295 research outputs found

    Multiplex serological investigation of antibodies against Ebola viruses in a large panel of African bat species

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    Introduction: The reservoir(s) and ecology of Ebola viruses (EBV) remains largely unknown, but previous detection of viral RNA and anti-EBV antibodies in bats suggests that they may play a role in zoonotic transmission. Objectives: Gain insight into the circulation of EBV in bat populations in West and Central Africa by testing for the presence of antibodies against different EBV, using high throughput technology. Materials and methods: Bats were captured across 7 regions in Cameroon and 4 in Guinea, and released immediately after collection of dried blood spots and biological data. Here we used a multiplex immunoassay with Luminex® technology for antibody detection against NP, GP and VP40 antigens for Zaire (EBOV), Sudan (SUDV), Bundibugyo (BDBV) and Reston (RESTV) EBV. In the absence of positive controls, cut-off values were determined using the change-point analysis method with bootstrapping (10 000 times). A sample was considered positive if the detected antibodies level was over the estimated cut-off for both NP and GP antigens. Results: We studied 1796 bats (Cameroon, n=1365 and Guinea, n=431) belonging to 10 genera of the frugivorous family Pteropodidae (n=641) and 12 genera of 6 insectivorous families (n=1155). Based on the change-point analysis, 0,2% (3/1796) of bats were positive for EBOV (E. helvum, n=1; M. angolensis, n=1 and Mops sp., n=1) and 0,1% (1/1796) for SUDV (R. aegyptiacus). A total of 7,9% (142/1796) reacted to at least one EBV antigen, mainly GP. These bats belonged mainly (97%) to 8 frugivorous species and one insectivorous genus (Mops). Conclusion: we confirm the presence of antibodies in 2 frugivorous bat species and 1 insectivorous genus previously found to be seropositive, as well as for the first time in M. angolensis, a frugivorous species. Using a stringent method of interpretation (change-point analysis), prevalence of EBV antibodies can be underestimated. More studies are needed to evaluate the extend of EBV in bats in areas at risk for EBV outbreaks in Africa and complementary less conservative methods to define cut-offs could be used for comparison in order to reflect natural circulation or exposure to Filoviruses. (Résumé d'auteur

    Validation of a collaboration readiness assessment tool for use by Supplemental Nutrition Assistance Program Education (SNAP-Ed) agencies and partners.

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    To evaluate content and face validity of a collaboration readiness assessment tool developed to facilitate collaborative efforts to implement policy, systems, and environment changes in Supplemental Nutrition Assistance Program–Education (SNAP-Ed).Evaluation of the validity of the tool involved 2 steps. Step 1 was conducted with 4 subject matter experts to evaluate content validity. Step 2 used an iterative cognitive testing process with 4 rounds and 16 SNAP-Ed staff and community partners to evaluate face validity.Subject matter experts found that survey items appropriately matched the content area indicated and adequately covered collective efficacy, change efficacy, and readiness. Cognitive testing with SNAP-Ed staff and partners informed modifications and resulted in adequate face validity.The ability to measure collaboration readiness will allow agencies and community partners that implement SNAP-Ed to target areas that facilitate collaboration efforts needed for policy, systems, and environment change and collective efficacy. Further cognitive testing of the tool with other populations is needed to ensure its applicability and usefulness. Evaluation of the reliability of the tool with a broad range of SNAP-Ed programs and community agencies is also recommended

    Estimating intervention dose of the multilevel multisite children’s healthy living program intervention

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    Increased community collective efficacy (CE), defined as social cohesion among neighbors and their willingness to intervene for common good, is associated with improved community health outcomes. However, processes to increase CE and estimate its dose within an intervention are not well understood. The 2 year Children's Healthy Living (CHL) intervention aimed to improve child behaviors known to affect obesity. We used data from CHL to estimate CE dose and examine its association with a successful outcome from CHL-reduction in children's recreational screen time. Monthly reports from nine intervention communities were quantified, and CE dose was calculated for each community overall, at 4 time intervals (6, 12, 18, and 24 months), and for each CE building block-social bonding, social bridging, social leveraging, empowerment, and civic engagement. CE dose at each time interval and change in screen time was correlated using Spearman's rho. Next, communities were categorized as having a high CE dose or a low CE dose, and differences between four high-dose and five low-dose communities were compared using a two-tailed t-test. The correlation between change in screen time and CE dose was significant (rs = 0.83, p = .003). Significantly more activities facilitating empowerment and civic engagement were conducted in high-dose communities, which were more likely to show improvements in screen time, than in low-dose communities. This method of estimating an intervention's CE dose and examining change over time and effect of CE and its building blocks on intervention outcomes shows promise

    Recruitment Strategies and Lessons Learned from the Children's Healthy Living Program Prevalence Survey

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    The US Affiliated Pacific region's childhood obesity prevalence has reached epidemic proportions. To guide program and policy development, a multi-site study was initiated, in collaboration with partners from across the region, to gather comprehensive information on the regional childhood obesity prevalence. The environmental and cultural diversity of the region presented challenges to recruiting for and implementing a shared community-based, public health research program. This paper presents the strategies used to recruit families with young children (n = 5775 for children 2 - 8 years old) for obesity-related measurement across eleven jurisdictions in the US Affiliated Pacific Region. Data were generated by site teams that provided summaries of their recruitment strategies and lessons learned. Conducting this large multi-site prevalence study required considerable coordination, time and flexibility. In every location, local staff knowledgeable of the community was hired to lead recruitment, and participant compensation reflected jurisdictional appropriateness (e.g., gift cards, vouchers, or cash). Although recruitment approaches were site-specific, they were predominantly school-based or a combination of school- and community-based. Lessons learned included the importance of organization buy-in; communication, and advance planning; local travel and site peculiarities; and flexibility. Future monitoring of childhood obesity prevalence in the region should consider ways to integrate measurement activities into existing organizational infrastructures for sustainability and cost-effectiveness, while meeting programmatic (e.g. study) goals

    Role of simian virus 40 in cancer incidence in solid organ transplant patients

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    Transplant recipients have an increased risk of developing cancer in comparison with the general population. We present here data on cancer development in transplanted subjects who received organs from donors whose DNA was previously examined for the genomic insertion of Simian Virus 40 (SV40). Active follow-up of 387 recipients of solid organs donated by 134 donors, not clinically affected by cancer, was performed through the National Transplant Center (NTC). The average length of follow-up after transplant was 671±219 days (range 0–1085 days). Out of 134 proposed donors, 120 were utilised for organ donation. Of these, 12 (10%) were classified as positive for SV40 genomic insertion. None of the 41 recipients of organs from SV40 positive donors developed a tumour during the follow-up. In all, 11 recipients of organs given by SV40 negative donors developed a tumour (cancer incidence: 0.015 per year). In conclusion, cancer rates observed in our study are comparable to what reported by the literature in transplanted patients. Recipients of solid organs from SV40 positive donors do not have an increased risk of cancer after transplant. The role of SV40 in carcinogenesis in transplanted patients may be minimal

    Clostridia in Premature Neonates' Gut: Incidence, Antibiotic Susceptibility, and Perinatal Determinants Influencing Colonization

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    Although premature neonates (PN) gut microbiota has been studied, data about gut clostridial colonization in PN are scarce. Few studies have reported clostridia colonization in PN whereas Bacteroides and bifidobacteria have been seldom isolated. Such aberrant gut microbiota has been suggested to be a risk factor for the development of intestinal infections. Besides, PN are often treated by broad spectrum antibiotics, but little is known about how antibiotics can influence clostridial colonization based on their susceptibility patterns. The aim of this study was to report the distribution of Clostridium species isolated in feces from PN and to determine their antimicrobial susceptibility patterns. Additionally, clostridial colonization perinatal determinants were analyzed.Of the 76 PN followed until hospital discharge in three French neonatal intensive care units (NICUs), 79% were colonized by clostridia. Clostridium sp. colonization, with a high diversity of species, increased throughout the hospitalization. Antibiotic courses had no effect on the clostridial colonization incidence although strains were found susceptible (except C. difficile) to anti-anaerobe molecules tested. However, levels of colonization were decreased by either antenatal or neonatal (during more than 10 days) antibiotic courses (p = 0.006 and p = 0.001, respectively). Besides, incidence of colonization was depending on the NICU (p = 0.048).This study shows that clostridia are part of the PN gut microbiota. It provides for the first time information on the status of clostridia antimicrobial susceptibility in PN showing that strains were susceptible to most antibiotic molecules. Thus, the high prevalence of this genus is not linked to a high degree of resistance to antimicrobial agents or to the use of antibiotics in NICUs. The main perinatal determinant influencing PN clostridia colonization appears to be the NICU environment

    Fecal Calprotectin Excretion in Preterm Infants during the Neonatal Period

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    Fecal calprotectin has been proposed as a non-invasive marker of intestinal inflammation in inflammatory bowel disease in adults and children. Fecal calprotectin levels have been reported to be much higher in both healthy full-term and preterm infants than in children and adults.To determine the time course of fecal calprotectin (f-calprotectin) excretion in preterm infants from birth until hospital discharge and to identify factors influencing f-calprotectin levels in the first weeks of life, including bacterial establishment in the gut.F-calprotectin was determined using an ELISA assay in 147 samples obtained prospectively from 47 preterm infants (gestational age, and birth-weight interquartiles 27–29 weeks, and 880–1320 g, respectively) at birth, and at 2-week intervals until hospital discharge. (p = 0.047).During the first weeks of life, the high f-calprotectin values observed in preterm infants could be linked to the gut bacterial establishment

    Emergence and spread of SARS-CoV-2 lineage B.1.620 with variant of concern-like mutations and deletions

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    Distinct SARS-CoV-2 lineages, discovered through various genomic surveillance initiatives, have emerged during the pandemic following unprecedented reductions in worldwide human mobility. We here describe a SARS-CoV-2 lineage - designated B.1.620 - discovered in Lithuania and carrying many mutations and deletions in the spike protein shared with widespread variants of concern (VOCs), including E484K, S477N and deletions HV69Delta, Y144Delta, and LLA241/243Delta. As well as documenting the suite of mutations this lineage carries, we also describe its potential to be resistant to neutralising antibodies, accompanying travel histories for a subset of European cases, evidence of local B.1.620 transmission in Europe with a focus on Lithuania, and significance of its prevalence in Central Africa owing to recent genome sequencing efforts there. We make a case for its likely Central African origin using advanced phylogeographic inference methodologies incorporating recorded travel histories of infected travellers

    The predominance of Human Immunodeficiency Virus type 1 (HIV-1) circulating recombinant form 02 (CRF02_AG) in West Central Africa may be related to its replicative fitness

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    BACKGROUND: CRF02_AG is the predominant HIV strain circulating in West and West Central Africa. The aim of this study was to test whether this predominance is associated with a higher in vitro replicative fitness relative to parental subtype A and G viruses. Primary HIV-1 isolates (10 CRF02_AG, 5 subtype A and 5 subtype G) were obtained from a well-described Cameroonian cohort. Growth competition experiments were carried out at equal multiplicity of infection in activated T cells and monocyte-derived dendritic cells (MO-DC) in parallel. RESULTS: Dual infection/competition experiments in activated T cells clearly indicated that CRF02_AG isolates had a significant replication advantage over the subtype A and subtype G viruses. The higher fitness of CRF02_AG was evident for isolates from patients with CD4+ T cell counts >200 cells/μL (non-AIDS) or CD4+ T cell counts <200 cells/μL (AIDS), and was independent of the co-receptor tropism. In MO-DC cultures, CRF02_AG isolates showed a slightly but not significantly higher replication advantage compared to subtype A or G isolates. CONCLUSION: We observed a higher ex vivo replicative fitness of CRF02_AG isolates compared to subtype A and G viruses from the same geographic region and showed that this was independent of the co-receptor tropism and irrespective of high or low CD4+ T cell count. This advantage in replicative fitness may contribute to the dominant spread of CRF02_AG over A and G subtypes in West and West Central Africa
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