Studies on the Virucidal Effects of UV-C of 233 nm and 275 nm Wavelengths

Among the physical decontamination methods, treatment with ultraviolet (UV) radiation is a suitable means of preventing viral infections. Mercury vapor lamps (254 nm) used for room decontamination are potentially damaging to human skin (radiation) and harmful to the environment (mercury). Therefore, other UV-C wavelengths (100-280 nm) may be effective for virus inactivation on skin without damaging it, e.g., far-UV-C radiation with a wavelength of 233 nm, which is absorbed in the outer layer of the skin and thus does not reach the deeper layers of the skin. For room disinfection, 275 nm UV-C LED lamps could be a more environmentally friendly alternative, since toxic mercury is avoided. A carrier test using multiple viruses was used to determine the TCID50/mL value on stainless steel, PVC, and glass carriers. In addition to the inactivation kinetics (233 nm), the necessary UV-C dose for 4 lg inactivation (275 nm) was investigated. The impact of irradiance on the inactivation efficacy was also assessed. The inactivation of the viruses was a function of the radiation dose. UV-C-radiation at 233 nm (80 mJ/cm2) inactivated from 1.49 ± 0.08 to 4.28 ± 0.18 lg depending on the virus used. To achieve a 4 lg inactivation (275 nm) for enveloped viruses, doses of up to 70 mJ/cm2 (SuHV-1) were sufficient. For non-enveloped viruses, a maximum dose of 600 mJ/cm2 (MS2) was necessary. Enveloped viruses were inactivated with lower doses compared to non-enveloped viruses. Higher radiation doses were required for inactivation at 275 nm in comparison to 254 nm. A more environmentally friendly alternative to mercury vapor lamps is available with 275 nm LED emitters. Radiation at 233 nm could serve as an additional prophylactic or therapeutic measure for virus inactivation in direct contact with human skin.

Induction of Tier 2 HIV-Neutralizing IgA Antibodies in Rhesus Macaques Vaccinated with BG505.664 SOSIP

BACKGROUND

A goal of mucosal human immunodeficiency virus type 1 (HIV-1) vaccines is to generate mucosal plasma cells producing polymeric IgA (pIgA)-neutralizing antibodies at sites of viral entry. However, vaccine immunogens capable of eliciting IgA neutralizing antibodies (nAbs) that recognize tier 2 viral isolates have not yet been identified.

METHODS

To determine if stabilized native-like HIV-1 envelope (Env) trimers could generate IgA nAbs, we purified total IgA and IgG from the banked sera of six rhesus macaques that had been found in a previous study to develop serum nAbs after subcutaneous immunization with BG505.664 SOSIP and 3M-052 adjuvant, which is a TLR7/8 agonist. The neutralization of autologous tier 2 BG505 T332N pseudovirus by the IgA and IgG preparations was measured using the TZM-bl assay. Anti-SOSIP binding antibodies (bAbs) were measured by ELISA.

RESULTS

The IgG samples were found to have significantly greater levels of both nAb and bAb. However, after normalizing the nAb titer relative to the concentration of bAb, SOSIP-specific IgA purified from 2/6 animals was found to neutralize just as effectively as SOSIP-specific IgG, and in 3/6 animals, neutralization by the specific IgA was significantly greater. The more potent neutralization by IgA in these three animals was associated with a higher percentage of anti-SOSIP J chain-bound (polymeric) antibody.

CONCLUSIONS

The parenteral vaccination of nonhuman primates with BG505.664 SOSIP generates HIV-1 tier 2 IgA nAbs in serum, including SOSIP-specific polymeric IgA, which appears to neutralize more efficiently than monomeric IgA or IgG. Mucosal delivery of this SOSIP or other stable Env trimers could generate locally synthesized polymeric IgA nAbs in mucosal tissues and secretions.

Prediction Model and Decision Analysis for Early Recognition of SDNS/FRNS in Children

Purpose

This study identified factors that identification of progression-predicting utility from steroid-sensitive nephrotic syndrome(SSNS) to steroid-dependent or frequently relapsing nephrotic syndrome (SDNS/FRNS) in patients and developed a corresponding predictive model.

Patients and Methods

This retrospective study analyzed clinical data from 756 patients aged 1 to 18 years, diagnosed with SSNS, who received treatment at the Department of Nephrology, Children's Hospital of Chongqing Medical University, between November 2007 and May 2023. We developed a shrinkage and selection operator (LASSO) - logistic regression model, which was visualized using a nomogram. The model's performance, validity, and clinical utility were evaluated through receiver operating characteristic curve analysis, confusion matrix, calibration plot, and decision curve analysis.

Results

The platelet-to-lymphocyte ratio (PLR) was identified as an independent risk factor for progression, with an odds ratio (OR) of 1.01 (95% confidence interval (CI) = 1.01-1.01, p = 0.009). Additionally, other significant factors included the time for urinary protein turned negative (OR = 1.17, 95% CI = 1.12-1.23, p < 0.001), estimated glomerular filtration rate(eGFR) (OR = 0.99, 95% CI = 0.98-0.99, p < 0.001), low-density lipoprotein (OR = 0.90, 95% CI = 0.83-0.97, p = 0.006), thrombin time (OR = 1.22, 95% CI = 1.07-1.39, p = 0.003), and neutrophil absolute counts (OR = 1.10, 95% CI = 1.02-1.18, p = 0.009). The model's performance was assessed through internal validation, yielding an area under the curve of 0.78 (0.73-0.82) for the training set and 0.81 (0.75-0.87) for the validation set.

Conclusion

PLR, eGFR, the time for urinary protein turned negative, low-density lipoprotein, thrombin time, and neutrophil absolute counts may be effective predictors for identifying SSNS patients at risk of progressing to SDNS/FRNS. These findings offer valuable insights for early detection and support the use of precision medicine strategies in managing SDNS/FRNS.

The inflammatory microenvironment of the lung at the time of infection governs innate control of SARS-CoV-2 replication

Severity of COVID-19 is affected by multiple factors; however, it is not understood how the inflammatory milieu of the lung at the time of SARS-CoV-2 exposure affects the control of viral replication. Here, we demonstrate that immune events in the mouse lung closely preceding SARS-CoV-2 infection affect viral control and identify innate immune pathways that limit viral replication. Pulmonary inflammatory stimuli including resolved, antecedent respiratory infections with Staphylococcus aureus or influenza, ongoing pulmonary Mycobacterium tuberculosis infection, ovalbumin/alum-induced asthma, or airway administration of TLR ligands and recombinant cytokines all establish an antiviral state in the lung that restricts SARS-CoV-2 replication. In addition to antiviral type I interferons, TNFα and IL-1 potently precondition the lung for enhanced viral control. Our work shows that SARS-CoV-2 may benefit from an immunologically quiescent lung microenvironment and suggests that heterogeneity in pulmonary inflammation preceding SARS-CoV-2 exposure may contribute to variability in disease outcomes.

Relationship between the risk of intestinal mucosal Epstein-Barr virus and/or cytomegalovirus infection and peripheral blood NK cells numbers in patients with ulcerative colitis: a cross-sectional study in Chinese population

Objective

This study aimed to analyze the relationship between the risk of common opportunistic pathogens Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection in intestinal mucosal tissues of Ulcerative Colitis (UC) patients and the number of peripheral blood NK cells.

Methods

UC patients admitted to a third-grade class-A hospital from January 2018 to December 2023 were selected as research population. Clinical data of the patients were collected from the electronic medical record system. Additionally, samples of intestinal mucosal tissues were obtained for real-time fluorescence quantitative PCR to detect and analyze the viral load of CMV and EBV. Blood samples were collected for lymphocyte subsets analysis. Multivariable logistic regression models analyses was used to determine the odds ratio (OR) and 95% confidence interval (95% CI) for the independent association between NK cells and EBV/CMV infections in UC. We further applied the restricted cubic spline analysis and smooth curve fitting to examine the non-linear relationship between them.

Results

378 UC patients were enrolled. Of these patients, there were 194 patients (51.32%) with EBV /CMV infection. In multivariable logistic regression analyses NK cells was independently associated with EBV and/or CMV infection after adjusted potential confounders (OR 8.24, 95% CI 3.75-18.13, p < 0.001). A nonlinear relationship was found between NK cells and EBV/CMV infections, which had a threshold around 10.169. The effect sizes and CIs below and above the threshold were 0.535 (0.413-0.692), p < 0.001 and 1.034 (0.904-1.183), p > 0.05, respectively.

Conclusion

There was a non-linear relationship between NK cells and EBV/CMV infections. The risk for EBV/CMV infections was not increased with increasing NK cells in individuals with NK cells ≥ 10.169%, whereas the risk for EBV and/or CMV infection was increased with an decreasing NK cells in those with NK cells < 10.169%. The risk of EBV/CMV infections increases when NK cells were below a certain level.

The progress of mother-to-child transmission of Human Immunodeficiency Virus (HIV) after Dolutegravir (DTG) optimization program: evidence from a multicenter cohort study in Ethiopia

BACKGROUND

Ethiopia aims to eliminate mother-to-child transmission (MTCT) of HIV by 2030. In 2020, Dolutegravir-based antiretroviral treatment (ART) regimen optimization was done for the Prevention of Mother-to-Child Transmission (PMTCT). However, data tracking progress, particularly post-rollout of the Dolutegravir (DTG)-based regimen, and the real-world effectiveness of the new regimen are unavailable.

METHODS

A multicenter retrospective cohort study was conducted among HIV-infected mothers and their HIV-exposed infants visiting the selected hospitals for routine care. Eligible participants were HIV-exposed infants enrolled in the PMTCT care from 2017 to 2022. However, only the 2021 and 2022 birth cohorts were considered post-DTG optimization considering 2020 a year of optimization. The cumulative incidence of perinatal MTCT tested at 6-8 weeks of infant age, and end of care MTCT tested at 18 months of age was assessed. The exposures of the study were the infant birth cohort years and the different ART regimens used for PMTCT of HIV.

RESULTS

Among a total of 2,643 routine care enrolled participants, 2521 (95.4%) HIV-exposed infants were included in the analysis. Of these, 210 were on follow-up and excluded from the breastfeeding MTCT analysis. A total of 30/2521(1.2%) [95% confidence interval (CI): 0.8-1.7%] were positive for HIV at 6-8 weeks. Additionally, 11 /2281 (0.50%) (95% CI: 0.3-0.9%) were positive during breastfeeding. At the end of the care, 41/2311 (1.8%) (95% CI: 1.3-2.4%) infants were HIV-positive. The highest end-of-care MTCT was reported in 2019 and 2022 birth cohorts while the lowest was in 2018 (P-value > 0.3). However, after adjusting for baseline characteristics, the trend showed a decrease in transmission rates following the rollout of DTG-based regimen, although statistical significance was not reached. The adjusted odds ratios (AORs) for perinatal, breastfeeding, and end-of-care transmission rates were 0.34 (95%CI: 0.08-1.39), 0.29(95%CI: 0.03-3.05), and 0.38(95%CI: 0.11-1.26) respectively. Compared with the Efavirenz (EFV)-based regimen, the DTG-based regimen was associated with a lower risk of MTCT in both the perinatal (AOR 0.23, 95% CI: 0.06-0.85) and at the end of care (AOR 0.27, 95% CI: 0.09-0.82). Pregnant women who started ART at late gestation had the highest transmission rate regardless of ART regimens (P-value < 0.001).

CONCLUSIONS

In the studied cohort population, we observed less than 3% MTCT rate at the end of PMTCT care. The findings might suggest the achievement of MTCT elimination at the hospital level. Although the DTG-based regimen demonstrated a lower risk of transmission, other contributing factors, such as late ART initiation, should be urgently addressed. Future research should focus on prospective designs, interventions targeting late ART initiation, and understanding regional disparities to further advance efforts to eliminate MTCT by 2030.

Usefulness of Point-of-Care Testing for Respiratory Viruses in a Pediatric Emergency Department Setting

Background: Respiratory tract infections (RTIs) are a leading cause of pediatric emergency department (PED) visits, especially in children under five. These infections are primarily viral, complicating diagnosis and management. This study assesses the impact of point-of-care (POC) rapid diagnostic tests for respiratory viruses on clinical and economic outcomes in a PED setting. Materials and Methods: A retrospective analysis of 1396 POC tests for RSV, adenovirus, and influenza A/B was conducted in the PED of the Giannina Gaslini Institute, Genoa, Italy, from December 2022 to April 2024. Demographics, blood tests, admissions, and readmission rates were evaluated. Statistical analyses were performed using appropriate tests for categorical and continuous variables. Results: Of the tests, 31.5% were positive for at least one virus. Positive patients were younger and had higher hospitalization rates (50.7% vs. 39.9%) but fewer blood tests (38.2% vs. 51.7%). Economic analysis indicated lower costs for virus-positive patients. RSV-positive patients showed a significant association with higher hospitalization rates (67.8%) and readmission within 72 h. Conclusions: POC testing significantly improves patient management in PEDs by enabling rapid diagnoses, reducing unnecessary tests and hospitalizations, and guiding appropriate treatment. This approach supports better resource allocation, crucial during peak seasons, and has implications for reducing antibiotic use and resistance. Further research is warranted to explore long-term impacts on patient outcomes and healthcare efficiency.

Povidone-iodine-induced scalp lesions in pediatric neurosurgery patients: a case series

PURPOSE

Povidone-iodine, or Betadine® (Atlantis Consumer Healthcare Inc., Bridgewater, NJ), is a commonly used agent for surgical site preparation. Although commonly used, it carries the risk of skin reactions, and multiple cases of intra-operative contact dermatitis and chemical burns have been reported. However, to our knowledge, there are currently no published cases of povidone-iodine-induced skin lesions in neurosurgical patients.

METHODS

A single-center retrospective chart review was performed to identify patients who developed scalp lesions secondary to chemical toxicity following neurosurgical procedures between October 1, 2021, and June 30, 2024.

RESULTS

Three patients were identified, ranging from 2.5 months to 14 years old. Two were positioned prone and the third in lateral decubitus. All patients' heads were supported by a horseshoe headrest covered with a gel pad and wrapped in a cotton roll. For two patients, Reston™ foam (3M©, St. Paul, MN) was added on the horseshoe. Surgical sites were prepped with isopropyl alcohol, Betadine®, and chlorohexidine. Two patients had their heads intermittently lifted throughout the procedure. Lesions were identified immediately after returning the patient to the supine position in the operating room and steadily improved over the course of one to five months with local wound care.

CONCLUSIONS

Careful preparation of the surgical site is an essential step in the prevention of surgical site infections. However, caution should be exercised during skin preparation to avoid pooling of povidone-iodine around dependent regions. Additional steps, such as scheduled head elevations and pressure dispersion, should be taken to mitigate factors contributing to these lesions.

Anti-RBD IgG dynamics following infection or vaccination

Identifying parameters influencing SARS-CoV-2 antibody dynamics post infection or vaccination is crucial for refining vaccination strategies. In a longitudinal analysis of 1340 samples from 375 healthcare workers, we characterized peak serological response and IgG half-life. Peak antibody titers post 2 vaccine doses were ∼ 20 times higher than natural infection; conversely, infected individuals had extended antibody half-life. Clinical and demographical factors such as BMI, age and smoking shaped peak response without affecting anti-RBD IgG half-life. A third mRNA vaccine dose increased peak antibody titers and prolonged half-life compared to the second dose. These findings underscore the diverse kinetics of SARS-CoV-2 antibody responses, which is influenced by immunization type/number and clinical factors.

Comparable and sustained levels of S1-RBD-IgG and S1-RBD-IgA in BNT162b2 homologous and CoronaVac-BNT162b2 heterologous booster vaccination: A 22-month prospective study in Malaysia

This prospective cohort study examines the long-term humoral immune responses post-COVID-19 vaccination in 146 individuals who received either a homologous three-dose BNT162b2 vaccine regimen (PPP) or two primary doses of CoronaVac followed by BNT162b2 booster (SSP) in Malaysia. The study focuses on serum anti-S1-RBD-IgG, -IgA, and -IgM, using the ELISA method. The results show that BNT162b2 outperformed CoronaVac in the two dose primary vaccination series. BNT162b2 booster dose significantly raised serum anti-S1-RBD-IgG and -IgA levels, sustaining this increase from 26 to 52 weeks after administration, regardless of the vaccine regimen. This leads to equivalent levels of anti-S1-RBD-IgG and -IgA after boosting with BNT162b2 in both groups. Breakthrough infections, particularly with the emergence of the Omicron variant, did not result in increased anti-S1-RBD-IgG and -IgA levels. No significant induction of anti-S1-RBD-IgM was observed following multiple vaccine doses. The long-term investigation revealed that PPP and SSP groups had comparable humoral immune responses to SARS-CoV-2, highlighting the advantage of mRNA booster dose in our cohort.

Investigating the potential role of capsaicin in facilitating the spread of coxsackievirus B3 via extracellular vesicles

Coxsackievirus B3 (CVB3) is a non-enveloped picornavirus that can cause systemic inflammatory diseases including myocarditis, pericarditis, pancreatitis, and meningoencephalitis. We have previously reported that following infection, CVB3 localizes to mitochondria, inducing mitochondrial fission and mitophagy, while inhibiting lysosomal degradation by blocking autophagosome-lysosome fusion. This results in the release of virus-laden mitophagosomes from the host cell as infectious extracellular vesicles (EVs) which allow non-lytic viral egress. Transient receptor potential vanilloid 1 (TRPV1/ TRPV1 ) is a heat and capsaicin-sensitive cation channel that regulates mitochondrial dynamics by inducing mitochondrial membrane depolarization and fission. In this study, we found that treating cells with the TRPV1 agonist capsaicin dramatically enhances CVB3 egress via EVs. Analysis of the released EVs revealed increased levels of viral capsid protein VP1/ VP1 , mitochondrial protein TOM70/ TOMM70 , and fission protein phospho-DRP1/ DNM1L (Ser 616). Moreover, these EVs exhibited increased levels of heat shock protein HSP70/ HSPA1A , suggesting a potential role of these chaperones in facilitating infectious EV release from cells. Furthermore, TRPV1 inhibition with capsazepine significantly reduced viral infection in vitro . We previously observed similar effects in vitro with another TRPV1 inhibitor SB-366791. Our current in vivo studies found that SB-366791 significantly mitigates pancreatic damage and reduces viral titers in mouse model of CVB3 pancreatitis. Given the lack of understanding regarding the factors that contribute to diverse clinical manifestations of CVB3, our study highlights capsaicin and TRPV1 as potential exacerbating factors that facilitates CVB3 dissemination via mitophagy-derived EVs.

IMPORTANCE

CVB3 is a prevalent pathogen responsible for a range of severe diseases, including myocarditis, pericarditis, pancreatitis, and meningoencephalitis. Despite its clinical significance, factors that determine the severity of CVB3 infection and why some individuals experience life-threatening manifestations while others have mild, cold-like symptoms remain poorly understood. This study provides new insights into the molecular mechanisms underlying CVB3 dissemination and pathogenesis. By investigating the role of capsaicin, a common dietary component, in modulating viral spread, we demonstrate that activation of TRPV1 by capsaicin enhances release of infectious CVB3 via mitophagy-derived EVs. Our results offer novel evidence that modulating TRPV1 activity could influence the clinical outcomes of CVB3 infection, opening new avenues for therapeutic interventions. Given the widespread consumption of capsaicin, this study highlights an important dietary factor that could play a role in shaping CVB3 pathogenesis and its clinical manifestations, underscoring the potential for targeted strategies to mitigate severe disease outcomes.

High-Dimensional Single-Cell Mass Cytometry Demonstrates Differential Platelet Functional Phenotypes in Infants With Congenital Heart Disease

BACKGROUND

Congenital heart disease (CHD) is a group of complex heart defects associated with hematologic abnormalities, including increased risk of thrombotic and bleeding events. Past studies have observed evidence of platelet hyperreactivity, while other studies showed decreased platelet activation in patients with CHD. The goal of this study was to develop a mass spectrometry approach to characterize single platelets in infants with CHD and identify potential etiology for such discrepant results.

METHODS

We enrolled 19 infants with CHD along with 21 non-CHD controls at Yale New Haven Children's Heart Center. A single-cell high-dimensional mass cytometry method was developed to quantitatively interrogate platelet surface markers in whole blood. Additionally, plasma cytokine analysis was performed through a multiplexed panel of 52 vascular and inflammatory markers to assess for platelet releasates.

RESULTS

We found that infants with CHD had significant differences in platelet activation and functional markers by mass cytometry compared with non-CHD controls. Based on cell surface markers, we classified the platelets into 8 subpopulations (P0 to P7). Distinct subpopulations of platelets (P1, P4, and P5) exhibiting decreased aggregatory phenotype but altered secretory phenotypes were also identified and found to be more abundant in the blood of infants with CHD. Electron microscopy identified increased proportion of hypogranular platelets in CHD. Moreover, cytokine analysis demonstrated an overall increase in plasma cytokines and biomarkers in CHD, including IL (interleukin)-6, IL-8, IL-27, RANTES (regulated upon activation, normal T cell expressed and secreted), and VWF (von Willebrand factor), which are expressed in platelet granules and can be released upon activation.

CONCLUSIONS

We developed a robust mass cytometry approach to identify platelet phenotypic heterogeneity. Infants with CHD had alterations in distinct subpopulations of platelets with overall reduced aggregatory phenotype and secretory dysfunction. These findings suggest that platelets in infants with CHD may be exhausted due to persistent stimulation and may explain both bleeding and thrombotic vascular complications associated with CHD.

Navigating monkeypox: identifying risks and implementing solutions

Monkeypox is a zoonotic disease caused by the orthopox virus, a double-stranded DNA virus that belongs the Poxviridae virus family. It is known to infect both animals (especially monkeys and rodents) and humans and causes a rash similar to smallpox. Humans can become infected with monkeypox virus (MPXV) when they get in close contact with infected animals (zoonotic transmission) or other infected people (human-human transmission) through their body fluids such as mucus, saliva, or even skin sores. Frequently observed symptoms of this disease include fever, headaches, muscle aches, and a rash that initially looks like a tiny bump before becoming a lump that is filled with fluid. Monkeypox symptoms also include an incubation period of 5-21 days, divided into prodromal and eruption phases. Several contributing factors, such as smallpox vaccine discontinuation, widespread intake of infected animal products as a source of protein, and high population density, amongst others, have been linked to an increase in the frequency of monkeypox outbreaks. The best course of action for diagnosing individuals who may be suffering from active monkeypox is to collect a sample of skin from the lesion and perform PCR molecular testing. Monkeypox does not presently have a specific therapy; however, supportive care can assist in managing symptoms, such as medication to lower body temperature and pain. Three major orthopoxvirus vaccines have been approved to serve as a preventive measure against monkeypox: LC16, JYNNEOS, and ACAM2000. The discovery that the monkeypox outbreak is communicable both among humans and within a population has sparked new public health worries on the possibility of the outbreak of another viral pandemic. Research and studies are still being conducted to gain a deeper understanding of this zoonotic viral disease. This review is therefore focused on deciphering monkeypox, its etiology, pathogenesis, transmission, risk factors, and control.

Clinical characteristics of Chinese children with EV-D68-associated pneumonia: A single-center retrospective analysis

BACKGROUND

Human enterovirus D68 (EV-D68) has been associated with an increase in mild-to-severe pediatric respiratory diseases in western countries. However, the prevalence and clinical characteristics of EV-D68-associated pneumonia in China remain understudied.

METHODS

Between January 2022 and January 2024, 28 patients with EV-D68-associated pneumonia were enrolled. We described the prevalence, demographic, and clinical characteristics of patients with EV-D68-associated pneumonia.

RESULTS

Among the 28 enrolled patients, the male-to-female ratio was 1.5:1, and the average age at onset was 4.6 ± 2.7 years. Four (14.3%) required intensive care support. Monoinfection occurred in 11 cases (39.3%), while coinfections were seen in 17 cases (60.7%). 82.1% of patients had a history of one or more atopic diseases. The primary symptoms of EV-D68-associated pneumonia included cough (100%), wheezing (53.6%), and fever (53.6%). Radiologically, patchy opacity was the predominant feature, observed in 72.7% of cases. No statistically significant differences were found in symptoms, laboratory tests, or imaging findings between the monoinfection and coinfection groups. Except for one case who developed quadriplegia sequelae, all patients had a favorable prognosis.

CONCLUSION

EV-D68 is not a common pathogen for community-acquired pneumonia in China. It mainly affects young children, particularly those with atopic constitution. The overall prognosis is favorable, although neurological complications are rare and may lead to severe sequelae. This study is the first investigation into the prevalence and clinical characteristics of EV-D68-associated pneumonia in China.

Recent developments in microfluidic passive separation to enable purification of platelets for transfusion

Platelet transfusion is a lifesaving therapy intended to prevent and treat bleeding. However, in addition to platelets, a typical unit also contains a large volume of supernatant that accumulates multiple pro-inflammatory contaminants, including residual leukocytes, microaggregates, microparticles, antibodies, and cytokines. Infusion of this supernatant is responsible for virtually all adverse reactions to platelet transfusions. Conventional methods for removing residual leukocytes (leukoreduction) and reducing the volume of transfused supernatant (volume reduction) struggle to mitigate these risks holistically. Leukoreduction filters can remove leukocytes and microaggregates but fail to reduce supernatant volume, whereas centrifugation can reduce volume, but it is ineffective against larger contaminants and damages platelets. Additionally, platelet purification based on these methods is often too logistically complex, time-consuming, and labor-intensive to implement routinely. Emerging microfluidic technologies offer promising alternatives through passive separation mechanisms that enable cell separation with minimal damage and drastically reduced instrumentation size and facility requirements. This review examines recent innovations in microfluidic cell separation that can be used for leukoreduction and volume reduction of platelets. It begins by defining the performance requirements that any separation method must meet to successfully replace conventional methods currently used to perform these tasks. Standard performance metrics are described, including leukocyte depletion efficiency, degree of volume reduction, processing throughput, and platelet recovery. Finally, the review outlines the primary challenges that must be overcome to enable simple-to-use, disposable microfluidic devices capable of both reducing the platelet unit volume and removing pro-inflammatory contaminants, while preserving most functional platelets for transfusion.

Postpandemic fluctuations of regional respiratory syncytial virus hospitalization epidemiology: potential impact on an immunization program in Switzerland

RSV hospitalization epidemiology is subject to rapid changes brought about by the COVID-19 pandemic and the prospect of vaccine prevention. The purpose of this report is to characterize recent epidemiologic and clinical fluctuations and to analyze their potential impact on an immunization program with nirsevimab. This is a 2018-2024 retrospective analysis of all hospitalizations caused by RSV in patients below 16 years of age occurring at an academic Children's Hospital that serves a defined population. We simulated the vaccine impact against RSV hospitalization by applying the expected effects of the infant immunization program with nirsevimab proposed in Switzerland to observed case counts. We analyzed 1339 hospitalizations. The consecutive occurrence of two major epidemics in 2022-2023 and 2023-2024 had never been recorded previously. The 2023-2024 season witnessed a major shift to older age. Only 61% of patients were below 12 months of age, while prepandemic long-term surveillance since 1997 found a range between 64 and 85% (median, 73%). Age below 3 months, prematurity, airway anomalies, congenital heart disease, and neuromuscular disorders were independently associated with ICU admission. Simulation of the vaccine impact using two scenarios of coverage and efficacy (scenario 1, 50% and 62%, respectively; scenario 2, 90% and 90%) and three different age distributions resulted in an infant vaccine impact of 31.0% (scenario 1) and 81.0% (scenario 2), respectively. Vaccine impact for all patients below 16 years ranged from 22.7 to 24.9% (scenario 1) and 54.2 to 68.8% (scenario 2).

CONCLUSION

RSV hospitalization epidemiology was characterized by substantial variability in patient age on admission. As the proposed RSV immunization program primarily targets infants, year-to-year fluctuation of cases among older children will cause a variability of vaccine impact of approximately 15%. This information may be useful for physicians and hospital administrators when they anticipate the resources needed during the winter season.

WHAT IS KNOWN

• RSV hospitalization epidemiology was subject to massive disturbances during the COVID-19 pandemic. • Extended half-life monoclonal antibodies and active maternal immunization offer new means of passive protection of infants against severe RSV disease.

WHAT IS NEW

• We demonstrate substantial year-to-year fluctuation of the age distribution at the time of RSV hospitalization. • Up to 40% of annual RSV hospitalizations in a given season occur in children above 12 months of age who do not benefit from maternal RSV immunization and may not be eligible for receipt of a monoclonal antibody.

Differential stress responsiveness determines intraspecies virulence heterogeneity and host adaptation in Listeria monocytogenes

Microbial pathogenesis is mediated by the expression of virulence genes. However, as microbes with identical virulence gene content can differ in their pathogenic potential, other virulence determinants must be involved. Here, by combining comparative genomics and transcriptomics of a large collection of isolates of the model pathogen Listeria monocytogenes, time-lapse microscopy, in vitro evolution and in vivo experiments, we show that the individual stress responsiveness of L. monocytogenes isolates determines their respective levels of virulence in vivo and reflects their degree of host adaptation. The transcriptional signature that accounts for the heterogeneity in the virulence of L. monocytogenes species is mediated by the stress response regulator SigB and driven by differential stress responsiveness. The tuning of SigB pathway responsiveness is polygenic and influenced by multiple, individually rare gene variations. This study reveals an overarching determinant of microbial virulence, challenging the paradigm of accessory virulence gene content as the major determinant of intraspecies virulence heterogeneity.

Heterologous mRNA/MVA delivering trimeric-RBD as effective vaccination regimen against SARS-CoV-2: COVARNA Consortium

Despite the high efficiency of current SARS-CoV-2 mRNA vaccines in reducing COVID-19 morbidity and mortality, waning immunity and the emergence of resistant variants underscore the need for novel vaccination strategies. This study explores a heterologous mRNA/Modified Vaccinia virus Ankara (MVA) prime/boost regimen employing a trimeric form of the receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein compared to a homologous MVA/MVA regimen. In C57BL/6 mice, the RBD was delivered during priming via an mRNA vector encapsulated in nanoemulsions (NE) or lipid nanoparticles (LNP), followed by a booster with a replication-deficient MVA-based recombinant virus (MVA-RBD). This heterologous mRNA/MVA regimen elicited strong anti-RBD binding and neutralizing antibodies (BAbs and NAbs) against both the ancestral SARS-CoV-2 strain and different variants of concern (VoCs). Additionally, this protocol induced robust and polyfunctional RBD-specific CD4 and CD8 T cell responses, particularly in animals primed with mLNP-RBD. In K18-hACE2 transgenic mice, the LNP-RBD/MVA combination provided complete protection from morbidity and mortality following a live SARS-CoV-2 challenge compared with the partial protection observed with mNE-RBD/MVA or MVA/MVA regimens. Although the mNE-RBD/MVA regimen only protects half of the animals, it was able to induce antibodies with Fc-mediated effector functions besides NAbs. Moreover, viral replication and viral load in the respiratory tract were markedly reduced and decreased pro-inflammatory cytokine levels were observed. These results support the efficacy of heterologous mRNA/MVA vaccine combinations over homologous MVA/MVA regimen, using alternative nanocarriers that circumvent intellectual property restrictions of current mRNA vaccine formulations.

One Year Duration of Immune Response Following a 3rd Booster Dose of mRNA Vaccine Against COVID-19 in 292 Patients With Hematological Malignancies in University Hospital Ostrava, Czech Republic

AIMS

To evaluate antibody response to mRNA vaccine, identify subgroups with poor response and to determine long-term antibody durability in hematological patients.

MATERIALS AND METHODS

We have vaccinated 292 patients with all hematological malignancies with a third dose of mRNA COMIRNATY vaccine with a 12-month follow-up period in our center in Ostrava, Czech Republic.

RESULTS

Antibody response for the whole cohort exceeded 74% through the whole 12-month follow-up. Lowest seroconversion was observed in CLL cohort (20/41, 48.8%), patients who received anti-CD20 therapy < 6 months before vaccination (8/30, 26.7%) and BTK inhibitors (3/6, 50.0%). On the contrary, patients with chronic myeloproliferative neoplasms and acute leukemia performed comparably with healthy population (33/33; 100% and 12/13; 92.3%, respectively). We have seen better results if the time interval between anti-CD20 therapy and additional vaccine dose was longer than 6 months (5/8 patients achieved seroconversion on 4th booster dose after previous failure). Also, 36 patients received a 4th dose of vaccine as a booster with measurable increase in protective antibodies in 50% (18/36).

CONCLUSIONS

Additional doses show promise for a well-timed revaccination even in poor responders. To our knowledge, no study comparable to our work in terms of follow-up length, vaccine consistency or variety of hematological malignancies and/or treatment has been reported yet. Our findings shed more light on long-term antibody response to mRNA vaccines against SARS-CoV-2 in patients with hematological cancer and bring important data for the evaluation of possible vaccine failure and scheduling of subsequent doses.

Clinical Presentation of Enterovirus D68 in a Swiss Pediatric University Center

BACKGROUND

Enterovirus D68 (EV-D68) is responsible for millions of infections. In the last decade, there has been an increase in the number of children requiring hospital or critical care admission due to severe respiratory illness. Nevertheless, the epidemiological and clinical importance of EV-D68 infections remains unclear.

OBJECTIVE

We aimed to determine the local prevalence of EV-D68 infection in pediatric patients and to characterize its clinical presentation and disease burden compared with non-EV-D68 enterovirus and human rhinovirus (RV) infections.

STUDY DESIGN

We performed a retrospective single-center study of children presenting with respiratory symptoms and positive respiratory panel polymerase chain reaction for EV/RV from November 2018 to December 2019. We tested EV/RV positive specimens with an EV-D68-specific polymerase chain reaction to discriminate EV-D68, non-EV-D68 and RV and compared their respective clinical presentation, outcomes and treatment.

RESULTS

We identified 224 patients (median age 21 months), of which 16 (7%) were EV-D68 positive. They presented with cough (88%), wheezing (62%) and dyspnea (75%). EV-D68 infection had an odds ratio regarding pediatric respiratory severity-score of 11.6 relative to non-EV-D68 [confidence intervals (CI): 3.51-41.14], and of 9.9 (CI: 3.75-27.95) relative to RV. The fitted logistic regression showed that the odds of intensive care were 5 times more likely with EV-D68 than RV infection (CI: 1.32-19.28; P = 0.001). Patients with EV-D68 infections were more likely to receive medical support in the form of supplementary oxygen, antibiotics and steroids.

CONCLUSIONS

EV-D68 infection is associated with higher morbidity and a higher likelihood of intensive care treatment than non-EV-D68 and RV infections.

The respiratory syncytial virus vaccine and monoclonal antibody landscape: the road to global access

Respiratory syncytial virus (RSV) is the second most common pathogen causing infant mortality. Additionally, RSV is a major cause of morbidity and mortality in older adults (age ≥60 years) similar to influenza. A protein-based maternal vaccine and monoclonal antibody (mAb) are now market-approved to protect infants, while an mRNA and two protein-based vaccines are approved for older adults. First-year experience protecting infants with nirsevimab in high-income countries shows a major public health benefit. It is expected that the RSV vaccine landscape will continue to develop in the coming years to protect all people globally. The vaccine and mAb landscape remain active with 30 candidates in clinical development using four approaches: protein-based, live-attenuated and chimeric vector, mRNA, and mAbs. Candidates in late-phase trials aim to protect young infants using mAbs, older infants and toddlers with live-attenuated vaccines, and children and adults using protein-based and mRNA vaccines. This Review provides an overview of RSV vaccines highlighting different target populations, antigens, and trial results. As RSV vaccines have not yet reached low-income and middle-income countries, we outline urgent next steps to minimise the vaccine delay.

Informative Value of a Sample Investigation with a Predefined Sample Size using the Example of Listeria monocytogenes in Food Safety

Foodborne diseases, especially those caused by zoonotic agents, pose a significant threat to human health. Food business operators are therefore responsible for producing safe food. To do this, they must regularly carry out appropriate sample investigations to detect zoonotic agents in their food before it leaves the factory. Depending on the issue investigated, there may be legal requirements for food business operators, usually specifying minimum sample sizes, such as Commission Regulation (EU) No 2073/2005. However, in most cases, there is no information on the precision, and therefore, on the significance of the results for these sample sizes. Regulatory veterinary authorities have a control function and, as a result, they are required to regularly evaluate the available investigations and their results. In addition, in certain crisis situations (e.g., foodborne outbreaks or suspected food contamination), authorities may guide food business operators in their investigations and conduct their own investigations to assess food safety measures. In such cases, as there are no legally defined sample sizes to be taken, the appropriate sample sizes must be determined by the authorities. This can lead to a conflict between the need for feasibility and the need for conclusiveness of the investigation potentially being a challenge for the regulatory authority in charge. This paper highlights the importance of thoughtful study design and the critical communication of available results by veterinary authorities on the background of a use case involving Listeria monocytogenes findings in a crisis situation. Using the minimum sample size, n = 5, required by Commission Regulation (EU) No 2073/2005 for the pathogen Listeria monocytogenes as a guide, the uncertainties associated with small sample sizes are highlighted. It also aims to facilitate the evaluation of studies performed and the assessment of further sample sizes.

Impaired mucosal IgA response in patients with severe COVID-19

Several studies have investigated the antibody response to SARS-CoV-2, focusing particularly on the systemic humoral immune response and the production of immunoglobulin G (IgG) antibodies. IgA antibodies play a crucial role in protecting against respiratory viral infections but have also been associated with the pathophysiology of COVID-19. We performed a prospective study of 169 COVID-19 patients - 50 with critical/severe (ICU), 47 with moderate (Non-ICU), and 72 with asymptomatic COVID-19 - to explore the humoral immune response to SARS-CoV-2 infection. We found that the early systemic IgA response strongly induced in patients with severe disease did not block IgG neutralization functions and activated FcRs more effectively than IgG. However, even if SIgA levels were high, mucosal IgA antibodies could not control the infection effectively in patients with severe disease. Our findings highlight the complexity of the immune response to SARS-CoV-2 exhibiting high systemic levels of IgA with strong neutralizing capacity in severe cases, together with higher levels of IgA-FcR activation than in asymptomatic patients. They also suggest the need for further research to fully understand the role of IgA and its structural alterations in mucosal tissues in cases of severe disease and the impact of these antibodies on disease progression.

Characterization of enteroviruses circulating among farm animals and children in Central African Republic

To characterize enteroviruses (EVs) circulating in farm animals in Central African Republic (CAR), we screened 192 stools of animals under 12 months belonging to family farms located in or near Bangui. To assess whether EV exchanges exist between these animals and humans, we also screened 195 stools of children who lived in contact with farm animals, as well as control stools of 358 children with no contact with farm animals. EVs were typed based on their capsid sequences.In children, all EVs belonged to species A, B and C, with EV-Cs accounting for 60%. Some EV-Cs shared recent common ancestors with lineages of vaccine-derived poliovirus that emerged in the country in 2019-2020. In animals, we identified EV-Gs that belonged to 10 different types, including a previously unknown one that we named EV-G28, while no EV-E or EV-F were observed. The CAR EV-Gs were genetically closely related to specimens sampled in other continents and some of them harboured the torovirus-derived insertion already reported in some EV-Gs. The worldwide circulation of EV-Gs is likely due the massive international trade of live animals. Besides, two human EV-Cs (coxsackievirus A17 and coxsackievirus A24) were detected in pigs, suggesting that these viruses could cross the species barrier. Our work provides original data on the epidemiology and ecology of EVs circulating among herd animals in Africa.

Platelets: A Potential Factor that Offers Strategies for Promoting Bone Regeneration

Bone defects represent a prevalent category of clinical injuries, causing significant pain and escalating health care burdens. Effectively addressing bone defects is thus of paramount importance. Platelets, formed from megakaryocyte lysis, have emerged as pivotal players in bone tissue repair, inflammatory responses, and angiogenesis. Their intracellular storage of various growth factors, cytokines, and membrane protein receptors contributes to these crucial functions. This article provides a comprehensive overview of platelets' roles in hematoma structure, inflammatory responses, and angiogenesis throughout the process of fracture healing. Beyond their application in conjunction with artificial bone substitute materials for treating bone defects, we propose the potential future use of anticoagulants such as heparin in combination with these materials to regulate platelet number and function, thereby promoting bone healing. Ultimately, we contemplate whether manipulating platelet function to modulate bone healing could offer innovative ideas and directions for the clinical treatment of bone defects. Impact statement Given that 5-10% of fracture patients with delayed bone healing or even bone nonunion, this review explores the potential role of platelets in bone healing (directly/indirectly) and proposes ideas and directions for the future as to whether it is possible to promote bone healing and improve fracture healing rates by modulating platelets.

Diversity, geographical distribution and predictive factors of Hepatitis C virus genotypes and subtypes in Rwanda

BACKGROUND

Existing data on the prevalence of hepatitis C virus (HCV) genotypes and subtypes in Rwanda need to be strengthened. The aim of this study was to identify HCV genotypes and subtypes among HCV-infected patients, as well as their geographical distribution in Rwanda, and to identify the social and economic factors that could influence HCV epidemiology which would make it possible to target national preventive and management actions for infected patients.

METHODS

This study included 560 patients with confirmed chronic HCV infection. Patients were recruited from various health facilities in the four provinces of Rwanda as well as in the City of Kigali and had never received treatment with direct-acting antiviral (DAAs). HCV viral loads were measured using Cobas® AmpliPrep/Cobas® TaqMan® HCV Quantitative Test, version 2.0. HCV genotyping was performed using an in-house sequencing protocol targeting the NS5B central region. Genotypic HCV prevalence was correlated with patient geographic location, sociodemographic, behavioral, lifestyle, and clinical factors.

RESULTS

HCV genotype 4 was detected in 99.3% of the patients, while genotype 3 was identified in 0.7%. A total of eight (8) HCV subtypes were detected, with 4k being the predominant subtype nationwide (49.5%), followed by subtypes 4r (21.2%), 4q (16.2%), 4v (7.9%), 4b (2.0%), 4l (1.8%), 4c and 3h represent 0.7% each. Our findings reveal subtype distribution variations among provinces. Subtype 4k was prevalent across regions, particularly in Kigali (64.0%) and the Eastern Province (61.6%). Subtype 4q was more common in the northern province (40.7%), 4r in the southern (43.9%) and western provinces (37.1%), and 4v in the eastern province (17.8%). Farmers exhibit a distinct infection profile compared to other occupations, showing a lower prevalence of subtype 4k but a higher prevalence of subtype 4r.

CONCLUSIONS

Our study revealed that HCV infection is unevenly distributed in Rwanda, dominated by HCV genotype 4, with considerable heterogeneity in the repartition of the different subtypes. We found potential associations between rural/urban lifestyles and HCV subtype profiles. Determined HCV distribution and diversity can serve as basis not only for HCV infection awareness and prevention campaigns, but also success and guidance for personalized treatment.

Povidone iodine-infused pars plana vitrectomy for severe Arthrographis kalrae fungal endophthalmitis

Purpose

Arthrographis kalrae is an opportunistic fungus that can cause a severe and atypical endophthalmitis. In limited studies, low-dose povidone iodine has been shown to be effective in treating fulminant bacterial endophthalmitis. In this case report, we describe the successful treatment of recalcitrant Arthrographis kalrae keratitis-associated endophthalmitis with intraocular povidone iodine during pars plana vitrectomy.

Observations

A patient with Arthrographis kalrae keratitis-associated endophthalmitis had persistent disease despite aggressive medical management. The infection resolved following pars plana vitrectomy with infusion of dilute povidone iodine. No toxicity was noted postoperatively.

Conclusions and importance

Povidone iodine-infused pars plana vitrectomy offers promise as a treatment for infectious endophthalmitis that fails medical management. This is the first report demonstrating eradication of fungal endophthalmitis using povidone iodine-infused pars plana vitrectomy.

Effect of treatment of chronic hepatitis c virus patients with direct-acting anti-retroviral drugs on semen and hormonal parameters

OBJECTIVE

Hepatitis C virus (HCV) infection is known to influence the seminal and hormonal parameters of infected men. This study was performed to assess the effects of HCV clearance using direct-acting antiviral (DAA) agents on semen and hormonal parameters.

METHODS

A total of 50 patients with chronic HCV were enrolled, and conventional semen analysis was performed according to World Health Organization guidelines. Basal levels of total testosterone, free testosterone (FT), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), prolactin, and sex hormone-binding globulin (SHBG) were assessed before and 3 months after treatment with DAAs.

RESULTS

Following DAA treatment, statistically significant increases were observed in sperm motility and the proportion of grade A sperm. Additionally, the percentage of abnormal forms was significantly decreased after treatment (p=0.000). However, no significant differences were observed in semen volume, concentration, or total sperm count. Sex hormone analysis of patients after DAA treatment revealed significant increases in FT, LH, and FSH levels, along with significant decreases in SHBG, prolactin, and E2 levels.

CONCLUSION

Following HCV clearance, we noted an improvement in sperm motility and an increase in the percentage of sperm with normal morphology. Treatment with DAAs was also associated with increased levels of FT and LH, along with decreased levels of SHBG, prolactin, and E2.

Neutralizing and enhancing monoclonal antibodies in SARS-CoV-2 convalescent patients: lessons from early variant infection and impact on shaping emerging variants

Serological studies of COVID-19 convalescent patients have identified polyclonal lineage-specific and cross-reactive antibodies (Abs), with varying effector functions against virus variants. Individual specificities of anti-SARS-CoV-2 Abs and their impact on infectivity by other variants have been little investigated to date. Here, we dissected at a monoclonal level neutralizing and enhancing Abs elicited by early variants and how they affect infectivity of emerging variants. B cells from 13 convalescent patients originally infected by D614G or Alpha variants were immortalized to isolate 445 naturally-produced anti-SARS-CoV-2 Abs. Monoclonal antibodies (mAbs) were tested for their abilities to impact the cytopathic effect of D614G, Delta, and Omicron (BA.1) variants. Ninety-eight exhibited robust neutralization against at least one of the three variant types, while 309 showed minimal or no impact on infectivity. Thirty-eight mAbs enhanced infectivity of SARS-CoV-2. Infection with D614G/Alpha variants generated variant-specific (65 neutralizing Abs, 35 enhancing Abs) and cross-reactive (18 neutralizing Abs, 3 enhancing Abs) mAbs. Interestingly, among the neutralizing mAbs with cross-reactivity restricted to two of the three variants tested, none demonstrated specific neutralization of the Delta and Omicron variants. In contrast, cross-reactive mAbs enhancing infectivity (n = 3) were found exclusively specific to Delta and Omicron variants. Notably, two mAbs that amplified in vitro the cytopathic effect of the Delta variant also exhibited neutralization against Omicron. These findings shed light on functional diversity of cross-reactive Abs generated during SARS-CoV-2 infection and illustrate how the balance between neutralizing and enhancing Abs facilitate variant emergence.

Session 4: mRNA and Self-Amplifying RNA (saRNA): Opportunities for Disease Prevention and Therapy

The unprecedented speed of developing vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, has propelled mRNA technologies into the public eye. The versatility of mRNA technology, often referred to as "plug and play," offers immense promise for rapidly updating vaccines to address newer variants of respiratory diseases and combat emerging infectious diseases and lethal pathogens, such as the Ebolavirus. However, the potential applications of mRNA technology extend well beyond prophylactic vaccines. This session explored the two primary mRNA platforms: nonreplicating mRNA and self-amplifying mRNA (variably referred to as saRNA, samRNA, or SAM). Presentation topics were on current research efforts aimed at broadening the applications of mRNA modalities beyond vaccines. Topics included opportunities for delivering mRNA via intra-tumoral and inhalational routes, immunological and systemic inflammatory responses elicited by these modalities, and regulatory considerations involved in the development and licensing of these technologies.

Rotavirus Infections: A 2-Year Comprehensive Review in Admitted Pediastric Patients Amid Conflicting National Policies

Highlighting rotavirus (RV) as a significant food and waterborne pathogen, particularly affecting infants and children, causing serious gastrointestinal infections and dehydration, is important. It should be noted that there are significant debates regarding the effectiveness and outcomes of RV vaccination. In contrast to Turkey's nonmandatory vaccination policy, many developed countries implement mandatory vaccination policies, raising questions about their impact on disease prevalence and healthcare expenditures. Our study aims to comprehensively understand RV infections in Turkey and compare them with countries that have mandatory vaccination policies. We found similar, and even better, hospitalization rates, length of hospital stays, and laboratory parameters demonstrating the effectiveness of Turkey's independent vaccination approach. These findings contribute valuable insights to global vaccination strategies and disease control.

Synergistic evolution: The dynamic adaptation of SARS-CoV-2 and human protective immunity in the real world

OBJECTIVES

SARS-CoV-2 is continually evolving with new variants to evade protective immunity and cause new infections. This study aimed to assess infection-acquired immunity and hybrid immunity against re-infection or severe COVID-19.

METHODS

During 2020-2023, we collected 890 serum samples from individuals infected with SARS-CoV-2 variants including wild type, D614G, Alpha, Delta, BA.1, BA.2, BA.2.76, BA.5.2, BF.7, XBB, and EG.5. The levels of serum neutralizing antibodies (NAbs) against 18 diverse SARS-CoV-2 variants were determined using a bead-based high-throughput broad neutralizing-antibody assay.

RESULTS

In the initial wave of the COVID-19 pandemic, >75% of the patients demonstrated robust NAb responses against the ancestral SARS-CoV-2, during a period when vaccines were not yet available. After the emergence of the Omicron variant, the seroprevalence of anti-Omicron NAbs among the patients increased rapidly. By April 2023, when XBB variant was predominant, approximately 80% of the patients demonstrated >50% neutralization against the highly immune-evasive XBB lineages. Three serotypes of SARS-CoV-2, namely non-Omicron, Omicron, and XBB serotypes, were identified, with the strong likelihood of further changes occurring as the virus mutating. Generally, NAbs elicited by a previous serotype could not typically effectively protect against another serotype that emerges later in the evolutionary stages.

CONCLUSION

Our results firstly demonstrated the synergistic evolution between host immunity and SARS-CoV-2 variants in the real world, which would be helpful to develop future vaccines and public health strategies.

The added value of perineal swabs when screening for asymptomatic methicillin-resistant Staphylococcus aureus colonization and risk factors for perineal carriage

We examined the added value of perineal swabs in addition to nose and throat swabs when screening for Methicillin-resistant Staphylococcus aureus colonization, and risk factors for perineal carriage in 6,642 patients. In our mainly primary care setting, the added value was 9.3%. Patients <3 or ≥80 had the highest risk.

Hepatitis C Virus-Core Antigen: Implications in Diagnostic, Treatment Monitoring and Clinical Outcomes

The hepatitis C virus (HCV) infection, a global health concern, can lead to chronic liver disease. The HCV core antigen (HCVcAg), a viral protein essential for replication, offers a cost-effective alternative to HCV RNA testing, particularly in resource-limited settings. This review explores the significance of HCVcAg, a key protein in the hepatitis C virus, examining its structure, function, and role in the viral life cycle. It also evaluates its clinical use in diagnosis and treatment monitoring, comparing its performance to the standard HCV RNA assay using data from PubMed and Google Scholar. HCVcAg assays show high pooled sensitivity (93.5%) and pooled specificity (99.2%) compared to HCV RNA assays, correlating closely (r = 0.87) with HCV RNA levels. Hence, HCVcAg testing offers a cost-effective way to diagnose active HCV infections and monitor treatment, especially in resource-limited settings, but its sensitivity can vary and standardization is needed. HCVcAg also predicts liver disease progression and assesses liver damage risk, aiding patient management. It helps to identify patients at risk for fibrosis or carcinoma, making it vital in hepatitis C care. HCVcAg testing can expand access to HCV care, simplify management, and contribute to global elimination strategies, especially in low- and middle-income countries.

Assessing advances in three decades of clinical antiretroviral therapy on the HIV-1 reservoir

BACKGROUNDAntiretroviral therapy (ART) has improved the clinical management of HIV-1 infection. However, little is known about how the latest ART recommendations affect the heterogeneity of the HIV-1 reservoir size.METHODSWe used a complete statistical approach to outline parameters underlying the diversity in HIV-1 reservoir size in a cohort of 892 people with HIV-1 (PWH) on suppressive ART for more than 3 years. Total HIV-1-DNA levels were measured in PBMCs using digital droplet PCR (ddPCR).RESULTSWe classified 179 (20%) participants as being low viral reservoir treated (LoViReT) (<50 HIV-1-DNA copies/106 PBMCs). Twenty variables were collected to explore their association with the LoViReT phenotype using machine learning approaches. LoViReT status was closely associated with higher nadir CD4, lower zenith pre-ART viral load, lower CD4 recovery, shorter time from diagnosis to undetectable viral load, and initiation of treatment with an integrase inhibitor-containing (InSTI-containing) regimen. Initiation of ART with any InSTI was also linked with a shorter time to undetectable viremia. Locally estimated scatterplot smoothing (LOESS) regression revealed a progressive reduction in the size of the HIV-1 reservoir in individuals who started ART after 2007. Similarly, a higher nadir CD4 and a shorter time to undetectable viremia were observed when treatment was initiated after that year.CONCLUSIONOur findings demonstrate that the progressive implementation of earlier, universal treatment at diagnosis and the use of InSTIs affected the size of the HIV-1 reservoir. Our work shows that effective management of infection is the first step toward reducing the reservoir and brings us closer to achieving a cure.FUNDINGNIH; Division of AIDS at the National Institute of Allergy and Infectious Diseases (NIAID), NIH; Merck Sharp & Dohme.

Enhanced and sustained biodistribution of HIV-1 neutralizing antibody VRC01LS in human genital and rectal mucosa

To prevent sexually-acquired HIV-1 infection by immunoprophylaxis, effective concentrations of broadly neutralizing antibodies are likely needed at mucosal sites of exposure. Here, we examine the biodistribution of monoclonal antibody VRC01 and its extended half-life variant, VRC01LS, in colorectal and genitourinary tracts of healthy adults 1-52 weeks after intravenous infusion. At 1-2 weeks, VRC01LS levels are ~3-4 times higher than VRC01 in serum (p = 0.048), rectal (p = 0.067), vaginal (p = 0.003) and cervical tissues (p = 0.003); these differences increase over time. Both antibodies primarily localize within rectal lamina propria and cervicovaginal stroma, with limited and variable epithelial distribution. Although 8-28% of serum mAb levels reach mucosal tissues, <3% are in seminal and rectal secretions. Elimination half-lives in mucosal tissues are 20-28 days for VRC01 and 51-68 days for VRC01LS. Thus, VRC01LS infusion achieves higher, sustained concentrations in human mucosal tissues than VRC01, supporting the future investigation of potent, long-acting LS-modified antibodies to prevent HIV-1.

Efficacy of 1% Povidone-Iodine in the Treatment of Anterior Blepharitis-Randomized Single-Center Controlled Trial

Background: Anterior blepharitis (AB) is a chronic eyelid inflammation with no definitive cure. Objectives: To assess the safety and efficacy of a 1% povidone-iodine (PVI) ophthalmic solution lid scrub compared to formulated eyelid wipes in treating AB. Design: A prospective, randomized, controlled, observer-masked, paired-eye trial. Methods: Sixty-three AB patients were randomly assigned to a 30-day treatment in which one eye underwent a daily lid scrub with 1% PVI solution (1% PVI group), while the fellow eye was treated with formulated eyelid wipes (control group). Clinical outcomes, such as blepharitis signs, tear breakup time, and corneal staining, were evaluated at study enrollment and exit visits. Symptom assessments utilized the visual analog scale (VAS) per eye and the ocular surface disease index (OSDI) questionnaire. Results: Fifty-two patients (mean age 62.3 years, 53.8% females) completed the treatment, while seven patients were lost to follow-up, three were non-compliant, and one sustained an eye trauma. After 30 days, both the 1% PVI and control groups exhibited significant improvements in symptoms, blepharitis signs, and corneal staining (p < 0.05). The 1% PVI scrubs were equally effective as eyelid wipes in most outcomes (p = 0.480) and superior in alleviating eyelid erythema (p = 0.007). Only the 1% PVI group showed a positive correlation between OSDI and VAS score improvements (r (52) = 0.353, p = 0.01). No adverse events related to either treatment modality were reported. Conclusions: A 1% PVI solution is an effective, safe, and well-tolerated treatment option for AB and is superior to formulated eyelid wipes in several subjective and objective measures.

Platelet Ido1 expression is induced during Plasmodium yoelii infection, altering plasma tryptophan metabolites

ABSTRACT

Platelets are immune responsive in many diseases as noted by changes in platelet messenger RNA in conditions such as sepsis, atherosclerosis, COVID-19, and many other inflammatory and infectious etiologies. The malaria causing Plasmodium parasite is a persistent public health threat and significant evidence shows that platelets participate in host responses to infection. Using a mouse model of nonlethal/uncomplicated malaria, non-lethal Plasmodium yoelii strain XNL (PyNL)-infected but not control mouse platelets expressed Ido1, a rate limiting enzyme in tryptophan metabolism that increases kynurenine at the expense of serotonin. Interferon-γ (IFN-γ) is a potent inducer of Ido1 and mice treated with recombinant IFN-γ had increased platelet Ido1 and IDO1 activity. PyNL-infected mice treated with anti-IFN-γ antibody had similar platelet Ido1 and metabolic profiles to that of uninfected controls. PyNL-infected mice become thrombocytopenic by day 7 after infection and transfusion of platelets from IFN-γ-treated wild-type mice but not Ido1-/- mice increased the plasma kynurenine-to-tryptophan ratio, indicating that platelets are a source of postinfection IDO1 activity. We generated platelet-specific Ido1 knockout mice to assess the contribution of platelet Ido1 during PyNL infection. Platelet-specific Ido1-/- mice had increased death and evidence of lung thrombi, which were not present in infected wild-type mice. Platelet Ido1 may be a significant contributor to plasma kynurenine in IFN-γ-driven immune processes and the loss of platelets may limit total Ido1, leading to immune and vascular dysfunction.

In Vitro and In Vivo Translational Insights into the Intraoperative Use of Antiseptics and Lavage Solutions Against Microorganisms Causing Orthopedic Infections

The growing antibiotic resistance of microorganisms causing postoperative infections following orthopedic surgeries underscores the urgent need for localized antiseptic and lavage delivery systems to enhance infection control. This study evaluates the in vitro effectiveness of antiseptic and lavage solutions-including polyhexanide, povidone-iodine, low-concentrated hypochlorite, Ringer's solution, and saline-against Staphylococcus epidermidis, Staphylococcus aureus MRSA, Cutibacterium acnes, Corynebacterium amycolatum, Pseudomonas aeruginosa, and Candida albicans. Using microplate models (Minimum Inhibitory Concentration, Minimum Biofilm Eradication Concentration, and Biofilm-Oriented Antiseptic Test assays), flow-based models (Bioflux system), and surfaces relevant to orthopedic implants (e.g., stainless steel disks/screws, Co-Cr-Mo, Ti-Al-Nb orthopedic alloys, and ultra-high-molecular-weight polyethylene), as well as a bio-nano-cellulose scaffold representing tissue, we assessed the solutions' activity. The cytotoxicity of the solutions was evaluated using osteoblast and keratinocyte cell lines, with additional in vivo insights gained through the Galleria mellonella larval model. The results show that polyhexanide-based solutions outperformed povidone-iodine in biofilm eradication in most tests applied, particularly on complex surfaces, whereas iodine demonstrated higher cytotoxicity in applied in vitro and in vivo tests. Low-concentration hypochlorite solutions exhibited minimal antibiofilm activity but also showed no cytotoxicity in cell line and G. mellonella larval models. These findings highlight the importance of careful antiseptic selection and rinsing protocols to balance infection control efficacy with tissue compatibility in orthopedic applications.

Identification of new bioactive molecules in platelet preparation, storage, and transfusion reactions for improved transfusion management

Platelet concentrates (PCs) intended for transfusion contain bioactive molecules that can be considered Biological Response Modifiers (BRMs), mainly originating from plasma regardless of the preparation process. During storage, NGAL and GDF-15 levels increase in single donor apheresis platelet concentrates (SDA-PC), whereas in buffy coat platelet concentrates (BC-PC), the levels of MIP1α, MCP-3, and HSAA increase, and GDF-15 levels decrease. These molecules, primarily released by leukocytes, may contribute to adverse reactions (ARs) following a PC transfusion. Notably, in SDA-PC or BC-PC transfusions that result in ARs, the levels of NGAL, HSAA, and GDF-15 are significantly elevated, while the levels of MDC and CX3CL1 are significantly reduced compared to transfusions without ARs. These biomarkers could potentially serve as predictors for PCs-induced ARs.

Respiratory Syncytial Virus: A WAidid Consensus Document on New Preventive Options

Background/Objectives: Respiratory syncytial virus (RSV) is a leading cause of respiratory infections, particularly affecting young infants, older adults, and individuals with comorbidities. Methods: This document, developed as a consensus by an international group of experts affiliated with the World Association of Infectious Diseases and Immunological Disorders (WAidid), focuses on recent advancements in RSV prevention, highlighting the introduction of monoclonal antibodies (mAbs) and vaccines. Results: Historically, RSV treatment options were limited to supportive care and the monoclonal antibody palivizumab, which required multiple doses. Recent innovations have led to the development of long-acting mAbs, such as nirsevimab, which provide season-long protection with a single dose. Nirsevimab has shown high efficacy in preventing severe RSV-related lower respiratory tract infections (LRTIs) in infants, reducing hospitalizations and ICU admissions. Additionally, new vaccines, such as RSVpreF and RSVpreF3, target older adults and have demonstrated significant efficacy in preventing LRTIs in clinical trials. Maternal vaccination strategies also show promise in providing passive immunity to newborns, protecting them during the most vulnerable early months of life. This document further discusses the global burden of RSV, its economic impact, and the challenges of implementing these preventative strategies in different healthcare settings. Conclusions: The evidence supports the integration of both passive (mAbs) and active (vaccines) immunization approaches as effective tools to mitigate the public health impact of RSV. The combined use of these interventions could substantially reduce RSV-related morbidity and mortality across various age groups and populations, emphasizing the importance of widespread immunization efforts.

Characterization of Platelet Receptors and Their Involvement in Immune Activation of These Cells

The article characterises platelets, pointing out the role and contribution of their numerous receptors determining their specific and broad immune activity. Three types of platelet receptors are described, that is, extracellular and intracellular receptors-TLR (toll-like receptors), NLR (NOD-like receptor), and RLR (RIG-I-like receptor); extracellular receptors-selectins and integrins; and their other extracellular receptors-CLR (C-type lectin receptor), CD (cluster of differentiation), TNF (tumour necrosis factor), among others. Outlining the contribution of these numerous platelet receptors to the intravascular immunity, it has been shown that they are formed by their fusion with pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs), and lifestyle-associated molecular patterns (LAMPs). They are initiating and effector components of signal transduction of these cells, and their expression and quantity determine the specific and broad functions of platelets towards influencing vascular endothelial cells, but mainly PRRs (pattern recognition receptors) of blood immune cells. These facts make platelets the fundamental elements that shape not only intravascular homeostasis, as previously indicated, but they become the determinants of immunity in blood vessels. Describing the reactions of the characterised three groups of platelet receptors with PAMP, DAMP and LAMP molecules, the pathways and participation of platelets in the formation and construction of intravascular immune status, in physiological states, but mainly in pathological states, including bacterial and viral infections, are presented, making these cells essential elements in the health and disease of mammals, including humans.

A Novel Heterozygous NFKB2 Variant in a Multiplex Family with Common Variable Immune Deficiency and Autoantibodies Against Type I IFNs

We studied a family with three male individuals across two generations affected by common variable immune deficiency (CVID). We identified a novel missense heterozygous variant (c.2602T>A:p.Y868N) of NFKB2 in all patients and not in healthy relatives. Functional studies of the mutant allele in an overexpression system and of the patients' cells confirmed the deleteriousness of the NFKB2 variant and genotype, respectively, on the activation of the non-canonical NF-κB signaling pathway. Impaired processing of p100 into p52 underlies p100 accumulation, which results in gain-of-function (GOF) of IκBδ inhibitory activity and loss-of-function (LOF) of p52 transcriptional activity. The three patients' plasma contained autoantibodies that neutralized IFN-α2 and/or IFN-ω, accounting for the severe or recurrent viral diseases of the patients, including influenza pneumonia in one sibling, and severe COVID-19 and recurrent herpes labialis in another. Our results confirm that NFKB2 alleles that are IκBδ GOF and p52 LOF can underlie CVID and drive the production of autoantibodies neutralizing type I IFNs, thereby predisposing to severe viral diseases.

Seasonal influenza vaccination: Attitudes and practices of healthcare providers in Jordan

BACKGROUND

Influenza is associated with significant global morbidity and mortality, with vaccination being the primary preventive strategy. Despite recommendations, influenza vaccine uptake among healthcare providers (HCPs) remains suboptimal, especially in the Eastern Mediterranean. We aimed to assess the attitudes and practices of HCPs in Jordan regarding seasonal influenza vaccination and assess sources of variation thereof.

METHODS

We conducted a cross-sectional survey study among a sample of HCPs practicing in Jordan (12/29/2020-04/26/2021). Participants completed a questionnaire assessing demographics, influenza vaccination history, attitudes, and practices. We used logistic regression to evaluate factors related to vaccine receipt and reasons for non-vaccination. We used proportional odds models to evaluate factors related to HCP recommendations and to compare opinions on influenza vaccination between ever- and never-vaccinated HCPs.

RESULTS

Of 305 survey initiates, 206 HCPs (67.5%) comprised the analytic sample. The median age was 35 years; 61.2% were women, and 43.7% were pharmacists. Over half (52.9%) never received an influenza vaccine; however, older age and self-identifying as a physician were associated with higher odds of having ever received the influenza vaccine. The main reasons for non-vaccination were related to the misassessment of risks and benefits. Prior receipt of influenza vaccination was strongly associated with odds of recommending vaccination (or = 10.5; 95% CI = [5.38-20.3]; p<0.001). The COVID-19 pandemic reportedly enhanced influenza vaccine acceptance among 48.5% of HCPs surveyed.

CONCLUSIONS

Low influenza vaccine uptake among healthcare providers in Jordan is related to misassessment of risks and benefits. Enhancing attitudes and confidence through tailored education is crucial to overcoming hesitancy and promoting sustained improvements in vaccination attitudes and practices among HCPs in Jordan.

mRNA-based platform for preventing and treating Staphylococcus aureus by targeted staphylococcal enterotoxin B

Staphylococcus aureus (S. aureus) possesses numerous virulence factors, with the increasing prevalence of drug-resistant strains heightening the threat posed by this pathogen. Staphylococcal enterotoxin B (SEB), a highly conserved toxin secreted by S. aureus, is also recognized as a potential bioweapon with super-antigenic activity. SEB represents a promising target in efforts to combat infections caused by S. aureus. We developed mRNA-based vaccine and antibody targeting SEB for both prophylactic and therapeutic purposes in varying S. aureus infection conditions. The mSEB mRNA vaccine (10 μg per mouse) induces more robust and persistent immune responses, including higher antibody titers and specific cellular immune responses, compared to immunization with 30 μg of mSEB protein adjuvanted with aluminum phosphate. Additionally, the anti-SEB mRNA antibody maintains secretion of anti-SEB monoclonal antibody (mAb) with a dosage that is 10 times lower than purified protein administration. The mRNA-based antibody exhibits superior pharmacokinetic profiles compared to its protein counterparts, efficiently neutralizing SEB and clearing S. aureus from circulation. Both the mRNA vaccine and mRNA antibody demonstrate preventive and therapeutic effects by eliciting specific immune responses and generating high-affinity antibodies in mice. We have laid the groundwork for the development and evaluation of mRNA-based vaccines and antibodies targeting SEB produced by S. aureus. Our studies demonstrate that these approaches are more effective than traditional protein-based vaccines and antibodies in terms of inducing immune responses, pharmacokinetics, and their prophylactic or therapeutic efficacy against S. aureus infections.

A Mutation in the Herpes Simplex Virus Type 1 (HSV-1) UL29 Gene is Associated with Anti-Herpesvirus Drugs' Susceptibility

Herpes simplex virus type 1 (HSV-1) acyclovir (ACV) resistance is acquired by mutations in the viral thymidine kinase (TK) or DNA polymerase (DNApol) genes. We previously obtained an ACV-resistant clone (HSV-1_VZV_TK_clone α) by sequential passages of HSV-1_VZV-TK, a recombinant virus which lacked its endogenous TK activity and instead expressed the varicella-zoster virus (VZV) TK ectopically. HSV-1_VZV_TK_clone α had been generated using an HSV-1_BAC in the presence of increasing concentrations of ACV. The ACV-resistant clone bore normal TK and DNApol genes. Here, we deployed next-generation full-genome sequencing of HSV-1_VZV_TK_clone α and identified a single nucleotide substitution, resulting in a P597L missense mutation in the UL29 gene product, the ICP8 protein. Recombinant HSV-1 encoding a P597L ICP8 protein was generated, and its properties and ability to confer drug resistance were analyzed. No difference in virus growth and UL29 expression was observed between the mutant recombinant, the wild type, and a revertant mutant viral strain, and susceptibility tests of these strains to ACV and other drugs using Vero, HEL, and ARPE19 cells identified that the recombinant UL29 mutant virus was resistant only to ACV. These results indicate that ICP8 may be involved in the anti-herpesvirus drugs' mechanism of action on HSV-1.

Characterization of oral microbiota of children with hand, foot, and mouth disease caused by enterovirus A 71

BACKGROUND

The association between alterations in the oral microbiome and hand, foot, and mouth disease (HFMD) has been observed in previous studies. Our study, therefore, aimed to identify the structural changes in the oral microbiota and biomarkers in children with HFMD caused by enterovirus A 71 (EV-A71).

METHODS

Children diagnosed with EV-A71 HFMD and healthy children recruited from April 2021 to September 2023 were included in the present study, and were categorized into EV-A71 and control groups, respectively. Oral swabs were collected and microbiota information was obtained using 16 S rRNA gene sequencing technology. Alpha-diversity and partial least squares discriminant analyses were conducted to compare microbial diversity, richness, and similarity between the two groups. Linear discriminant analysis effect size was employed to identify microbial taxa with significant differences, and determined the key genera among them.

RESULTS

The study included a total of 80 children, with 50 assigned to the EV-A71 group and 30 to the control group. No significant differences were found between the two groups in terms of age (2.2 ± 1.2 vs. 2.7 ± 1.2 years; age range: 1-5 years; P = 0.114) or sex (56% vs. 60% boys, P = 0.726). The oral microbiota structure in the EV-A71 group differed from that in the control group. The EV-A71 group showed significant reductions in both the Shannon index (P = 0.037) and the abundance-based coverage estimator (ACE) index (P < 0.001). The key genus changes were marked by a significant decrease in the abundance of Capnocytophaga (P = 0.002) and Leptotrichia (P = 0.033) in the EV-A71 group.

CONCLUSION

In children with EV-A71 HFMD, the oral microbiota showed changes in composition, with a significant reduction in diversity and richness. The changes in key genera were a marked decrease in the abundance of Capnocytophaga and Leptotrichia.

A Quick Sequential Organ Failure Assessment (qSOFA) Score Greater than 1 and Shortened Ampicillin Use Predict Death and One-Year Mortality in Hospitalized Patients with Non-Perinatal Invasive Listeriosis: A Retrospective Analysis of 118 Consecutive Cases

Listeria monocytogenes causes listeriosis, a serious foodborne illness with a high mortality rate, especially in vulnerable populations. It accounts for 19% of foodborne deaths, with invasive cases having a mortality rate of up to 44%, leading to conditions like meningitis, bacteremia, and meningoencephalitis. However, the prognostic factors remain unclear. This study examines the hospital outcomes of invasive listeriosis and identifies risk factors for in-hospital and one-year mortality. We analyzed the electronic medical records of 118 hospitalized patients with non-perinatal, culture-proven invasive listeriosis collected over a 21-year period. The in-hospital mortality rate was 36.4%, with only 33.1% surviving one year and 22.0% surviving two years. The key findings indicate that a quick Sequential Organ Failure Assessment (qSOFA) score of ≥2 (OR 106.59, p < 0.001), respiratory failure (OR 7.58, p = 0.031), and shorter ampicillin duration (OR 0.53, p = 0.012) independently predicted poorer in-hospital outcomes. Additionally, a qSOFA score of ≥2 (OR 8.46, p < 0.001) and shorter ampicillin duration (OR 0.65, p < 0.001) were linked to higher one-year mortality. This study is the first to identify a qSOFA score of ≥2 as a significant marker for high-risk invasive listeriosis patients, with poorer outcomes linked to a qSOFA score of ≥2, respiratory failure, and shorter ampicillin use.

The Impact of Cytomegalovirus Infection on Ulcerative Colitis Relapse: A Multicenter Retrospective Cohort Study

Purpose

Cytomegalovirus (CMV) infection exacerbates intestinal inflammation in ulcerative colitis (UC) patients, yet the effect of CMV infection on UC relapse has not been fully elucidated. This study aimed to investigate the impact of CMV infection on UC relapse and identify associated risk factors.

Patients and Methods

This multicenter retrospective cohort study included UC patients who visited research centers from January 2016 to December 2020. Univariate and multivariate Cox regression analyses were conducted to explore risk factors for UC relapse. Propensity score matching was used to balance the differences in the clinical characteristics between the groups.

Results

A total of 298 UC patients participated in this study, including 19 with CMV colitis, 37 with CMV viremia, and 242 CMV-negative patients. The 2-year cumulative recurrence rate was higher in patients with CMV colitis than that in CMV-negative patients (84.21% vs 51.65%, p = 0.01). Univariate and multivariate Cox regression analyses confirmed that fecal calprotectin ≥ 250 µg/g, Montreal classification E3, CMV colitis, duration > 48 months, and serum albumin < 30 g/L were independent risk factors for UC relapse at 2 years, whereas the use of biologics for induction of remission was identified as an independent protective factor.

Conclusion

Our study suggests that the risk of relapse increases among UC patients with CMV colitis over two years. Risk factors for UC relapse at 2 years include fecal calprotectin ≥ 250 μg/g, Montreal classification E3, CMV colitis, UC duration > 48 months, and albumin < 30 g/L, whereas the use of biologics during induction is a protective factor.