Determination of Natural Radioactivity Level and Hazard Assessment of Groundwater Samples from Mining Area in the North Region of Burkina Faso

The activity concentrations of Natural Radionuclides 238U. 232Th and 40K in groundwater samples were measured using a Gamma Spectrometry with High Purity Germanium detector. Also. Radiological Hazard due to these Natural Radionuclides through water ingestion is investigated. The mean activity concentrations of 238U, 232Th and 40K in water samples from boreholes were found to be 0.36 ± 0.07 Bq.L-1. 0.50 ±0.09 Bq.L-1 and 5.32 ± 0.76 Bq.L-1 respectively.  The average Annual Committed Effective Dose was 0.16 ± 0.02 mSv. The  results obtained are below the recommended levels of 10.0 Bq.L-1   and 1.0 Bq.L-1  for 238U and 232Th  respectively for drinking water quality established by the WHO and 1 mSv per year dose limit recommended by the ICRP for public radiation exposure. These results indicate insignificant radiological hazard due to ingestion of NORMS in drinking water from boreholes by the communities in this area. 

Increase in the prevalence of mutations associated with sulfadoxine-pyrimethamine resistance in Plasmodium falciparum isolates collected from early to late pregnancy in Nanoro, Burkina Faso.

BACKGROUND: Pregnant women are a high-risk group for Plasmodium falciparum infections, which may result in maternal anaemia and low birth weight newborns, among other adverse birth outcomes. Intermittent preventive treatment with sulfadoxine-pyrimethamine during pregnancy (IPTp-SP) is widely implemented to prevent these negative effects of malaria. However, resistance against SP by P. falciparum may decrease efficacy of IPTp-SP. Combinations of point mutations in the dhps (codons A437, K540) and dhfr genes (codons N51, C59, S108) of P. falciparum are associated with SP resistance. In this study the prevalence of SP resistance mutations was determined among P. falciparum found in pregnant women and the general population (GP) from Nanoro, Burkina Faso and the association of IPTp-SP dosing and other variables with mutations was studied. METHODS: Blood spots on filter papers were collected from pregnant women at their first antenatal care visit (ANC booking) and at delivery, from an ongoing trial and from the GP in a cross-sectional survey. The dhps and dhfr genes were amplified by nested PCR and products were sequenced to identify mutations conferring resistance (ANC booking, n = 400; delivery, n = 223; GP, n = 400). Prevalence was estimated with generalized estimating equations and for multivariate analyses mixed effects logistic regression was used. RESULTS: The prevalence of the triple dhfr mutation was high, and significantly higher in the GP and at delivery than at ANC booking, but it did not affect birth weight. Furthermore, quintuple mutations (triple dhfr and double dhps mutations) were found for the first time in Burkina Faso. IPTp-SP did not significantly affect the occurrence of any of the mutations, but high transmission season was associated with increased mutation prevalence in delivery samples. It is unclear why the prevalence of mutations was higher in the GP than in pregnant women at ANC booking. CONCLUSION: The high number of mutants and the presence of quintuple mutants in Burkina Faso confirm concerns about the efficacy of IPTp-SP in the near future. Other drug combinations to tackle malaria in pregnancy should, therefore, be explored. An increase in mutation prevalence due to IPTp-SP dosing could not be confirmed

Efficacy and immunogenicity of R21/Matrix-M vaccine against clinical malaria after 2 years' follow-up in children in Burkina Faso: a phase 1/2b randomised controlled trial

BACKGROUND: Malaria is a leading cause of morbidity and mortality worldwide. We previously reported the efficacy of the R21/Matrix-M malaria vaccine, which reached the WHO-specified goal of 75% or greater efficacy over 12 months in the target population of African children. Here, we report the safety, immunogenicity, and efficacy results at 12 months following administration of a booster vaccination. METHODS: This double-blind phase 1/2b randomised controlled trial was done in children aged 5-17 months in Nanoro, Burkina Faso. Eligible children were enrolled and randomly assigned (1:1:1) to receive three vaccinations of either 5 μg R21/25 μg Matrix-M, 5 μg R21/50 μg Matrix-M, or a control vaccine (the Rabivax-S rabies vaccine) before the malaria season, with a booster dose 12 months later. Children were eligible for inclusion if written informed consent could be provided by a parent or guardian. Exclusion criteria included any existing clinically significant comorbidity or receipt of other investigational products. A random allocation list was generated by an independent statistician by use of block randomisation with variable block sizes. A research assistant from the University of Oxford, independent of the trial team, prepared sealed envelopes using this list, which was then provided to the study pharmacists to assign participants. All vaccines were prepared by the study pharmacists by use of the same type of syringe, and the contents were covered with an opaque label. Vaccine safety, efficacy, and a potential correlate of efficacy with immunogenicity, measured as anti-NANP antibody titres, were evaluated over 1 year following the first booster vaccination. The population in which the efficacy analyses were done comprised all participants who received the primary series of vaccinations and a booster vaccination. Participants were excluded from the efficacy analysis if they withdrew from the trial within the first 2 weeks of receiving the booster vaccine. This trial is registered with ClinicalTrials.gov (NCT03896724), and is continuing for a further 2 years to assess both the potential value of additional booster vaccine doses and longer-term safety. FINDINGS: Between June 2, and July 2, 2020, 409 children returned to receive a booster vaccine. Each child received the same vaccination for the booster as they received in the primary series of vaccinations; 132 participants received 5 μg R21 adjuvanted with 25 μg Matrix-M, 137 received 5 μg R21 adjuvanted with 50 μg Matrix-M, and 140 received the control vaccine. R21/Matrix-M had a favourable safety profile and was well tolerated. Vaccine efficacy remained high in the high adjuvant dose (50 μg) group, similar to previous findings at 1 year after the primary series of vaccinations. Following the booster vaccination, 67 (51%) of 132 children who received R21/Matrix-M with low-dose adjuvant, 54 (39%) of 137 children who received R21/Matrix-M with high-dose adjuvant, and 121 (86%) of 140 children who received the rabies vaccine developed clinical malaria by 12 months. Vaccine efficacy was 71% (95% CI 60 to 78) in the low-dose adjuvant group and 80% (72 to 85) in the high-dose adjuvant group. In the high-dose adjuvant group, vaccine efficacy against multiple episodes of malaria was 78% (95% CI 71 to 83), and 2285 (95% CI 1911 to 2568) cases of malaria were averted per 1000 child-years at risk among vaccinated children in the second year of follow-up. Among these participants, at 28 days following their last R21/Matrix-M vaccination, titres of malaria-specific anti-NANP antibodies correlated positively with protection against malaria in both the first year of follow-up (Spearman's ρ -0·32 [95% CI -0·45 to -0·19]; p=0·0001) and second year of follow-up (-0·20 [-0·34 to -0·06]; p=0·02). INTERPRETATION: A booster dose of R21/Matrix-M at 1 year following the primary three-dose regimen maintained high efficacy against first and multiple episodes of clinical malaria. Furthermore, the booster vaccine induced antibody concentrations that correlated with vaccine efficacy. The trial is ongoing to assess long-term follow-up of these participants and the value of further booster vaccinations. FUNDING: European and Developing Countries Clinical Trials Partnership 2 (EDCTP2), Wellcome Trust, and NIHR Oxford Biomedical Research Centre. TRANSLATION: For the French translation of the abstract see Supplementary Materials section

Efficacy of a low-dose candidate malaria vaccine, R21 in adjuvant Matrix-M, with seasonal administration to children in Burkina Faso: a randomised controlled trial.

BACKGROUND: Stalled progress in controlling Plasmodium falciparum malaria highlights the need for an effective and deployable vaccine. RTS,S/AS01, the most effective malaria vaccine candidate to date, demonstrated 56% efficacy over 12 months in African children. We therefore assessed a new candidate vaccine for safety and efficacy. METHODS: In this double-blind, randomised, controlled, phase 2b trial, the low-dose circumsporozoite protein-based vaccine R21, with two different doses of adjuvant Matrix-M (MM), was given to children aged 5-17 months in Nanoro, Burkina Faso-a highly seasonal malaria transmission setting. Three vaccinations were administered at 4-week intervals before the malaria season, with a fourth dose 1 year later. All vaccines were administered intramuscularly into the thigh. Group 1 received 5 μg R21 plus 25 μg MM, group 2 received 5 μg R21 plus 50 μg MM, and group 3, the control group, received rabies vaccinations. Children were randomly assigned (1:1:1) to groups 1-3. An independent statistician generated a random allocation list, using block randomisation with variable block sizes, which was used to assign participants. Participants, their families, and the local study team were all masked to group allocation. Only the pharmacists preparing the vaccine were unmasked to group allocation. Vaccine safety, immunogenicity, and efficacy were evaluated over 1 year. The primary objective assessed protective efficacy of R21 plus MM (R21/MM) from 14 days after the third vaccination to 6 months. Primary analyses of vaccine efficacy were based on a modified intention-to-treat population, which included all participants who received three vaccinations, allowing for inclusion of participants who received the wrong vaccine at any timepoint. This trial is registered with ClinicalTrials.gov, NCT03896724. FINDINGS: From May 7 to June 13, 2019, 498 children aged 5-17 months were screened, and 48 were excluded. 450 children were enrolled and received at least one vaccination. 150 children were allocated to group 1, 150 children were allocated to group 2, and 150 children were allocated to group 3. The final vaccination of the primary series was administered on Aug 7, 2019. R21/MM had a favourable safety profile and was well tolerated. The majority of adverse events were mild, with the most common event being fever. None of the seven serious adverse events were attributed to the vaccine. At the 6-month primary efficacy analysis, 43 (29%) of 146 participants in group 1, 38 (26%) of 146 participants in group 2, and 105 (71%) of 147 participants in group 3 developed clinical malaria. Vaccine efficacy was 74% (95% CI 63-82) in group 1 and 77% (67-84) in group 2 at 6 months. At 1 year, vaccine efficacy remained high, at 77% (67-84) in group 1. Participants vaccinated with R21/MM showed high titres of malaria-specific anti-Asn-Ala-Asn-Pro (NANP) antibodies 28 days after the third vaccination, which were almost doubled with the higher adjuvant dose. Titres waned but were boosted to levels similar to peak titres after the primary series of vaccinations after a fourth dose administered 1 year later. INTERPRETATION: R21/MM appears safe and very immunogenic in African children, and shows promising high-level efficacy. FUNDING: The European & Developing Countries Clinical Trials Partnership, Wellcome Trust, and National Institute for Health Research Oxford Biomedical Research Centre

Comparison of effectiveness of two different artemisininbased combination therapies in an area with high seasonal transmission of malaria in Burkina Faso

In Sahelian countries such as Burkina Faso, malaria transmission is seasonal with a high incidence of transmission during the rainy season. This study aimed to compare the effectiveness of the two recommended treatments (Artemether-Lumefantrine and Artesunate-Amodiaquine) for uncomplicated malaria in Burkina Faso regarding this seasonal variation of malaria transmission. This is part of a randomized open label trial comparing the effectiveness and safety of Artemether-Lumefantrine versus Artesunate-Amodiaquine according to routine practice in Nanoro. Patients with uncomplicated falciparum malaria were recruited all year round and followed-up for 28 days. To distinguish recrudescences from new infections, dried blood spots from day 0 and day of recurrent parasitaemia were used for nested-PCR genotyping of the polymorphic loci of the merozoite surface proteins 1 and 2. Seasonal influence was investigated by assessing the treatment outcomes according to the recruitment period of the patients. Two main groups (dry season versus rainy season) were defined following the seasonal characteristics of the study area. In Artemether- Lumefantrine group, the uncorrected cure rate was 76.5% in dry season versus 37.9% in rainy season. In Artesunate-Amodiaquine group, this was 93.3% and 57.1% during dry and rainy seasons, respectively. After PCR adjustment, the cure rate decreased from 85.9% in dry season to 75.0% in rainy season in Artemether-Lumefantrine group. In Artesunate-Amodiaquine group, it was 93.3% in dry season and 80.7% during the rainy season. During the rainy season around 50% of patients had a new malaria episode by Day 28. The cure rate of both Artemether-Lumefantrine and Artesunate-Amodiaquine treatments was higher in dry season compared to rainy season due to high incidence of reinfections during the rainy season. For this reason, in addition to the curative effect, the post-treatment prophylactic effect should be taken into account in the choice of antimalarial regimens

Human capital on the move: Education as a determinant of internal migration in selected INDEPTH surveillance populations in Africa

Background: Education, as a key indicator of human capital, is considered one of the major determinants of internal migration, with previous studies suggesting that human capital accumulates in urban areas at the expense of rural areas. However, there is fragmentary evidence concerning the educational correlates of internal migration in sub-Saharan Africa. Objective: The study questions whether more precise measures of migration in Health and Demographic Surveillance System (HDSS) populations support the hypothesis that migrants are self-selected on human capital and more educated people are more likely to leave rural areas or enter urban areas within a geographical region. Methods: Using unique longitudinal data representing approximately 900,000 people living in eight sub-Saharan African HDSS sites that are members of the INDEPTH Network, the paper uses Event History Analysis techniques to examine the relationship between formal educational attainment and in- and out-migration, over the period 2009 to 2011. Results: Between 7Š and 27Š of these local populations are moving in or out of the HDSS area over this period. Education is positively associated with both in- and out-migration in the Kenyan HDSS areas; however, the education effect has no clear pattern in the HDSS sites in Burkina Faso, Mozambique, and South Africa. Conclusions: Empirical results presented in this paper confirm a strong age profile of migration consistent with human capital expectation, yet the results point to variability in the association of education and the propensity to migrate. In particular, the hypothesis of a shift of human capital from rural to urban areas is not universally valid

Optimal Approach and Strategies to Strengthen Pharmacovigilance in Sub-Saharan Africa: A Cohort Study of Patients Treated with First-Line Artemisinin-Based Combination Therapies in the Nanoro Health and Demographic Surveillance System, Burkina Faso.

Resource-limited countries face challenges in setting up effective pharmacovigilance systems. This study aimed to monitor the occurrence of adverse events (AEs) after the use of artemisinin-based combination therapies (ACTs), identify potential drivers of reporting suspected adverse drug reactions (ADRs) and monitor AEs among women who were inadvertently exposed to ACTs in the first trimester of pregnancy.info:eu-repo/semantics/publishe

Determinants of Plasmodium falciparum multiplicity of infection and genetic diversity in Burkina Faso.

Investigating malaria transmission dynamics is essential to inform policy decision making. Whether multiplicity of infection (MOI) dynamic from individual infections could be a reliable malaria metric in high transmission settings with marked variation in seasons of malaria transmission has been poorly assessed. This study aimed at investigating factors driving Plasmodium falciparum MOI and genetic diversity in a hyperendemic area of Burkina Faso.info:eu-repo/semantics/publishe