Stomoxys calcitrans : évaluation du rôle dans la transmission de Besnoitia besnoiti et nouveaux moyens de contrôle

La mouche charbonneuse, Stomoxys calcitrans, est une mouche hématophage commune et cosmopolite. Elle est le vecteur de nombreux agents pathogènes dont Besnoitia besnoiti, une coccidie parasite des bovins à l’origine de la formation de kystes cutanés. La compétence vectorielle de S. calcitrans pour B. besnoiti reste cependant mal connue. Dans ce travail, la persistance des formes bradyzoites et tachyzoites de B. besnoiti a été évaluée sur les pièces buccales et dans le tractus digestif des mouches. Dans ces conditions expérimentales, B. besnoiti persiste deux jours au maximum chez les stomoxes. La destruction rapide du parasite chez ce vecteur suggère que la transmission vectorielle mécanique ne peut avoir lieu que très peu de temps après un repas contaminant sur un hôte bovin infecté. De plus, nous avons étudié la capacité des stomoxes à transmettre les formes bradyzoites ou tachyzoites à des lapins, utilisés ici comme animaux modèles de besnoitiose. Des repas interrompus de stomoxes ont été réalisés sur des bovins en phase chronique de besnoitiose (source de formes bradyzoites dans leur peau) ou bien sur du sang contaminé avec des tachyzoites de culture. Le repas a ensuite été complété sur des lapins. Les résultats de cette étude ont montré que 300 stomoxes sont suffisants pour transmettre des bradyzoites virulents d’un bovin à un lapin qui a montré des signes de besnoitiose aigue et une séroconversion. Dans la troisième partie de ce travail, des méthodes alternatives aux insecticides ont été testées afin de proposer des stratégies de contrôle efficaces et pérennes contre ces vecteurs. L’attractivité pour les stomoxes de sept types d’écrans bleus, présentant entre eux de légères variations de réflectance autour de 460 nm, a été étudiée, de même que les facteurs influençant l’efficacité des pièges (hauteur par rapport au sol, orientation est ou ouest de l’écran, proximité de différents hôtes ou d’un tas de fumier). Les résultats ont montré une très grande attractivité, de très hauts niveaux de capture et une grande sélectivité de tous les écrans testés. Un total de 164692 stomoxes a été capturé au cours de l’étude (soit 24 jours de piégeage avec 4 écrans par jour et 8 heures par jour). La moitié inférieure des écrans a capturé la majorité des stomoxes (70%), de même, le nombre de stomoxes capturés par la partie de l’écran orientée à l’Est est plus important que sur la face orientée à l’Ouest. Ces éléments soulignent l’intérêt de cetype de dispositifs dans la lutte contre les stomoxe

Investigation of antioxidant and antimicrobial activity of zingiber officinale roscoe oleosin on airborne pathogenic microorganisms / Mohd Faez Sharif... [et al.]

Zingiber Officinale Roscoe or ginger has been found to have characteristics that are beneficial to human beings for different purposes. In this study, oleoresins from both young and mature gingers were studied to evaluate their antioxidant and antimicrobial activity on common airborne pathogenic microorganisms. The total phenolic and antioxidant contents were tested using the Folin–Ciocalteu method and DPPH (2, 2-diphenyl-1- picrylhydrazyl) scavenging activity assay respectively. Meanwhile, antimicrobial activity was determined using the disc diffusion and minimum inhibitory concentration (MIC) against two pathogenic bacteria and fungi; namely S. aureus, P. aeruginosa, C. albicans, and A. niger. Young ginger oleoresin exhibits higher total phenolic contents (129.5869 ± 14.27 GAE) and antioxidant activity (99.06 % ± 1.41) than matured ginger oleoresin. In the antimicrobial study, the result showed that both young and matured oleoresins were able to inhibit the growth of common airborne pathogenic bacteria. However, common airborne pathogenic fungi were resistant to both oleoresin of ginger extract. The oleoresin was able to suppress the growth of S. aureus at the low concentration of 1 mg/ml rather than P. aeruginosa at 10 mg/ml. Young ginger possess higher antioxidant and antibacterial activity than matured ginger

Collapsibility of PMMA based material in direct investment casting

Over recent years, the rapid growth of Additive manufacturing (AM) has benefits the Direct Investment Casting (DIC) process for intricate design in which significantly reduces the cost when associated with low volume production. Nevertheless, ceramic shells cracking has been recognized as critical problem when involved direct casting in which leads to incomplete collapsibility. Therefore, this study presents a numerical and experimental on poly(methyl) methacrylate (PMMA) pattern collapsibility for investment casting process and the stress analysis study on the ceramic shells. Study revealed that there were significant average of 5.8 % reduction of stress between square and polygon patterns. This study was conducted to examine the collapsibility of AM materials in the IC process

Collapsibility of PMMA Based Material in Direct Investment Casting

Over recent years, the rapid growth of Additive manufacturing (AM) has benefits the Direct Investment Casting (DIC) process for intricate design in which significantly reduces the cost when associated with low volume production. Nevertheless, ceramic shells cracking has been recognized as critical problem when involved direct casting in which leads to incomplete collapsibility. Therefore, this study presents a numerical and experimental on poly(methyl) methacrylate (PMMA) pattern collapsibility for investment casting process and the stress analysis study on the ceramic shells. Study revealed that there were significant average of 5.8 % reduction of stress between square and polygon patterns. This study was conducted to examine the collapsibility of AM materials in the IC process

Collapsibility of PMMA Based Material in Direct Investment Casting

Over recent years, the rapid growth of Additive manufacturing (AM) has benefits the Direct Investment Casting (DIC) process for intricate design in which significantly reduces the cost when associated with low volume production. Nevertheless, ceramic shells cracking has been recognized as critical problem when involved direct casting in which leads to incomplete collapsibility. Therefore, this study presents a numerical and experimental on poly(methyl) methacrylate (PMMA) pattern collapsibility for investment casting process and the stress analysis study on the ceramic shells. Study revealed that there were significant average of 5.8 % reduction of stress between square and polygon patterns. This study was conducted to examine the collapsibility of AM materials in the IC process

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Stomoxys calcitrans : assessment of the role in the transmission of Besnoitia besnoiti and new methods of control

La mouche charbonneuse, Stomoxys calcitrans, est une mouche hématophage commune et cosmopolite. Elle est le vecteur de nombreux agents pathogènes dont Besnoitia besnoiti, une coccidie parasite des bovins à l’origine de la formation de kystes cutanés. La compétence vectorielle de S. calcitrans pour B. besnoiti reste cependant mal connue. Dans ce travail, la persistance des formes bradyzoites et tachyzoites de B. besnoiti a été évaluée sur les pièces buccales et dans le tractus digestif des mouches. Dans ces conditions expérimentales, B. besnoiti persiste deux jours au maximum chez les stomoxes. La destruction rapide du parasite chez ce vecteur suggère que la transmission vectorielle mécanique ne peut avoir lieu que très peu de temps après un repas contaminant sur un hôte bovin infecté. De plus, nous avons étudié la capacité des stomoxes à transmettre les formes bradyzoites ou tachyzoites à des lapins, utilisés ici comme animaux modèles de besnoitiose. Des repas interrompus de stomoxes ont été réalisés sur des bovins en phase chronique de besnoitiose (source de formes bradyzoites dans leur peau) ou bien sur du sang contaminé avec des tachyzoites de culture. Le repas a ensuite été complété sur des lapins. Les résultats de cette étude ont montré que 300 stomoxes sont suffisants pour transmettre des bradyzoites virulents d’un bovin à un lapin qui a montré des signes de besnoitiose aigue et une séroconversion. Dans la troisième partie de ce travail, des méthodes alternatives aux insecticides ont été testées afin de proposer des stratégies de contrôle efficaces et pérennes contre ces vecteurs. L’attractivité pour les stomoxes de sept types d’écrans bleus, présentant entre eux de légères variations de réflectance autour de 460 nm, a été étudiée, de même que les facteurs influençant l’efficacité des pièges (hauteur par rapport au sol, orientation est ou ouest de l’écran, proximité de différents hôtes ou d’un tas de fumier). Les résultats ont montré une très grande attractivité, de très hauts niveaux de capture et une grande sélectivité de tous les écrans testés. Un total de 164692 stomoxes a été capturé au cours de l’étude (soit 24 jours de piégeage avec 4 écrans par jour et 8 heures par jour). La moitié inférieure des écrans a capturé la majorité des stomoxes (70%), de même, le nombre de stomoxes capturés par la partie de l’écran orientée à l’Est est plus important que sur la face orientée à l’Ouest. Ces éléments soulignent l’intérêt de cetype de dispositifs dans la lutte contre les stomoxes.The Stable fly, Stomoxys calcitrans, is a common and worldwide-distributed blood-feeding fly. It is the vector of numerous pathogens including Besnoitia besnoiti, a cyst-forming coccidian parasite of cattle. Vector competency of S. calcitrans for B. besnoiti remains poorly understood. We investigated here the persistence of bradyzoites and tachyzoites forms of B. besnoiti on mouthparts and in digestive tract of S. calcitrans. In experimental conditions, B. besnoiti proved to persist until two days in stable flies. The fast destruction of parasite within this vector suggests that mechanical transmission could occur a short time only after a contaminated blood meal. Moreover, we investigated the competence of stable flies to transmit immediately B besnoiti bradyzoites and tachyzoites to susceptible rabbits after an interrupted blood meal on chronically infected cows (source of bradyzoites) or on a tachyzoite-contaminated blood meal. The results show that 300 S. calcitrans only were able to transmit virulent bradyzoites to rabbits which suffered from clinical signs of acute besnoitiosis and seroconverted. In the third part of this study, we examined sustainable methods as alternative to insecticides but efficient to control this pest. Seven different types of blue screens, with slight differences in their reflectance around 460 nm, were tested in order to evaluate their attractiveness for stable flies and to determine the factors associated with the efficiency of trapping (height of screens, east versus west side of blue screen, proximity of different hosts and manure). The results showed high attractiveness, high number of captures and very high selectivity of all tested screens, with a total number of 164692 stable flies during the study (24 days of capture, 4 blue screens per day, 8 hours per day). The results showed that the lower part of the blue screens caught the majority of stable flies, whereas the east orientation was the most attractive which caught up to 60 % of the total number captured of stable flies. Taking together, these results are highlighting the interest of these new devices in the future control of stable flies

Discrimination and stigma – an interview study with nurses concerning persons living with HIV/AIDS in Nairobi

Background: There are approximately 1.5 million people living with HIV in Kenya. The prevalence is at a lower level than at the peak of the epidemic because of free antiretroviral treatment, education and new methods to HIV testing. The nurses’ work situation is difficult trying to reach persons living with HIV in a society where stigma is common and therefore we were curious to learn more about nurses’ personal experiences, to get a wider understanding of the situation.  Aim: The aim was to describe nurses’ perspective of the complexity of caring for persons with HIV/AIDS in Nairobi, Kenya. Method: The chosen design was a descriptive qualitative study consisting of semi-structured interviews with eight nurses in Nairobi, Kenya.The material was analyzed using qualitative content analysis. Results: Two main categories were identified in this study: Nurses’ strategies and approach to initiate care and Challenges in caring for people with HIV/AIDS. Four sub-categories were then formed out of the main categories: Approaching and building relationships with people that live with HIV/AIDS, strategies for reaching out to people that live with HIV/AIDS, structural barriers among people living with HIV/AIDS and practical obstacles within the healthcare system. Discussion: The discussion addresses difficulties among nurses when it comes to persuading persons living with HIV/AIDS to receive treatment. The nursing role consists of caring for the patient, counseling and giving hope. Nurses are being affected emotionally when approaching persons living with HIV/AIDS since factors like stigma and fear of abandonment stand in the way for reaching out and giving treatment. Lack of resources in healthcare is another factor that causes frustration among nurses.