sequencing revealed the co-circulation of two strains of dengue virus serotype 1, both genetically linked to strains previously identified in Asia. Notably, all patients with ophthalmic symptoms were infected with viruses from a single cluster within genotype I, which harbored several unique mutations. These findings suggest that the rare ocular complications observed during this outbreak may be associated with specific viral cluster. Further laboratory studies are required to confirm this potential link.

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A Case Report Describing a Persistent SARS-CoV-2 Infection Outcomes and Mutations Associated with B-cell Deficiency

Mohamed, R.; Shipe, A.; Lail, A.; Emmen, I. E.; Vuyk, W.; Minor, N. R.; Bradley, T.; Gifford, A.; Wilson, N. A.; O'Connor, D.; Garonzik Wang, J.; Smith, J.

2026-02-17 infectious diseases 10.64898/2026.02.13.26346281 medRxiv
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BackgroundImmunocompromised (IC) individuals are at increased risk for persistent SARS-CoV-2 infections and can develop new viral mutations and lineages not seen in the community. In this case report, a persistent SARS-CoV-2 infection (330 days) in an IC patient is examined for viral mutations and mutations associated with cryptic lineages. Case PresentationThe patient was followed in a longitudinal study examining persistent SARS-CoV-2 in IC patients. The patient provided stool and nasal swab samples biweekly until 28 days post-enrollment, then monthly, and then quarterly after 12 month post enrollment until the participant was no longer positive for SARS-CoV-2. Staff performed RT-qPCR and viral sequencing on the samples. Viral mutations from the XBK lineage were already present in the initial sample. By the end of the infection period, there were 40 fixed consensus changes from XBK of which two mutations were typical for cryptic lineages. Mutations increased steadily over time, with most mutations fixed by day 253, including the cryptic typical mutations. ConclusionThis case demonstrates the potential for persistent SARS-CoV-2 infections to develop mutations and lineages in IC patients and highlights the need for continued SARS-CoV-2 monitoring and treatment in this vulnerable population.

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Exploratory analyses of Immunologic Features in a Randomized, Placebo-Controlled Trial of Nirmatrelvir/Ritonavir for Long COVID

Bhattacharjee, B.; Sawano, M.; Hooper, W. B.; Wang, K.; Tabachnikova, A.; Monteiro, V. S.; Lu, P.; Baevova, P.; Rodrigues, G. C.; Fisher, V. L.; Caraballo, C.; Khera, R.; Li, S.-X.; Herrin, J.; Christian, D.; Coppi, A.; Warner, F.; Holub, J.; Henriquez, Y.; Johnson, M. A.; Goddard, T. B.; Rocco, E.; Hummel, A. C.; Mouslmani, M. A.; Carr, K. D.; Charnas, L.; Jesus, M. D.; Nepert, D.; Abreu, P.; Ziegler, F. W.; Spertus, J.; Guan, L.; Krumholz, H.; Iwasaki, A.

2026-02-26 public and global health 10.64898/2026.02.24.26347001 medRxiv
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This exploratory analysis of PAX LC, a Phase 2, 1:1 randomized, double-blind, superiority, placebo-controlled trial examined whether treatment with nirmatrelvir/ritonavir (NMV/r) versus placebo/ritonavir (PBO/r) in individuals with Long COVID could reveal immune features associated with symptom improvement. Eighty-two participants (n=45 PBO/r; n=37 NMV/r) provided blood samples at baseline (Day 0) and post-treatment (Day 28). Baseline demographic and immunological phenotypes were similar in the two groups. No significant differences were observed in major immune cell populations or organ function markers between NMV/r vs. PBO/r groups, or before vs. after the treatment. Modest hematologic changes were noted in the NMV/r arm. SARS-CoV-2-specific IgG levels remained constant, with changes in total immunoglobulin subtypes and isotypes in both arms. Both arms showed similar shifts in cytokine levels. Notably, the levels of S1 and Spike proteins in circulation remained unchanged post-treatment. Regardless of the treatment arm, participants with self-reported symptom improvement showed reductions in the level of the inflammatory chemokine RANTES. Taken together, the findings of this study demonstrate limited virological and immunological changes in response to nirmatrelvir, contributing insights into the reason for the lack of benefit of the 15-day NMV/r treatment in Long COVID.

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Comparative LUSZ Therapeutic Study (LUSZ_AVIST) of Antiviral, Antiretroviral, and Immunosuppressive Treatments in Hospitalized COVID-19 Patients with High-Risk Factors, Biomarkers, and Disease Progression.

Makdissy, N.; Makdessi, E. W.; Fenianos, F.; Nasreddine, N.; Daher, W.; El Hamoui, S.

2026-04-13 respiratory medicine 10.64898/2026.04.10.26350587 medRxiv
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COVID-19 has spread rapidly and caused a global pandemic making it one of the deadliest in history. Early identification of patients with coronavirus disease 2019 who may develop critical illness is of immense importance. Therefore, novel biomarkers were needed to identify patients who will suffer rapid disease progression to severe complications and death. Many treatments were adopted including the antiviral Remdesivir, the antiretroviral Lopinavir /Ritonavir and Tocilizumab. Our study aimed not only to specify high-risk factors and biomarkers of fatal outcome in hospitalized subjects with coronavirus but also to compare the efficacy of the three considered treatments to help clinicians better choose a therapeutic strategy and reduce mortality. We divided the population (n=711) into four main groups based according to the WHO ordinal severity scale. The percentage of mortality, in and out the hospital, the length of stay in the hospital, the pulmonary inflammatory lesion and its distribution, the SARS-CoV-2 IgM and IgG variations at admission, the inflammatory markers, the complete blood count, the coagulation factors and enzymes, proteins and electrolytes profile, glucose and lipid profile, and other relevant markers were measured. The significance of the observed variation was assessed by multivariate and ANOVA analyses. We succeeded to establish a novel predictive scoring model of disease progression based on a cohort of Lebanese hospitalized patients relying on the pulmonary inflammatory lesions, inflammation biomarkers such as LDH, D-Dimer, CRP, IL-6 and the lymphocyte count, the number of comorbidities and the age of the patient which all were significantly correlated with the illness severity showing best outcomes with immunomodulatory and anticoagulant treatments by the results. As top tier, Tocilizumab was more efficient than the two other treatments in non-severe cases but none of the used treatments was insanely effective alone to reduce mortality in severe cases.

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Mass-Standardised IgG Response to Fourteen SARS-CoV-2 Spike Protein variants and Antibody Subclass analysis for IgG subclasses and IgE for a Long COVID Patient Cohort

Elangovan, A.; Harper, D.; James-Pemberton, P.; Kohli, S.; Watson, C.; Shaw, A.

2026-01-27 infectious diseases 10.64898/2026.01.26.26344863 medRxiv
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A multivariant total subclass analysis has been performed for a control cohort (n=15) and a long COVID patient cohort (n=15) measuring the IgG1, IgG2, IgG3, IgG4 and IgE response to the following 14 variants of SARS-CoV-2: Wuhan, Alpha, Delta, BA.1, BA.2, BA.5, EG.5.1, XBB.1.5, BA.2.75, CH.1.1, BA.2.12.1, BQ.1.1, JN.1, and KP.3. Significant differences (p < 0.05 and p < 0.005) between concentrations of IgG subclasses by variant were found in 24% of variants and in mean-normalised distributions. The medians of the mean-normalised distributions were significantly lower for IgG1 (p < 0.05) in long COVID patients compared with controls, and significantly higher (p < 0.005) for levels of IgG3, IgG4 and IgE for long COVID patients. A preliminary diagnostics classification analysis performed by variation of the mean-normalised upper and lower percentiles symmetrically for IgG3 showed a long COVID diagnostic sensitivity of 80%, and specificity of 80% for the 60th percentile threshold of the control cohort. Three types of long COVID can be identified: patients with at least one variant below the threshold (hypo-immune), patients with at least one variant above the threshold (hyperimmune) and patients with IgG3 levels within the reference range. The multivariant subclass spectrum indicates IgG4 and IgE elevations due to potential chronic antigen exposure from persistent virus or autoimmunity and may indicate potential therapeutic interventions.

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Diagnostic Classification for Long Covid Patients identifying Persistent Virus and Hyperimmune Pathophysiologies

James-Pemberton, P.; Harper, D.; Wagerfield, P.; Watson, C.; Hervada, L.; Kohli, S.; Alder, S.; Shaw, A.

2026-04-22 infectious diseases 10.64898/2026.04.21.26351402 medRxiv
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A multiplex diagnostic test is evaluated for self-reported long COVID associated persistent symptoms and a poor recovery from a SARS-CoV-2 infection. A mass-standardised concentration of total antibodies (AC), high-quality (HQ) antibodies and percentage of HQ antibodies (HQ%) is assessed against a spectrum of spike proteins to the SARS-CoV-2 variants: Wuhan, , {delta}, and the Omicron variants BA.1, BA.2, BA.2.12.1, BA.2.75, BA.5, CH.1.1, BQ.1.1 and XBB.1.5 in three cohorts. A cohort of control patients (n = 46) recovered (CC) and a cohort of self-declared long COVID patients (n = 113) (LCC). A nested Receiver Operating Characteristic (ROC) analysis, performed for the variant with lowest HQ concentration in the spectrum, produced an area under the curve and AUC = 0.61 (0.53-0.70) for the CC vs LCC cohorts. For the LCC cohort, the cut-off thresholds for AC = 0.8 mg/L, HQ = 1.5 mg/L and HQ% of 34% were determined, leading to a 71% sensitivity and 66% specificity derived by the Youden metric. The cohorts may be fully classified based on ROC and outlier analysis to give an incidence of persistent virus 62% (95% CI 52% - 71%), hyperimmune 12% (95% CI 7% - 20%) and unclassified, 26% (95% CI 18% - 35%). The overall diagnostic accuracy for both the hyper and hypo immune is 69%. All clinical interventions can now be tailored for the heterogenous long COVID patient cohort.

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Efficacy and Safety of Iguratimod Combined with Yunke Injection in the Treatment of Ankylosing Spondylitis

shiyu, z.; chen, l.

2026-03-17 rheumatology 10.64898/2026.03.12.26348262 medRxiv
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BackgroundBiologics and Janus kinase (JAK) inhibitors carry specific risks for Ankylosing Spondylitis patients at risk of tuberculosis infection or those with contraindications such as a history of cancer, there is an urgent need to explore safe and effective alternative treatment options. AimsTo evaluate the efficacy and safety of Iguratimod combined with Yunke injection in the treatment of ankylosing spondylitis at risk of tuberculosis infection or those with a history of cancer. Study DesignRetrospective cohort study. MethodsA retrospective study was conducted on 48 patients with ankylosing spondylitis who had received treatment over the past 3 years and had a history of tuberculosis infection or malignancy. Their treatment regimens and therapeutic outcomes were analyzed, with particular attention to the progression of tuberculosis and malignancy. ResultsThere was 30 patients receiving Iguratimod combined with Yunke injection treatment, and non-steroidal anti-inflammatory drugs (NSAIDs) were added when pain was severe,referred to as the observation group; 18 patients took Iguratimod and NSAIDs, referred to as the contral group. After treatment of 24 months, both groups showed significant improvements in Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath Ankylosing Spondylitis Functional Index (BASFI), modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), Erythrocyte Sedimentation Rate (ESR), and C-Reactive Protein (CRP), and overall levels could achieve low disease activity. However, the improvement of observation groupin was better than that in the control group, P<0.05. Moreover, the use of NSAIDs in the observation group was significantly less than that in the control group, P<0.001. ConclusionThis study shows that Iguratimod combined with Yunke injection has good efficacy in patients with ankylosing spondylitis who cannot use biologics or JAK inhibitors, not only alleviating pain and morning stiffness but also slowing radiographic progression and reducing the dose of NSAIDs. The combination has a synergistic effect and does not increase adverse reactions. This therapy provides a novel option for patients with specific ankylosing spondylitis.

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Comprehensive Immunophenotyping of Monocytes and Dendritic Cells Suggests Distinct Pathophysiology in Chronic Fatigue Syndrome and Long COVID

Petrov, S. I.; Bozhkova, M.; Ivanovska, M.; Kalfova, T.; Dudova, D.; Todorova, Y.; Dimitrova, R.; Murdjeva, M.; Taskov, H.; Nikolova, M.; Maes, M.

2026-04-12 allergy and immunology 10.64898/2026.04.10.26350613 medRxiv
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Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID are complex chronic conditions that often follow infectious triggers with overlapping clinical features but poorly defined pathophysiological relationships. This study aimed to identify disease-specific immune signatures through multiparameter immunophenotyping of monocytes, dendritic cells, and T-cell subsets. A total of 207 participants were included (ME/CFS: n = 103; long COVID: n = 63; healthy controls: n = 41). Peripheral blood mononuclear cells were analyzed using multiparameter flow cytometry. Statistical analyses included non-parametric testing, age-adjusted ANCOVA, correlation network analysis, and principal component analysis (PCA). Long COVID was characterized by increased M2-like monocyte polarization, elevated CD80 expression across monocyte subsets, expansion of dendritic cells, and reduced expression of activation markers, indicating persistent immune activation with features of immune exhaustion. In contrast, ME/CFS exhibited reduced costimulatory molecule expression, impaired CCR7-mediated immune cell trafficking, and less coordinated activation patterns, consistent with a state of immune suppression. Correlation network analysis revealed more extensive and integrated immune interactions in long COVID, while PCA identified distinct immunophenotypic components and enabled moderate discrimination between the two conditions. These findings demonstrate that ME/CFS and long COVID are characterized by distinct immune profiles, supporting the concept of divergent immunopathological mechanisms. The identified signatures may contribute to biomarker development and guide targeted therapeutic approaches.

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Establishment of Contextually Appropriate Cut Offs for Orthopoxvirus Serologic Assays in an Mpox-Endemic Setting

Frederick, C.; Merritt, S.; Halbrook, M.; Mukadi, P.; Anta, Y.; Kompany-Kisenzele, J. P.; Tambu, M.; Makangara-Cigolo, J.-C.; Hasivirwe Vakaniaki, E.; Kenye, M.; Lunyanga, L.; Kacita, C.; Kalonji, T.; Kinanga, C.; Linsuke, S.; Hensley, L. E.; Bogoch, I. I.; Shaw, S. Y.; Hoff, N. A.; Mbala-Kingebeni, P.; Rimoin, A. W.; Kindrachuk, J.

2026-04-14 infectious diseases 10.64898/2026.04.10.26350607 medRxiv
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Mpox virus (MPXV) gained increased attention following the declaration of two Public Health Emergencies of International Concern (PHEICs) in 2022 and 2024. The rapid spread of MPXV and the increase in human-to-human transmission highlighted the need for improved diagnostic tools for characterizing infection patterns and transmission dynamics. While PCR is effective for detecting active infections, serological approaches can help identify previous or asymptomatic infections and support retrospective surveillance. However, many serological assays developed during recent outbreaks have not been evaluated in endemic settings such as the Democratic Republic of the Congo (DRC). This study aims to define antigen-specific serological cutoff values to differentiate MPXV-seroreactive individuals from those with other orthopoxvirus (OPXV) exposure or different vaccination histories, specifically for use in the DRC. Here, we analyzed 134 individuals, divided into six distinct cohorts with different exposures. Serum samples were tested using Mesoscale Discovery (MSD) to screen for five MPXV and vaccinia virus (VACV) orthologous antigens: A29L/A27L, A35R/A33R, B6R/B5R, E8L/D8L, and M1R/L1R. Receiver operating characteristic (ROC) analysis identified the best-performing antigens and established seroreactivity cutoff values. A binary composite rule was also evaluated to improve the classification of these results. We identified three MPXV antigens, E8L (cut-off=12.33 AU/mL), A35R (cut-off=5.22 AU/mL), and B6R (cut-off=9.77 AU/mL), that showed the strongest discriminatory performance in the dataset. Collectively, these three antigens form a significant panel that demonstrated clear separation between our mpox survivor cohort and other OPXV-exposed individuals.

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Shifts in the pathogen spectrum and epidemiology of respiratory tract infections in the post-COVID-19 era: A study from Quzhou, Eastern China

Yang, R.; Wang, M.; Lyu, L.; You, J.; Huang, S.; Zhan, B.

2026-03-24 pathology 10.64898/2026.03.20.26348947 medRxiv
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Background: Although the relaxation of COVID-19 containment measures in China has altered the transmission dynamics of respiratory pathogens, regional data on post-pandemic epidemiological characteristics remain limited.Objective: This study aimed to investigate the pathogen spectrum and epidemiological characteristics of acute respiratory infections (ARIs) in Quzhou City from 2023 to 2024, providing a scientific basis for local prevention and control strategies.Methods: A total of 2,800 respiratory specimens were collected from November 2023 to July 2024, comprising 1,960 influenza-like illness (ILI) cases from outpatient/emergency departments and 840 severe acute respiratory infection (SARI) cases from inpatient departments. All samples were tested for 13 common respiratory pathogens using multiplex fluorescence quantitative PCR. Etiological and epidemiological analyses were performed based on detection results and case information. Results: The overall ARI positivity rate was 59.28% (1,660/2,800), with a male-to-female ratio of 1.07:1 (1,447/1,353). The three most prevalent pathogens were influenza virus (Flu, 23.21%, 650/2,800), Streptococcus pneumoniae (SP, 13.14%, 368/2,800), and adenovirus (ADV, 8.39%, 235/2,800). Single pathogen infections accounted for 73.55% (1,221/1,660) of positive cases, while co-infections with two or more pathogens accounted for 26.45% (439/1,660), yielding an overall co-infection rate of 15.68% (439/2,800). No significant gender difference was observed in detection rates. However, significant differences were found across case types, temporal periods, age groups, and geographic regions (P < 0.01). Children aged [&le;]5 years exhibited the highest positivity rate (78.00%, 378/525), while adults aged [&ge;]65 years showed the lowest (34.53%, 144/417). Among surveillance regions, Kaihua County had the highest positivity rate (72.47%), and Changshan County the lowest (40.55%). Conclusions: Multiple respiratory pathogens and co-infections are prevalent in Quzhou City, with distinct age-specific and seasonal patterns. These findings underscore the need for continuous multi-pathogen surveillance and integrated prevention strategies for influenza and other respiratory infectious diseases in the post-pandemic era.

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Drug Repurposing: A Potential Therapeutic Strategy for the Treatment of Chikugunya Virus

Zondi, S.; Mtambo, S.; Buthelezi, N.; Shunmugam, L.; Magwenyane, A.; Kumalo, H. M.

2026-02-19 bioinformatics 10.64898/2026.02.19.706773 medRxiv
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Chikungunya virus (CHIKV) infection is one of the major public health concerns in several countries around the world. CHIKV non-structural protein 2 (nsP2) is a promising drug design target due to the enzymes multifunctional properties that facilities viral replication and propagation. To date, there is an evident lack of preventative and therapeutic developments that can be used against CHIKV. Drug repurposing is a time saving and cost-effective method used for the development of new drugs. In this study, drug repurposing was implemented with the use of HIV/HCV protease inhibitors to inhibit the active site of nsP2. Molecular dynamics simulations and analysis revealed the stability of two drugs, Indinavir and Paritaprevir. Indinavir forms a hydrogen bond with a major residue, which closes the flexible loop, situated in close proximity to the active site. This conformational shift in the orientation of the enzyme prevents accessibility to the active site thus disrupting the nsP2 protein from functioning effectively in viral replication. In conclusion, the findings of this study identified Indinavir was identified as a promising CHIKV nsP2 inhibitor. This study will provide the basis to further facilitate the drug repurposing strategy as an alternative approach for drug design of CHIKV inhibitors as well as other viral families.

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Patients' Ideas, Concerns, Expectations in Physiotherapy: A Questionnaire Study

Dani, R.; Dave, D.

2026-04-06 rehabilitation medicine and physical therapy 10.64898/2026.04.06.26350229 medRxiv
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Global healthcare is targeting patient-centred care, as it leads to better health outcomes and higher level of patient satisfaction. Patient-centred communication, is an important part of patient-centred care because it focuses on involving patients in their care. Recent surveys both nationally and globally have shown that patients are not involved enough in their own healthcare decisions. This problem is especially common among the elderly with chronic conditions. This study aimed to describe patient-healthcare professional interactions, expectations, and satisfaction in physiotherapy within an understudied context, thereby providing important, specific data on ICE dynamics and satisfaction in the specific setting. Cross-sectional study of participants in scheduled consultations was conducted. Two government physiotherapy centres, seven private physiotherapy centres and two trust centres with physiotherapy facilities in Gujarat, India. 232 patients (from various public and private physiotherapy clinics) participated in the study. Patients' ideas, concerns, expectations (ICE) and satisfaction were explored. Almost 88% of patients reported their thoughts and explanations about their symptoms during the consultation. Most patients described not having any concerns about the diagnosis/treatment, and more than two-third of patients consulting PTs expected explanation for their symptoms. Almost 90% patients were satisfied with the consultation. The study revealed that while most patients conveyed their thoughts during consultations, very few expressed their concerns. Overall, patients were satisfied with their consultations.

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Association Between SARS-CoV-2 Mutations and Disease Severity Reveals Risk and Protective Effects Among Community-Sampled Patients in Israel

Eliyahu, H.; Barda, N.; Mandelboim, M.; Lustig, Y.; Zuckerman, N. s.

2026-01-29 epidemiology 10.64898/2026.01.26.26344903 medRxiv
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SARS-CoV-2 mutations play a key role in viral evolution, in immune escape, and potentially in disease severity. However, the clinical impact of most mutations remains poorly understood, particularly across different variants. A historical observational study was conducted using SARS-CoV-2 whole-genome sequencing data linked to clinical metadata from 175,503 COVID-19 cases in Israel. The dataset was stratified into four variant-specific periods: B.1.1.7, B.1.617.2, BA.1, and BA.2. Logistic regression models were applied separately within each period to assess the association between individual mutations and the need for hospitalization, adjusting for age, gender, and time since vaccination. False discovery rate correction was used to account for multiple testing. A total of 18 SARS-CoV-2 mutations were significantly associated with COVID-19 severity, of which eight remained statistically significant after false discovery rate correction. Among these, two were associated with increased risk and six with reduced risk. Most were non-synonymous mutations located in functionally relevant regions such as the spike protein and non-structural proteins. This study provides a variant-stratified assessment of SARS-CoV-2 mutations associated with clinical severity, revealing both known and novel associations. The findings highlight the importance of integrating genomic and clinical data in public health surveillance and may inform future outbreak preparedness by identifying mutations with potential clinical impact.

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Pathology of dose dependent inocula of H5N8 avian influenza viruses in experimentally infected chicken

Ponnusamy, B.; Kumar, M.; Murugkar, H. V.; Nagarajan, S.; Tosh, C.; Panickan, S.; Desai, D.; Kalaiyarasu, S.; Dhanapal, S.; Katherukamem, R.; Gautam, S.; Singh, V. P.; Sanyal, A.

2026-01-28 microbiology 10.64898/2026.01.27.700741 medRxiv
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In the present study, we assessed the pathogenicity of H5N8 avian influenza viruses belongs to the clade 2.3.4.4b in chicken. Birds of three different dose groups, 102, 104, and 106 EID50 were used in the study. No mortality was observed in 102 EID0 group. Percent cumulative mortality of 104 and 106 EID50 group was 66.67 and 100 %, respectively. Varying duration of MDT of 3.2 and 2 days was observed in 104 and 106 EID50 group, respectively. The CID50 of virus was found to be 104.5 EID50. High no. of viral RNA copies were found both in oropharyngeal and cloacal swabs and in various organs of birds infected in 104 and 106 EID50 group. Significant gross and histological changes and presence of viral antigen in various organs were observed in 104 and 106 EID50 group. So, the study concludes that Indian HPAI, H5N8 isolates are highly pathogenic in nature to chicken by affecting most organs systemically. CID50 of this H5N8 virus indicates poor adaption in chicken and it implies poor transmission possibility of this virus for host species in field condition. Though this virus is highly pathogenic in nature as that of HPAI, H5N1 viruses, absence of endothelial staining in most organ attributes variation in replication process and pathogenesis from HPAI, H5N1 viruses. Hence, further studies need to be done to elucidate the pathobiology of this virus in various bird species. HighlightsO_LIH5N8 virus belong to the clade 2.3.4.4b, Indian isolate is highly pathogenic in nature as that of HPAIV, H5N1. C_LIO_LIThe dose inocula, 102 EID50 is noninfectious to chicken. C_LIO_LIThe dose inocula, 104 and 106 EID50 had caused significant mortality in the inoculated chicken with MDT of 2 and 3.2 days, respectively. C_LIO_LIH5N8 virus was detected with high viral titres in clocal and oral shedding and in multiple organ with the dose inocula, 104 and 106 EID50. C_LIO_LI104 and 106 EID50 of H5N8 inocula virus caused significant gross and histological changes in multiple organs and viral antigens were detected in respective organs. C_LI

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Characterisation of naturally occurring MERS-CoV Spike mutations and their impact on entry and neutralisation.

Dempsey, R.; Goldswain, H.; Newman, J.; Thakur, N.; MacGill, T.; Myers, T.; Orr, R.; Bailey, D.; Stuart, J. P.; Aljabr, W.; Hiscox, J. A.

2026-02-17 microbiology 10.64898/2026.02.17.706312 medRxiv
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In this study the phenotypic consequences of naturally occurring single nucleotide polymorphisms (SNPs) in the MERS-CoV Spike protein were investigated. The impact of Spike mutations on virus entry and neutralisation of contemporary MERS-CoV strains is not currently well understood. Naturally occurring mutations were identified by aligning 584 MERS-CoV Spike sequences from either human clinical isolates collected between 2012 - 2024 or from viruses passaged in human cells. Fifteen SNPs of interest occurring in the NTD, RBD and adjacent to the S1/S2 cleavage site were selected for further characterisation based on their location in the Spike protein, frequency and identification in previous studies. A representative clade B, lineage 5 wildtype Spike sequence, which reflected those carried by MERS-CoV viruses circulating in the Middle East, was used in this study. The mutations of interest were introduced to the wildtype backbone to generate Spike variants. A lentiviral-based pseudotyping system was then used to investigate the impact of these Spike mutations on entry and neutralisation. I529T, E536K and L745F were shown to improve MERS-CoV entry. L411F, T424I, L506F, L745F and T746K were found to increase resistance to neutralisation by pooled patient sera. This study has identified novel naturally occurring Spike mutations that resulted in phenotypic differences in virus entry and neutralisation of contemporary MERS-CoV strains. Continued investigation of the phenotypic consequences of naturally occurring MERS-CoV Spike mutations is essential for assessing the risk to public health, especially given the pandemic potential of this virus. ImportanceThe main aim of this study was to investigate the impact of naturally occurring MERS-CoV Spike mutations on virus entry and neutralisation. The phenotypic consequences of mutations occurring in the Spike protein of contemporary MERS-CoV strains are not currently well understood. Improving our understanding is of particular importance due to MERS-CoV continuing to pose a public health risk, with frequent spillover events and mounting evidence of human-to-human transmission since the virus emerged in 2012. A major concern is that as MERS-CoV continues to evolve, it may become more infectious, resulting in increased transmission between humans. To add to this, surveillance is limited and there are currently no specific medical countermeasures available to treat MERS-CoV disease. The MERS-CoV Spike pseudotyping system developed in this study is a useful tool that could be used alongside surveillance systems to rapidly assess novel Spike mutations in functional assays. This MERS-CoV pseudotyping system could also be used to aid the development of medical countermeasures such as vaccines, antivirals and antibody therapies.

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Identification of the novel inhibitors against M. tuberculosis ESX-1 secretion system EccA1 enzyme using virtual screening, docking and dynamics simulation techniques

Kumar, R.; saxena, a. K.

2026-04-14 bioinformatics 10.64898/2026.04.09.717399 medRxiv
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The M. tuberculosis ESX-1 secretion system EccA1 enzyme is involved in the secretion of virulence factors and is essential for virulence and bacterial survival within the phagosome. Development of the small molecular inhibitors abolishing EccA1 function can yield new antivirulence drugs. In this study, we modeled the full-length EccA1 (573 residues, Mw [~]62.4 kDa) structure, which contains N-terminal TPR domain and a C-terminal CbxX/CfqX type ATPase domain. We have identified five ZINC compounds having binding energy i. e. Z1 (ZINC000004513760, -43.45 kcal/mol), Z2 (ZINC000000001793, -49.56 kcal/mol), Z3 (ZINC000005390388, -55.83 kcal/mol), Z4 (ZINC000257294577, -52.33 kcal/mol), Z5 (ZINC000004824264, -44.44 kcal/mol) through virtual screening of the ZINC compounds targeting C-terminal ATPase pocket of EccA1. The Z1-Z5 compounds were compared with ADP substrate having binding energy (Adenosine diphosphate, -35.00 kcal/mol), p97 ATPase inhibitors i.e. NMS873 (3-[3-cyclopentylsulfanyl-5-[[3-methyl-4-(4 methylsulfonylphenyl)phenoxy]methyl]-1,2,4-triazol-4-yl]pyridine, -48.68 kcal/mol), and CB5083 (1-[4-(benzylamino)-5H,7H,8H-pyrano[4,3-d]pyrimidin-2-yl]-2-methyl-1H-indole-4-carboxamide, -50.88 kcal/mol) against EccA1. The Z1-Z5 compounds exhibited good Absorption, Distribution, Metabolism, and/or Excretion properties (ADMTE). Pharmacokinetic properties and Lipinskys rule of five for Z1-Z5 compounds showed drug-like properties. 100 ns dynamics simulation analysis on EccA1 complexed with (i) Z1-Z5 compounds (ii) ADP substrate and (iii) NMS873 and CB5083 inhibitors showed high stability and biologically relevant conformation during dynamics simulation. These data indicate that Z1-Z5 compounds may act as potential inhibitors against EccA1 and provide avenues for new antivirulence drug development after in vitro and in vivo clinical trials.

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Hemophagocytic lymphohistiocytosis (HLH) in 2025 Dengue outbreak in Chittagong, Bangladesh

Uddin, M. N.; Abdullah, S. M. F.; Dhar, N.; Khan, N.; Biswas, R. S. R.

2026-02-17 infectious diseases 10.64898/2026.02.14.26346308 medRxiv
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IntroductionHemophagocytic lymphohistiocytosis (HLH) is a serious condition induced by Dengue virus which becomes fatal if not detected early and treated appropriately. So objectives of the present study are to observe the different patterns of presentations, clinical features and outcome of HLH induced by Dengue. MethodsIn this observational study, 14 patients admitted and diagnosed HLH as per diagnostic criteria, were included after informed written consent. Study conducted in a period of six months from 01/07/2025 to 31/12/2025. All patients were followed up till discharge. After collection, all data were analyzed by Microsoft Excel 2010. Ethical clearance was taken from Ethical Review Board of the Medical College. ResultsAmong 14 cases, male were more affected then the female (78.6% VS 21.4%) and majority were in between 20 to 50 years age groups. Clinical data showed, all 14 cases had fever for >7 days, joint pain 3(21.4%), headache 11(78.6%), skin rashes 10(71.4%), retro-orbital pain 2(14.3%), vomiting 11(78.6%),bleeding 10(71.4%), cough 4(28.6%), loose motion 9(64.3%), abdominal pain 7(50.0%), anorexia 2(14.3%), Melaena 2(14.3%), jaundice 4(28.6%) and spleenomegaly 9(64.3%). One(7.1%) case had history of Hypertension. Laboratory data showed different level of Bi or Pancytopenia, high ferritin, high TG, low fibrinogen, raised liver enzymes and low sodium. Dengue RT PCR and serology results showed 8(42.9%) cases were both IG M and Ig G dengue antibody positive, 6 cases were RT PCR positive, 2 cases were IgM and another 4 cases were IgG positive. Outcome of patients revealed, among all 14 cases12(85.8%) patients improved uneventfully and 2 were shifted to ICU where one improved and one died. ConclusionDengue is prevailing for long time and different complications are evolving and HLH is a relatively newer incident among the dengue patients. Infection by different serotypes at different time or multiple dengue serotype infection may be related with HLH and it might be a future subject to explore and to evaluate.

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Current Policies And Practices For Testing And Treatment Of Chronic Hepatitis B And C Infection In High-Burden Countries In The WHO European Region

Otani, M.; Naveira, M. C. M.; Bivol, S.

2026-01-30 public and global health 10.64898/2026.01.25.26344684 medRxiv
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Chronic hepatitis B and hepatitis C remain major public health concerns in the WHO European Region, where an estimated 10.6 million people were living with HBV infection and 7.7 million with HCV infection in 2022. Despite this substantial burden, diagnosis and treatment coverage remain low, posing a significant challenge to achieving the WHO regional goal of viral hepatitis elimination by 2030. To assess country-level progress and gaps in hepatitis testing and treatment, the WHO Regional Office for Europe conducted a survey among nine high burden countries, receiving responses from eight: Armenia, Azerbaijan, Belarus, Kazakhstan, Kyrgyzstan, the Republic of Moldova, Turkmenistan and Uzbekistan. The survey examined national policies, testing availability, treatment regimens, service delivery approaches, and key implementation barriers. Most countries reported having national HBV and HCV guidelines aligned with international standards, although planned updates were inconsistent. Point of care PCR viral load testing was available in five countries, but coverage of test costs varied, and reflex PCR testing had been implemented in only four. First line antiviral regimens largely followed international guidance; however, medication prices and national coverage differed considerably, with out of pocket payment requirements persisting in several settings. All countries reported the use of non invasive tests for liver disease staging, though coverage for elastography remains limited. Service delivery has become increasingly decentralized, with HBV and HCV testing and care available across multiple levels of the health system and integrated into primary care and HIV clinics in most countries. Nevertheless, provision of HCV treatment in harm reduction settings remains rare, limiting access for populations at highest risk. Overall, the findings indicate strong political commitment but highlight persistent gaps in testing access, treatment affordability, and service delivery models. Addressing these gaps through tailored country specific strategies, expanded financial protection, and strengthened integration of services will be essential to accelerate progress toward the 2030 elimination targets.

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Combined Effects of Severe Immunocompromise and Prolonged Virus Shedding on Within-Host SARS-CoV-2 Evolution in COVID-19

Hirata, Y.; Takahashi, K.; Iwamoto, N.; Dam Jeong, Y.; Miyamoto, S.; Kawasaki, J.; Mine, S.; Iida, S.; Saito, S.; Ainai, A.; Kanno, T.; Katano, H.; Sasaki, N.; Horiba, K.; Ishikane, M.; Kamegai, K.; Harrison, M. T.; Itoh, N.; Akazawa, N.; Okumura, N.; Haraguchi, M.; Sakoh, T.; Morishima, M.; Araoka, H.; Uchida, N.; Hase, R.; Marumo, Y.; Adachi, T.; Matsue, K.; Saito, T.; Ohmagari, N.; Iwami, S.; Suzuki, T.

2026-04-17 infectious diseases 10.64898/2026.04.14.26350918 medRxiv
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Background: Prolonged SARS-CoV-2 infection in immunocompromised individuals may accelerate virus evolution within the host, raising concerns about the virus evading immunity, developing resistance, and forming novel variants of concern. However, the determinants and public health implications of within-host viral evolution in this population remain incompletely understood. Methods: We performed longitudinal analyses of SARS-CoV-2 genomes from 91 patients with COVID-19 who were classified as being severely or moderately immunocompromised. Using serial measurements of viral RNA loads and infectious titers, we modeled the shedding dynamics of the virus and stratified the infected cases by upper respiratory virus shedding duration to assess associations with within-host evolutionary dynamics. Results: Shedding modeling identified two profiles of shedding duration: intermediate and long. The long shedding profile (shedding lasting >21 days) was found in 14.8% of moderately immunocompromised cases and 72.1% of severely immunocompromised cases. Frequent single-nucleotide variants accumulated specifically in severely immunocompromised individuals with the long shedding phenotype, correlating positively with shedding duration. By contrast, mutations remained limited in moderately immunocompromised individuals with the long shedding phenotype and in severely immunocompromised individuals with the intermediate shedding phenotype. We identified mutations in the spike receptor-binding domain associated with monoclonal antibody resistance; however, we found no fitness-enhancing mutations for inter-host transmission, and antiviral drug resistance mutations were rare. Instead, mutations were introduced frequently and randomly across the entire viral genome. Conclusions: Prolonged upper respiratory virus shedding exceeding 21 days combined with severe immunocompromise is a risk factor of the accumulation of within-host SARS-CoV-2 mutations. Although no variants of concern emerged, the introduction of genome-wide random mutations suggests that the risk for novel variant generation cannot be excluded. These findings highlight the need for intensive antiviral strategies to limit shedding duration to less than 21 days in severely immunocompromised patients, and for immunological investigations to elucidate the host factors underlying residual shedding control in those who achieve clearance within this threshold.