Over 10% efficient wide bandgap CIGSe solar cells on transparent substrate with Na predeposition treatment

With the recent rise of new photovoltaic applications, it has become necessary to develop specific optoelectronic properties for thin‐film technologies such as Cu(In,Ga)Se2 and to take advantage of their high degree of tunability. The feasibility of efficient wide bandgap absorbers on transparent conductive oxide substrates is, in that context, of critical importance. Using an original approach based on a predeposition sodium treatment, Cu(In,Ga)Se2 absorbers fabricated by sputtering and reactive annealing with a Ga to (Ga + In) content over 0.7 and an optical bandgap above 1.4 eV are deposited on transparent fluorine‐doped tin oxide films, with the insertion of an ultrathin MoSe2 layer preserving the contact's ohmicity. Different material characterizations are carried out, and a thorough Raman analysis of the absorber reveals that the sodium pretreatment significantly enhances the Ga incorporation into the chalcopyrite matrix, along with markedly improving the film's morphology and crystalline quality. This translates to a spectacular boost of the photovoltaic performance for the resulting solar cell as compared with a reference device without Na, specifically in the voltage and fill factor. Eventually, an efficiency exceeding 10% is obtained without antireflection coating, a record value bridging the gap with the state of the art on nontransparent substrates

Vivax malaria in Mauritania includes infection of a Duffy-negative individual

<p>Abstract</p> <p>Background</p> <p>Duffy blood group polymorphisms are important in areas where <it>Plasmodium vivax </it>is present because this surface antigen is thought to act as a key receptor for this parasite. In the present study, Duffy blood group genotyping was performed in febrile uninfected and <it>P. vivax</it>-infected patients living in the city of Nouakchott, Mauritania.</p> <p>Methods</p> <p><it>Plasmodium vivax </it>was identified by real-time PCR. The Duffy blood group genotypes were determined by standard PCR followed by sequencing of the promoter region and exon 2 of the Duffy gene in 277 febrile individuals. Fisher's exact test was performed in order to assess the significance of variables.</p> <p>Results</p> <p>In the Moorish population, a high frequency of the <it>FYB^ES/FYB^ES</it>genotype was observed in uninfected individuals (27.8%), whereas no <it>P. vivax</it>-infected patient had this genotype. This was followed by a high level of <it>FYA/FYB</it>, <it>FYB/FYB</it>, <it>FYB/FYB^ES</it>and <it>FYA/FYB^ES</it>genotype frequencies, both in the <it>P. vivax</it>-infected and uninfected patients. In other ethnic groups (Poular, Soninke, Wolof), only the <it>FYB^ES/FYB^ES</it>genotype was found in uninfected patients, whereas the <it>FYA/FYB^ES</it>genotype was observed in two <it>P. vivax</it>-infected patients. In addition, one patient belonging to the Wolof ethnic group presented the <it>FYB^ES/FYB^ES</it>genotype and was infected by <it>P. vivax</it>.</p> <p>Conclusions</p> <p>This study presents the Duffy blood group polymorphisms in Nouakchott City and demonstrates that in Mauritania, <it>P. vivax </it>is able to infect Duffy-negative patients. Further studies are necessary to identify the process that enables this Duffy-independent <it>P. vivax </it>invasion of human red blood cells.</p

Clinical Features and Mortality Associated with Severe Malaria in Adults in Southern Mauritania

International audienceSevere malaria in adults is not well-studied in Sahelian Africa. Clinical features and mortality associated with severe Plasmodium falciparum malaria in adult patients hospitalized in Kiffa, southern Mauritania, were analysed. Patients over 15 years old admitted for severe malaria between August 2016 and December 2019 were included in the present retrospective study. The World Health Organization (WHO) criteria were used to define severe malaria. The presenting clinical characteristics and outcome were compared. Of 4266 patients hospitalized during the study period, 573 (13.4%) had a positive rapid diagnostic test for malaria, and 99 (17.3%; mean age, 37.5 years; range 15–79 years; sex-ratio M/F, 2.1) satisfied the criteria for severe malaria. On admission, the following signs and symptoms were observed in more than one-fourth of the patients: fever (98%), impairment of consciousness (81.8%), multiple convulsions (70.7%), cardiovascular collapse (61.6%), respiratory distress (43.4%), severe anaemia ≤ 80 g/L (36.4%), haemoglobinuria (27.3%), and renal failure (25.3%). Patients were treated with parenteral quinine or artemether. Fourteen (14.1%) patients died. Multiple convulsions, respiratory distress, severe anaemia, haemoglobinuria, acute renal failure, jaundice, and abnormal bleeding occurred more frequently (p < 0.05) in deceased patients. Mortality due to severe falciparum malaria is high among adults in southern Mauritania. An adoption of the WHO-recommended first-line treatment for severe malaria, such as parenteral artesunate, is required to lower the mortality rate associated with severe malaria

Performance of a Commercial Multiplex Allele-Specific Polymerase Chain Reaction Kit to Genotype African-Type Glucose-6-Phosphate Dehydrogenase Deficiency

International audienceABSTRACT. 8-Aminoquinoline antimalarial drugs (primaquine, tafenoquine) are required for complete cure of Plasmodium vivax malaria, but they are contraindicated in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. In the absence of spectrophotometry, which is a gold standard for measuring G6PD activity, G6PD genotyping is one of the alternatives to establish a database and distribution map of G6PD enzyme deficiency in Mauritania, which has become a new epicenter of P. vivax malaria in West Africa. The aim of our study was to assess the performance of multiplex allele-specific polymerase chain reaction (PCR) (African-type Diaplex C™ G6PD kit) against PCR–restriction fragment length polymorphism and sequencing. Of 146 mutations associated with G6PD A − genotypes in 177 blood samples from Mauritanian patients, all but two samples were identified correctly using multiplex allele-specific PCR (100% sensitivity and 99% specificity; “almost perfect agreement” between allele-specific PCR and PCR-restriction fragment length polymorphism/sequencing, with a kappa coefficient of 0.977). Despite a suboptimal PCR protocol for dried blood spots and the inability of the commercial assay to predict unequivocally the G6PD enzyme level in heterozygous females, the African-type Diaplex C™ G6PD genotyping kit seemed to be a valuable screening tool for male subjects and for research purposes in resource-limited countries where spectrophotometer and DNA sequencing are not available

Malaria prevalence in Mauritania: a systematic review and meta-analysis

Abstract Background Understanding malaria epidemiology is a critical step toward efficient malaria control and elimination. The objective of this meta-analysis was to derive robust estimates of malaria prevalence and Plasmodium species from studies conducted in Mauritania and published since 2000. Methods The present review followed the PRISMA guidelines. Searches were conducted in various electronic databases such as PubMed, Web of Science, and Scopus. To obtain pooled prevalence of malaria, meta-analysis was performed using the DerSimonian-Laird random-effects model. Methodological quality of eligible prevalence studies was assessed using Joanna Briggs Institute tool. Inconsistency and heterogeneity between studies were quantified by the I2 index and Cochran’s Q test. Publication bias was assessed with funnel plots and Egger’s regression tests. Results A total of 16 studies with a good individual methodological quality were included and analysed in this study. The overall random effects pooled prevalence of malaria infection (symptomatic and asymptomatic) across all included studies was 14.9% (95% confidence interval [95% CI]: 6.64, 25.80, I2 = 99.8%, P < 0.0001) by microscopy, 25.6% (95% CI: 8.74, 47.62, I2 = 99.6%, P < 0.0001) by PCR and 24.3% (95% CI: 12.05 to 39.14, I2 = 99.7%, P < 0.0001) by rapid diagnostic test. Using microscopy, the prevalence of asymptomatic malaria was 1.0% (95% CI: 0.00, 3.48) against 21.46% (95% CI: 11.03, 34.21) in symptomatic malaria. The overall prevalence of Plasmodium falciparum and Plasmodium vivax was 51.14% and 37.55%, respectively. Subgroup analysis showed significant variation (P = 0.039) in the prevalence of malaria between asymptomatic and symptomatic cases. Conclusion Plasmodium falciparum and P. vivax are widespread in Mauritania. Results of this meta-analysis implies that distinct intervention measures including accurate parasite-based diagnosis and appropriate treatment of confirmed malaria cases are critical for a successful malaria control and elimination programme in Mauritania

Assessment of CareStart G6PD rapid diagnostic test and CareStart G6PD biosensor in Mauritania

International audienceAbstract Background The elimination of Plasmodium vivax malaria requires 8-aminoquinolines, which are contraindicated in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to the risk of acute haemolytic anaemia. Several point-of-care devices have been developed to detect G6PD deficiency. The objective of the present study was to evaluate the performance of two of these devices against G6PD genotypes in Mauritania. Methods Outpatients were screened for G6PD deficiency using CareStart™ rapid diagnostic test (RDT) and CareStart™ G6PD biosensor in Nouakchott, Mauritania, in 2019–2020. African-type and Mediterranean-type G6PD genotypes commonly observed in Africa were determined by polymerase chain reaction-restriction fragment length polymorphism and sequencing. Qualitative variables were compared using Fisher’s exact test. Results Of 323 patients (74 males and 249 females), 5 males and 2 homozygous females had the African-type A- genotype: A −(202) in 3 males and 2 females and G6PD A −(968) in 2 males. Among heterozygous females, 13 carried G6PD A −(202) , 12 G6PD A −(968) , and 3 G6PD A −(542) variants. None had the Mediterranean-type G6PD genotype. Eight had a positive G6PD RDT result, including all 7 hemizygous males and homozygous females with A- or A-A- (0.12 to 2.34 IU/g haemoglobin, according to G6PD biosensor), but RDT performed poorly (sensitivity, 11.1% at the cut-off level of < 30%) and yielded many false negative tests. Thirty-seven (50.0%) males and 141 (56.6%) females were anaemic. The adjusted median values of G6PD activity were 5.72 and 5.34 IU/g haemoglobin in non-anaemic males ( n = 35) and non-anaemic males and females ( n = 130) with normal G6PD genotypes using G6PD biosensor, respectively. Based on the adjusted median of 5.34 IU/g haemoglobin, the performance of G6PD biosensor against genotyping was as follows: at 30% cut-off, the sensitivity and specificity were 85.7% and 91.7%, respectively, and at 80% cut-off, the sensitivity was 100% while the specificity was 64.9%. Conclusions Although this pilot study supports the utility of biosensor to screen for G6PD deficiency in patients, further investigation in parallel with spectrophotometry is required to promote and validate a more extensive use of this point-of-care device in areas where P. vivax is highly prevalent in Mauritania. Graphic abstrac

Malaria epidemiology in Kobeni department, southeastern Mauritania from 2015 to 2017

International audienc

Arthropod-Borne Viruses in Mauritania: A Literature Review

International audienceDuring the past four decades, recurrent outbreaks of various arthropod-borne viruses have been reported in Mauritania. This review aims to consolidate the current knowledge on the epidemiology of the major arboviruses circulating in Mauritania. Online databases including PubMed and Web of Science were used to retrieve relevant published studies. The results showed that numerous arboviral outbreaks of variable magnitude occurred in almost all 13 regions of Mauritania, with Rift Valley fever (RVF), Crimean–Congo hemorrhagic fever (CCHF), and dengue (DEN) being the most common infections. Other arboviruses causing yellow fever (YF), chikungunya (CHIK), o’nyong-nyong (ONN), Semliki Forest (SF), West Nile fever (WNF), Bagaza (BAG), Wesselsbron (WSL), and Ngari (NRI) diseases have also been found circulating in humans and/or livestock in Mauritania. The average case fatality rates of CCHF and RVF were 28.7% and 21.1%, respectively. RVF outbreaks have often occurred after unusually heavy rainfalls, while CCHF epidemics have mostly been reported during the dry season. The central and southeastern regions of the country have carried the highest burden of RVF and CCHF. Sheep, cattle, and camels are the main animal reservoirs for the RVF and CCHF viruses. Culex antennatus and Cx. poicilipes mosquitoes and Hyalomma dromedarii, H. rufipes, and Rhipicephalus everesti ticks are the main vectors of these viruses. DEN outbreaks occurred mainly in the urban settings, including in Nouakchott, the capital city, and Aedes aegypti is likely the main mosquito vector. Therefore, there is a need to implement an integrated management strategy for the prevention and control of arboviral diseases based on sensitizing the high-risk occupational groups, such as slaughterhouse workers, shepherds, and butchers for zoonotic diseases, reinforcing vector surveillance and control, introducing rapid point-of-care diagnosis of arboviruses in high-risk areas, and improving the capacities to respond rapidly when the first signs of disease outbreak are identified

Assessment of drug resistance associated genetic diversity in Mauritanian isolates of Plasmodium vivax reveals limited polymorphism

International audienceBackgroundPlasmodium vivax is the predominant malaria species in northern Mauritania. Molecular data on P. vivax isolates circulating in West Africa are scarce. The present study analysed molecular markers associated with resistance to antifolates (Pvdhfr and Pvdhps), chloroquine (Pvmdr1), and artemisinin (Pvk12) in P. vivax isolates collected in two cities located in the Saharan zone of Mauritania.MethodsBlood samples were obtained from P. vivax-infected patients recruited for chloroquine therapeutic efficacy study in 2013 and febrile patients spontaneously consulting health facilities in Nouakchott and Atar in 2015-2016. Fragments of Pvdhfr (codons 13, 33, 57, 58, 61, 117, and 174), Pvdhps (codons 382, 383, 512, 553, and 585), Pvmdr1 (codons 976 and 1076) and Pvk12 (codon 552) genes were amplified by PCR and sequenced.ResultsMost of the isolates in Nouakchott (126/154, 81.8%) and Atar (44/45, 97.8%) carried the wild-type Pvdhfr allelic variant (IPFSTSI). In Nouakchott, all mutants (28/154; 18.2%) had double Pvdhfr mutations in positions 58 and 61 (allelic variant IPFRMSI), whereas in Atar only 1 isolate was mutant (S117N, allelic variant IPFSTNI). The wild-type Pvdhps allelic variant (SAKAV) was found in all tested isolates (Nouakchott, n=93; Atar, n=37). Few isolates in Nouakchott (5/115, 4.3%) and Atar (3/79, 3.8%) had the mutant Pvmdr1 allele 976F or 1076L, but not both, including in pre-treatment isolates obtained from patients treated successfully with chloroquine. All isolates (59 in Nouakchott and 48 in Atar) carried the wild-type V552 allele in Pvk12.ConclusionsPolymorphisms in Pvdhfr, Pvdhps, Pvmdr1, and Pvk12 were limited in P. vivax isolates collected recently in Nouakchott and Atar. Compared to the isolates collected in Nouakchott in 2007-2009, there was no evidence for selection of mutants. The presence of one, but not both, of the two potential markers of chloroquine resistance in Pvmdr1 in pre-treatment isolates did not influence the clinical outcome, putting into question the role of Pvmdr1 mutant alleles 976F and 1076L in treatment failure. Molecular surveillance is an important component of P. vivax malaria control programme in the Saharan zone of Mauritania to predict possible emergence of drug-resistant parasites

Seasonal abundance, blood meal sources and insecticide susceptibility in major anopheline malaria vectors from southern Mauritania

Abstract Background Malaria is endemic in the southernmost Sahelian zone of Mauritania where the major known mosquito vector is Anopheles arabiensis. Understanding seasonal population dynamics, feeding preferences and insecticide resistance status of these vectors in the area is essential to improve vector control measures implemented at a local scale. Here, malaria vector populations’ bionomics is described in two sentinel sites located in the Sahelian zone of Mauritania. Methods Between September 2014 and December 2016, longitudinal entomological surveys were conducted in Kobeni (15°49'N, 09°24'W) and Rosso (16°30'N; 15°48'W), two localities in the southern Sahelian zone of Mauritania. Adult mosquitoes were collected using indoor pyrethrum spray catch (PSC). Morphological and PCR-based methods were used to identify the species, detect Plasmodium parasites and analyze blood meals in individual mosquitoes. WHO insecticide susceptibility tests were performed with malathion (5%), bendiocarb (0.1%), permethrin (0.75%) and deltamethrin (0.05%) using female An. gambiae (s.l.) reared from larval and pupal collections from natural breeding sites. Results A total of 2702 Anopheles mosquitoes were collected by PSC during the study period comprising 2291 Anopheles gambiae (s.l.), 376 Anopheles rufipes and 35 Anopheles pharoensis. In Rosso, all mosquitoes from the An. gambiae (s.l.) complex were molecularly identified as An. arabiensis (n = 455/455, 100%). Anopheles pharoensis represented 2.5% (n = 35/1420) of the specimens collected by PSC in Rosso. In Kobeni, An. arabiensis was dominant (n = 278/301, 92.3%) and occurred together with Anopheles coluzzii (n = 18/301, 6%) and An. gambiae (s.s.) (n = 3/301, 1%). Two An. coluzzii × An. arabiensis hybrids were also detected (0.7%) in Kobeni, and An. rufipes was the only other Anopheles species found resting indoors (n = 376/1277, 29.4%). There was an average of 5.6 and 3.6 indoor resting female An. gambiae (s.l.) per room in Kobeni and Rosso, respectively. Indoor resting female An. gambiae (s.l.) mosquitoes in both sites fed most frequently on bovine blood (35.5% in Rosso and 37% in Kobeni). The proportion of An. gambiae (s.l.) mosquitoes that took human blood was significantly higher in Kobeni (HBI = 37%) than in Rosso (HBI = 5.6%) and 32% of An. gambiae (s.l.) mosquitoes contained blood from more than one host species. None of the 1414 tested mosquitoes in both sites were found positive for Plasmodium spp. sporozoites. WHO insecticide resistance tests revealed resistance to permethrin in the An. arabiensis population from Rosso (mortality = 64%) as well as reduced mortality to deltamethrin (mortality = 97%). Conclusion This study provides updated information on the composition and dynamics of the malaria vector system in southern Mauritania where malaria is endemic. Such data are a necessary prerequisite to devise and implement tailored malaria elimination strategies in areas of low residual transmission