Novel β-lactam/β-lactamase inhibitor combinations (BL/BLICs) such as ceftazidime/avibactam (CAZ/AVI), meropenem/vaborbactam (MEM/VAB), imipenem/relebactam (IMP/REL) and aztreonam/avibactam (ATM/AVI) have expanded therapeutic choices against KPC-producing K. pneumoniae. However, emerging resistance threatens their long-term efficacy. We investigated the prevalence, genomic mechanisms, and clinical correlates of resistance to these agents among KPC-producing K. pneumoniae bloodstream isolates. Consecutive KPC-producing K. pneumoniae bloodstream isolates collected between 2021 and 2024 at a tertiary university hospital were tested for susceptibility to novel BL/BLICs and comparators. Whole-genome sequencing (WGS) was performed on isolates resistant to any BL/BLIC to characterise genetic backgrounds. Clinical data from corresponding patients were analysed to explore risk factors and outcomes. Among 178K. pneumoniae isolates, ATM/AVI, IMP/REL and MEM/VAB retained excellent in vitro activity (≥ 96% susceptible), while 11% were resistant to CAZ/AVI. One hundred fifty-four (86.5%) were susceptible to all BL/BLICs, whereas 24 (13.5%) displayed resistance to at least one agent, most commonly CAZ/AVI. WGS revealed a genetically diverse population mainly comprising high-risk clones ST512 and ST101. Resistance was driven by KPC variants (KPC-31, KPC-167, KPC-93, KPC-49, KPC-14, KPC-121, KPC-33) and porin disruptions (OmpK36 insertions, OmpK35 loss). Most patients (91%) had prior colonisation and recent β-lactam exposure; median time to resistance emergence was 47days. The 28-day mortality among patients with BL/BLIC-resistant infections was 21.7%. Resistance to novel BL/BLICs among KPC-producing K. pneumoniae is emerging in Italian hospitals, largely mediated by blaKPC variants and porin defects under selective antibiotic pressure. While ATM/AVI, MEM/VAB and IMP/REL remain highly active, resistance to CAZ/AVI is increasingly frequent. Continuous genomic surveillance and optimised antimicrobial stewardship are essential to preserve the efficacy of these last-line agents.

This study investigated changes in the incidence and age distribution of RSV-associated lower respiratory tract infections (RSV-LRTI) among children in Northern Bavaria after the general recommendation of Nirsevimab immunization in 2024. Postnatal Nirsevimab immunization coverage was assessed at the University Hospital Würzburg (UKW) in children born between 11/2024 and 03/2025. Age distribution of in- and outpatients < 2 years with PCR-confirmed RSV-LRTI was assessed from UKW (ICD-10 based) and pediatric practices in Würzburg for November-March in 2022/23 (S1), 2023/24 (S2) and 2024/25 (S3). Age distribution of RSV cases from nationwide mandatory laboratory RSV surveillance (Robert Koch-Institute) was analyzed for November-March in 2023/24 and 2024/25. Between 11/2024 and 03/2025, postnatal Nirsevimab immunization coverage for newborns at the UKW was 68% (566/833). In the RSV seasons S1/S2/S3, 98/84/29 children < 2 years with RSV-LRTI were hospitalized. The proportion of children < 1 year decreased from 78%/80% in S1/S2 to 42% in S3 (S1 vs. S3 p < 0.001, S2 vs. S3 p < 0.001). In 36/68/30 outpatients < 2 years with RSV-LRTI, the proportion of children < 1 year decreased from 44%/60% in S1/S2 to 33% in S3 (S1 vs. S3 p = 0.358; S2 vs. S3 p = 0.014). In nationwide laboratory RSV surveillance, 23,171/12,826 children < 2 years were reported in S2/S3, with a decrease in the proportion of children < 1 year from 65% in S2 to 47% in S3 (p < 0.001). We observed a clear decrease of RSV-LRTI in hospitalized and outpatient infants < 1 year of age in the first RSV season, suggesting a relevant impact following Nirsevimab recommendation in Germany.

There is a lack of systematic data on cerebrospinal fluid (CSF) findings in the different clinical manifestations of tick-borne encephalitis (TBE) and according to the duration of neurological involvement. This study aims to evaluate and compare routine CSF parameters in TBE patients presenting with meningitis, meningoencephalitis, or meningoencephalomyelitis, and to assess temporal changes in CSF during the first 10days after the onset of neurological symptoms. We analysed 15 CSF parameters in 717 consecutive adult patients hospitalized for TBE at the Department of Infectious Diseases, University Medical Centre Ljubljana, Slovenia. Among these patients, 230 (32%) had meningitis, 446 (62%) meningoencephalitis, and 41 (6%) meningoencephalomyelitis. CSF findings differed significantly among the three clinical presentations. Leukocyte count, neutrophil proportion, protein levels, immunoglobulin concentrations (IgM, IgG, IgA), and intrathecal synthesis quotients were highest in meningoencephalomyelitis and lowest in meningitis. These differences remained largely significant after adjusting for confounding factors. CSF abnormalities were detectable from day one of neurological symptoms, peaked around days 4-5, and then stabilized or showed mild improvement. Neutrophils predominated during the first two days, followed by a predominance of lymphocytes and monocytes from day 3 onward. This pattern was consistent in meningitis and meningoencephalitis but less pronounced in meningoencephalomyelitis. Clinical manifestations of TBE exhibit distinct CSF profiles. Abnormalities are most pronounced in meningoencephalomyelitis and least in meningitis. These alterations appear early, peak within the first days, and then stabilize or improve, although this pattern is less predictable in meningoencephalomyelitis.

The detection of pathogens causing infections by conventional diagnostic methods can be challenging and next-generation sequencing (NGS) technology offers a promising alternative method. In this study, we evaluated the performance of real-time metagenomic next-generation sequencing (rt-mNGS) for the detection of pathogens in respiratory samples. We used rt-mNGS, using the Seqstant LiveGene Analysis platform, on 335 respiratory samples in comparison to conventional culture results. We observed an overall good concordance in 71.64% (240/335) of the methods. The rt-mNGS outperformed the gold standard culture in 16.12% (54/335) of the samples, while the culture was superior in detecting the clinically relevant pathogen in 12.24% (41/335) of the samples. The non-inferiority of rt-mNGS was statistically significant (δ = 10, α = 0.05, 1 - β = 0.8). We also observed that the real-time analysis of NGS data is beneficial in obtaining reliable, timely results, as the initial report at cycle 46 exhibits a Positive Predictive Value (PPV) of 93.75% at the species-level with a sensitivity of 32.09%. Overall, our study showed the non-inferiority of rt-mNGS compared to the standard-of-care microbiology for respiratory samples with statistical significance. Moreover, the rt-mNGS method exhibited superior sensitivity and superior overall performance. It also uniquely detected certain organisms that are typically hard to culture. However, rt-mNGS reported a higher number of false positives and faced limitations in detecting Aspergillus spp. In conclusion, the study highlights the potential of rt-mNGS as a powerful tool in clinical diagnostics of respiratory infections and beyond.

PurposeTo identify enteric pathogens in pediatric acute gastroenteritis (AGE) and assess their etiological relevance by comparison with samples during asymptomatic period.MethodsChildren < 2 years of age (n = 89) were prospectively enrolled as part of the population-based birth cohort LoewenKIDS. Asymptomatic stool samples were collected regularly, and symptomatic samples were collected after the occurrence of > 3 loose stools and/or one vomiting in 24 h. Intraindividual pairs of symptomatic and preceding asymptomatic samples for each child were analyzed for 25 enteric pathogens via multiplex real-time RT-PCR.ResultsEnteric viruses were detected in 64% (57/89) of symptomatic samples and significantly associated with gastrointestinal symptoms (Odds Ratio [OR] 3.9; 95% Confidence Interval [CI] 2.1–7.3). The most common viruses in AGE were norovirus (Genogroups GI and GII) (36%, 32/89) and adenovirus (27%, 24/89). Bacteria were detected in 46% (41/89) of symptomatic samples and 43% (38/89) of asymptomatic ones, with no association to symptoms (OR 1.1; 95% CI 0.6-2). The most common bacteria in AGE were Enteropathogenic Escherichia coli (28%, 25/89) and Clostridium difficile (16%, 14/89). Dientamoeba fragilis was the only detected parasite in AGE (7%, 6/89), and was not associated with symptoms (OR 1.4; 95% CI 0.4–5.5). Pathogen loads in symptomatic and asymptomatic pairs correlated with symptoms for norovirus GII, astrovirus and sapovirus (each p < 0.01), but not for other pathogens.ConclusionThis study supports the clinical significance of detection of viral pathogens in young children with acute gastroenteritis and without relevant comorbidities in high-income countries, but limits the significance of enteric bacterial and parasitic pathogens detection, partly due to constraints in their specific identification.Trial registrationClinicaltrials.Gov Identifier: NCT02654210.Supplementary InformationThe online version contains supplementary material available at 10.1007/s15010-025-02670-1.

Hepatitis E represents an increasingly significant yet often overlooked public health issue in India, contributing substantially to both sporadic hepatitis cases and widespread waterborne outbreaks. Hepatitis E virus (HEV) is the foremost cause of acute viral hepatitis (AVH) in India and spreads primarily through contaminated water. Genotype-specific differences in transmission routes, ranging from enteric routes in developing regions to zoonotic routes in industrialized settings, underscore the complexity of its epidemiology. Vulnerable populations such as pregnant women, animal handlers, and immunocompromised individuals face a markedly increased risk of severe disease outcomes, including fulminant hepatic failure and chronic infection, in cases of coinfection with hepatitis B virus.This comprehensive review delves into Indian epidemiological trends, clinical features, diagnostic approaches, and current management options for HEV. While most infections are self-limiting, ribavirin has shown efficacy in select high-risk populations. However, the absence of an approved vaccine in India remains a critical gap in preventive strategies. Emerging therapeutics and vaccine candidates are currently in various stages of development. However, challenges such as the genetic diversity of HEVs, lack of long-term efficacy data, and limited public awareness hinder progress.This review emphasizes the urgent need for strengthened national surveillance systems, improved water and sanitation infrastructure, and integrated public health policies tailored for high-risk groups. A multipronged approach that combines epidemiological vigilance, clinical preparedness, and policy-driven interventions is imperative to halt the silent transmission of hepatitis E in India.

IntroductionSevere viral infections are common in patients requiring admission to intensive care units (ICU). Furthermore, these patients often have additional secondary or co-infections. Despite their prevalence, it remains uncertain to what extent those additional infections contribute to worse outcomes for patients with severe viral infections requiring ICU admission. This study aims to characterise severe viral infections requiring admission to intensive care, and describe their viral aetiology, the incidence of additional infections, and their clinical outcomes.MethodsThis retrospective single-centre cohort included consecutive adults admitted to the intensive care unit (ICU) with a positive polymerase chain reaction (PCR) test for viral infection from 2015 to 2024. Patients with SARS-CoV-2 were not included in this analysis. The data were retrieved from all available electronic databases. Patients were further stratified to compare severe viral infections alone to those with other microbiology confirmed co-infection (within 48 h of admission) and secondary infection (48 h after ICU admission).ResultsWe identified 222 with positive PCR for viral infection admitted to ICU. The majority were admitted with radiographic evidence of pneumonia (73.0%). Rhinovirus (28.4%), influenza A (18.5%), and RSV (16.2%) were the most common viral pathogens. Of the total, 149 patients had viral infection alone, 50 had co-infections, and 23 developed secondary infections. 30-day and ICU mortality were similar for viral alone, co-infection and secondary infection groups. Although those with secondary infection had a greater hospital and ICU length of stay, this was not reflected in the duration of mechanical ventilation or 30-day hospital mortality.ConclusionIn our large cohort of severe viral infections where Rhinovirus was the most common pathogen. This patient population constitute a high burden of respiratory support. The study also characterised 22.5% had co-infection, and 10% had subsequent secondary infection. While patients with secondary infections had prolonged ICU and hospital stay, the 30-day mortality was similar between all groups.Supplementary InformationThe online version contains supplementary material available at 10.1007/s15010-025-02637-2.