Malar J

Background While sub-microscopic malarial infections are frequent and potentially deleterious during pregnancy, routine molecular detection is still not feasible. This study aimed to assess the performance of a Histidine Rich Protein 2 (HRP2)-based ultrasensitive rapid diagnostic test (uRDT, Alere Malaria Ag Pf) for the detection of infections of low parasite density in pregnant women. Methods This was a retrospective study based on samples collected in Benin from 2014 to 2017. A total of 942 whole blood samples collected in 327 women in the 1st and 3rd trimesters and at delivery were tested by uRDT, conventional RDT (cRDT, SD BIOLINE Malaria Ag Pf), microscopy, quantitative polymerase chain-reaction (qPCR) and Luminex-based suspension array technology targeting P. falciparum HRP2. The performance of each RDT was evaluated using qPCR as reference standard. The association between infections detected by uRDT, but not by cRDT, with poor maternal and birth outcomes was assessed using multivariate regression models. Results The overall positivity rate detected by cRDT, uRDT, and qPCR was 11.6% (109/942), 16.2% (153/942) and 18.3% (172/942), respectively. Out of 172 qPCR-positive samples, 68 were uRDT-negative. uRDT had a significantly better sensitivity (60.5% [52.7–67.8]) than cRDT (44.2% [36.6–51.9]) and a marginally decreased specificity (93.6% [91.7–95.3] versus 95.7% [94.0–97.0]). The gain in sensitivity was particularly high (33%) and statistically significant in the 1st trimester. Only 28 (41%) out of the 68 samples which were qPCR-positive, but uRDT-negative had detectable but very low levels of HRP2 (191 ng/mL). Infections that were detected by uRDT but not by cRDT were associated with a 3.4-times (95%CI 1.29–9.19) increased risk of anaemia during pregnancy. Conclusions This study demonstrates the higher performance of uRDT, as compared to cRDTs, to detect low parasite density P. falciparum infections during pregnancy, particularly in the 1st trimester. uRDT allowed the detection of infections associated with maternal anaemia

Influence mutuelle des prises de terre: Determination du circuit electrique equivalent d'un reseau de prise de terre

The present brings back the work carried out on the development of a simple and practical method of calculation of the earth electrodes and their mutual influence starting from an equivalent electric circuit of the networks of earth electrode within the framework of the research which is led to the LERTI on the protection of the electric systems against the defects of any kind. Through several tests of different methods of calculation of parameters of the earth in static regime, we analyse the various compilation on a system of two earth electrodes in heterogeneous model of ground with two layers. These methods are specially the numeric method of calculation and the experimental method of direct measurements of the parameters and the rise of potential. We note that the consideration of mutual resistance between the two earth electrodes makes it possible to determine the mutual influence that the earth electrodes can have one on the other when a defect intervenes on one of them. Cette présentation rapporte les travaux effectués sur la mise au point d’une méthode simple et pratique de calcul des prises de terre et leur influence mutuelle à partir d’un circuit électrique équivalent des réseaux de prise de terre dans le cadre de la recherche qui se mène au LERTI sur la protection des systèmes électriques contre les défauts de tout genre. Sur expérimentations des différentes méthodes de calcul des paramètres de prise de terre en régime statique, nous avons analysé les résultats de calcul sur un système de deux prises de terre en modèle de sol hétérogène à deux couches. Ces méthodes sont surtout la méthode numérique de calcul (que nous n’avons pas développée) et la méthode expérimentale de mesures directes sur site des paramètres et la montée de potentiel. Nous constatons que la considération de la résistance mutuelle entre les deux prises de terre permet de déterminer l’influence mutuelle que les prises de terre peuvent avoir l’une sur l’autre lorsqu’un défaut intervient sur l’une d’elles

Caractérisation d’une cellule photovoltaïque organique ITO/PEDOT: PSS/P3HT/PCBM/Yb/Al fabriquée en atmosphère ambiante.

La condition de dépôt de la couche active est un aspect important dans la fabrication des cellules photovoltaïques organiques. Dans ce papier, nous présentons les résultats de la caractérisation de cellules photovoltaïques obtenues par dépôt physique en atmosphère ambiante en dehors d’une boîte à gant. Nous analysons les paramètres électriques extraits de la caractéristique courant-tension de ces cellules obtenues par mesure et traitées dans l’environnement OriginPro8. L’analyse des paramètres qui entrent en jeu dans la détermination de l’efficacité photovoltaïque et l’étude de l’effet de la couche encapsulante d’alumine nous permettent d’entre voir que dans les techniques de fabrication des cellules organiques sur substrat souples à base de PCBM et du P3HT ; un dépôt à la tournette en atmosphère ambiante est possible.Mots clés : atmosphère ambiante, dépôt à la tournette, photovoltaïque organique.Spin coating of polymer in ambiente atmosphere during fabrication of photovoltaic device is the way which we explore in this paper. A characterization of this device with OriginPro8 and the analysis of the parameters from voltage and current density curve under dark and light and the first degradation process allow us to hope that it is possible to make photovoltaic device base on P3HT and PCBM in ambiente atmosphere.Keywords: ambiente atmosphere, spincoating organic photovoltaïc, polymer organic

Gestational age-related changes in the peripheral blood cell composition of sub-Saharan African women

Gestational age-related changes in the cellular composition of peripheral blood have not been described in sub-Saharan African settings. We conducted longitudinal cohort studies in Beninese and Tanzanian mothers with quantification of peripheral blood mononuclear cell-types ex vivo using flow cytometry. Between the second trimester and delivery the frequency of CD4(+) T cells declined significantly, contrasting with a non-significant increase in CD8(+) T cells, but no changes in T-regulatory, NK or NKT cell frequencies. Antigen-presenting cell profiles were also unaltered, although non-significant trends were evident. These changes resemble in some respects those reported during pregnancies in developed countries, but differ in others

Clin Infect Dis

Background: In sub-Saharan Africa, malaria in the first half of pregnancy is harmful for both the mother and her foetus. However, malaria in the 1st trimester of pregnancy, when women are usually not protected against malaria, has been little investigated. For the first time, we assessed the effects of malaria in the 1st trimester on maternal and birth outcomes using a preconceptional study design. Methods: From June 2014 to March 2017, 1214 women of reproductive age were recruited and followed monthly until 411 became pregnant. Pregnant women were then followed from 5-6 weeks of gestation until delivery. Path analysis was used to assess the direct effect (i.e., not mediated by malaria in the 2nd or 3rd trimester) of malaria in the 1st trimester on maternal anaemia and poor birth outcomes. The cumulative effect of infections during pregnancy on the same outcomes was also evaluated. Results: The prevalence of malaria infection in the 1st trimester was 21.8%. Malaria in the 1st trimester was significantly associated with maternal anaemia in the 3rd trimester (adjusted odds ratio [aOR]: 2.25, 95% CI 1.11, 4.55). While we did not evidence any direct effect of 1st trimester malaria infections on birth outcomes, their association with infections later in pregnancy tended to increase the risk of low birthweight. Conclusions : alaria infections in the 1st trimester were highly prevalent and have deleterious effects on maternal anaemia. They highlight the need for additional preventive measures starting in early pregnancy, or even before conception

Prevalence and clinical impact of malaria infections detected with a highly sensitive HRP2 rapid diagnostic test in Beninese pregnant women [+ correction 2020, vol. 19, no 1, art. 328]

Background While sub-microscopic malarial infections are frequent and potentially deleterious during pregnancy, routine molecular detection is still not feasible. This study aimed to assess the performance of a Histidine Rich Protein 2 (HRP2)-based ultrasensitive rapid diagnostic test (uRDT, Alere Malaria Ag Pf) for the detection of infections of low parasite density in pregnant women. Methods This was a retrospective study based on samples collected in Benin from 2014 to 2017. A total of 942 whole blood samples collected in 327 women in the 1st and 3rd trimesters and at delivery were tested by uRDT, conventional RDT (cRDT, SD BIOLINE Malaria Ag Pf), microscopy, quantitative polymerase chain-reaction (qPCR) and Luminex-based suspension array technology targeting P. falciparum HRP2. The performance of each RDT was evaluated using qPCR as reference standard. The association between infections detected by uRDT, but not by cRDT, with poor maternal and birth outcomes was assessed using multivariate regression models. Results The overall positivity rate detected by cRDT, uRDT, and qPCR was 11.6% (109/942), 16.2% (153/942) and 18.3% (172/942), respectively. Out of 172 qPCR-positive samples, 68 were uRDT-negative. uRDT had a significantly better sensitivity (60.5% [52.7-67.8]) than cRDT (44.2% [36.6-51.9]) and a marginally decreased specificity (93.6% [91.7-95.3] versus 95.7% [94.0-97.0]). The gain in sensitivity was particularly high (33%) and statistically significant in the 1st trimester. Only 28 (41%) out of the 68 samples which were qPCR-positive, but uRDT-negative had detectable but very low levels of HRP2 (191 ng/mL). Infections that were detected by uRDT but not by cRDT were associated with a 3.4-times (95%CI 1.29-9.19) increased risk of anaemia during pregnancy. Conclusions This study demonstrates the higher performance of uRDT, as compared to cRDTs, to detect low parasite density P. falciparum infections during pregnancy, particularly in the 1st trimester. uRDT allowed the detection of infections associated with maternal anaemia

Submicroscopic infections with Plasmodium falciparum during pregnancy and their association with circulating cytokine, chemokine, and cellular profiles

The immunological consequences of pregnancy-associated malaria (PAM) due to Plasmodium falciparum have been extensively investigated in cross-sectional studies conducted at delivery, but there have been very few longitudinal studies of changes due to PAM during pregnancy. We conducted a prospective study in Benin to investigate the changes associated with PAM in groups of 131 and 111 women at inclusion in the second trimester and at delivery, respectively. Infected women were identified by standard microscopic examinations of blood smears and by quantitative PCR (qPCR) assays and were matched to uninfected control women by age, gestational age, and gravidity. We quantified plasma levels of a panel of soluble immunological mediators and other mediators, as well as the frequencies of peripheral blood mononuclear cell types. Comparisons of these variables in infected and uninfected women used multivariate analyses, and we also assessed the predictive value of variables measured at inclusion for pregnancy outcomes at delivery. In multivariate analyses, peripheral plasma interleukin 10 (IL-10) and gamma interferon-inducible protein 10 (IP-10) levels were associated with PAM at inclusion and at delivery, while higher IL-10 levels distinguished qPCR-detectable submicroscopic infections at inclusion but not at delivery. Maternal anemia at delivery was associated with markers of proinflammatory (increased frequency of monocytes) and anti-inflammatory (increased IL-10 levels and increased activation of regulatory T cells) activity measured at inclusion. Elevated concentrations of IL-10 are associated with the majority of P. falciparum infections during pregnancy, but this marker alone does not identify all submicroscopic infections. Reliably identifying such occult infections will require more sensitive and specific methods