Respiratory infections acquired in hospital depend on close contact, which may be affected by hospital population density. Models of infectious disease transmission typically assume that contact rates are independent of density (frequency dependence) or proportional to it (linear density dependence), without justification. We evaluate these assumptions by measuring contact rates in hospitals under different population densities.
View Article and Find Full Text PDFEur J Clin Microbiol Infect Dis
December 2024
Purpose: Non-optimal vaginal microbiota lacking lactobacilli and comprising a wide array of anaerobic bacteria, typified by community state type (CST) IV, have been associated with adverse gynecological and pregnancy outcomes. Here, we investigate the stability of the vaginal microbiota sampled every 6 months over 18 months and how samples distantly collected combined with exposures could provide insight on future microbiota compositional changes.
Methods: Vaginal microbiota dynamics were analyzed in 241 female students aged 18-24 years and negative for Chlamydia trachomatis and Neisseria gonorrhoeae.
Pneumocystis pneumonia (PCP) is a life-threatening complication after allogeneic hematopoietic cell transplantation (allo-HCT). However, allo-HCT procedures have evolved toward older patients, unrelated donors, and reduced-intensity conditioning, possibly modifying the risks. Polymerase chain reaction (PCR), widely used nowadays, is more sensitive than microscopy diagnostic methods.
View Article and Find Full Text PDFThis 16-month-long multicentre retrospective study of 225 allogeneic haematopoietic stem cell transplantation (alloHSCT) recipients with COVID-19 examines risk factors for severity and mortality, describing the successive waves of infections (from March to June 2020 and from August 2020 to June 2021). We confirm the negative role of low respiratory tract disease and immunosuppressive treatment. We highlight significantly lower percentages of severe forms and COVID-19-related mortality during the second wave.
View Article and Find Full Text PDFCohort and nested case-control (NCC) designs are frequently used in pharmacoepidemiology to assess the associations of drug exposure that can vary over time with the risk of an adverse event. Although it is typically expected that estimates from NCC analyses are similar to those from the full cohort analysis, with moderate loss of precision, only few studies have actually compared their respective performance for estimating the effects of time-varying exposures (TVE). We used simulations to compare the properties of the resulting estimators of these designs for both time-invariant exposure and TVE.
View Article and Find Full Text PDFBackground: Statins represent candidates for drug repurposing in Parkinson's disease (PD). Few studies examined the role of reverse causation, statin subgroups, and dose-response relations based on time-varying exposures.
Objectives: We examined whether statin use is associated with PD incidence while attempting to overcome the limitations described previously, especially reverse causation.
Genital human papillomavirus (HPV) infections are caused by a broad diversity of genotypes. As available vaccines target a subgroup of these genotypes, monitoring transmission dynamics of nonvaccine genotypes is essential. After reviewing the epidemiological literature on study designs aiming to monitor those dynamics, we evaluated their abilities to detect HPV-prevalence changes following vaccine introduction.
View Article and Find Full Text PDFJ Hematol Oncol
November 2022
Since the emergence of the Omicron variant of SARS-CoV-2, though considered less virulent, hospitalization and death rates among immunocompromised patients remain high, especially for poor responders to vaccination. We conducted a retrospective multicentric study to evaluate pre-exposure prophylaxis with AZD7442 (tixagevimab/cilgavimab) for preventing COVID-19 in adult allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. Among the 161 patients of our cohort, 22 (14%) contracted COVID-19 after a median follow-up of 105 days, but no severe form was observed.
View Article and Find Full Text PDFObjectives: We aimed to investigate the 1-month humoral response to two or three doses of a messenger RNA coronavirus disease 2019 (COVID-19) vaccine as a primary vaccination regimen in specific populations compared with that in healthy adults.
Methods: Agence Nationale Recherche contre le Sida (ANRS)0001S-COV-POPART (NCT04824651) is a French nation-wide, multi-centre, prospective, observational cohort study assessing the immune response to COVID-19 vaccines routinely administered to 11 sub-groups of patients with chronic conditions and two control groups. Patients and controls who received at least two vaccine doses and whose results 1 month after the second dose were available were included.
Background: Available treatments for Parkinson's disease (PD) are only partially or transiently effective. Identifying existing molecules that may present a therapeutic or preventive benefit for PD (drug repositioning) is thus of utmost interest.
Objective: We aimed at detecting potentially protective associations between marketed drugs and PD through a large-scale automated screening strategy.
Human papillomaviruses are common sexually transmitted infections, caused by a large diversity of genotypes. In the context of vaccination against a subgroup of genotypes, better understanding the role of genotype interactions and human sexual behavior on genotype dynamics is essential. Herein, we present an individual-based model that integrates realistic heterosexual partnership behaviors and simulates interactions between vaccine and non-vaccine genotypes.
View Article and Find Full Text PDFWe report the results of the French Temporary Authorization of Use (ATU) compassionate program of letermovir for primary prophylaxis conducted in 21 transplant centers. Patients were CMV seropositive allogeneic hematopoietic cell transplantation recipients and at high risk for CMV infection. Primary prophylaxis was defined as initiation of letermovir between day 0 and day +28 post-transplant.
View Article and Find Full Text PDFIntroduction: Understanding how hospital staff members (HSMs), including healthcare workers, acquired severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the first wave can guide the control measures in the current second wave in Europe.
Methods: From March 5 to May 10, 2020, the Raymond-Poincaré Hospital held a weekday consultation for HSMs for PCR testing. HSMs were requested to complete a questionnaire on their potential exposure to SARS-CoV-2.
In order to identify cytomegalovirus (CMV)-seropositive patients who are at risk of developing CMV infection following first allogeneic hematopoietic cell transplantation (allo-HCT), we built up a scoring system based on patient/donor characteristics and transplantation modalities. To this end, 3690 consecutive patients were chronologically divided into a derivation cohort (2010-2012, n = 2180) and a validation cohort (2013-2014, n = 1490). Haploidentical donors were excluded.
View Article and Find Full Text PDFThe presence of IKZF1 gene mutations is associated with poor prognosis of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The goal of this retrospective study was to evaluate outcome of allogeneic hematopoietic cell transplantation (allo-HCT) in this population. Ninety-five patients transplanted in first (n = 75) or second (n = 20) complete remission (CR) from either HLA-matched sibling (n = 32), unrelated (n = 47) or haploidentical (n = 16) donor were included in the analysis.
View Article and Find Full Text PDFLetermovir potently inhibits the cytomegalovirus (CMV)-terminase complex. Letermovir primary prophylaxis given for the first 3 months after allogeneic hematopoietic cell transplantation (HCT) has been shown to reduce clinically significant CMV infection and is well tolerated. Until now, only case reports or small retrospective series have been published on the use of letermovir for a secondary prophylaxis (SP) of CMV infection or diseases after HCT.
View Article and Find Full Text PDFWe characterized the composition and structure of the vaginal microbiota in a cohort of 149 women with genital Chlamydia trachomatis infection at baseline who were followed quarterly for 9 months after antibiotic treatment. At time of diagnosis, the vaginal microbiota was dominated by Lactobacillus iners or a diverse array of bacterial vaginosis-associated bacteria including Gardnerella vaginalis. Interestingly, L.
View Article and Find Full Text PDFObjectives: New molecular techniques have allowed describing groups of bacterial communities in the vagina (community state types (CST)) that could play an important role in (CT) infection. Our aim was to describe the distribution of CST in a population of young women in France.
Methods: A cross-sectional study was carried out in June 2015 among anonymous young women attending a STI clinic in Bordeaux, France.
Background: Genital infection with Chlamydia trachomatis (Ct) is the most common bacterial sexually transmitted infection, especially among young women. Mostly asymptomatic, it can lead, if untreated, to pelvic inflammatory disease (PID), tubal factor infertility and ectopic pregnancy. Recent data suggest that Ct infections are not controlled in France and in Europe.
View Article and Find Full Text PDFGiven the long latency period of pancreatic cancer, exploring the influence of early and midlife exposures will further advance our understanding of the disease. We assessed associations between diet and pancreatic cancer incidence in the National Institutes of Health (NIH)-AARP (formerly American Association of Retired Persons) Diet and Health Study. In 1996, a total of 303,094 participants completed 2 food frequency questionnaires that assessed diet at ages 12-13 years and 10 years previously.
View Article and Find Full Text PDFBackground: The attributable risk (AR) measures the proportion of disease cases that can be attributed to an exposure in the population. Several definitions and estimation methods have been proposed for survival data.
Methods: Using simulations, we compared four methods for estimating AR defined in terms of survival functions: two nonparametric methods based on Kaplan-Meier's estimator, one semiparametric based on Cox's model, and one parametric based on the piecewise constant hazards model, as well as one simpler method based on estimated exposure prevalence at baseline and Cox's model hazard ratio.