Experimental study of a Capillary Pumped Loop assisted with a mechanical pump placed at the evaporator inlet

International audienceThe heat transfer performances of capillary-driven evaporators are still improving while their pumping capacity remains drastically limited by the porous wick structure. The pump assistance allows this capillary limit to be overcome and more largely, gives the opportunity of an important enhancement of capillary two-phase loops operating range. An experimental device made of a Capillary Pumped Loop coupled with a controlled centrifugal pump located at the inlet of the evaporator was proposed. We have shown that the hybrid system acts as it would in a simple capillary-driven regime with an operating loop pressure drop far beyond the capillary limit (more than 60 kPa i.e. more than 6 times the evaporator capillary limit with methanol) while preserving the evaporator thermal efficiency due to vaporisation. Moreover, we have found that the pump assistance significantly increases the system robustness during large amplitude heat load step and startup by influencing the liquid subcooling and flow rate at the evaporator inlet

Enterovirus meningitis in Mayotte French Comoros Island, March-June 2019

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Necker-Pasteur Clinical Metagenomics: Part 2. Contribution to Pathogen Discovery

International audienceClinical metagenomics fuels pathogen discovery but a comprehensive research environment is required to address critical questions such as imputability, physiopathology of novel identified infectious agents, and development of new diagnostic tools. The Institut Pasteur, in close collaboration with specialized hospital clinical services and laboratories including (neuro)pathologists, along with other academic labs, seeks to address these topics. We review some of the major identifications done in the course of our historical partnership with hospitals, by highlighting the place and the contribution of research works following identification of new or unexpected microorganisms. The list includes novel human pathogens with a zoonotic potential (Astrovirus VA1, Umbre orthobunyavirus, European Bat Lyssavirus 1) and known pathogens with unexpected or atypical presentation (Rubella virus, Rabies, Dengue)

Renal arcuate vein thrombosis–induced acute kidney injury: a rare multiple-Hit–mediated disease

International audienceBackgroundRenal arcuate vein thrombosis (RAVT) is a rare and recently recognized cause of acute kidney injury (AKI) in young adults. However, the precise incidence and underlying pathophysiologic mechanisms leading to AKI in these patients remain elusive.MethodsThis study included all patients who underwent a kidney biopsy over a 40-month period sent to the pathology department of Necker-Enfants Malades Hospital, with evidence of RAVT. We performed coagulation tests, genetic testing for thrombophilia, complete urine toxicologic screening and kidney metagenomic sequencing to identify an underlying cause of thrombosis.ResultsWe report five pediatric cases of RAVT discovered on kidney biopsy performed in the setting of unexplained AKI. Investigations did not reveal an underlying cause of thrombosis but only a significant nonsteroidal anti-inflammatory drugs (NSAIDs) use was reported in 4/5 patients, supporting a potential link between NSAIDs use and RAVT. By performing metagenomic sequencing on kidney biopsy samples, we detected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in the kidney of one patient. These results suggest that systemic SARS-CoV-2 infection may also be a key contributing factor of renal thrombosis, particularly by inducing potential endothelial disruption.ConclusionsIn conclusion, RAVT-induced AKI appears to be a multiple hit–mediated disease in which NSAIDs consumption and viral infection such as SARS-CoV-2 may be crucial contributing factors. These findings may have significant public health implications given the prevalence of NSAIDs use in the general population. Increased awareness and additional study of future cases may lead to a better understanding of this rare cause of AKI in children and young adults

A prospective study evaluating congenital CMV infection in Mayotte and La Reunion Islands (France)

International audienceOBJECTIVES Congenital cytomegalovirus infection (cCMV) affects around 3400 newborns each year in France, of whom 700 will develop sequelae, primarily sensorineural hearing loss. Our objectives were (1) to evaluate incidence of cCMV in two French departments located in the Indian Ocean: Mayotte and La Reunion, and (2) evaluate interest and feasibility/acceptability of universal screening of cCMV at birth. MATERIAL AND METHODS We implemented a universal neonatal CMV screening in Mayotte during 7 months in 2019 and in La Reunion during one month in March 2020. Saliva swabs were collected in the first three days of life, and tested for CMV DNA by PCR. A short survey allowed evaluating whether this screening is acceptable and feasible. RESULTS: A total of 1026 newborns were screened: 854 in Mayotte and 172 in La Reunion. In Mayotte, cCMV incidence was evaluated at a minimum of 1.6 % (95 % CI 0.94-2.81). In La Reunion, cCMV incidence was evaluated at a minimum of 1.2 % (95 % CI -0.20-4.57). All cCMV infants were born to mothers with non-primary CMV infection. Only 0.7 % parents refused the screening. CONCLUSIONS cCMV incidence in Mayotte and La Reunion is higher than in metropolitan France. This diagnosis should not be overlooked, especially since the time dedicated to screening and its feeling by the parents seem to be acceptable

Severe relapse of SARS‐CoV‐2 infection in a kidney transplant recipient with negative nasopharyngeal SARS‐CoV‐2 RT‐PCR after rituximab

International audienceImmunocompromised patients may experience prolonged viral shedding after their initial SARS-CoV-2 infection, however, symptomatic relapses after remission currently remain rare. We herein describe a severe COVID-19 relapse case of a kidney transplant recipient (KTR) following rituximab therapy, 3 months after a moderate COVID-19 infection, despite viral clearance after recovery of the first episode. During the clinical relapse, the diagnosis was established on a broncho-alveolar lavage specimen (BAL) by RT-PCR. The infectivity of the BAL sample was confirmed on a cell culture assay. Whole genome sequencing confirmed the presence of an identical stain (Clade 20A). However, it had an acquired G142D mutation and a larger deletion of 3-amino-acids at position 143-145. These mutations located within the N-terminal domain are suggested to play a role in viral entry. The diagnosis of a COVID-19 relapse should be considered in the setting of unexplained persistent fever and/or respiratory symptoms in KTRs (especially for those after rituximab therapy), even in patients with previous negative naso-pharyngeal SARS-CoV-2 PCR

Circovirus hepatitis infection in heart-lung transplant patient, France

International audienceIn March 2022, a 61-year-old woman in France who had received a heart-lung transplant sought treatment with chronic hepatitis mainly characterized by increased liver enzymes. After ruling out common etiologies, we used metagenomic next-generation sequencing to analyze a liver biopsy sample and identified an unknown species of circovirus, tentatively named human circovirus 1 (HCirV-1). We found no other viral or bacterial sequences. HCirV-1 shared 70% amino acid identity with the closest known viral sequences. The viral genome was undetectable in blood samples from 2017–2019, then became detectable at low levels in September 2020 and peaked at very high titers (10^10 genome copies/mL) in January 2022. In March 2022, we found >10^8 genome copies/g or mL in the liver and blood, concomitant with hepatic cytolysis. We detected HCirV-1 transcripts in 2% of hepatocytes, demonstrating viral replication and supporting the role of HCirV-1 in liver damage

Clinical value of serial quantitative analysis of cytomegalovirus DNA in blood and saliva over the first 24 months of life congenital infection: the French Cymepedia Cohort

International audienceObjective: To evaluate cytomegalovirus (CMV) viral load dynamics in blood and saliva during the first two years of life in symptomatic and asymptomatic infected infants and to identify whether these kinetics could have practical clinical implications.Study design: The Cymepedia cohort prospectively included 256 congenitally infected neonates followed for two years. Whole blood and saliva were collected at inclusion, months 4 and 12, and saliva at months 18 and 24. Real-time CMV PCR was performed, results expressed as log10 IU/mL in blood and in copies/mL in saliva.Results: Viral load in saliva progressively decreased from 7.5 log10 at birth to 3.3 log10 at month 24. CMV PCR in saliva was positive in 100% and 96% of infants at 6 and 12 months, respectively. In the first month of life, neonatal saliva viral load <5 log10 was related to a late CMV transplacental passage. Detection in blood was positive in 92% (147/159) of neonates in the first month of life. No viral load threshold values in blood or saliva could be associated with a high risk of sequelae. Neonatal blood viral load <3 log10 IU/ml had a 100% negative predictive value (NPV) for long-term sequelae.Conclusions: Viral loads in blood and saliva by CMV PCR testing in congenital infection fall over the first 24 months. In this study of infants affected mainly after primary maternal infection during pregnancy, all salivary samples were positive in the first 6 months of life and sequelae were not seen in infants with neonatal blood viral load <3 log10 IU/mL