Semi-automated morphometric analysis of human embryos can reveal correlations between total embryo volume and clinical pregnancy

what is known already: Morphometric analysis of a large group of embryos has revealed the potential to optimize algorithms for image-analysis systems for the grading of embryos and predicting pregnancy outcomes. study design, size, duration: Oocytes and embryos were obtained from 458 patients who underwent single embryo transfer on Day 3 after IVF/ICSI, between September 2006 and December 2010 at the Leuven University Fertility Center, Belgium. In total, the data set contained 2796 embryos including 458 embryos that were transferred on Day 3. Ongoing pregnancy was defined as the presence of at least one intrauterine gestational sac at 20 weeks. participants/materials, setting, methods: Patients included in this study were younger than 36 years, entering their first (n ¼ 375) or second (n ¼ 83) IVF/ICSI cycle and were only included once. Patients were excluded if the cycle included biopsy for PGD or if donor sperm/donor oocytes were used. Based on the 26 sequential images of the same embryo taken at one time point in different planes, the software calculates the total cytoplasmic volume for each time point, from which any reduction or change in the volume with time can be assessed (which helps interpret the degree of fragmentation) and the size of blastomeres. The diameter of the smallest and largest blastomere and the total volume of each embryo were extracted from the computer-assisted scoring system database and the coefficient of diversity was calculated for Days 1, 2 and 3. A logistic regression analysis was performed to determine the range of embryo volume associated with an increased chance of pregnancy. main results and the role of chance: On Day 3, blastomeres of 8-cell stage embryos were less divergent in size than those of 6-, 7-, 9-cell stage embryos. Although, the coefficients of diversity (ratio of the largest:smallest blastomeres) of implanted embryos tended to be lower than for non-implanted embryos, the difference was only significant for 6-cell stage embryos (P ¼ 0.02). After logistic regression, an association between total embryo volume and pregnancy was observed which had a quadratic nature: both lower and higher volumes were associated with a lower probability of successful pregnancy. A significant association was identified between total embryo volume and pregnancy rate on both Days 2 (P ¼ 0.003) and 3 (P ¼ 0.0003). Diagnostic measures (sensitivity, specificity, positive predictive value, accuracy and c-statistics) of the defined volume range were relatively poor. However, results showed a good negative predictive value [76.86% (95% confidence interval 71.03-82.02) on Day 3]. limitations, reasons for caution: A general disadvantage of studies evaluating the impact of a characteristic on the implantation potential of an embryo is the fact that the best embryo is chosen for transfer. No comparisons can therefore be made with the other embryos. Moreover, the decision process is currently based on a non-automated, standard scoring system, which means that a 'bias' in the selection process is always present. wider implications of the findings: Our results are an important step towards the development of an automated computer-assisted scoring system for the morphological characteristics of human embryos to improve embryo selection for optimizing implantation potential. Total embryo volume appears to be one of the objective characteristics that should be included. study funding/competing interest(s): None. trial registration number: Not applicable

Global Distribution of O Serotypes and Antibiotic Resistance in Extraintestinal Pathogenic Escherichia coli Collected From the Blood of Patients With Bacteremia Across Multiple Surveillance Studies

Background: Extraintestinal pathogenic Escherichia coli (ExPEC) is the leading cause of bacteremia worldwide, with older populations having increased risk of invasive bacterial disease. Increasing resistance to first-line antibiotics and emergence of multidrug-resistant (MDR) strains represent major treatment challenges. ExPEC O serotypes are key targets for potential multivalent conjugate vaccine development. Therefore, we evaluated the O serotype distribution and antibiotic resistance profiles of ExPEC strains causing bloodstream infections across 4 regions. Methods: Blood culture isolates from patients aged ≥60 years collected during 5 retrospective E. coli surveillance studies in Europe, North America, Asia-Pacific, and South America (2011-2017) were analyzed. Isolates were O serotyped by agglutination; O genotyping was performed for nontypeable isolates. Antimicrobial susceptibility testing was also conducted. Results: Among 3217 ExPEC blood culture isolates, the most ubiquitous O serotype was O25 (n = 737 [22.9%]), followed by O2, O6, O1, O75, O15, O8, O16, O4, O18, O77 group, O153, O9, O101/O162, O86, and O13 (prevalence of ≥1%). The prevalence of these O serotypes was generally consistent across regions, apart from South America; together, these 16 O serotypes represented 77.6% of all ExPEC bacteremia isolates analyzed. The overall MDR frequency was 10.7%, with limited variation between regions. Within the MDR subset (n = 345), O25 showed a dominant prevalence of 63.2% (n = 218). Conclusions: Predominant O serotypes among ExPEC bacteremia isolates are widespread across different regions. O25 was the most prevalent O serotype overall and particularly dominant among MDR isolates. These findings may inform the design of multivalent conjugate vaccines that can target the predominant O serotypes associated with invasive ExPEC disease in older adults

Protocol for a phase 3 trial to evaluate the effectiveness and safety of a heterologous, two-dose vaccine for Ebola virus disease in the Democratic Republic of the Congo.

INTRODUCTION: Ebola virus disease (EVD) continues to be a significant public health problem in sub-Saharan Africa, especially in the Democratic Republic of the Congo (DRC). Large-scale vaccination during outbreaks may reduce virus transmission. We established a large population-based clinical trial of a heterologous, two-dose prophylactic vaccine during an outbreak in eastern DRC to determine vaccine effectiveness. METHODS AND ANALYSIS: This open-label, non-randomised, population-based trial enrolled eligible adults and children aged 1 year and above. Participants were offered the two-dose candidate EVD vaccine regimen VAC52150 (Ad26.ZEBOV, Modified Vaccinia Ankara (MVA)-BN-Filo), with the doses being given 56 days apart. After vaccination, serious adverse events (SAEs) were passively recorded until 1 month post dose 2. 1000 safety subset participants were telephoned at 1 month post dose 2 to collect SAEs. 500 pregnancy subset participants were contacted to collect SAEs at D7 and D21 post dose 1 and at D7, 1 month, 3 months and 6 months post dose 2, unless delivery was before these time points. The first 100 infants born to these women were given a clinical examination 3 months post delivery. Due to COVID-19 and temporary suspension of dose 2 vaccinations, at least 50 paediatric and 50 adult participants were enrolled into an immunogenicity subset to examine immune responses following a delayed second dose. Samples collected predose 2 and at 21 days post dose 2 will be tested using the Ebola viruses glycoprotein Filovirus Animal Non-Clinical Group ELISA. For qualitative research, in-depth interviews and focus group discussions were being conducted with participants or parents/care providers of paediatric participants. ETHICS AND DISSEMINATION: Approved by Comité National d'Ethique et de la Santé du Ministère de la santé de RDC, Comité d'Ethique de l'Ecole de Santé Publique de l'Université de Kinshasa, the LSHTM Ethics Committee and the MSF Ethics Review Board. Findings will be presented to stakeholders and conferences. Study data will be made available for open access. TRIAL REGISTRATION NUMBER: NCT04152486