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Assessing early detection ability through spatial arrangements in environmental surveillance for poliovirus: A simulation-based study
Get PDFDetecting the circulation of poliovirus in its early stages is paramount for swift public health action. While environmental surveillance (ES) is promising for enhancing early pathogen detection, the influence of spatial arrangement of ES sites on early detection remains unclear. Here, we aim to assess the early detection ability of ES by varying the number and location of ES sites using the simulation-based approach utilising geographic and demographic characteristics of South Africa as a case study of a non-endemic country. We developed a stochastic meta-population model among unimmunised children aged under 5 years old, assuming a single introduction of wild poliovirus serotype 1. We constructed six scenarios by combining three importation risk distributions (predicated on population size, approximations of international inbound travel volume and border crossing volume) with two ES site layout strategies (proportionate to population size and importation risks via land border crossings). We showed a modest number of strategically positioned ES sites can achieve a high early detection ability given assumed importation risks were geographically confined while dispersed importation risks reduced the effectiveness of ES. Our sensitivity analysis suggested that implementing the ES across large areas with low sampling frequency consistently resulted in a better early detection ability against various importation scenarios than implementing the ES in limited areas with high sampling frequency. Although we acknowledge the challenges of translating our simulated outcomes for real-world situations, our study has implications for deciding the scale and site selection of ES.PLOS ONE, 20, art. no. e0325789; 2025journal articl
Micro-nanobubbles for removing membrane foulants from the surface of nanofiltration membranes in drinking water applications
No full textMembrane fouling is an inevitable phenomenon in nanofiltration (NF) membrane treatment. In particular, direct treatment of surface water using submerged NF membranes can induce increased fouling due to the absence of a pre-filtration process. This study aimed to optimize membrane cleaning conditions using micro-nanobubbles (MNBs) during submerged NF membrane treatment. The system using NF270 membranes was operated at a constant flux of 6 L/m2h with weekly MNB cleaning intervals. The results showed that MNB cleaning for over 90 min achieved full recovery of water permeance. During long-term operation (49 days), weekly MNB cleaning restored the transmembrane pressure to its initial value within the first four filtration cycles. The rejection of dissolved organic carbon remained high (>74%), indicating that MNB cleaning did not compromise the quality of treated water. However, the cleaning efficiency decreased in subsequent filtration cycles. The cleaning effect of MNBs was attributed to the shear force and collapse phenomenon, which reduced the formation of a cake layer comprising organic matter (e.g., protein-like substances) and bacterial cells on the NF membrane surface. These results demonstrate the effectiveness of MNB cleaning in mitigating fouling during submerged NF treatment.Separation and Purification Technology, 377, art. no. 134259; 2025journal articl
ガルトゥングの平和概念に基づく中学校社会科授業開発―メタ認知能力育成の視点から－
Get PDF長崎大学教育学部教育実践研究紀要, 24, pp.33-41; 2025departmental bulletin pape
ADHD傾向のある児童における自己主張行動の変容を目的とした取り組み
Get PDF長崎大学教育学部教育実践研究紀要, 24, pp.107-116; 2025departmental bulletin pape
教育実習の現状と課題―「総仕上げ的･見習い修行的教育実習」と「研究的教育実習」の観点から―
Get PDF長崎大学教育学部教育実践研究紀要, 24, pp.165-174; 2025departmental bulletin pape
Development of a Novel, Highly Sensitive System for Evaluating Ebola Virus Particle Formation
Get PDFEbola virus (EBOV) causes severe hemorrhagic fevers in humans, and effective countermeasures remain limited. The EBOV-encoded major matrix protein VP40 is essential for viral assembly, budding, and particle release, making it a promising target for antiviral drug development. However, no approved drugs currently target the viral particle formation process. In this study, we established a simple and highly sensitive screening system to evaluate VP40-mediated virus-like particle (VLP) formation under biosafety level −2 conditions. The system uses the HiBiT luminescence-based reporter fused to VP40, allowing for the detection of VP40 release. Our results demonstrate that the HiBiT sequence fused at the N-terminus [HiBiT-VP40 (N)] retains VP40′s ability to form VLPs, supporting its use as a functional reporter. Furthermore, we validated the system by assessing the role of Rab11-dependent trafficking in VP40-mediated budding and by evaluating the effect of nocodazole, a microtubule depolymerizer, on VLP release. This novel screening system provides a convenient and reliable platform for screening potential inhibitors targeting the late stages of EBOV infection, including viral particle formation and release. Additionally, its potential adaptability to other filoviruses suggests wide applicability in the discovery and development of additional novel therapeutic agents.Viruses, 17(7), art. no. 1016; 2025journal articl
Antimicrobial use for influenza-like illnesses in Nha Trang, Vietnam: a cross-sectional study
Get PDFObjectives: This study aimed to investigate the characteristics and management of influenza-like illnesses (ILIs) in the outpatient and inpatient settings in Vietnam. Design: A cross-sectional, observational study. Setting and participants: We conducted a questionnaire survey of 407 individuals with ILI symptoms who presented to public community health centres and the paediatric ward of a public hospital in the city of Nha Trang, Khanh Hoa Province, Vietnam, from December 2022 to March 2023. Interventions: Not applicable. Primary and secondary outcome measures: No primary and secondary outcomes were pre-specified because this study was an explanatory study. The basic characteristics of the participants are presented using descriptive statistics. We conducted multivariable logistic regression analysis to examine the factors associated with the prescription of antibiotics to outpatients with ILIs. Results: A total of 198 outpatients and 200 inpatients were enrolled in the study. Most inpatients were children under 5 years of age and experienced longer illness durations and higher costs, with almost all patients receiving antibiotics. The rate of antimicrobial prescription for ILIs was 79.3% for outpatients and 99.5% for inpatients. The median health-related quality of life score of participants aged ≥18 years during illness was 0.796 (IQR 0.674–0.922). Logistic regression analysis indicated a negative association between a definite diagnosis of viral infection by rapid diagnostic test and outpatient antibiotic prescription (OR: 0.20, p=0.006). Conclusions: This study underscores the widespread inappropriate antimicrobial use for ILIs in a community in Vietnam, which contributes to an avoidable economic and health burden. The results of this study suggest that implementing diagnostic tools may support antimicrobial stewardship efforts.BMJ Open, 15(8), art. no. e094949; 2025journal articl
Revealing viral hepatitis epidemiology in the Democratic Republic of Congo: insights from yellow fever surveillance reanalysis
Get PDFBackground: Yellow fever surveillance systems are designed to identify cases of acute febrile jaundice, a clinical syndrome used to monitor the emergence of yellow fever outbreaks. However, this syndrome has diverse etiologies, particularly viral hepatitis. This study investigates the seroepidemiology of viral hepatitis A (HAV), B (HBV), C (HCV), and E (HEV) among cases initially suspected to be yellow fever, aiming to elucidate the epidemiology of viral hepatitis in the Democratic Republic of Congo (DRC) and provide insights for improving public health interventions. Methods: A retrospective cross-sectional study was conducted using serum samples collected between 2017 and 2018 through national yellow fever surveillance in the DRC. Samples from individuals testing negative for yellow fever were tested for IgM antibodies against HAV, HBc, HCV, and HEV and HBs antigen using validated ELISA kits. Acute HBV infection was defined by both HBc IgM and HBs antigen positivity. Multivariable logistic regression was used to assess the association of demographic, geographic, and environmental factors with each hepatitis type. Results: Among 1239 participants (58.8% male; median age: 16 years), seroprevalence was 16.1, 11.2, 5.0, and 3.1% for HAV, HBV, HCV and HEV, respectively. HAV prevalence was highest in the youngest age group and rural residents. In contrast, the youngest group was most protected from HBV. HCV prevalence was highest in the oldest age groups. HEV exhibited higher prevalence during the dry season and in a humid subtropical climate. Several provinces were identified as hotspots of HAV, HCV and HEV. Conclusions: Viral hepatitis is a major cause of acute febrile jaundice in the DRC with notable geographic and seasonal trends. National yellow fever surveillance is a valuable resource for understanding hepatitis epidemiology, though careful interpretation is necessary. Tailored interventions are required for mitigating the burden of viral hepatitis in each province.Tropical Medicine and Health, 53(1), art. no. 17; 2025journal articl
