Parasitémies à Plasmodium falciparum ou P. malariae chez les porteurs du trait drépanocytaire dans différents biotopes du Bénin

La prévalence du paludisme en fonction du phénotype de l'hémoglobine et la fréquence du gène S ont été recherchées dans deux différents biotopes du Bénin. Dans aucun d'eux, la prévalence du paludisme n'est significativement différente entre les porteurs du trait drépanocytaire et les autres. De même, la prévalence du trait drépanocytaire n'est pas modifiée par l'âge. En revanche, en région holoendémique, la densité parasitaire moyenne à #P. falciparum$ est significativement plus faible chez les sujets AS que chez les sujets AA. La présence du trait drépanocytaire ne réduit pas le risque d'infection palustre mais semble diminuer l'importance de la parasitémie. (Résumé d'auteur

Infections with Plasmodium falciparum during pregnancy affect VAR2CSA DBL-5 domain-specific T cell cytokine responses

Background: Current knowledge of human immunological responses to pregnancy-associated malaria-specific Plasmodium falciparum protein VAR2CSA concerns almost exclusively B cell-driven antibody-mediated activity. Knowledge of VAR2CSA-specific T cell-mediated activity is minimal by comparison, with only a single published report of a study investigating VAR2CSA-derived peptide-specific T cell responses. The study described here represents an attempt to redress this balance. Methods: Within the framework of a cohort study of 1037 pregnant Beninese, sub-groups were selected on the basis of the documented presence/absence of infection with P. falciparum and conducted detailed immunological assessments both at inclusion into the study and at delivery. Peripheral blood mononuclear cells were isolated, stimulated in vitro, and VAR2CSA DBL-5 domain-specific, IFN-gamma-secreting T-cell frequencies and cytokine responses were quantified using flow cytometric techniques. Multivariate analyses were used to determine primarily whether the T cell-mediated DBL5-specific activity measured was associated with infection by P. falciparum adjusted for gravidity, anaemia and other cofactors. Results: Infections with P. falciparum detected at inclusion were associated with enhanced non-specific TNF responses, whilst diminished non-specific and DBL-5-specific IL-10 responses were associated with infections detected at delivery. Infections during pregnancy led to enhanced non-specific and DBL-5-specific IFN-gamma responses detectable at delivery but to concomitantly lower DBL-5-specific CD8+ IFN-gamma responses. Prospective assessments indicated that non-specific pro-inflammatory responses detectable at inclusion in the study were associated with the occurrence of infections subsequently during pregnancy. Conclusions: The findings represent a first step in elucidating the quantity and quality of cellular immunological responses to VAR2CSA, which will help in the development of the primary vaccine candidate for prevention of pregnancy-associated malaria

Acquisition of natural humoral immunity to <i>P. falciparum</i> in early life in Benin:impact of clinical, environmental and host factors

To our knowledge, effects of age, placental malaria infection, infections during follow-up, nutritional habits, sickle-cell trait and individual exposure to Anopheles bites were never explored together in a study focusing on the acquisition of malaria antibody responses among infants living in endemic areas. Five hundred and sixty-seven Beninese infants were weekly followed-up from birth to 18 months of age. Immunoglobulin G (IgG), IgG1 and IgG3 specific for 5 malaria antigens were measured every 3 months. A linear mixed model was used to analyze the effect of each variable on the acquisition of antimalarial antibodies in 6- to 18-month old infants in univariate and multivariate analyses. Placental malaria, nutrition intakes and sickle-cell trait did not influence the infant antibody levels to P. falciparum antigens. In contrary, age, malaria antibody levels at birth, previous and present malaria infections as well as exposure to Anopheles bites were significantly associated with the natural acquisition of malaria antibodies in 6- to 18-month old Beninese infants. This study highlighted inescapable factors to consider simultaneously in an immuno-epidemiological study or a vaccine trial in early life

Findings of the Survey on Prevention of Plagiarism in Lithuanian Research Journals

AbstractAt the end of 2011, the Association of Lithuanian Serials initiated a survey, which aimed to ascertain whether Lithuanian journal editors, reviewers and authors encountered plagiarism, self-plagiarism and how they understood originality of a paper. Additionally, the survey looked at methods used for plagiarism prevention by editors and reviewers as well as ways, in which editors managed issues related to plagiarism. The survey suggests that no unanimous decision exists regarding the originality of a manuscript and that editors expect reviewers to identify plagiarism with little use of technologies. While answering to survey questions, respondents provided numerous comments. This demonstrates that plagiarism is a burning issue and scientific misconduct policy is needed in Lithuania. The survey was conducted during the period when the Lithuanian Research Council initiated the procedure for establishing the Ombudsman position. The Lithuanian Research Council funded several projects in 2012 and 2013, the aim of which was to familiarise the Lithuanian academic community with plagiarism prevention technologies and ethical aspects in academic publishing. The projects administrated by the Association of Lithuanian Serials provide research journal publishers and researchers related to journal publishing with a possibility of using CrossCheck system and discussing editorial policies

Семантичні зміни в лексичному складі російської та української мов

Использование вычислительной техники и радиоэлектроники способствовало формированию специальной группы лексических единиц. Номинация новых явлений и понятий является актуальной проблемой нынешнего этапа развития языка. Изменение семантического наполнения – это один из способов решения данной проблемы. Расширение или сужение семантического объема слов способствует обогащению лексической системы, а именно терминологии.Використання обчислювальної техніки та радіоелектроніки спричинило формування спеціальної групи лексичних одиниць. Номінація нових явищ та понять є актуальною проблемою теперішнього етапу розвитку мови. Зміна семантичного об'єму – це один із засобів вирішення даної проблеми. Звуження або розширення семантичного наповнення сприяє збагаченню лексичної системи, а саме термінології.Using of radio-electronic devices forced the formation of a special group of lexical units. The nomination of new processes and notions is an actual problem of today's language development. Semantic changes of existing units is one of the decisions of the problem. Widening and narrowing of semantic meanings promotes the enrichment of lexical system, especially the system of terminology

The Impact of Maternal Depression and Parent–Child Interactions on Risk of Parasitic Infections in Early Childhood: A Prospective Cohort in Benin

Objectives: Maternal depression occurs in 13–20% of women from low-income countries, which is associated with negative child health outcomes, including diarrheal disease. However, few studies have investigated its impact on child risk of infectious disease. We studied the impacts of maternal depressive symptoms and parent–child interactions, independently, on the risk of Plasmodium falciparum malaria and soil-transmitted helminth infection in Beninese children. Methods: Our population included mothers and children enrolled in a clinical trial during pregnancy (MiPPAD) in Benin. The Edinburgh Postnatal Depression Scale (EPDS) assessed maternal depressive symptoms and the home observation measurement of the environment (HOME) assessed parent–child interactions. Blood and stool sample analyses diagnosed child malaria and helminth infection at 12, 18, and 24 months. Negative binomial and Poisson regression models with robust variance tested associations. Results: Of the 302 mother–child pairs, 39 (12.9%) mothers had depressive symptoms. Median number of malaria episodes per child was 3 (0–14) and 29.1% children had at least one helminth infection. Higher EPDS scores were associated with lower HOME scores; relative risk (RR) 0.97 (95% confidence interval (CI) 0.95, 0.99), particularly with lower acceptance, involvement, and variety subscales; RR 0.92 (95% CI 0.85, 0.99), RR 0.82 (95% CI 0.77, 0.88), RR 0.93 (95% CI 0.88, 0.99), respectively. However, neither exposure was associated with risk of parasitic infection in children. Conclusions for Practice: Maternal depressive symptoms are associated with poor parent–child interactions, particularly acceptance of behavior, involvement with children, and variety of interactions, but these exposures do not independently impact risk of parasitic infection in children

Concordance of three alternative gestational age assessments for pregnant women from four African countries: A secondary analysis of the MIPPAD trial

Background: At times, ultrasound is not readily available in low resource countries in Africa for accurate determination of gestational age, so using alternative methods is pivotal during pregnancy. These assessments are used to aid the risk analysis for an infant and management strategies for premature delivery, if necessary. Currently, date of last menstrual period, fundal height measurements, and the New Ballard Score are commonly used in resource-limited settings. However, concordance of these measures is unknown for sub-Saharan Africa. We obtained data from an open-label randomized controlled trial, to assess the concordance of these alternative assessment methods. The purpose of our study was to determine the agreement between these alternative methods when used in sub-Saharan African populations. Methods: A total of 4,390 pregnant women from Benin, Gabon, Mozambique and Tanzania were included in our analysis. The assessment methods compared were: 1) reported last menstrual period, 2) symphysis-fundal height measurement, and 3) the New Ballard Score. The Bland-Altman method and intraclass correlation coefficient (ICC) were used to test the degree of agreement. Survival range gestational age, used as an inclusion criterion for further analysis, was from 22 to 44 weeks. Findings: Plots showed a lack of agreement between methods and the 95% limits of agreement too wide to be clinically useful. ICC = 0.25 indicated poor agreement. A post-hoc analysis, restricted from 32 to 42 weeks, was done to check for better agreement in this near-term population. The plots and ICC = 0.16 still confirmed poor agreement. Conclusion: The alternative assessments do not result in comparable outcomes and discrepancies are far beyond the clinically acceptable range. Last menstrual period should not be used as the only estimator of gestational age. In the absence of reliable early ultrasound, symphysis-fundal height measurements may be most useful during pregnancy for fetal risk assessment and the New Ballard Score after delivery as a confirmation of these estimations and for further neonatal management. However, promotion of portable ultrasound devices is required for accurate assessment of gestational age in sub-Sahara Africa

Resisting and tolerating P. falciparum in pregnancy under different malaria transmission intensities.

BACKGROUND: Resistance and tolerance to Plasmodium falciparum can determine the progression of malaria disease. However, quantitative evidence of tolerance is still limited. We investigated variations in the adverse impact of P. falciparum infections among African pregnant women under different intensities of malaria transmission. METHODS: P. falciparum at delivery was assessed by microscopy, quantitative PCR (qPCR) and placental histology in 946 HIV-uninfected and 768 HIV-infected pregnant women from Benin, Gabon, Kenya and Mozambique. Resistance was defined by the proportion of submicroscopic infections and the levels of anti-parasite antibodies quantified by Luminex, and tolerance by the relationship of pregnancy outcomes with parasite densities at delivery. RESULTS: P. falciparum prevalence by qPCR in peripheral and/or placental blood of HIV-uninfected Mozambican, Gabonese and Beninese women at delivery was 6% (21/340), 11% (28/257) and 41% (143/349), respectively. The proportion of peripheral submicroscopic infections was higher in Benin (83%) than in Mozambique (60%) and Gabon (55%; P = 0.033). Past or chronic placental P. falciparum infection was associated with an increased risk of preterm birth in Mozambican newborns (OR = 7.05, 95% CI 1.79 to 27.82). Microscopic infections were associated with reductions in haemoglobin levels at delivery among Mozambican women (-1.17 g/dL, 95% CI -2.09 to -0.24) as well as with larger drops in haemoglobin levels from recruitment to delivery in Mozambican (-1.66 g/dL, 95% CI -2.68 to -0.64) and Gabonese (-0.91 g/dL, 95% CI -1.79 to -0.02) women. Doubling qPCR-peripheral parasite densities in Mozambican women were associated with decreases in haemoglobin levels at delivery (-0.16 g/dL, 95% CI -0.29 to -0.02) and increases in the drop of haemoglobin levels (-0.29 g/dL, 95% CI -0.44 to -0.14). Beninese women had higher anti-parasite IgGs than Mozambican women (P < 0.001). No difference was found in the proportion of submicroscopic infections nor in the adverse impact of P. falciparum infections in HIV-infected women from Kenya (P. falciparum prevalence by qPCR: 9%, 32/351) and Mozambique (4%, 15/417). CONCLUSIONS: The lowest levels of resistance and tolerance in pregnant women from areas of low malaria transmission were accompanied by the largest adverse impact of P. falciparum infections. Exposure-dependent mechanisms developed by pregnant women to resist the infection and minimise pathology can reduce malaria-related adverse outcomes. Distinguishing both types of defences is important to understand how reductions in transmission can affect malaria disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT00811421 . Registered 18 December 2008

Young adolescent girls are at high risk for adverse pregnancy outcomes in sub-Saharan Africa: an observational multicountry study

Objectives: One of Africa's most important challenges is to improve maternal and neonatal health. The identification of groups at highest risk for adverse pregnancy outcomes is important for developing and implementing targeted prevention programmes. This study assessed whether young adolescent girls constitute a group at increased risk for adverse birth outcomes among pregnant women in sub-Saharan Africa. Setting: Data were collected prospectively as part of a large randomised controlled clinical trial evaluating intermittent preventive treatment of malaria in pregnancy (NCT00811421—Clinical Trials.gov), conducted between September 2009 and December 2013 in Benin, Gabon, Mozambique and Tanzania. Participants: Of 4749 participants, pregnancy outcomes were collected for 4388 deliveries with 4183 live births including 83 multiple gestations. Of 4100 mothers with a singleton live birth delivery, 24% (975/4100) were adolescents (≤19 years of age) and 6% (248/4100) were aged ≤16 years. Primary and secondary outcome measures: Primary outcomes of this predefined analysis were preterm delivery and low birth weight. Results: The overall prevalence of low birthweight infants and preterm delivery was 10% (371/3851) and 4% (159/3862), respectively. Mothers aged ≤16 years showed higher risk for the delivery of a low birthweight infant (OR: 1.96; 95% CI 1.35 to 2.83). Similarly, preterm delivery was associated with young maternal age (≤16 years; OR: 2.62; 95% CI 1.59 to 4.30). In a subanalysis restricted to primiparous women: preterm delivery, OR 4.28; 95% CI 2.05 to 8.93; low birth weight, OR: 1.29; 95% CI 0.82 to 2.01. Conclusions: Young maternal age increases the risk for adverse pregnancy outcomes and it is a stronger predictor for low birth weight and preterm delivery than other established risk factors in sub-Saharan Africa. This finding highlights the need to improve adolescent reproductive health in sub-Saharan Africa

Impact of helminth infection during pregnancy on cognitive and motor functions of one-year-old children

Objective To determine the effect of helminth infection during pregnancy on the cognitive and motor functions of one-year-old children. Methods Six hundred and thirty five singletons born to pregnant women enrolled before 29 weeks of gestation in a trial comparing two intermittent preventive treatments for malaria were assessed for cognitive and motor functions using the Mullen Scales of Early Learning, in the TOVI study, at twelve months of age in the district of Allada in Benin. Stool samples of pregnant women were collected at recruitment, second antenatal care (ANC) visit (at least one month after recruitment) and just before delivery, and were tested for helminths using the Kato-Katz technique. All pregnant women were administered a total of 600 mg of mebendazole (100 mg two times daily for 3 days) to be taken after the first ANC visit. The intake was not directly observed. Results Prevalence of helminth infection was 11.5%, 7.5% and 3.0% at first ANC visit, second ANC visit and at delivery, respectively. Children of mothers who were infected with hookworms at the first ANC visit had 4.9 (95% CI: 1.3–8.6) lower mean gross motor scores compared to those whose mothers were not infected with hookworms at the first ANC visit, in the adjusted model. Helminth infection at least once during pregnancy was associated with infant cognitive and gross motor functions after adjusting for maternal education, gravidity, child sex, family possessions, and quality of the home stimulation. Conclusion Helminth infection during pregnancy is associated with poor cognitive and gross motor outcomes in infants. Measures to prevent helminth infection during pregnancy should be reinforced