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Background: This study describes the laboratory evaluation of a novel diagnostic platform for malaria. The Magneto Optical Test (MOT) is based on the bio-physical detection of haemozoin in clinical samples. Having an assay time of around one minute, it offers the potential of high throughput screening. Methods: Blood samples of confirmed malaria patients from different regions of Africa, patients with other diseases and healthy non-endemic controls were used in the present study. The samples were analysed with two reference tests, i.e. an histidine rich protein-2 based rapid diagnostic test (RDT) and a conventional Pan-Plasmodium PCR, and the MOT as index test. Data were entered in 2 × 2 tables and analysed for sensitivity and specificity. The agreement between microscopy, RDT and PCR and the MOT assay was determined by calculating Kappa values with a 95% confidence interval. Results: The observed sensitivity/specificity of the MOT test in comparison with clinical description, RDT or PCR ranged from 77.2 - 78.8% (sensitivity) and from 72.5 - 74.6% (specificity). In general, the agreement between MOT and the other assays is around 0.5 indicating a moderate agreement between the reference and the index test. However, when RDT and PCR are compared to each other, an almost perfect agreement can be observed (k = 0.97) with a sensitivity and specificity of >95%. Conclusions: Although MOT sensitivity and specificity are currently not yet at a competing level compared to other diagnostic test, such as PCR and RDTs, it has a potential to rapidly screen patients for malaria in endemic as well as non-endemic countries. [ABSTRACT FROM AUTHOR]

Sulphadoxine-pyrimethamine (SP) is only used for intermittent preventive treatment during pregnancy (IPTp) in most Sub-Saharan African countries. However, there are concerns about the efficacy of IPTp-SP because of increasing resistance. Combinations of point mutations in the dhps and dhfr genes of Plasmodium falciparum are associated with SP resistance, in particular the quintuple dhfr (N51, C59, S108) − dhps (codons A437, K540) mutant. In Nanoro, Burkina Faso, filter paper samples from pregnant women at first antenatal care visit and at delivery plus samples from the general population (GP) were studied for dhfr and dhps mutations by sequencing. Quintuple mutants were present in 2 delivery and 4 GP samples. This is the first time the quintuple mutation is found in Burkina Faso and although the prevalence is still very low, emergence of the quintuple mutation could highly diminish the efficacy of IPTp-SP. Close surveillance of SP resistance mutations is therefore warranted. [ABSTRACT FROM AUTHOR]

Introduction: Polymorphonuclear neutrophils (PMN) are involved in pathogen clearance by phagocytosis. However, the role of PMNs in the efficacy of artemisinin-based combination therapy (ACT) is poorly understood., Methodology: In a prospective longitudinal in vivo study, neutrophil rates were compared with malaria carriage after treatment with different ACTs: Artemether - lumefantrine (AL), Artesunate - amodiaquine (ASAQ), Dihydroartemisinin - piperaquine (DP) or Pyronaridine artesunate (PA). The study cases were classified as having neutropenia, normal neutrophil levels or neutrophilia depending on the level of neutrophils in the blood. This study included 3148 patients and was analyzed using R., Results: On day 7, only four patients in the neutropenia group and treated with AL had a malaria positive blood smear based on microscopy. On day 28, the rate of recurrent parasitemia in the AL arm was significantly higher in neutropenia patients (50.9%) than in patients with normal rates of neutrophils (43.1%) or in those with neutrophilia (6.0%) (p < 0.001). In ASAQ arm, the rate of recurrent Plasmodium falciparum parasitemia was 58.8% in the neutropenia group versus 29.4% in patients with normal rates of neutrophils and 11.8% in patients with neutrophilia (p < 0.001). No patient treated with DP with normal neutrophil counts or neutrophilia was carrying malaria parasites on day 28. Among the 15 patients with parasitemia on day 28 in the PA arm, 11 (73.33%) had neutropenia while 4 (26.67%) had a normal neutrophil count (p < 0.001)., Conclusions: Patients with neutropenia had higher rates of recurrent P. falciparum parasitemia after ACT., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2023 Moussa Djimde, Kassoum Kayentao, Japhet Kabalu Tshiongo, Bakary Fofana, Charles Arama, Sodiomon B Sirima, Jean Bosco Ouedraogo, Abdoul Habib Beavogui, Issaka Sagara, Alassane Dicko, Petra F Mens, Henk DFH Schallig, Abdoulaye Djimde.)