A Monte Carlo multimodal inversion of surface waves

The analysis of surface wave propagation is often used to estimate the S-wave velocity profile at a site. In this paper, we propose a stochastic approach for the inversion of surface waves, which allows apparent dispersion curves to be inverted. The inversion method is based on the integrated use of two-misfit functions. A misfit function based on the determinant of the Haskell–Thomson matrix and a classical Euclidean distance between the dispersion curves. The former allows all the modes of the dispersion curve to be taken into account with a very limited computational cost because it avoids the explicit calculation of the dispersion curve for each tentative model. It is used in a Monte Carlo inversion with a large population of profiles. In a subsequent step, the selection of representative models is obtained by applying a Fisher test based on the Euclidean distance between the experimental and the synthetic dispersion curves to the best models of the Monte Carlo inversion. This procedure allows the set of the selected models to be identified on the basis of the data quality. It also mitigates the influence of local minima that can affect the Monte Carlo results. The effectiveness of the procedure is shown for synthetic and real experimental data sets, where the advantages of the two-stage procedure are highlighted. In particular, the determinant misfit allows the computation of large populations in stochastic algorithms with a limited computational cost

SARS-CoV-2 infection among hospitalised pregnant women and impact of different viral strains on COVID-19 severity in Italy: a national prospective population-based cohort study

OBJECTIVE: The primary aim of this article was to describe SARS-CoV-2 infection among pregnant women during the wild-type and Alpha-variant periods in Italy. The secondary aim was to compare the impact of the virus variants on the severity of maternal and perinatal outcomes. DESIGN: National population-based prospective cohort study. SETTING: A total of 315 Italian maternity hospitals. SAMPLE: A cohort of 3306 women with SARS-CoV-2 infection confirmed within 7 days of hospital admission. METHODS: Cases were prospectively reported by trained clinicians for each participating maternity unit. Data were described by univariate and multivariate analyses. MAIN OUTCOME MEASURES: COVID-19 pneumonia, ventilatory support, intensive care unit (ICU) admission, mode of delivery, preterm birth, stillbirth, and maternal and neonatal mortality. RESULTS: We found that 64.3% of the cohort was asymptomatic, 12.8% developed COVID-19 pneumonia and 3.3% required ventilatory support and/or ICU admission. Maternal age of 30-34 years (OR 1.43, 95% CI 1.09-1.87) and ≥35 years (OR 1.62, 95% CI 1.23-2.13), citizenship of countries with high migration pressure (OR 1.75, 95% CI 1.36-2.25), previous comorbidities (OR 1.49, 95% CI 1.13-1.98) and obesity (OR 1.72, 95% CI 1.29-2.27) were all associated with a higher occurrence of pneumonia. The preterm birth rate was 11.1%. In comparison with the pre-pandemic period, stillbirths and maternal and neonatal deaths remained stable. The need for ventilatory support and/or ICU admission among women with pneumonia increased during the Alpha-variant period compared with the wild-type period (OR 3.24, 95% CI 1.99-5.28). CONCLUSIONS: Our results are consistent with a low risk of severe COVID-19 disease among pregnant women and with rare adverse perinatal outcomes. During the Alpha-variant period there was a significant increase of severe COVID-19 illness. Further research is needed to describe the impact of different SARS-CoV-2 viral strains on maternal and perinatal outcomes

Comparative evaluation of the new xTAG GPP multiplex assay in the laboratory diagnosis of acute gastroenteritis. Clinical assessment and potential application from a multicentre Italian study.

Objective: Gastroenteritis caused by a single pathogen or multiple pathogens remains a major diagnostic challenge for the laboratory. The treatment of diarrhoea is based on microbiological results. Diagnosis is achieved using different laboratory techniques that have variable sensitivity and specificity. xTAG GPP is a new multiplex PCR assay that simultaneously detects 15 different pathogens responsible for diarrhoea. The results of the first multicentre study in Italy to evaluate the potential clinical application of the GPP assay in the laboratory diagnosis of diarrhoea are reported here. Methods: Faeces specimens (N = 664) from hospitalized patients were tested with the GPP assay using a Luminex 200 instrument. All specimens were run using comparator methods following a routine algorithm: culture for bacteria, enzyme immunoassay and PCR for viruses, and microscopy for parasites. Results: Of the samples tested with the GPP, 53.61% (356/664) gave positive results, as compared to 45.33% by routine testing. Of the positive specimens, 34.55% showed the presence of genomic DNA from multiple pathogens. The Luminex method showed an increase in the percentage of positivity of 8.28%. Conclusions: The GPP assay can be considered a helpful tool for the detection of gastrointestinal pathogens, with a hands-on time of 5 h; it provides accurate data for the clinical management of hospitalized patients and for epidemiological surveillance

A total blood volume or more transfused during pregnancy or after childbirth: Individual patient data from six international population-based observational studies.

BackgroundThis study aimed to compare incidence, management and outcomes of women transfused their blood volume or more within 24 hours during pregnancy or following childbirth.MethodsCombined analysis of individual patient data, prospectively collected in six international population-based studies (France, United Kingdom, Italy, Australia, the Netherlands and Denmark). Massive transfusion in major obstetric haemorrhage was defined as transfusion of eight or more units of red blood cells within 24 hours in a pregnant or postpartum woman. Causes, management and outcomes of women with massive transfusion were compared across countries using descriptive statistics.FindingsThe incidence of massive transfusion was approximately 21 women per 100,000 maternities for the United Kingdom, Australia and Italy; by contrast Denmark, the Netherlands and France had incidences of 82, 66 and 69 per 100,000 maternities, respectively. There was large variation in obstetric and haematological management across countries. Fibrinogen products were used in 86% of women in Australia, while the Netherlands and Italy reported lower use at 35-37% of women. Tranexamic acid was used in 75% of women in the Netherlands, but in less than half of women in the UK, Australia and Italy. In all countries, women received large quantities of colloid/crystalloid fluids during resuscitation (>3·5 litres). There was large variation in the use of compression sutures, embolisation and hysterectomy across countries. There was no difference in maternal mortality; however, variable proportions of women had cardiac arrests, renal failure and thrombotic events from 0-16%.InterpretationThere was considerable variation in the incidence of massive transfusion associated with major obstetric haemorrhage across six high-income countries. There were also large disparities in both transfusion and obstetric management between these countries. There is a requirement for detailed evaluation of evidence underlying current guidance. Furthermore, cross-country comparison may empower countries to reference their clinical care against that of other countries

Hookworm infection in infants: a case report and review of literature.

BACKGROUND: Hookworm infections (Necator americanus, Ancylostoma duodenale) are common in rural areas of tropical and subtropical countries. Human acquisition results from direct percutaneous invasion of infective larvae from contaminated soil. Overall, almost 472 million people in developing rural countries are infected. According to simulation models, hookworm disease has a global financial impact of over US$100 billion a year. Hookworm infection in newborn or infancy is rare, and most of the cases reported in literature are from endemic countries. Here, we describe the case of an infant with an Ancylostoma duodenale infection and review the literature currently available on this topic. CASE PRESENTATION: An Italian 2-month-old infant presented with vomit and weight loss. Her blood exams showed anemia and eosinophilia and stool analysis resulted positive for hookworms' eggs, identified as Ancylostoma duodenale with real time-PCR. Parasite research on parents' stools resulted negative, and since the mother travelled to Vietnam and Thailand during pregnancy, we assumed a transplacental transmission of the infection. The patient was treated successfully with oral Mebendazole and discharged in good conditions. DISCUSSION: Hookworm helminthiasis is a major cause of morbidity in children in the tropics and subtropics, but rare in developed countries. Despite most of the patients is usually asymptomatic, children are highly exposed to negative sequelae such as malnutrition, retarded growth and impaired cognitive development. In infants and newborns, the mechanism of infection remains unclear. Although infrequent, vertical transmission of larvae can occur through breastfeeding and transplacentally. Hookworm infection should be taken into account in children with abdominal symptoms and unexplained persistent eosinophilia. The treatment of infants infected by hookworm has potential benefit, but further studies are needed to define the best clinical management of these cases

Management of major obstetric hemorrhage prior to peripartum hysterectomy and outcomes across nine European countries

Introduction Peripartum hysterectomy is applied as a surgical intervention of last resort for major obstetric hemorrhage. It is performed in an emergency setting except for women with a strong suspicion of placenta accreta spectrum (PAS), where it may be anticipated before cesarean section. The aim of this study was to compare management strategies in the case of obstetric hemorrhage leading to hysterectomy, between nine European countries participating in the International Network of Obstetric Survey Systems (INOSS), and to describe pooled maternal and neonatal outcomes following peripartum hysterectomy.Material and methods We merged data from nine nationwide or multi-regional obstetric surveillance studies performed in Belgium, Denmark, Finland, France, Italy, the Netherlands, Slovakia, Sweden and the UK collected between 2004 and 2016. Hysterectomies performed from 22 gestational weeks up to 48 h postpartum due to obstetric hemorrhage were included. Stratifying women with and without PAS, procedures performed in the management of obstetric hemorrhage prior to hysterectomy between countries were counted and compared. Prevalence of maternal mortality, complications after hysterectomy and neonatal adverse events (stillbirth or neonatal mortality) were calculated.Results A total of 1302 women with peripartum hysterectomy were included. In women without PAS who had major obstetric hemorrhage leading to hysterectomy, uterotonics administration was lowest in Slovakia (48/73, 66%) and highest in Denmark (25/27, 93%), intrauterine balloon use was lowest in Slovakia (1/72, 1%) and highest in Denmark (11/27, 41%), and interventional radiology varied between 0/27 in Denmark and Slovakia to 11/59 (79%) in Belgium. In women with PAS, uterotonics administration was lowest in Finland (5/16, 31%) and highest in the UK (84/103, 82%), intrauterine balloon use varied between 0/14 in Belgium and Slovakia to 29/103 (28%) in the UK. Interventional radiology was lowest in Denmark (0/16) and highest in Finland (9/15, 60%). Maternal mortality occurred in 14/1226 (1%), the most common complications were hematologic (95/1202, 8%) and respiratory (81/1101, 7%). Adverse neonatal events were observed in 79/1259 (6%) births.Conclusions Management of obstetric hemorrhage in women who eventually underwent peripartum hysterectomy varied greatly between these nine European countries. This potentially life-saving procedure is associated with substantial adverse maternal and neonatal outcome.Research into fetal development and medicin