Malaria diagnosis challenges and pfhrp2 and pfhrp3 gene deletions using pregnant women as sentinel population in Nanoro region, Burkina Faso.

Malaria in pregnancy causes adverse consequences and prompt and accurate diagnosis is essential for case management. In malaria endemic countries, diagnosis is mainly based on rapid diagnostic tests (RDT) and microscopy. However, increasing reports of false negatives caused by low parasitemia and pfhrp2/3 deletions raise concerns about HRP2-based RDT usefulness. This study aimed to assess RDT and microscopy performance and to describe pfhrp2/3 deletions in a cohort of 418 pregnant women in Burkina Faso. Malaria was diagnosed using RDT and microscopy and blood samples were collected during antenatal care visits. Diagnostic results were compared to PCR as gold standard. Pfhrp2 and pfhrp3 deletions were characterized for patients with confirmed P. falciparum infection. RDT had better sensitivity (76%) but lower specificity (83%) than microscopy (sensitivity = 57%; specificity = 98%). Low parasitemia (<150 parasites/µL), especially in multigravidae, was the principal factor causing false negatives by both methods. Moreover, pfhrp2 deletion frequency among overall false negatives by RDT was 21.43%. Higher frequency of deletions was found among all samples, independently of RDT result, for example around 2% of samples had double deletions meaning that the majority of deletions had no effect on RDT testing. Finally, it was found higher pfhrp2 deletion in women with lower uterine height during the first trimester. Wider and National surveillance study of deletions is recommended among pregnant women and in Burkina Faso.

The public health impact and cost-effectiveness of the R21/Matrix-M malaria vaccine: a mathematical modelling study.

BACKGROUND: The R21/Matrix-M vaccine has demonstrated high efficacy against Plasmodium falciparum clinical malaria in children in sub-Saharan Africa. Using trial data, we aimed to estimate the public health impact and cost-effectiveness of vaccine introduction across sub-Saharan Africa. METHODS: We fitted a semi-mechanistic model of the relationship between anti-circumsporozoite protein antibody titres and vaccine efficacy to data from 3 years of follow-up in the phase 2b trial of R21/Matrix-M in Nanoro, Burkina Faso. We validated the model by comparing predicted vaccine efficacy to that observed over 12-18 months in the phase 3 trial. Integrating this framework within a mathematical transmission model, we estimated the cases, malaria deaths, and disability-adjusted life-years (DALYs) averted and cost-effectiveness over a 15-year time horizon across a range of transmission settings in sub-Saharan Africa. Cost-effectiveness was estimated incorporating the cost of vaccine introduction (dose, consumables, and delivery) relative to existing interventions at baseline. We report estimates at a median of 20% parasite prevalence in children aged 2-10 years (PfPR2-10) and ranges from 3% to 65% PfPR2-10. FINDINGS: Anti-circumsporozoite protein antibody titres were found to satisfy the criteria for a surrogate of protection for vaccine efficacy against clinical malaria. Age-based implementation of a four-dose regimen of R21/Matrix-M vaccine was estimated to avert 181 825 (range 38 815-333 491) clinical cases per 100 000 fully vaccinated children in perennial settings and 202 017 (29 868-405 702) clinical cases per 100 000 fully vaccinated children in seasonal settings. Similar estimates were obtained for seasonal or hybrid implementation. Under an assumed vaccine dose price of US$3, the incremental cost per clinical case averted was $7 (range 4-48) in perennial settings and $6 (3-63) in seasonal settings and the incremental cost per DALY averted was $34 (29-139) in perennial settings and $30 (22-172) in seasonal settings, with lower cost-effectiveness ratios in settings with higher PfPR2-10. INTERPRETATION: Introduction of the R21/Matrix-M malaria vaccine could have a substantial public health benefit across sub-Saharan Africa. FUNDING: The Wellcome Trust, the Bill & Melinda Gates Foundation, the UK Medical Research Council, the European and Developing Countries Clinical Trials Partnership 2 and 3, the NIHR Oxford Biomedical Research Centre, and the Serum Institute of India, Open Philanthropy.

Enhanced effect of seasonal malaria chemoprevention when coupled with nutrients supplementation for preventing malaria in children under 5 years old in Burkina Faso: a randomized open label trial.

BACKGROUND: In rural African settings, most of the children under the coverage of Seasonal Malaria Chemoprevention (SMC) are also undernourished at the time of SMC delivery, justifying the need for packaging malarial and nutritional interventions. This study aimed at assessing the impact of SMC by coupling the intervention with nutrients supplementation for preventing malaria in children less than 5 years old in Burkina Faso. METHODS: A randomized trial was carried out between July 2020 and June 2021 in the health district of Nanoro, Burkina Faso. Children (n = 1059) under SMC coverage were randomly assigned to one of the three study arms SMC + Vitamin A (SMC-A, n = 353) or SMC + Vitamin A + Zinc (SMC-AZc, n = 353) or SMC + Vitamin A + PlumpyDoz(tm) (SMC-APd, n = 353)-a medium quantity-lipid-based nutrient supplement (MQ-LNS). Children were followed up for one year that included an active follow-up period of 6 months with scheduled monthly home visits followed by 6 months passive follow-up. At each visit, capillary blood sample was collected for malaria diagnosis by rapid diagnosis test (RDT). RESULTS: Adding nutritional supplements to SMC had an effect on the incidence of malaria. A reduction of 23% (adjusted IRR = 0.77 (95%CI 0.61-0.97) in the odds of having uncomplicated malaria in SMC-APd arm but not with SMC-AZc arm adjusted IRR = 0.82 (95%CI 0.65-1.04) compare to control arm was observed. A reduction of 52%, adjusted IRR = 0.48 (95%CI 0.23-0.98) in the odds of having severe malaria was observed in SMC-APd arm compared to control arm. Besides the effect on malaria, this combined strategy had an effect on all-cause morbidity. More specifically, a reduction of morbidity odds of 24%, adjusted IRR = 0.76 (95%CI 0.60-0.94) in SMC-APd arm compared to control arm was observed. Unlike clinical episodes, no effect of nutrient supplementation on cross sectional asymptomatic infections was observed. CONCLUSION: Adding nutritional supplements to SMC significantly increases the impact of this intervention for preventing children from malaria and other childhood infections. TRIAL REGISTRATION: NCT04238845.

A genomic appraisal of invasive Salmonella Typhimurium and associated antibiotic resistance in sub-Saharan Africa.

Invasive non-typhoidal Salmonella (iNTS) disease manifesting as bloodstream infection with high mortality is responsible for a huge public health burden in sub-Saharan Africa. Salmonella enterica serovar Typhimurium (S. Typhimurium) is the main cause of iNTS disease in Africa. By analysing whole genome sequence data from 1303 S. Typhimurium isolates originating from 19 African countries and isolated between 1979 and 2017, here we show a thorough scaled appraisal of the population structure of iNTS disease caused by S. Typhimurium across many of Africa's most impacted countries. At least six invasive S. Typhimurium clades have already emerged, with ST313 lineage 2 or ST313-L2 driving the current pandemic. ST313-L2 likely emerged in the Democratic Republic of Congo around 1980 and further spread in the mid 1990s. We observed plasmid-borne as well as chromosomally encoded fluoroquinolone resistance underlying emergences of extensive-drug and pan-drug resistance. Our work provides an overview of the evolution of invasive S. Typhimurium disease, and can be exploited to target control measures.

Baseline malarial and nutritional profile of children under seasonal malaria chemoprevention coverage in the health district of Nanoro, Burkina Faso.

Seasonal Malaria chemoprevention (SMC) is one of the large-scale life-saving malaria interventions initially recommended for the Sahel subregion, including Burkina Faso and recently extended to other parts of Africa. Initially, SMC was restricted to children 3 to 59 months old, but an extension to older children in some locations was recently recommended. Further characterization of SMC population profile beyond age criterion is necessary for understanding factors that could negatively impact the effectiveness of the intervention and to define complementary measures that could enhance its impact. Children were assessed through a cross-sectional survey during the first month of the 2020 SMC campaign (July-August 2020) as part of the SMC-NUT project in the health district of Nanoro. Parameters such as body temperature, weight, height, mid-upper arm circumference (MUAC) were assessed. In addition, blood sample was collected for malaria diagnosis by rapid diagnostic tests (RDT) and microscopy, and for haemoglobin measurement. A total of 1059 children were enrolled. RDT positivity rate (RPR) was 22.2%, while microscopy positivity rate (MPR) was 10.4%, with parasitaemia levels ranging from 40 to 70480/µL. RPR and MPR increased as patient age increased. Wasting was observed in 7.25% of children under SMC coverage while the prevalence of stunting and underweight was 48.79% and 23.38%, respectively. As the age of the children increased, an improvement in their nutritional status was observed. Finally, undernourished children had higher parasite densities than children with adequate nutritional status. In the health district of Nanoro, children who received Seasonal Malaria Chemoprevention (SMC) were mostly undernourished during the period of SMC delivery, suggesting the need for combining the SMC with synergistic interventions against malnutrition to achieve best impact.

Effects of maternal antenatal treatment with two doses of azithromycin added to monthly sulfadoxine-pyrimethamine for the prevention of low birth weight in Burkina Faso: an open-label randomized controlled trial.

BACKGROUND: Exposure during pregnancy to malaria and sexually-transmitted infections is associated with adverse birth outcomes including low birth weight (LBW). This study aimed at assessing if the adjunction of two doses of azithromycin to sulfadoxine-pyrimethamine for the intermittent preventive treatment of malaria in pregnancy can reduce LBW. METHODS: A two parallel-groups, open-label randomized controlled trial involving pregnant women (16 to 35 years of age and 12 to 24 weeks of gestation as confirmed by last menstrual period or fundal height) was conducted in rural Burkina Faso. Women were assigned in a 1:1 ratio either to use azithromycin (1 g daily for 2 days) during the second and third trimesters of pregnancy plus monthly sulfadoxine-pyrimethamine (1500/75 mg) (SPAZ) (intervention) or to continue using a monthly sulfadoxine-pyrimethamine (1500/75 mg) (SP) (control). Primary outcome was a LBW (birth weight measured within 24 h after birth < 2500 g). Secondary outcomes including stillbirth, preterm birth or miscarriage are reported together with safety data. RESULTS: A total of 992 pregnant women underwent randomization (496 per group) and 898 (90.5%) valid birth weights were available (450 in SPAZ and 448 in SP). LBW incidence was 8.7% (39/450) in SPAZ and 9.4% (42/448) in controls (p-value = 0.79). Compared with controls, pregnant women with SPAZ showed a risk ratio (RR) of 1.16 (95% confidence interval (CI 0.64-2.08]) for preterm births, 0.75 (95% CI 0.17-3.35) for miscarriage and 0.64 (95% CI 0.25-1.64) for stillbirths. No treatment-related serious adverse events (SAEs) have been observed, and there was no significant difference in the number of SAEs (13.5% [67/496] in SPAZ, 16.7% [83/496] in SP, p-value = 0.18) or AEs (17.1% [85/496] in SPAZ, 18.8% [93/496] in SP, p-value = 0.56). CONCLUSION: Adequate prevention regimen with monthly sulfadoxine-pyrimethamine given to all pregnant women has been proved to reduce the risk of LBW in malaria endemic areas. Adding azithromycin to the regimen does not offer further benefits, as far as women receive a malaria prevention regimen early enough during pregnancy. Trial registration Pan African Clinical Trial Registry ( https://pactr.samrc.ac.za/Search.aspx ): PACTR201808177464681. Registered 21 August 2018.

Effect of Intrapartum Azithromycin vs Placebo on Neonatal Sepsis and Death: A Randomized Clinical Trial.

Importance: Neonatal sepsis is a leading cause of neonatal mortality. New interventions are needed to decrease neonatal sepsis and mortality in regions with highest burden. Objective: To evaluate the efficacy of intrapartum azithromycin to reduce neonatal sepsis or mortality, as well as neonatal and maternal infections. Design, Setting, and Participants: This double-blind, placebo-controlled, randomized clinical trial enrolled and followed up birthing parents and their infants at 10 health facilities in The Gambia and Burkina Faso, West Africa, between October 2017 and May 2021. Interventions: Participants were assigned at random to receive oral azithromycin (2 g) or placebo (ratio 1:1) during labor. Main Outcomes and Measures: The primary outcome was a composite of neonatal sepsis or mortality, with the former defined based on microbiologic or clinical criteria. Secondary outcomes were neonatal infections (skin, umbilical, eye and ear infections), malaria, and fever; postpartum infections (puerperal sepsis, mastitis), fever, and malaria; and use of antibiotics during 4-week follow-up. Results: The trial randomized 11 983 persons in labor (median age, 29.9 years). Overall, 225 newborns (1.9% of 11 783 live births) met the primary end point. The incidence of neonatal mortality or sepsis was similar in the azithromycin and placebo groups (2.0% [115/5889] vs 1.9% [110/5894]; risk difference [RD], 0.09 [95% CI, -0.39 to 0.57]), as was the incidence of neonatal mortality (0.8% vs 0.8%; RD, 0.04 [95% CI, -0.27 to 0.35]) and neonatal sepsis (1.3% vs 1.3%; RD, 0.02 [95% CI, -0.38 to 0.43]). Newborns in the azithromycin group compared with the placebo group had lower incidence of skin infections (0.8% vs 1.7%; RD, -0.90 [95% CI, -1.30 to -0.49]) and need for antibiotics (6.2% vs 7.8%; RD, -1.58 [95% CI, -2.49 to -0.67]). Postpartum parents in the azithromycin group had lower incidence of mastitis (0.3% vs 0.5%; RD, -0.24 [95% CI, -0.47 to -0.01]) and puerperal fever (0.1% vs 0.3%; RD, -0.19 [95% CI, -0.36 to -0.01]). Conclusions and Relevance: Azithromycin administered orally during labor did not reduce neonatal sepsis or mortality. These results do not support routine introduction of oral intrapartum azithromycin for this purpose. Trial Registration: ClinicalTrials.gov Identifier: NCT03199547.

Malaria prevention knowledge, attitudes, and practices (KAP) among adolescents living in an area of persistent transmission in Senegal: Results from a cross-sectional study.

INTRODUCTION: While malaria morbidity has sharply declined in several areas in Senegal, it remains an important problem in the southern part of the country, particularly among adolescents. Understanding adolescents' knowledge, attitudes, prevention and care-seeking practices is important to inform more targeted interventions aimed at optimizing adolescents' uptake of malaria prevention and control measures. This study assessed malaria-related knowledge, attitudes, and practices (KAP) among adolescents living in a highly persistent transmission area in Senegal. METHODS: A community-based cross-sectional survey was conducted among 391 adolescents living in the Saraya health district. A multistage random sampling technique was used to select households. An electronic questionnaire developed on Open Data Kit (ODK), was used to collect data on socio-demographic characteristics, household assets, adolescents' knowledge of malaria, as well as their attitudes with regards to malaria prevention, and care-seeking behaviors. Bivariate and multivariate analyses were performed to assess factors associated with adolescents' KAP towards malaria. RESULTS: Nearly, one-third of the participants had good knowledge of malaria (34.4%) and good practice in regards to malaria preventive measures (32.8%) while 59.0% had a positive attitude and 73.8% had good care-seeking behavior regarding malaria. Multivariate analysis revealed that a primary (aOR = 5.43, p = 0.002) or secondary level of education (aOR = 10.41, p = 0.000) was associated with good knowledge of malaria transmission, signs, and prevention measures. Male individuals had lower knowledge compared to female ones (aOR = 0.40, p = 0.001). Individuals belonging to households from the highest wealth quintile were more likely to have a positive attitude towards malaria compared to those from households in the lowest wealth quintile (aOR = 3.49, p = 0.004). The odds of positive attitude towards malaria decreased among participants with koranic and primary education level, respectively (aOR = 0.14, p = 0.005) and (aOR = 0.24, p = 0.019). A positive attitude was 1.89 more likely to be (aOR = 1.89, p = 0.026) associated with good practice of prevention measures compared to adolescents who demonstrated negative attitudes. Individuals from households in the fourth (aOR = 0.42, p = 0.024), middle (aOR = 0.34, P = 0.005), and second (aOR = 0.42, p = 0.027) wealth quintiles were less likely to use malaria prevention measures compared to those from households in the highest wealth quintile. CONCLUSION: The study revealed that adolescents, generally have poor levels of malaria knowledge and low uptake of malaria prevention and control interventions. Targeted interventions for high-risk adolescents are needed, that focus on improving their knowledge of the disease and effective preventive measures, and on increasing their access to health care services and LLINs.

Could combined rapid diagnostic testing for malaria and c-reactive protein be helpful for the diagnosis and management of febrile illnesses in children under-5 years of age in rural Burkina Faso?

BACKGROUND: Febrile illnesses are among the most important reasons for medical consultation in sub-Saharan Africa and are frequently treated with antimicrobials due to the unavailability of appropriate diagnostic tools. This practice leads to antimicrobial resistance, with increasing mortality and morbidity as result. One of the few accessible diagnostic tools available in low resource settings is malaria rapid diagnostic tests (mRDTs) which contributed to reducing the over-prescription of anti-malarials, but cannot guide antibiotic prescriptions. To circumvent this problem, we explored whether combined testing with mRDT and c-reactive protein (CRP) could improve the diagnosis of febrile illnesses and subsequent prescription of antibiotics. METHODS: Clinical specimens (blood, stool and urine) collected from 396 febrile children (axillary temperature of ≥ 37.5 °C) were analyzed with rapid diagnostic tests (malaria and CRP) and microbiology culture to establish the possible cause of fever. Actual antimicrobial prescriptions given to the children were compared with those that could be given based on combined CRP-malaria testing. RESULTS: In total, 68.7% (272/396) of malaria cases were diagnosed by mRDT-Pf-HRP-2. CRP test was positive in 84.3% (334/396) of the children, but bacterial infections were confirmed in 12.4% (49/396) of them. A possible cause of fever could not be established in 20.5% (81/396) of cases. Based on the diagnostic practice in place, 265 of the children with a positive mRDT-Pf-HRP-2 received anti-malarial treatment. Furthermore, 89.5% (111/124) of negative mRDT results received antibiotic treatment and 37.1% (46/124) received antimalarial treatment. Of these 124 cases, 80 had positive CRP tests and 44 negative CRP tests. If the results of CRP testing are considered, 44 CRP/mRDT negative children would not get antibiotic treatment, resulting in a 35.5% reduction in antibiotic prescriptions. However, 2 cases with a bacterial infection would be denied appropriate treatment. CONCLUSION: Combining mRDT-PfHRP2 with CRP testing is particularly useful in children for whom both tests are negative as it results in a reduction of antibiotics prescriptions. However, there is a risk to miss potential severe bacterial infections and a close follow-up of these cases is strongly recommended.

Diagnostic Performance of Plasmodium falciparum Histidine-Rich Protein-2 Antigen-Specific Rapid Diagnostic Test in Children at the Peripheral Health Care Level in Nanoro (Burkina Faso).

(1) Background: Malaria control has strongly benefited from the implementation of rapid diagnostic tests (RDTs). The malaria RDTs used in Burkina Faso, as per the recommendation of the National Malaria Control Program, are based on the detection of histidine-rich protein-2 (PfHRP2) specific to Plasmodium falciparum, which is the principal plasmodial species causing malaria in Burkina Faso. However, there is increasing concern about the diagnostic performance of these RDTs in field situations, and so constant monitoring of their accuracy is warranted. (2) Methods: A prospective study was performed in the health district of Nanoro, where 391 febrile children under 5 years with an axillary temperature ≥37.5 °C presenting at participating health facilities were subjected to testing for malaria. The HRP2-based RDT and expert microscopy were used to determine the diagnostic performance of the former. Retrospectively, the correctness of the antimalaria prescriptions was reviewed. (3) Results: Taking expert malaria microscopy as the gold standard, the sensitivity of the employed RDT was 98.5% and the specificity 40.5%, with a moderate agreement between the RDT testing and microscopy. In total, 21.7% of cases received an inappropriate antimalarial treatment based on a retrospective assessment with expert microscopy results. (4) Conclusion: Malaria remains one of the principal causes of febrile illness in Burkina Faso. Testing with HRP2-based RDTs is inaccurate, in particular, due to the low specificity, which results in an over-prescription of antimalarials, with emerging antimalarial drug resistance as an important risk and many children not being treated for potential other causes of fever.

Impact and operational feasibility of adding malaria infection screening using an ultrasensitive RDT for placental and fetal outcomes in an area of high IPTP-SP coverage in Burkina Faso: the ASSER MALARIA pilot study protocol.

BACKGROUND: Malaria infection during pregnancy (MIP) is not only deleterious to the woman, but it also puts her fetus at increased risk of adverse outcomes, such as preterm delivery, low birth weight, and intrauterine growth retardation. Additionally, all-cause mortality during the first year of life in babies born to women with malaria during pregnancy is also increased. Many interventions such as IPTp-SP and long-lasting insecticidal nets have proven to be efficient at reducing malaria in pregnancy burden but adherence to recommended policies remains poor. In sub-Saharan Africa, malaria in pregnancy is often asymptomatic and many malaria infections may be missed due to the inadequate performance of the current rapid diagnostic test to detect low-level parasitemias. Therefore, additional strategies such as intermittent screening with ultrasensitive rapid diagnostic tests and treatment with an effective artemisinin-based combination therapy in addition to IPTp-SP could reduce placental malaria, peripheral malaria infection at delivery, and low birth weight. METHODS: This pilot 2-group randomized open trial with a nested qualitative social behavioral will be carried out in Nanoro district in which 340 pregnant women will be recruited. Pregnant women will be randomized into two groups and followed on a monthly basis until delivery. In the intervention group, monthly screening using ultrasensitive rapid diagnostic tests and treatment of those found to be infected with dihydroartemisinin-piperaquine will be performed. In addition, a reminder will be sent to increase the uptake of IPTp-SP doses per woman. During scheduled and unscheduled visits, malaria infection, hemoglobin level, and other clinical outcomes will be assessed and compared by the group. The primary feasibility outcome will evaluate the study site's capacity to enroll participants and the women's perception and acceptability of the intervention. The primary clinical outcome will be the prevalence of placental malaria at delivery. DISCUSSION: The present protocol aims to evaluate the feasibility on a large-scale and also to demonstrate the impact and the operational feasibility of additional screening with ultrasensitive rapid diagnostic tests and treatment with DHA-PQ on placental malaria, low birth weight, and peripheral malaria infection at delivery in a high-burden setting in Burkina Faso. TRIAL REGISTRATION: ClinicalTrials.gov , ID: NCT04147546 (14 October 2019).

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.

Prospective observational study to evaluate the clinical and biological safety profile of pyronaridine-artesunate in a rural health district in Burkina Faso.

The assessment in real-life conditions of the safety and efficacy of new antimalarial drugs is of greatest interest. This study aimed to monitor and evaluate both clinical and biological safety of pyronaridine-artesunate (PA) in real-life conditions in Burkina Faso's health system. This was a single-arm, open-label study, where patients attending Nanoro health facilities with uncomplicated malaria were consented to be part of a cohort event monitoring (CEM). At inclusion (day-0), PA was administered orally once a day for 3 days. Patients spontaneous reported any clinical adverse events (AEs) occurring within 28 days following the treatment. Additionally, the study focused on AEs of special interest (AESI), namely clinical signs related to hepatotoxicity and increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). A nested subset of patients with blood sample collection at day-0 and day-7 were monitored to investigate the effect of PA on biochemistry parameters. From September 2017 to October 2018, 2786 patients were treated with PA. About 97.8% (2720/2786) of patients did not report any AE. The most commonly reported events were respiratory, thoracic, and mediastinal disorders (8.3 per 1000), infections and infestations (7.9 per 1000), and gastrointestinal disorders (7.2 per 1000). No clinical or biological hepatotoxicity event related to PA was reported during the follow-up. Changes in biochemistry parameters remained within laboratory reference ranges. The study showed that PA is a well-tolerated drug and should be considered as a good option by malaria control programs in countries where existing first-line antimalarial drugs are continuously threatened by the emergence of drug resistance.

Assessment of Recovery Time, Worsening, and Death among Inpatients and Outpatients with COVID-19, Treated with Hydroxychloroquine or Chloroquine plus Azithromycin Combination in Burkina Faso.

OBJECTIVES: Our study aimed to assess the statistical relationship between the use of chloroquine phosphate or hydroxychloroquine plus azithromycin (CQ/HCQ + AZ) and virological recovery, disease worsening, and death among out- and inpatients with COVID-19 in Burkina Faso. METHODS AND DESIGNS: This was a retrospective observational study that compared outcomes in terms of time to recovery, worsening, and death in patients who received CQ/HCQ + AZ and those who did not using a multivariable Cox or Poisson model before and after propensity matching. RESULTS: Of the 863 patients included in the study, about 50% (432/863) were home-based follow-up patients and 50% were inpatients. Of these, 83.3% (746/863) received at least 1 dose of CQ/HCQ + AZ and 13.7% (118/863) did not. There were no significant differences in associated time to recovery for patients receiving any CQ/HCQ + AZ (adjusted HR 1.44; 95% CI 0.76-2.71). Similarly, there was no significant association between CQ/HCQ + AZ use and worsening (adjusted IRR 0.80; 95% CI 0.50-1.50). However, compared with the untreated group, the treated group had a lower risk of death (adjusted HR 0.20; 95% CI 0.10-0.44). CONCLUSIONS: The study provided valuable additional information on the use of CQ/HCQ in patients with COVID-19 and did not show any harmful outcomes of CQ/HCQ + AZ treatment.

Boosting the impact of seasonal malaria chemoprevention (SMC) through simultaneous screening and treatment of household members of children receiving SMC in Burkina Faso: a protocol for a randomized open label trial.

BACKGROUND: Plasmodium falciparum malaria remains a major public health concern in sub-Sahara Africa. Seasonal malaria chemoprevention (SMC) with amodiaquine + sulfadoxine-pyrimethamine is one of the most important preventive interventions. Despite its implementation, the burden of malaria is still very high in children under five years old in Burkina Faso, suggesting that the expected impact of this promising strategy might not be attained. Development of innovative strategies to improve the efficacy of these existing malaria control measures is essential. In such context, we postulate that screening and treatment of malaria in household members of children receiving SMC could greatly improve the impact of SMC intervention and reduce malaria transmission in endemic settings. METHODS: This randomized superiority trial will be carried out in the Nanoro health district, Burkina Faso. The unit of randomisation will be the household and all eligible children from a household will be allocated to the same study group. Households with 3-59 months old children will be assigned to either (i) control group (SMC alone) or (ii) intervention (SMC+ screening of household members with standard Histidin Rich Protein Rapid Diagnostic Test (HRP2-RDT) and treatment if positive). The sample size will be 526 isolated households per arm, i.e., around 1052 children under SMC coverage and an expected 1315 household members. Included children will be followed-up for 24 months to fully cover two consecutive malaria transmission seasons and two SMC cycles. Children will be actively followed-up during the malaria transmission seasons while in the dry seasons the follow-up will be passive. CONCLUSION: The study will respond to a major public health concern by providing evidence of the efficacy of an innovative strategy to boost the impact of SMC intervention.

Safety of Chloroquine or Hydroxychloroquine Plus Azithromycin for the Treatment of COVID-19 Patients in Burkina Faso: An Observational Prospective Cohort Study.

INTRODUCTION: Though chloroquine derivatives are used in the treatment of coronavirus disease 2019 (COVID-19) in many countries worldwide, doubts remain about the safety and efficacy of these drugs, especially in African communities where published data are scarce. METHODS: We conducted an observational prospective cohort study from April 24 to September 03, 2020, in Burkina Faso to assess (as primary outcome) the clinical, biological, and cardiac (electrocardiographic) safety of chloroquine or hydroxychloroquine plus azithromycin administered to COVID-19 patients. The main secondary outcomes were all-cause mortality and median time of viral clearance. RESULTS: A total of 153 patients were enrolled and followed for 21 days. Among patients who took at least one dose of chloroquine or hydroxychloroquine (90.1% [138/153]), few clinical adverse events were reported and were mainly rash/pruritus, diarrhea, chest pain, and palpitations. No statistically significant increase in hepatic, renal, and hematological parameters or electrolyte disorders were reported. However, there was a significant increase in the QTc value without exceeding 500ms, especially in those who received chloroquine phosphate. Three adverse events of special interest classified as serious (known from chloroquine derivatives) were recorded namely pruritus, paresthesia, and drowsiness. One case of death occurred. The average onset of SARS-CoV-2 PCR negativity was estimated at 7.0 (95% CI: 5.0-10.0) days. CONCLUSION: Hydroxychloroquine appeared to be well tolerated in treated COVID-19 patients in Burkina Faso. In the absence of a robust methodological approach that could generate a high level of scientific evidence, our results could at least contribute to guide health decisions that should be made based on different sources of scientific evidence including those from our study.

Malaria and curable sexually transmitted and reproductive tract coinfection among pregnant women in rural Burkina Faso.

BACKGROUND: Malaria and sexually transmitted/reproductive tract infections (STI/RTI) are leading and preventable causes of low birthweight in sub-Saharan Africa. Reducing their impact on pregnancy outcomes requires efficient interventions that can be easily integrated into the antenatal care package. The paucity of data on malaria and STI/RTI coinfection, however, limits efforts to control these infections. This study aimed to determine the prevalence and associated factors of malaria and STI/RTI coinfection among pregnant women in rural Burkina Faso. METHODS: A cross-sectional survey was conducted among 402 pregnant women attending antenatal clinics at the Yako health district. Sociodemographic and behavioral data were collected, and pregnant women were tested for peripheral malaria by microscopy. Hemoglobin levels were also measured by spectrophotometry and curable bacterial STI/RTI were tested on cervico-vaginal swabs using rapid diagnostic test for chlamydia and syphilis, and Gram staining for bacterial vaginosis. A multivariate logistic regression model was used to assess the association of malaria and STI/RTI coinfection with the characteristics of included pregnant women. RESULTS: The prevalence of malaria and at least one STI/RTI coinfection was 12.9% (95% confidence interval, CI: [9.8-16.7]), malaria and bacterial vaginosis coinfection was 12.2% (95% CI: [9.3-15.9]), malaria and chlamydial coinfection was 1.6% (95% CI: [0.6-3.8]). No coinfection was reported for malaria and syphilis. The individual prevalence was 17.2%, 7.2%, 0.6%, 67.7% and 73.3%, respectively, for malaria infection, chlamydia, syphilis, bacterial vaginosis and STI/RTI combination. Only 10% of coinfections were symptomatic, and thus, 90% of women with coinfection would have been missed by the symptoms-based diagnostic approach. In the multivariate analysis, the first pregnancy (aOR = 2.4 [95% CI: 1.2-4.7]) was the only factor significantly associated with malaria and STI/RTI coinfection. Clinical symptoms were not associated with malaria and STI/RTI coinfection. CONCLUSION: The prevalence of malaria and curable STI/RTI coinfection was high among pregnant women. The poor performance of the clinical symptoms to predict coinfection suggests that alternative interventions are needed.

[Polymorphisms in Plasmodium falciparum parasites and mutations in the resistance genes Pfcrt and Pfmdr1 in Nanoro area, Burkina Faso]. / Polymorphisme de Plasmodium falciparum et mutations des gènes de résistance Pfcrt et Pfmdr1 dans la zone de Nanoro, Burkina Faso.

INTRODUCTION: from a genetic point of view P. falciparumis extremely polymorphic. There is a variety of parasite strains infesting individuals living in malaria endemic areas. The purpose of this study is to investigate the relationship between polymorphisms in Plasmodium falciparum parasites and Pfcrt and Pfmdr1 gene mutations in Nanoro area, Burkina Faso. METHODS: blood samples from plasmodium carriers residing in the Nanoro Health District were genotyped using nested PCR. Parasite gene mutations associated with resistance to antimalarial drugs were detected by PCR-RFLP. RESULTS: samples of 672 patients were successfully genotyped. No msp1and msp2allelic families exhibited an increase in developing mutations in resistance genes. However, mutant strains of these genes were present at greater levels in monoclonal infections than in multi-clonal infections. CONCLUSION: this study provides an overview of the relationship between polymorphisms in Plasmodium falciparum parasites and mutations in resistance genes. These data will undoubtedly contribute to improving knowledge of the parasite´s biology and its mechanisms of resistance to antimalarial drugs.

Pathogens associated with acute diarrhea, and comorbidity with malaria among children under five years old in rural Burkina Faso.

INTRODUCTION: acute diarrhea in children under five years is a public health problem in developing countries and particularly in malaria-endemic areas where both diseases co-exist. The present study examined the etiology of childhood diarrhea and its comorbidity with malaria in a rural area of Burkina Faso. METHODS: conventional culture techniques, direct stools examination, and viruses´ detection by rapid tests were performed on the fresh stools and microscopy was used to diagnose malaria. Some risk factors were also assessed. RESULTS: on a total of 191 samples collected, at least one pathogen was identified in 89 cases (46.6%). The proportions of pathogens found on the 89 positive stool samples were parasites 51.69% (46 cases), viruses 39.33% (35 cases), and bacteria 14.61% (13 cases), respectively. The relationship between malaria and infectious diarrhea was significant in viral and parasites causes (p=0.005 and 0.043 respectively). Fever, vomiting and abdominal pain were the major symptoms associated with diarrhea, with 71.51%, 31.72% and 23.66% respectively. The highest viral diarrhea prevalence was reported during the dry season (OR=5.29, 95% CI: 1.74 - 16.07, p=0.001) while parasite diarrhea was more encountered during the rainy season (OR=0.41, 95% CI: 0.33 - 0.87, p=0.011). CONCLUSION: Giardia spp and rotavirus were the leading cause of acute diarrhea in Nanoro, Burkina Faso with a predominance of rotavirus in children less than 2 years. Parasite and viral diarrhea were the most pathogens associated with malaria. However, the high rate of negative stool samples suggests the need to determine other enteric microorganisms.