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This study aimed to determine the resistance of diarrheagenic Escherichia coli (DEC) strains to β-lactams antibiotics and to perform the molecular characterization of extended-spectrum β-lactamases (ESBLs) and integrons genes. It was carried out from August 2013 to October 2015 and involved 31 DEC strains isolated from diarrheal stools samples collected from children less than 5 years. The identification and characterization of DEC strains were done through the standard biochemical tests that were confirmed using API 20E and polymerase chain reaction (PCR). The antibiogram was realized by the disk diffusion method, then an amplification of the β-lactamase resistance genes and integrons by PCR was done. Out of the 419 E. coli, 31 isolates (7.4%) harbored the DEC virulence genes. From these DEC, 21 (67.7%) were ESBL-producing E. coli. Susceptibility to ESBL-producing E. coli showed that the majority of isolates were highly resistant to amoxicillin (77.4%), amoxicillin-clavulanic acid (77.4%), and piperacillin (64.5%). The following antibiotic resistance genes and integron were identified: blaTEM (6.5%), blaSHV (19.4%), blaOXA (38.7%), blaCTX-M (9.7%), Int1 (58.1%), and Int3 (19.4%). No class 2 integron (Int2) was characterized. Because of the high prevalence of multidrug-resistant ESBL organisms found, there is a need of stringent pediatric infection control measures.

Edible oils are vital constituents that provide energy and serve as a carrier of fat-soluble vitamins such as vitamin A. This article aims to evaluate the physicochemical properties and assess the vitamin A content of 45 edible oil samples (37 of palm oil and 8 of cotton seed oil) sold in five markets in Ouagadougou, Burkina Faso. A retinol palmitate standard was used as a control sample for vitamin A content assessment. The physicochemical properties, including the moisture content, acid value, peroxide value, saponification value, and mineral oils content, were determined according to the International Organization for Standardization. Vitamin A levels were assessed by the High-Performance Liquid Chromatography method. The average values of moisture, acid, peroxide contents, and vitamin A were 0.09%, 0.53 mg KOH/g, 6.24 ± 2.92 meq O2/kg, and 6.70 ± 14.26 mg of Vit A/Kg, respectively. Our samples were soap and mineral oils free. However, several samples did not comply with Codex Alimentarius standards for water content (4.44%), acid peroxide values (10%), and vitamin A levels (80%).

Malaria remains the most common parasitic disease on the planet, with 229 million cases and 409,000 deaths worldwide in 2019, including 274,030 children under the age of 5. It is one of the most important infectious diseases in the world and its control is compromised by the spread of the parasite's resistance to antimalarial drugs. This study aims to review the literature of resistant Plasmodium falciparum genes over the past twenty years. One hundred and five (105) articles were collected and read while the resistance of P. falciparum was being studied. Several P. falciparum gene resistances antimalarial drugs were discovered over the past twenty years. The most recent one is the Kelch13 gene of P. falciparum (Pfkelch13) which has showed resistance to artemisinin in Asia. In Africa, this gene represents a potential candidate for resistance to artemisinin, although no resistance was reported.

Host responses to infection with the malaria parasite Plasmodium falciparum vary among individuals for reasons that are poorly understood. Here we reveal metabolic perturbations as a consequence of malaria infection in children and identify an immunosuppressive role of endogenous steroid production in the context of P. falciparum infection. We perform metabolomics on matched samples from children from two ethnic groups in West Africa, before and after infection with seasonal malaria. Analysing 306 global metabolomes, we identify 92 parasitaemia-associated metabolites with impact on the host adaptive immune response. Integrative metabolomic and transcriptomic analyses, and causal mediation and moderation analyses, reveal an infection-driven immunosuppressive role of parasitaemia-associated pregnenolone steroids on lymphocyte function and the expression of key immunoregulatory lymphocyte genes in the Gouin ethnic group. In children from the less malaria-susceptible Fulani ethnic group, we observe opposing responses following infection, consistent with the immunosuppressive role of endogenous steroids in malaria. These findings advance our understanding of P. falciparum pathogenesis in humans and identify potential new targets for antimalarial therapeutic interventions.

BackgroundA blood-stage vaccine targeting the erythrocytic-stages of the malaria parasite Plasmodium falciparum could play a role to protect against clinical disease. Antibodies against the P. falciparum serine repeat antigen 5 (SE47 and SE36 domains) correlate well with the absence of clinical symptoms in sero-epidemiological studies. A previous phase Ib trial of the recombinant SE36 antigen formulated with aluminum hydroxyl gel (BK-SE36) was promising. This is the first time the vaccine candidate was evaluated in young children below 5 years using two vaccination routes.MethodsSafety and immunogenicity of BK-SE36 was assessed in a double-blind, randomized, controlled, age de-escalating phase Ib trial. Fifty-four Burkinabe children in each age cohort, 25–60 or 12–24 months, were randomized in a 1:1:1 ratio to receive three doses of BK-SE36 either by intramuscular (BK IM) or subcutaneous (BK SC) route on Day 0, Week 4, and 26; or the control vaccine, Synflorix®via IM route on Day 0, Week 26 (and physiological saline on Week 4). Safety data and samples for immunogenicity analyses were collected at various time-points.ResultsOf 108 subjects, 104 subjects (96.3%) (Cohort 1: 94.4%; Cohort 2: 98.1%) received all three scheduled vaccine doses. Local reactions, mostly mild or of moderate severity, occurred in 99 subjects (91.7%). The proportion of subjects that received three doses without experiencing Grade 3 adverse events was similar across BK-SE36 vaccines and control arms (Cohort 1: 100%, 89%, and 89%; and Cohort 2: 83%, 82%, and 83% for BK IM, BK SC, and control, respectively). BK-SE36 vaccine was immunogenic, inducing more than 2-fold change in antibody titers from pre-vaccination, with no difference between the two vaccination routes. Titers waned before the third dose but in both cohorts titers were boosted 6 months after the first vaccination. The younger cohort had 2-fold and 4-fold higher geometric mean titers compared to the 25- to 60-month-old cohort after 2 and 3 doses of BK-SE36, respectively.ConclusionBK-SE36 was well tolerated and immunogenic using either intramuscular or subcutaneous routes, with higher immune response in the younger cohort.Clinical Trial Registrationhttps://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=934, identifier PACTR201411000934120.

Seasonal Malaria Chemoprevention (SMC), which combines amodiaquine (AQ) with sulfadoxine-pyrimethamine (SP), is an effective and promising strategy, recommended by WHO, for controlling malaria morbidity and mortality in areas of intense seasonal transmission. Despite the effectiveness of this strategy, a number of controversies regarding the impact of the development of malaria-specific immunity and challenges of the strategy in the context of increasing and expanding antimalarial drugs resistance but also the limited coverage of the SMC in children make the relevance of the SMC questionable, especially in view of the financial and logistical investments. Indeed, the number of malaria cases in the target group, children under 5 years old, has increased while the implementation of SMC is been extended in several African countries. This ambivalence of the SMC strategy, the increase in the prevalence of malaria cases suggests the need to evaluate the SMC and understand some of the factors that may hinder the success of this strategy in the implementation areas. The present review discusses the impact of the SMC on malaria morbidity, parasite resistance to antimalarial drugs, molecular and the immunity affecting the incidence of malaria in children. This approach will contribute to improving the malaria control strategy in highly seasonal transmission areas where the SMC is implemented.

Seasonal Malaria Chemoprevention (SMC), which combines amodiaquine (AQ) with sulfadoxine-pyrimethamine (SP), is an effective and promising strategy, recommended by WHO, for controlling malaria morbidity and mortality in areas of intense seasonal transmission. Despite this strategy, the number of malaria cases in the target group, children under five years old, has increased while the implementation of SMC will be extended in several African countries. This increase in the prevalence of malaria cases suggests the need to evaluate SMC and understand some of the factors that may hinder the success of this strategy in the intervention areas. The present review discusses the impact of SMC on target population morbidity, parasite resistance to antimalarial drugs, molecular and the immunity affecting the incidence of malaria in children under five years old. This approach will contribute to improving the malaria control strategy in highly seasonal transmission areas.

Background and objective: In recent years, carbapenemase-producing Enterobacterales (CPE) resistance to antibiotics has dramatically increased leading to limitations of their treatment options. In the present study, we investigated the occurrence of carbapenemase-producing Escherichia coli and Salmonella in rural Burkina Faso.Materials and methods: Salmonella isolates were serotyped according to the Kauffman White scheme. Diarrheagenic Escherichia coli (DEC) strains was identified using 16-plex Polymerase Chain Reaction (PCR), whereas antibiotic susceptibility was realized using the disk diffusion method. Furthermore, multiplex PCR assays were carried out using oligonucleotides to detect the presence of genes of the blaKPC, blaVIM, blaIMP, blaTEM, blaSHV, blaOXA and blaCTX-M types in all E. coli and Salmonella strains.Results: The study highlighted high resistance rates of the identified bacteria to common antibiotics. Likewise, two strains of E. coli were imipenem resistant with carbapenemase-encoding genes. The genes detected were Klebsiella pneumoniae carbapenemase (KPC), Verona integrin-encoded metallo-β-lactamase (VIM) and Imipenemase (IMP-2) reaching a rate of 40% each in E. coli strains. However, no Salmonella carbapenemases blaKPC, blaVIM or blaIMP were detected.Conclusion: This study showed that for a real-time infection control and prompt application of antimicrobial chemotherapy, characterization of carbapenemase-producing Enterobacterales in patients is crucial.Keywords: Antibiotics, Carbapenemase-Producing Enterobacterales, children, Burkina Faso

Background Malaria case management relies on World Health Organization (WHO)-recommended artemisinin-based combination therapy (ACT), and a continuous understanding of local community knowledge, attitudes, and practices may be a great support for the success of malaria disease control efforts. In this context, this study aimed to identify potential facilitators or barriers at the community level to inform a health district-wide implementation of multiple first-line therapies (MFT) as a new strategy for uncomplicated malaria case management. Methods A community-based cross-sectional study using a mixed-method design was carried out from November 2018 to February 2019, in the health district (HD) of Kaya in Burkina Faso. Quantitative data were collected using a standardized questionnaire from 1394 individuals who had fever/malaria episodes four weeks prior to the survey. In addition, 23 focus group discussions (FGDs) were conducted targeting various segments of the community. Logistic regression models were used to assess the predictors of community care-seeking behaviours. Results Overall, 98% (1366/1394) of study participants sought advice or treatment, and 66.5% did so within 24 h of fever onset. 76.4% of participants preferred to seek treatment from health centres as the first recourse to care, 5.8% were treated at home with remaining drug stock, and 2.3% preferred traditional healers. Artemether-lumefantrine (AL) was by far the most used anti-malarial drug (98.2%); reported adherence to the 3-day treatment regimen was 84.3%. Multivariate analysis identified less than 5 km distance travelled for care (AOR = 2.7; 95% CI 2.1–3.7) and education/schooling (AOR = 1.8; 95% CI 1.3–2.5) as determinants of prompt care-seeking for fever. Geographical proximity (AOR = 1.5, 95% CI 1.2–2.1), having a child under five (AOR = 4.6, 95% CI 3.2–6.7), being pregnant (AOR = 6.5, 95% CI 1.9–22.5), and living in an urban area (AOR = 2.8, 95% CI 1.8–4.2) were significant predictors for visiting health centres. The FGDs showed that participants had good knowledge about malaria symptoms, prevention tools, and effective treatment. Behaviour change regarding malaria treatment and free medication for children under five were the main reasons for participants to seek care at health centres. Conclusions The study showed appropriate knowledge about malaria and positive community care-seeking behaviour at health centres for fever/malaria episodes. This could potentially facilitate the implementation of a MFT pilot programme in the district. ClinicalTrials.gov Identifier: NCT04265573.

Aim: The present study aimed to evaluate the Plasmodium falciparum genetic diversity according to the host hemoglobin and G6PD genetic variants during the course of malaria in infected children aged from 2 to 10 years and living in endemic area in Burkina Faso. Study Design: The study was designed as a longitudinal follow up conducted between May 2015 and February 2016 in Banfora health district, Burkina Faso. Methodology: We included 136 subjects (73 males and 63 females; age range from 2-10 years). Blood thick and thin film was done by capillary blood. Venous blood was collected for DNA extraction. Malaria diagnosis was done by microscopy. Human and parasite DNA were extracted based on Qiagen kit procedure. Then, hemoglobin and G6PD were genotyped by RLFP-PCR while the msp1, msp2 and eba175 genes were typed by a nested PCR. All PCR products were analyzed by electrophoresis on a 1.5-2% agarose gel and alleles categorized according to the molecular weight. Results: The prevalence of hemoglobin type was 19.11% for abnormal hemoglobin and 80.9% for normal hemoglobin carriage. The prevalence of G6PD type was 91.18% for normal and 8.82% for G6PD deficiency carriage, respectively. The prevalence of msp1 allelic families was 81.60%, 80.80% and 67.20% for k1, ro33 and mad20 respectively while for msp2 gene, fc27 and 3D7 allelic family the prevalence was 70.53% and 69.64% respectively. The eba175 allelic families’ distribution showed 77.31% and 40.21% for fcr3 and Camp respectively. There was no difference in multiplicity of infection (MOI) according to hemoglobin genotypes and G6PD types. We found that k1 was the predominant allelic family of msp1 in normal hemoglobin genotype (AA) and normal G6PD type. The mixed infection of eba175 was statistically higher in abnormal hemoglobin (p=0.04). There was no statistical difference between fcr3 and camp prevalence excepted in G6PD deficient type. The polymorphism results showed that the prevalence of 450 bp in fc27 was statistically significantly higher in normal hemoglobin variant carriers (AA) than abnormal hemoglobin carriers (p=2.10 -4)). However, the prevalence of 350 bp in fc27 was statistically higher in normal G6PD than deficient G6PD carriers (p=0.034). Conclusion: Our result showed that the distribution of msp1 and eba75 polymorphism could be influenced by hemoglobin and G6PD variants. These results suggest that hemoglobin and G6PD could influence P. falciparum genetic diversity.

With high annual mortality rates among young children, antimicrobial resistant salmonellosis is considered a major public health concern worldwide. Antimicrobial resistant salmonellosis is a worldwide health issue, particularly in low income countries with high microbially-derived food contaminations. As a result, it is important to better understand the biological factors that may control these bacteria’s dissemination low immunity individuals such as children. Thus, a sound epidemiological surveillance and control of salmonellosis (that is, tet and catA1) requires a better understanding of the role that class 1, 2 and 3 integrons play in the spread of these antimicrobial resistant genes. A total of 275 stool samples of children suffering of diarrhea in rural Burkina Faso were collected and their Salmonella species were screened. The antimicrobial resistance determinants were investigated by Polymerase Chain Reaction, checking the presence of class 1, 2, 3 integrons, tet and catA1 resistance genes. Seven of the nine confirmed Salmonella strains (78%) were multidrug resistant while 100% were resistant to amoxicillin. Antibiotic resistance genes catA and tet were present in 11.1 and 22.2%, respectively. Integrons were detected as follows: Int1 (44.4%) and Int2 (22.2%). No class 3 integron was detected. A surveillance and control programme of antimicrobial drug resistant Salmonella species is of paramount importance for limiting spread of these pathogens among children. Key words: Antibiotic resistance genes, Class 1 and 2 integrons, Salmonella, children.

Introduction: In spite of considerable progress, malaria remains a public health problem in many areas, particularly in sub-Saharan Africa. One major complexity of malaria disease is caused by the development and the spread of vector and parasite resistance to insecticides and antimalarial drugs respectively. The Pfcrt76T gene mutation has been validated as a marker conferring resistance to chloroquine and other antimalarial drugs. The extension of Plasmodium falciparum resistance to commonly used antimalarial drugs (chloroquine, sulfadoxine-pyrimethamine) led to the adoption and the use of artemisinin-based combinations in Burkina Faso since 2005. Aims: The present study was initiated to assess the prevalence of the Pfcrt76T mutation in two different malaria epidemiological setting after a decade of introduction of artemisinin-based combination therapies (ACTs) in Burkina Faso. Methodology: The study population consisted of 181 uncomplicated malaria patients recruited in Banfora and Saponé health districts in 2012 and 2013. Blood samples were collected from finger prick on filter paper, dried and sent to the Molecular Biology Laboratory at Centre National de Recherche et de Formation sur le Paludisme (CNRFP) for molecular analyzes. DNA of Plasmodium falciparum was extracted with DNA extraction kit (Qiagen®) and the Pfcrt76T mutation was determined based on Polymerase Chain Reaction / Restriction Fragment Length Polymorphism technique (RFLP). Results: The results of this study showed that the frequency of the pfcrt76T mutant allele (33.7%) was statistically lower than the Pfcrt76K wild-type allele (57.4%) in the study area. Moreover, the prevalence of Pfcrt76T mutation was neither associated with the patient age nor with the parasite density while a significant difference was observed between the two epidemiological setting, Banfora and Saponé. Conclusion: The findings of this study has shown a drop in the prevalence of mutant parasites Pfcrt76T in both the study area eight years after the introduction of ACTs compared to previous studies.

Objective Candida albicans is a yeast with multiple genotypes. It's a commensal fungus colonizing various sites. However, when the host's immune system weakens, it becomes pathogenic and is responsible for various lesions. In Burkina Faso, antifungal drugs are frequently used, particularly fluconazole, the most used systemic antifungal. This antifungal drug and other antifungal drugs are often used for self-medication or prescribed outside of antifungal susceptibility test results. These situations led to the emergence of Candida albicans strains resistant to antifungal drugs commonly used in Burkina Faso. The aim of this study was to determine the types of Candida albicans using PCRs targeting 25S rDNA and ALT repeat sequences of the RPS and to establish their azoles and polyenes susceptibility profile. Material and methods Antifungal susceptibility testing by disk diffusion method was performed in accordance with CLSI document M44-A for yeasts and the manufacturer's instructions. Candida albicans isolates were genotyped using specific PCR primers of the rDNA and RPS genes. Results Ten (10) RPS types of Candida albicans were found in our study: The most common RPS types are A3 (40.6%), A2 (24.0%) and A2/3 (14.6%) for genotype A, B2/3 (5.2%) for genotype B and C2 (3.2%) for genotype C. The Azole resistance, especially fluconazole (74.4%), was the most common with genotype A, including A3 (36.6%), A2 (18. 3%). Polyene resistance was rare with nystatin, only A3 (1.2%) resistant isolate to nystatin was observed. For amphotericin B, the highest observed resistance rates were A3 (11.0%) and A2/3 (8.5%) for the genotype A and B2 (10.0%), B3 (10.0%) and B2/3 (10.0%) for genotype B. Conclusion Our study showed that Candida albicans resistance to azoles, especially to fluconazole, is an important phenomenon in Ouagadougou, and several genotypes RPS types are involved. Thus, fluconazole would not be an antifungal agent for first-line prescribing for treatment of candidiasis in Ouagadougou. This study will be continued to determine the molecular mechanisms involved in these antifungal resistances, for further research of new molecules with different action targets.

A recent randomized controlled trial, the WANECAM (West African Network for Clinical Trials of Antimalarial Drugs) trial, conducted at seven centers in West Africa, found that artemether-lumefantrine, artesunate-amodiaquine, pyronaridine-artesunate, and dihydroartemisinin-piperaquine all displayed good efficacy. However, artemether-lumefantrine was associated with a shorter interval between clinical episodes than the other regimens. In a further comparison of these therapies, we identified cases of persisting submicroscopic parasitemia by quantitative PCR (qPCR) at 72 h posttreatment among WANECAM participants from 5 sites in Mali and Burkina Faso, and we compared treatment outcomes for this group to those with complete parasite clearance by 72 h. Among 552 evaluable patients, 17.7% had qPCR-detectable parasitemia at 72 h during their first treatment episode. This proportion varied among sites, reflecting differences in malaria transmission intensity, but did not differ among pooled drug treatment groups. However, patients who received artemether-lumefantrine and were qPCR positive at 72 h were significantly more likely to have microscopically detectable recurrent Plasmodium falciparum parasitemia by day 42 than those receiving other regimens and experienced, on average, a shorter interval before the next clinical episode. Haplotypes of pfcrt and pfmdr1 were also evaluated in persisting parasites. These data identify a possible threat to the parasitological efficacy of artemether-lumefantrine in West Africa, over a decade since it was first introduced on a large scale.

Background The aim of this study was to determine the resistance of diarrheagenic Escherichia coli strains to β-lactams antibiotics and to perform the molecular characterization of Extended Spectrum β-lactamases (ESBL) and integrons genes. Methods This study was carried out from August 2013 to October 2015 and involved 31 DEC strains isolated from diarrheal stools samples collected from children less than five years of age. The identification and characterization of DEC strains was done through the standard biochemical tests those were confirmed using API 20E and Polymerase Chain Reaction (PCR). The determination of antimicrobial resistance was realized by the disk diffusion method then an amplification of the β-lactamase resistance genes and integrons by PCR was done. Results Out of the 419 E. coli strains identified, 31 isolates (7.4%) harbored the DEC virulence genes. From these DEC, 21 (67.7%) were ESBL-producing E. coli. Susceptibility to ESBL-producing E. coli showed that the majority of isolates were highly resistant to amoxicillin (77.4%), amoxicillin clavulanic acid (77.4%) and piperacillin (64.5%). The following antibiotic resistance genes and integron were identified from the 31 DEC isolates: blaTEM (6.5%), blaSHV (19.4%), blaOXA (38.7%) blaCTX−M (9.7%), Int1 (58.1%) and Int3 (19.4%). No class 2 integrons (Int2) was characterized. Conclusions Because of the high prevalence of multidrug-resistant ESBL organisms found in this study among pediatric patients, there is a need of stringent pediatric infection control measures.

Background: Malaria is known to have a negative impact on pregnant women and their foetuses. This infection during pregnancy represents a major public health problem in tropical and subtropical regions. The aim of this study was to determine the prevalence and risk factor of Plasmodium falciparum in pregnant women the city of Ouagadougou (Burkina Faso). Methods: A cross-sectional study was conducted from April 2019 to March 2020 in four health districts within Ouagadougou, capital city. Samples were collected from the placenta from 531 women after delivered Plasmodium falciparum then by PCR. Results: The prevalence placental malaria with of Plasmodium falciparum was estimated at 7.53%. The status of unemployment and/ or the status of residence around the city of Ouagadougou represent risk of malaria infection.Conclusion: Malaria in pregnancy is responsible for several complications so emphasis should be placed on communication about malaria control in pregnancy and, the behavior of pregnant women and health workers as well.

Background For uncomplicated Plasmodium falciparum malaria, highly efficacious single-dose treatments are expected to increase compliance and improve treatment outcomes, and thereby may slow the development of resistance. The efficacy and safety of a single-dose combination of artefenomel (800 mg) plus ferroquine (400/600/900/1200 mg doses) for the treatment of uncomplicated P. falciparum malaria were evaluated in Africa (focusing on children ≤ 5 years) and Asia. Methods The study was a randomized, double-blind, single-dose, multi-arm clinical trial in patients aged > 6 months to kelch-13 mutations were explored. Results A total of 373 patients were treated: 289 African patients ≤ 5 years (77.5%), 64 African patients > 5 years and 20 Asian patients. None of the treatment arms met the target efficacy criterion for PCR-adjusted ACPR at Day 28 (lower limit of 95% confidence interval [CI] > 90%). PCR-adjusted ACPR at Day 28 [95% CI] in the PP Set ranged from 78.4% [64.7; 88.7%] to 91.7% [81.6; 97.2%] for the 400 mg to 1200 mg ferroquine dose. Efficacy rates were low in Vietnamese patients, ranging from 20 to 40%. A clear relationship was found between drug exposure (artefenomel and ferroquine concentrations at Day 7) and efficacy (primary endpoint), with higher concentrations of both drugs resulting in higher efficacy. Six distinct kelch-13 mutations were detected in parasite isolates from 10/272 African patients (with 2 mutations known to be associated with artemisinin resistance) and 18/20 Asian patients (all C580Y mutation). Vomiting within 6 h of initial artefenomel administration was common (24.6%) and associated with lower drug exposures. Conclusion The efficacy of artefenomel/ferroquine combination was suboptimal in African children aged ≤ 5 years, the population of interest, and vomiting most likely had a negative impact on efficacy. Trial registration ClinicalTrials.gov, NCT02497612. Registered 14 Jul 2015, https://clinicaltrials.gov/ct2/show/NCT02497612?term=NCT02497612&draw=2&rank=1

Aims: The aim of this study is to assess the prevalence of hemoglobin abnormalities and G6PD deficiency and their respective influence on anemia occurring in less than five years old children with clinical P. falciparum malaria living in Burkina Faso. Study Design: The study was a cross-sectional survey with descriptive focus conducted from December 2010 to January 2013 in Saponé health district and from May to October 2011 in Banfora health district. Clinical and laboratory data were collected. Blood smears on slides for malaria diagnosis by microscopy, hemoglobin level and filter paper for the detection of human genetic factors were performed. Methodology: A total of 386 subjects from Saponé (131) and Banfora (255) were enrolled. DNA collected from each sample was extracted using chelex-100 method and the human genetic resistance factors background was assessed by RFLP-PCR. Abnormal hemoglobin patients were classified as NonAA while AA was defined the normal hemoglobin. Results: In this study, 70.98% (274/386) were classified normal hemoglobin (AA) while 29.02% (112/386) of subjects were carrying at least one abnormal (NonAA) allele: 24.35%AC, 3.63% AS, 0.78%CC and 0.26%SC. G6PD deficiency was 9.59% (37/386) among which, 4.92% for male and 4.66% in female. However, this gender difference was not statistically significant (p=1.00). 319/367 (86.92%) of the patients were anemic (59.4% with moderate anemia and 20.98% with mild anemia). The prevalence of anemia in G6PD deficient subjects was 83.33% (of which 58.33% were moderate anemia and 22.22% mild anemia). The difference between types of hemoglobin (p=0.64) in the occurrence of anemia (AA 87.64% and Non AA 85.18%) was not statistically significant. Conclusion: This study showed that the prevalence of these genetic factors was relatively low among children with clinical falciparum malaria with high parasite density. In addition, these factors appear to have no effect on anemia.

Aims: The aim of this study was to assess the impact of hemoglobin polymorphisms and G6PD deficiency on the course of uncomplicated malaria infection in children aged from 2 to 10 years in Burkina Faso. Study Design: The study was conducted as a longitudinal study in Banfora health district. A total of 150 children aged from 2 to 10 years was enrolled and followed up between May 2015 and February 2016. Blood samples were collected at four different time points: before infection (Visit 1), during asymptomatic parasitemia (Visit 2), during symptomatic parasitemia (Visit 3) and three weeks after treatment (Visit 4). Clinical examination, hematology parameters and malaria diagnosis using microscopy were performed. Hemoglobin and G6PD typing were done using PCR-RFLP. Hemoglobin AA genotypes were defined as normal hemoglobin while Hemoglobin AC, AS and SS were defined as abnormal hemoglobin (hb non-AA). Results: The prevalence of hemoglobin (hb) genotypes was 81.21% for AA while hb non-AA genotypes were estimated at 18.79% (12.08% for hbAC, 6.04% for hbAS and 0.67% for HbSC). The prevalence of G6PD genotypes was 89.26% and 10.74% for normal G6PDn and G6PD deficiency respectively. The prevalence of asymptomatic carriers of P. falciparum was not affected neither by the genotypes of Hemoglobin, nor by the G6PD deficiency. Conversely, the risks of developing uncomplicated malaria in G6PD deficiency (G202A) group, was significantly lower (p = 0.04). The results showed a significant difference (p˂0.0001) in the means of P. falciparum parasite densities between asymptomatic and symptomatic phase in Hemoglobin AA genotypes carriers while the means of parasite density was comparable in non-Hemoglobin AA carriers. Conclusion: Our study showed that G6PD deficiency protects against clinical malaria while P. falciparum parasite density increasing was correlated with carrying hemoglobin genotypes AA.

Additional file 1. Study methods. Supplementary information regarding enrolment procedures, randomization, administration of study treatments, justification of the doses of ferroquine and artefenomel, dose adjustment to body weight, use of rescue treatment and definition of treatment failure.

Additional file 2. Study results. Supplementary data regarding patient demographics, baseline characteristics, compliance/exposure, as well as further efficacy and safety data.

Additional file 4. Exposure–response analysis details. Supplementary document including tables and figures to provide further methodological details and results on the exposure–response analysis.

Additional file 3. Pharmacokinetic analysis details. Supplementary document including tables and figures to provide further methodological details and results on the pharmacokinetic analysis.

Additional file 5. Electrocardiogram (ECG) exposure–response analysis details. Supplementary document including tables and figures to provide further methodological details and results on the ECG exposure–response analysis.

Host responses to infection with the malaria parasite Plasmodium falciparum vary among individuals for reasons that are poorly understood. Here we reveal metabolic perturbations as a consequence of malaria infection in children and identify an immunosuppressive role of endogenous steroid production in the context of P. falciparum infection. We perform metabolomics on matched samples from children from two ethnic groups in West Africa, before and after infection with seasonal malaria. Analysing 306 global metabolomes, we identify 92 parasitaemia-associated metabolites with impact on the host adaptive immune response. Integrative metabolomic and transcriptomic analyses, and causal mediation and moderation analyses, reveal an infection-driven immunosuppressive role of parasitaemia-associated pregnenolone steroids on lymphocyte function and the expression of key immunoregulatory lymphocyte genes in the Gouin ethnic group. In children from the less malaria-susceptible Fulani ethnic group, we observe opposing responses following infection, consistent with the immunosuppressive role of endogenous steroids in malaria. These findings advance our understanding of P. falciparum pathogenesis in humans and identify potential new targets for antimalarial therapeutic interventions.

Background: The emergence and spread of multidrug-resistant gram-negative bacteria (MDR) has become a major public health concern worldwide. This resistance is caused by enzymes-mediated genes (i.e., extended spectrum beta-lactamases) that are common in certain Enterobacterioceae species. However, the distribution of these genes is poorly documented in Burkina Faso. This study aims to determine the prevalence and distribution of the resistant genes coding for broad spectrum beta-lactamases and quinolones in rural Burkina Faso.Methods: Multiplex PCR assays were carried out to detect ESBL-encoding genes, including blaOXA, blaTEM, blaCTX-M, blaSHV. The assays also assessed the presence of quinolone resistance gene namely qnrA, qnrB and qnrS in the quinolone-resistance DEC and Salmonella strains.Results: The Extended-Spectrum Beta-Lactamases (ESBL) resistance phenotype was reported in all the E. coli isolates (5/5). Cross-resistance phenotype to quinolones (CRQ) was shown by one Salmonella strain (1/9) and three E. coli (3/5). Cross-resistance phenotypes to fluoroquinolones (CRFQ) were harboured by one Salmonella (1/9) and carbapenemase phenotypes were detected in two E. coli strains (2/5). Whilst the blaOXA genes were detected in 100% (5/5) of E. coli isolates and in 33.33% (3/9) Salmonella isolates. One strain of E. coli (1/5) harbored the blaCTX-M gene and the qnrB gene simultaneously.Conclusions: This study identified β-lactam (bla) and quinolone resistance (qnr) genes in multidrug-resistant E. coli and Salmonella spp. in rural Burkina Faso. Our finding which highlighted the enterobacteriaceae strains resistance to β-lactams and quinolones are of high interest for adequate management of antimicrobial resistant genes outbreak in Burkina Faso.

Background: In recent years, carbapenemase-producing Enterobacterales (CPE) resistance to antibiotics has dramatically increased leading to limitations of their treatment options. In the present study, we investigated the occurrence of carbapenemase-producing Escherichia coli and Salmonella in rural Burkina Faso. Methods: Salmonella isolates were serotyped according to the Kauffman White scheme. Diarrheagenic Escherichia coli (DEC) strains was identified using 16-plex Polymerase Chain Reaction (PCR), whereas antibiotic susceptibility was realized using the disk diffusion method. Furthermore, multiplex PCR assays were carried out using oligonucleotides to detect the presence of genes of the blaKPC, blaVIM, blaIMP, blaTEM, blaSHV, blaOXA and blaCTX-M types in all E. coli and Salmonella strains.Results: The study highlighted high resistance rates of the identified bacteria to common antibiotics. Likewise, two strains of E. coli were imipenem resistant with carbapenemase-encoding genes. The genes detected were Klebsiella pneumoniae carbapenemase (KPC), Verona integrin-encoded metallo-β-lactamase (VIM) and Imipenemase (IMP-2) reaching a rate of 40% each in E. coli strains. However, no Salmonella carbapenemases blaKPC, blaVIM or blaIMP were detected.Conclusions: This study showed that for a real-time infection control and prompt application of antimicrobial chemotherapy, characterization of carbapenemase-producing Enterobacterales in patients is crucial.

Background. The World Health Organization (WHO) pre-qualified a single-dose typhoid conjugate vaccine (TCV) in December 2017. WHO requested data on co-administration of TCV with Expanded Programme on Immunisation vaccines in typhoid-endemic countries. We tested co-administration of Typbar TCV® [Bharat Biotech International] with routine group A meningococcal conjugate vaccine (MCV-A) and measles-rubella (MR) vaccine. Methods: We conducted a double-blind, randomised, controlled trial at Schiphra Protestant Hospital outpatient paediatric clinic, Ouagadougou, Burkina Faso. Children recruited at routine 15-month vaccination visits were randomly assigned (1:1:1) to intramuscularly receive: Group 1) TCV plus control vaccine (inactivated polio vaccine) and MCV-A 28 days later; Group 2) TCV and MCV-A; or, Group 3) MCV-A and control vaccine. Routine MR vaccine was administered subcutaneously at day 0 to all participants. The primary outcome was safety, assessed by local and systemic reactions at 0, 3, and 7 days after immunisation; and unsolicited adverse events and serious adverse events 28 days and 6 months after immunisation, respectively. Primary analysis included all participants receiving at least one intramuscular vaccine. Immunogenicity was assessed as a secondary endpoint. ClinicalTrials.gov identifier NCT03614533. Findings: Between December 3, 2018 and February 18, 2019, we recruited and vaccinated 150 children: Group 1 (n=49), Group 2 (n=50), and Group 3 (n=51). Solicited local and systemic symptoms were infrequent and similar for TCV and control recipients, as were adverse events (Group 1: 61·2%, 95% CI 46·2-74·8; Group 2: 64·0%, 95% CI 49·2-77·1; Group 3: 68·6%, 95% CI 54·1-80·9) and serious adverse events (Group 1: 2·0%, 95% CI 0·1-10·9; Group 2: 8·0%, 95% CI 2·2-19·2; Group 3: 5·9%, 95% CI 1·2-16·2). No serious adverse events were related to vaccination. TCV generated robust immunity without interference with MCV-A or MR vaccine. Interpretation: TCV can be safely co-administered with routine MCV-A and MR vaccine. Trial Registration: y. The trial is registered at ClinicalTrials.gov, Identifier NCT03614533. Funding: Bill & Melinda Gates Foundation. Declaration of Interests: The authors have no competing interests to declare. Ethics Approval Statement: The study was approved by ethics committees in Burkina Faso (Comite d’Ethique pour la Recherche en Sante [CERS], Ouagadougou, Burkina Faso) and Maryland, USA (Institutional Review Board, University of Maryland, Baltimore), and by the Regulatory Authority in Burkina Faso (L’Agence Nationale de Regulation Pharmaceutique, Ouagadougou, Burkina Faso).

The recent World Malaria report shows that progress in malaria elimination has stalled. Current data acquisition by NMCPs depend on passive case detection and clinical reports focused mainly on Plasmodium falciparum (Pf). In recent times, several countries in sub-Saharan Africa have reported cases of Plasmodium vivax (Pv) with a considerable number being Duffy negative. The burden of Pv and Plasmodium ovale (Po) appear to be more than acknowledged. Similarly, the contribution of asymptomatic malaria in transmission is hardly considered by NMCPs in Africa. Inclusion of these as targets in malaria elimination agenda is necessary to achieve elimination goal, as these harbor hypnozoites. The Pan African Vivax and Ovale Network (PAVON) is a new consortium of African Scientists working in Africa on the transmission profile of Pv and Po. The group collaborates with African NMCPs to train in Plasmodium molecular diagnostics, microscopy, and interpretation of molecular data from active surveys to translate into policy. Details of the mission, rational and modus operandi of the group are outlined.

Objective Candida albicans is a yeast with multiple genotypes. It’s a commensal fungus colonizing various sites. However, when the host’s immune system weakens, it becomes pathogenic and is responsible for various lesions. In Burkina Faso, antifungal drugs are frequently used, particularly fluconazole, the most used systemic antifungal. This antifungal drug and other antifungal drugs are often used for self-medication or prescribed outside of antifungal susceptibility test results. These situations led to the emergence of Candida albicans strains resistant to antifungal drugs commonly used in Burkina Faso. The aim of this study was to determine the types of Candida albicans using PCRs targeting 25S rDNA and ALT repeat sequences of the RPS and to establish their azoles and polyenes susceptibility profile. Material and methods Antifungal susceptibility testing by disk diffusion method was performed in accordance with CLSI document M44-A for yeasts and the manufacturer’s instructions. Candida albicans isolates were genotyped using specific PCR primers of the rDNA and RPS genes. Results Ten (10) RPS types of Candida albicans were found in our study: The most common RPS types are A3 (40.6%), A2 (24.0%) and A2/3 (14.6%) for genotype A, B2/3 (5.2%) for genotype B and C2 (3.2%) for genotype C. The Azole resistance, especially fluconazole (74.4%), was the most common with genotype A, including A3 (36.6%), A2 (18. 3%). Polyene resistance was rare with nystatin, only A3 (1.2%) resistant isolate to nystatin was observed. For amphotericin B, the highest observed resistance rates were A3 (11.0%) and A2/3 (8.5%) for the genotype A and B2 (10.0%), B3 (10.0%) and B2/3 (10.0%) for genotype B. Conclusion Our study showed that Candida albicans resistance to azoles, especially to fluconazole, is an important phenomenon in Ouagadougou, and several genotypes RPS types are involved. Thus, fluconazole would not be an antifungal agent for first-line prescribing for treatment of candidiasis in Ouagadougou. This study will be continued to determine the molecular mechanisms involved in these antifungal resistances, for further research of new molecules with different action targets.

PRIMVAC is a VAR2CSA-derived placental malaria vaccine candidate aiming to prevent serious clinical outcomes of Plasmodium falciparum infection during pregnancy. We assessed the safety and immunogenicity of PRIMVAC adjuvanted with Alhydrogel or glucopyranosyl lipid adjuvant in stable emulsion (GLA-SE) in French and Burkinabe women who were not pregnant., Bundesministerium für Bildung und Forschung, through Kreditanstalt für Wiederaufbau, Germany; Inserm, and Institut National de Transfusion Sanguine, France; Irish Aid, Department of Foreign Affairs and Trade, Ireland.

While significant advances have been made in understanding Plasmodium falciparum gametocyte biology and its relationship with malaria parasite transmission, the gametocyte sex ratio contribution to this process still remains a relevant research question. The present review discusses the biology of sex determination in P. falciparum, the underlying host and parasite factors, the sex specific susceptibility to drugs, the effect of sex ratio dynamics on malaria parasite transmission and the development of gametocyte sex specific diagnosis tools. Despite the inherent differences across several studies and approaches, the emerging picture highlights a potentially relevant contribution of the P. falciparum gametocyte sex ratio in the modulation of malaria parasite transmission. The increasing availability of molecular methods to measure gametocyte sex ratio will enable evaluation of important parameters, such as the impact of drug treatment on gametocyte sex ratio in vitro and in vivo as well as the changes of gametocyte sex ratios in natural infections, key steps towards elucidating how these parameters affect parasite infectiousness to the mosquito vectors.

Background: Individuals living in malaria-endemic regions develop naturally acquired immunity against severe malarial disease, but it is unclear whether immunity that affects the establishment of infections develops following continuous natural exposure. Methods: We cleared schoolchildren in Burkina Faso of possible sub-patent infections and examined them weekly for incident infections by PCR. Plasma samples collected at enrolment were used to quantify antibodies to the pre-eryhrocytic-stage antigens circumsporozoite protein (CSP) and liver stage antigen. Sporozoite gliding inhibition by naturally acquired antibodies was assessed using Plasmodium falciparum NF54 sporozoites; hepatocyte invasion was assessed using the human HC-04 hepatoma cell line and NF54 sporozoites. The associations between these functional pre-erythrocytic immunity phenotypes and time to PCR-detected infection were studied. Results: A total of 51 children were monitored; the median time to first detection of infection by PCR or development of clinical symptoms was 28 days. Anti-CSP antibody titres showed a strong positive association with sporozoite gliding motility inhibition (P

IntroductionAs demonstrated in mathematical models, the simultaneous deployment of multiple first-line therapies (MFT) for uncomplicated malaria, using artemisinin-based combination therapies (ACTs), may extend the useful therapeutic life of the current ACTs. This is possible by reducing drug pressure and slowing the spread of resistance without putting patients’ life at risk. We hypothesised that a simultaneous deployment of three different ACTs is feasible, acceptable and can achieve high coverage rate if potential barriers are properly identified and addressed.Methods and analysisWe plan to conduct a quasi-experimental study in the Kaya health district in Burkina Faso. We will investigate a simultaneous deployment of three ACTs, artemether–lumefantrine, pyronaridine–artesunate, dihydroartesinin–piperaquine, targeting three segments of the population: pregnant women, children under five and individuals aged five years and above. The study will include four overlapping phases: the formative phase, the MFT deployment phase, the monitoring and evaluation phase and the post-evaluation phase. The formative phase will help generate baseline information and develop MFT deployment tools. It will be followed by the MFT deployment phase in the study area. The monitoring and evaluation phase will be conducted as the deployment of MFT progresses. Cross-sectional surveys including desk reviews as well as qualitative and quantitative research methods will be used to assess the study outcomes. Quantitatives study outcomes will be measured using univariate, bivariate and multivariate analysis, including logistic regression and interrupted time series analysis approach. Content analysis will be performed on the qualitative data.Ethics and disseminationThe Health Research Ethics Committee in Burkina Faso approved the study (Clearance no. 2018-8-113). Study findings will be disseminated through feedback meetings with local communities, national workshops, oral presentations at congresses, seminars and publications in peer-reviewed scientific journals.Trial registration numberNCT04265573.

Highlights • Antibody dynamics and role in young the infants’ low susceptibility to febrile malaria were investigated. • No evidence for association of antibody titres with clinical protection was found. • Evidence for consistently low antibody titres in high and low transmission areas. • Other antibodies, other antibody-mediated mechanisms or other protecting factors may be operating., Background Young infants have reduced susceptibility to febrile malaria compared with older children, but the mechanism for this remains unclear. There are conflicting data on the role of passively acquired antibodies. Here, we examine antibody titres to merozoite surface antigens in the protection of children in their first two years of life in two settings with differing malaria transmission intensity and compare these titres to previously established protective thresholds. Methods Two cohorts of children aged four to six weeks were recruited in Banfora, Burkina and Keur Soce, Senegal and followed up for two years. Malaria infections were detected by light microscopic examination of blood smears collected at active and passive case detection visits. The titres of antibodies to the Plasmodium falciparum recombinant merozoite proteins (AMA1-3D7, MSP1-19, MSP2-Dd2, and MSP3-3D7) were measured by enzyme-linked immunosorbent assay at 1–6, 9, 12, 15 and 18 months of age and compared with the protective thresholds established in Kenyan children. Results Antibody titres were below the protective thresholds throughout the study period and we did not find any association with protection against febrile malaria. Antibodies to AMA1 and MSP1-19 appeared to be markers of exposure in the univariate analysis (and so associated with increasing risk) and adjusting for exposure reduced the strength and significance of this association. Conclusion The antibody levels we measured are unlikely to be responsible for the apparent protection against febrile malaria seen in young infants. Further work to identify protective antibody responses might include functional assays and a wider range of antigens.

Background: Individuals living in malaria-endemic regions develop immunity against severe malaria, but it is unclear whether immunity against pre-erythrocytic stages that blocks initiation of blood-stage infection after parasite inoculation develops following continuous natural exposure. Methods: We cleared schoolchildren living in an area (health district of Saponé, Burkina Faso) with highly endemic seasonal malaria of possible sub-patent infections and examined them weekly for incident infections by nested PCR. Plasma samples collected at enrolment were used to quantify antibodies to the pre-eryhrocytic-stage antigens circumsporozoite protein (CSP) and Liver stage antigen 1 (LSA-1). In vitro sporozoite gliding inhibition and hepatocyte invasion inhibition by naturally acquired antibodies were assessed using Plasmodium falciparum NF54 sporozoites. Associations between antibody responses, functional pre-erythrocytic immunity phenotypes and time to infection detected by 18S quantitative PCR were studied. Results: A total of 51 children were monitored. Anti-CSP antibody titres showed a positive association with sporozoite gliding motility inhibition (P

Cette etude a pour objectif d’evaluer l’effet d’un programme de prise en charge integree communautaire du paludisme et de la pneumonie (PCCP/P) sur l’efficacite de l’artemether-lumefantrine (AL). Ainsi, nous avons conduit deux essais cliniques ouverts, unicentriques avant et apres le PCCP/P sur l’efficacite therapeutique de l’AL. Au total 210 enfants de 6–59 mois ont ete inclus dans l’etude, soit 105 avant et 105 apres le PCCP/P. La reponse clinique et parasitologique adequate etait respectivement de 90,5 % et 86,7 % avant et apres le PCCP/P (p = 0,516). Nos resultats indiquent un maintien de l’efficacite therapeutique de l’AL au cours de ce programme.

Diarrheagenic Escherichia coli (DEC) is important bacteria of children’s endemic and epidemic diarrhea worldwide. The aim of this study was to determine the prevalence of DEC isolated from stool samples collected from children with acute diarrhea living in Ouagadougou, Burkina Faso. From August 2013 to October 2015, stool samples were collected from 315 children under 5 years of age suffering from diarrhea in the “Centre Médical avec Antenne Chirurgicale (CMA)” Paul VI and the CMA of Schiphra. E. coli were isolated and identified by standard microbiological methods, and the 16-plex PCR method was used to further characterize them. Four hundred and nineteen (419) E. coli strains were characterized, of which 31 (7.4%) DEC pathotypes were identified and classified in five E. coli pathotypes: 15 enteroaggregative E. coli (EAEC) (48.4%), 8 enteropathogenic E. coli (EPEC) (25.8%) with 4 typical EPEC and 4 atypical EPEC, 4 enteroinvasive E. coli (EIEC) (12.9%), 3 enterohemorrhagic E. coli (EHEC) 9.67%, and 1 enterotoxigenic E. coli (ETEC) 3.2%. The use of multiplex PCR as a routine in clinical laboratory for the detection of DEC would be a useful mean for a rapid management of an acute diarrhea in children.

Background. Differentiation between gametocyte-producing Plasmodium falciparum clones depends on both high levels of stage-specific transcripts and high genetic diversity of the selected genotyping marker obtained by a high-resolution typing method. By analyzing consecutive samples of one host, the contribution of each infecting clone to transmission and the dynamics of gametocyte production in multiclone infections can be studied. Methods. We have evaluated capillary electrophoresis based differentiation of 6 length-polymorphic gametocyte genes. RNA and DNA of 25 µL whole blood from 46 individuals from Burkina Faso were simultaneously genotyped. Results. Highest discrimination power was achieved by pfs230 with 18 alleles, followed by pfg377 with 15 alleles. When assays were performed in parallel on RNA and DNA, 85.7% of all pfs230 samples and 59.5% of all pfg377 samples contained at least one matching genotype in DNA and RNA. Conclusions. The imperfect detection in both, DNA and RNA, was identified as major limitation for investigating transmission dynamics, owing primarily to the volume of blood processed and the incomplete representation of all clones in the sample tested. Abundant low-density gametocyte carriers impede clone detectability, which may be improved by analyzing larger volumes and detecting initially sequestered gametocyte clones in follow-up samples

Background: Individuals living in malaria-endemic regions develop immunity against severe malaria, but it is unclear whether immunity against pre-erythrocytic stages that blocks initiation of blood-stage infection after parasite inoculation develops following continuous natural exposure. Methods: We cleared schoolchildren living in an area (health district of Saponé, Burkina Faso) with highly endemic seasonal malaria of possible sub-patent infections and examined them weekly for incident infections by nested PCR. Plasma samples collected at enrolment were used to quantify antibodies to the pre-eryhrocytic-stage antigens circumsporozoite protein (CSP) and Liver stage antigen 1 (LSA-1). In vitro sporozoite gliding inhibition and hepatocyte invasion inhibition by naturally acquired antibodies were assessed using Plasmodium falciparum NF54 sporozoites. Associations between antibody responses, functional pre-erythrocytic immunity phenotypes and time to infection detected by 18S quantitative PCR were studied. Results: A total of 51 children were monitored. Anti-CSP antibody titres showed a positive association with sporozoite gliding motility inhibition (PIn vitro hepatocyte invasion was inhibited by naturally acquired antibodies (median inhibition, 19.4% [IQR 15.2-40.9%]), and there were positive correlations between invasion inhibition and gliding inhibition (P=0.005, Spearman’s ρ=0.67) and between invasion inhibition and CSP-specific antibodies (P=0.002, Spearman’s ρ=0.76). Survival analysis indicated longer time to infection in individuals displaying higher-than-median sporozoite gliding inhibition activity (P=0.01), although this association became non-significant after adjustment for blood-stage immunity (P = 0.06). Conclusions: In summary, functional antibodies against the pre-erythrocytic stages of malaria infection are acquired in children who are repeatedly exposed to Plasmodium parasites. This immune response does not prevent them from becoming infected during a malaria transmission season, but might delay the appearance of blood stage parasitaemia. Our approach could not fully separate the effects of pre-erythrocytic-specific and blood-stage-specific antibody-mediated immune responses in vivo; epidemiological studies powered and designed to address this important question should become a research priority.

BackgroundDespite major progress in the past decade, malaria remains a major public health problem in sub-Saharan Africa. West and Central Africa account for nearly 2/3 of the burden currently attributable to falciparum malaria. Artemisinin-based combination therapies (ACT) are a cornerstone of our strategy for controlling and eventually eliminating malaria. However, reduced responsiveness/resistance to artemisinin derivatives and to ACTs, an increasing problem in South-East Asia is a major concern. It is of utmost importance to develop new antimalarial drugs from novel chemical classes that can replace ACTs. KAF156, an imidazolepiperazine, is a leading candidate in the antimalarial drug development pipeline. Combination of KAF156 with a Solid Dispersion Formulation of lumefantrine (LUM-SDF) is expected to be fast acting, fully curative, improve patient adherence and can potentially reduce malaria transmission.MethodsWANECAM II proposes to advance the clinical development of KAF156 through clinical trials in adults and children, with integrated capacity building and infrastructure development activities. The trial programme will be undertaken in the context of networking, team-building, leadership development and community engagement schemes that will involve intra-European, European-African and intra-African collaborative activities. WANECAM II will accelerate the clinical study of children less than 2 years of age which are the key target for new antimalarial treatments.ResultsBy the end of the project, the results are expected to contribute to the registration of KAF156/LUM-SDF through stringent regulatory health authorities, increase biomedical research capacity in the consortium and effectively promote networking among the respective teams. A new clinical research team in Niger, a grossly underrepresented country in the African research landscape, will be developed and further increase capacity and infrastructure in the consortium.ConclusionProviding a new antimalarial drug combination that does not contain an artemisinin derivative and is effective against resistant P. falciparum strains as well as gametocytes and that is likely to be taken in 3 or fewer single doses will be a major advance in the field. The new combination of KAF156 with LUM-SDF is expected to provide such major advance upon successful conclusion of the WANECAM II project.

BackgroundReports from Southeast Asia showed delayed parasite clearance after treatment with known artemisinin-based combination therapies (ACTs), the first-line treatment for malaria. We then carried out a study in the framework of the WANECAM clinical trial to assess comparatively the parasite clearance time and rate from P. falciparum malaria patients repeatedly treated with the artesunate-amodiaquine (ASAQ), dihydroartemisinin-piperaquine (DHA-PQ) and artesunate-pyronaridine (PYR).MethodsA randomised, phase III/IV comparative, multicentre, open-label, parallel 3-arms trial was conducted in Banfora Health District area comparing the efficacy of a three-day regimen of DHA-PQ, PYR with ASAQ for the treatment of children (above 6 months) and adults with uncomplicated falciparum malaria. From August 2012 to December 2013, each randomised patient was followed up for 42 days over a period of two years. Treatment was directly observed, and blood smear samples were collected twice daily (12 hour±2 hour) until parasite clearance.The endpoints of the present sub-study were parasite clearance rate and time. The secondary endpoints included PCR-corrected and uncorrected cure rates.ResultsOut of 2843 screened patients, 763 were recruited for parasite clearance endpoint analyses. The median parasite clearance time (PCT) was 24.1 hour (2-sided 95% CI, 24.0 to 24.2 hour), 23.9 hour (2-sided 95% CI, 23.8 to 24.0 hour) and 24.2 hour (2-sided 95% CI, 24.1 to 24.5 hour), in PYR and DHA-PQ, respectively. The PCR-corrected efficacy rates were estimated at 99.8%; 99.7%; 99.9%, at day 28% and 99.3%; 99.7%–99.9% in PYR, ASAQ and DHA-PQ, respectively.ConclusionThe parasite clearance times were comparable among the three ACT arms of treatment and their efficacy was comparable and higher than 99%. There was no delay in parasite clearance time (PCT ≥72 hour).

BackgroundMalaria elimination and its ultimate eradication will require drugs targeting all stages of the parasite’s life cycle. Yet, very few drugs are known to be effective on the sexual stages (gametocytes) of Plasmodium falciparum. Artemisinin-based combination therapy (ACT) has been shown to have some early-stage gametocytocidal effects on in vitro and in feeding experiments. However, field studies showed that artesunate reduces but does not prevent post-treatment transmission of P. falciparum to mosquitos.Methods763 children and adult patients with acute uncomplicated Plasmodium sp. malaria were included in a phase IIIb/IV comparative, randomised, multi-centre, open label, parallel 3-arm clinical trial to assess safety and efficacy of repeated administration of pyronaridine-artesunate, dihydroartemisinin-piperaquine or artemether-lumefantrine or artesunate-amodiaquine over a two-year period. Drugs were given based on the body weight and volunteers were followed up for 42 days. Clinical signs and symptoms were recorded and filter paper and blood smears collected during each visit. Malaria parasites were assessed and parasite density development stages determined by light microscopy.ResultsP. falciparum gametocyte was 1.9%, during the two years of follow-up. From the three treatment arms, artesunate-amodiaquine was the arm bearing more P. falciparum gametocyte with 68.7%, dihydroartemisinin-piperaquine accounted for 6.3% and pyronaridine-artesunate for 25%. P. falciparum gametocyte was more pronounced in populations having parasite density ≤1 00 000 parasites/µl compared to above parasitaemia.ConclusionRepeated ACTs treatment didn’t clear P. falciparum gametocyte in a population infected with uncomplicated malaria.

En prelude a la mise en oeuvre de la strategie de prise en charge communautaire du paludisme avec l’artemether-lumefantrine (AL), nous avons evalue son efficacite therapeutique chez les enfants vivant dans une zone rurale, de transmission intense du paludisme. Nous avons conduit un essai clinique ouvert, non controle et unicentrique de septembre 2009 a decembre 2009 chez les enfants de 6–59 mois qui consultaient dans les formations sanitaires pour paludisme simple. Le critere d’evaluation principal etait le taux de guerison clinique et parasitologique a j28 corrige par la PCR. Au total, 106 enfants ont ete retenus. La clairance parasitaire a deux jours de traitement etait de 99,04 % et la reponse clinique et parasitologique adequate a j28 corrigee par la PCR etait de 90,5 %. Nos resultats confirment l’efficacite de la combinaison AL.

The malaria vaccine candidate antigens erythrocyte binding antigen 175 (EBA-175), merozoite surface protein 3 (MSP-3), and apical membrane antigen (AMA-1) from Plasmodium falciparum isolates from countries in central and west Africa were assessed for allelic diversity. Samples were collected on filter paper from 600 P. falciparum-infected symptomatic patients in Cameroon, Republic of Congo, Burkina Faso, Ghana, and Senegal and screened for class-specific amplification fragments. Genetic diversity, assessed by mean heterozygosity, was comparable among countries. We detected a clinical increase in eba 175 F-allele frequency from west to east across the study region. No statistical difference in msp-3 allele distribution between countries was observed. The ama-1 3D7 alleles were present at a lower frequency in central Africa than in West Africa. We also detected little to no genetic differentiation among sampling locations. This finding indicates that, at least at the level of resolution offered by restriction fragment length polymorphism analysis, these antigens showed remarkable genetic homogeneity throughout the region sampled, perhaps caused by balancing selection to maintain a diverse array of antigen haplotyes.

Prior to a chimpanzee adenovirus-based (ChAd63) malarial vaccine trial, sera were collected to assess ChAd63-specific neutralizing antibody titers in Banfora (Burkina Faso). The low neutralizing antibody titers reported in both adults and children (median titers, 139.1 and 35.0, respectively) are encouraging for the potential use of ChAd63 as a malarial vaccine vector.

We performed a single-blind, randomized phase 1 trial of the long synthetic peptide (LSP) of merozoite surface protein-3 (MSP3) in adults living in Burkina Faso. Thirty eligible volunteers were randomized to receive either the MSP3-LSP candidate vaccine or tetanus toxoid vaccine as a control. A dose of each vaccine was administered on days 0, 28 and 112 and the vaccine was formulated with aluminium hydroxide. Humoral immune responses were assessed by ELISA at days 0, 28, 56, 112, 140, 252 and 365 and cell-mediated immune responses by lymphoproliferation assay and by ELISA on days 0, 56 and 140. IgG responses to four peptides of MSP3 were similar in both vaccine groups. Higher IgG concentrations were recorded after the beginning of malaria high transmission season in both vaccine groups. The lymphocyte proliferation and the production of IFN-gamma in response to stimulation with the four overlapping peptides increased following vaccination in the MSP3-LSP vaccine group, but did not change appreciably in the control group. In contrast to natural infection, MSP3-LSP did not boost humoral responses to the four overlapping peptides of MSP3 to any detectable degree in our semi-immune adult. MSP3-LSP may be more immunogenic in young children with little or no acquired immunity.

There is longstanding evidence that immunoglobulin G (IgG) has a role in protection against clinical malaria, and human antibodies of the cytophilic subclasses are thought to be particularly critical in this respect. In this cohort study, 286 Burkinabè children 6 months to 15 years old were kept under malaria surveillance in order to assess the protective role of antibody responses against four antigens which are currently being evaluated as vaccine candidates: apical membrane antigen 1 (AMA1), merozoite surface protein 1-19 (MSP1-19), MSP3, and glutamate-rich protein (GLURP). Total IgG, IgM, and IgG subclass responses were measured just before the malaria transmission season. The incidence of malaria was 2.4 episodes per child year of risk. After adjusting for the confounding effects of age, the level of total IgG to GLURP was strongly associated with reduced malaria incidence (incidence rate ratio associated with a doubling of total IgG, 0.79; 95% confidence interval, 0.66 to 0.94;P= 0.009.); there was a borderline statistically significant association between the level of total IgG to MSP3 and malaria incidence and no evidence of an association for total IgG to AMA1 and to MSP1-19. Of the IgG subclass responses studied, only IgG3 and IgG4 against GLURP and IgG1 against AMA1 were associated with reduced risk of clinical malaria. There was no evidence of an interaction between responses to AMA1 and baseline parasitemia in their effects on malaria incidence. Currently included in malaria vaccine formulations for clinical trials in humans, these blood-stage antigens, AMA1 and GLURP, offer good prospects for malaria vaccine development.