Impact of biological clogging and pretreatments on the operation of soil aquifer treatments for wastewater reclamation

Globally, sustainable water management is required to minimize water security, and soil aquifer treatments (SATs) are widely applied in wastewater reclamation. Clogging problems limit the sustainable operation of SATs (i.e., the decrease of infiltration rate), and Physical clogging has been widely studied. However, the effect of biological clogging on the operation of SATs is still unclear. Thus, this study focuses on the effects of biological clogging in an SAT system and demonstrates that the clogging process in an SAT column. In this study, the infiltration rate in the A2O ​+ ​NaN3 water column decreased slightly, to 6–7 ​cm/h with an average rate of 0.01 ​cm/h per month after 240 ​d, compared with an average rate of 0.3 ​cm/h per month in the columns fed by filtered A2O water. The fastest reduction in infiltration rate, caused by biological clogging, occurred in the first 60 ​d and corresponded to the highest reduction in hydraulic conductivity of 0–2.5 ​cm layer. For alleviating clogging, this study illustrated that removing suspended solids from A2O water by filtration helped reduce approximately 25% of polysaccharides and heterotrophic bacteria. In comparison, pre-ozonation of A2O water helped to reduce approximately 70% of the biomass in the surface layer of the A2O ​+ ​O3 column. Thus, ozonation of wastewater effluent helps control biological clogging in SAT

土壌浸透処理の持続的運転のための条件探索

京都大学0048新制・課程博士博士(工学)甲第21097号工博第4461号新制||工||1693(附属図書館)京都大学大学院工学研究科都市環境工学専攻(主査)教授 伊藤 禎彦, 教授 田中 宏明, 准教授 西村 文武学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDGA

Viral and bacterial microorganisms in Vietnamese children with severe and non-severe pneumonia

International audienceTo investigate potential respiratory pathogens in children with community-acquired pneumonia (CAP) and risk factors for severe disease. This prospective study was conducted among 467 children at the Thai Binh Paediatric Hospital, Vietnam between 1 July 2020 and 30 June 2021. Clinical data and laboratory results were collected. Twenty-four respiratory microorganisms were tested from nasopharyngeal swabs using real-time PCR. Logistical regression was used to estimate a factor’s adjusted odd ratios of the severity of disease. Mean age of patients = 15.4 ± 13.3 months, 63.0% were male. Over 97% of patients had a positive PCR result. 87% of patients were positive for multiple (up to eight) microorganisms. Rhinovirus (46%), respiratory syncytial virus (RSV) (24%), enterovirus (17%), and parainfluenza viruses-3 (13%) were the most frequent viruses. H. influenzae (61%), S. pneumoniae (45%) and M. catarrhalis (30%) were the most common bacteria. 128 (27%) cases were classified as severe pneumonia. Presence of smokers at home (aOR 2.11, 95% CI 1.27–3.52, P value = 0.004), CRP level ≥ 50 mg/dL (aOR 6.11, 95% CI 3.86–9.68, P value < 0.0001), RSV (aOR 1.78, 95% CI 1.07–2.96, P value = 0.03) and H. influenzae (aOR 1.66, 95% CI 1.03–2.67, P value = 0.04) PCR detection associated with a higher risk of severe pneumonia; ,. Causative agents of pneumonia in children are complex. Children positive with RSV and H. influenzae need to be closely monitored to prevent severe pneumonia

Sterols from Vietnamese marine sponge Tethya aurantium

Chemical investigation on Vietnamese marine sponge Tethya aurantium resulted in the isolation of five sterols, including 5R,6R-epoxy-24R*-ethylcholesta-8-en-3β,7α-diol (1), 24-methylenecholesta-5-en-3β-ol (2), 24-norcholesta-5,22E-dien-3β-ol (3), 5α,8α-epidioxy-24R*-ethylcholesta-6-en-3β-ol (4), and 5α,8α-epidioxy-24S-methylcholesta-6,22E-dien-3β-ol (5). Their chemical structures were successfully determined using NMR and ESI-MS analysis as well as in comparison with the reported literatures. Stereochemistry of C-24 in the side chain of isolated sterols was also discussed. This is the first study on chemical constituents from the sponge T. aurantium. Keywords. Steroid, Tethya aurantium, Vietnamese sponge

Outbreak of central nervous system infections among children in Thai Binh, Viet Nam

International audienceFrom July to October 2020, 99 cases of central nervous system (CNS) infections were identified in Thai Binh Pediatric Hospital, Viet Nam, representing a five-fold increase compared to the baseline incidence during the previous five years. Clinical data were retrospectively collected. Cerebrospinal fluid specimens (CSF) were secondarily tested for pathogens using viral culture and PCR assays. Patient median age was 5 years (0-12 years); 58.6% were male. Of these children, 83.8% had CSF white blood culture (WBC) counts of ≥ 10 cells/µL, including 58 of 99 (58.6%) with a WBC count ≥ 100 cells/µL. Overall, 72 (72.7%) patients had confirmed infections with a pathogen identified in the CSF, the majority of which (66) were enterovirus. Sequencing results suggested that the rise of incidence observed in 2020 was due to Echovirus 4 (n = 45), Echovirus 30 (n = 8), and Echovirus 6 (n = 1) circulation. A confirmed CNS infection was significantly associated with older age (≥5 years, OR = 3.64, p = 0.03) and with an increased WBC count in the CSF (OR = 6.38, p-value = 0.01 for WBCs from 10 to <100 and OR = 7.90, p-value = 0.002 for WBCs ≥100). Ninety-seven (97) of 99 (98.0%) children received empiric antimicrobial treatment, and 35 (35.3%) were treated with multiple antibiotics. Eighty-four (84) patients (84.9%) were discharged home, and 11 (11.1%) were transferred to the National Hospital because their condition had worsened. No deaths were recorded. Point-of-care tests, including real-time PCR assays to identify common pathogens, should be implemented for more accurate diagnosis and more appropriate antibiotic use

Aetiology of Acute Undifferentiated Fever Among Children Under the Age of Five in Vietnam: A Prospective Study

International audienceAbstract Background To investigate the aetiology of acute undifferentiated fever (AUF) among children under the age of five in Vietnam. Methods This prospective study was conducted in the Thai Binh paediatric hospital, between July 2020 and July 2021 among children with AUF at admission. Real-time PCR testing 18 microbial pathogens were done on blood samples. Results 286 children were included, with median age of 16 months. 64.7% were male. 53.9% were positive for at least one pathogen by PCR. Enterovirus, human herpesvirus 6, adenovirus, and varicella zoster virus PCR were positive for 31.1, 12.6, 1.4, and 1.0% patients, respectively. Other pathogens tested negative by PCR. During the hospital stay, based on clinical criteria 47.2% children secondarily presented with signs of respiratory tract infections, 18.9% had hand, foot and mouth disease, 4.6% had chickenpox. 4.2% presented signs of central nervous system infections, 1.0% had dengue (antigenic test) and 1.0% had signs of gastrointestinal infection. Finally, 23.1% patients presented a fever with or without a rash and no other symptoms and ultimately received a diagnosis of AUF. Conclusion Real-time PCR of blood is useful for detecting pathogens and diagnosing infectious causes of AUF. Further prospective studies with blood and urine culture testing and PCR investigation of not only blood but also cerebrospinal fluid, throat, and skin samples according to symptoms would be of interest to confirm the predominance of viral infections in children with AUF and to guide therapeutic options