Treatment Of Falciparum Malaria Research Articles

Artemisinin resistance and malaria elimination: Where are we now?

The emergence of artemisinin resistance is a major obstacle to the global malaria eradication/elimination programs. Artemisinin is a very fast-acting antimalarial drug and is the most important drug in the treatment of severe and uncomplicated malaria. For the treatment of acute uncomplicated falciparum malaria, artemisinin derivatives are combined with long half-life partner drugs and widely used as artemisinin-based combination therapies (ACTs). Some ACTs have shown decreased efficacy in the Southeast Asian region. Fortunately, artemisinin has an excellent safety profile and resistant infections can still be treated successfully by modifying the ACT. This review describes the pharmacological properties of ACTs, mechanisms of artemisinin resistance and the potential changes needed in the treatment regimens to overcome resistance. The suggested ACT modifications are extension of the duration of the ACT course, alternating use of different ACT regimens, and addition of another antimalarial drug to the standard ACTs (Triple-ACT). Furthermore, a malaria vaccine (e.g., RTS,S vaccine) could be added to mass drug administration (MDA) campaigns to enhance the treatment efficacy and to prevent further artemisinin resistance development. This review concludes that artemisinin remains the most important antimalarial drug, despite the development of drug-resistant falciparum malaria.

Ethical considerations in deploying triple artemisinin-based combination therapies for malaria: An analysis of stakeholders' perspectives in Burkina Faso and Nigeria.

BackgroundArtemisinin-based combination therapies (ACTs) are the recommended treatment for uncomplicated Plasmodium falciparum malaria in all malaria endemic countries. Artemisinin resistance, partner drug resistance, and subsequent ACT failure are widespread in Southeast Asia. The more recent independent emergence of artemisinin resistance in Africa is alarming. In response, triple artemisinin-based combination therapies (TACTs) are being developed to mitigate the risks associated with increasing drug resistance. Since ACTs are still effective in Africa, where malaria is mainly a paediatric disease, the potential deployment of TACTs raises important ethical questions. This paper presents an analysis of stakeholders’ perspectives regarding key ethical considerations to be considered in the deployment of TACTs in Africa provided they are found to be safe, well-tolerated and effective for the treatment of uncomplicated malaria.MethodsWe conducted a qualitative study in Burkina Faso and Nigeria assessing stakeholders’ (policy makers, suppliers and end-users) perspectives on ethical issues regarding the potential future deployment of TACTs through 68 in-depth interviews and 11 focus group discussions.FindingsSome respondents suggested that there should be evidence of local artemisinin resistance before they consider deploying TACTs, while others suggested that TACTs should be deployed to protect the efficacy of current ACTs. Respondents suggested that additional side effects of TACTs compared to ACTs should be minimal and the cost of TACTs to end-users should not be higher than the cost of current ACTs. There was some disagreement among respondents regarding whether patients should have a choice of treatment options between ACTs and TACTs or only have TACTs available, while ACTs are still effective. The study also suggests that community, public and stakeholder engagement activities are essential to support the introduction and effective uptake of TACTs.ConclusionAddressing ethical issues regarding TACTs and engaging early with stakeholders will be important for their potential deployment in Africa.

Degradation kinetics of artesunate for the development of an ex-tempore intravenous injection

BackgroundArtesunate is recommended by the World Health Organization (WHO) for parenteral treatment of severe Plasmodium falciparum malaria. However, artesunate is inherently unstable in an aqueous solution and hydrolyses rapidly after its preparation for injection. Therefore, the aim of the study was to evaluate the stabilizing effects of phosphate buffer and mannitol against short-term (ex-tempore) artesunate hydrolysis.MethodsA HPLC–UV isocratic method was developed using a reversed-phase fused core column (HALO RP-C18) and a mobile phase consisting of a mixture of 45% ammonium formate 10 mM in water (pH 4.5) and 55% methanol. Artesunate was formulated as aqueous solutions using a design of experiment (DOE) to investigate the artesunate stabilizing effects of pH (8–10), phosphate buffer strength (0.3–0.5 M), and mannitol (0–0.22 mmol/mL). The solutions were incubated at predefined temperatures (5, 25, and 40 °C) with subsequent analysis. Arrhenius equation was applied to model and evaluate the stability results.ResultsThe developed HPLC-based method using fused-core stationary phase allowed to selectively quantify artesunate in the presence of its main hydrolysis degradants; namely β-dihydroartemisinin (β-DHA) and α-dihydroartemisinin (α-DHA) within 10 min. By applying the Arrhenius equation, the rate of hydrolysis of the drug increased approximately by 3.4 as the temperature raised by 10 °C. Buffer strength was found to be the main factor affecting the hydrolysis rate constants at 5 and 25 °C (p < 0.05), the activation energy (p = 0.009), and the frequency factor (p = 0.045). However, the effect of the buffer was predominant on the activation energy and hydrolysis rate constants, revealing its stabilizing effect on the drug at lower buffer strength (0.3 M). Within the investigated range (pH = 8–10), pH was found to influence the activation energy, with a positive stabilizing effect in the pH range of 8–9. The addition of mannitol as stabilizing agent into artesunate aqueous formulation did not show an improved response.ConclusionPhosphate buffer was the main stability determining factor of artesunate in the aqueous intravenous (i.v.) formulation and was found to be more effective in stabilizing artesunate at a buffer strength of 0.3 M in pH 8–9, while mannitol lacked stabilizing effect.

Efficacy of Artemether-Lumefantrine and Dihydroartemisinin-Piperaquine for the Treatment of Uncomplicated Plasmodium falciparum Malaria among Children in Western Kenya, 2016 to 2017.

Antimalarial resistance threatens global malaria control efforts. The World Health Organization (WHO) recommends routine antimalarial efficacy monitoring through a standardized therapeutic efficacy study (TES) protocol. From June 2016 to March 2017, children with uncomplicated P. falciparum mono-infection in Siaya County, Kenya were enrolled into a standardized TES and randomized (1:1 ratio) to a 3-day course of artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP). Efficacy outcomes were measured at 28 and 42 days. A total of 340 children were enrolled. All but one child cleared parasites by day 3. PCR-corrected adequate clinical and parasitological response (ACPR) was 88.5% (95% CI: 80.9 to 93.3%) at day 28 for AL and 93.0% (95% CI: 86.9 to 96.4%) at day 42 for DP. There were 9.6 times (95% CI: 3.4 to 27.2) more reinfections in the AL arm compared to the DP arm at day 28, and 3.1 times (95% CI: 1.9 to 4.9) more reinfections at day 42. Both AL and DP were efficacious (per WHO 90% cutoff in the confidence interval) and well tolerated for the treatment of uncomplicated malaria in western Kenya, but AL efficacy appears to be waning. Further efficacy monitoring for AL, including pharmacokinetic studies, is recommended.

Genetic variability (785A > G, 516G > T and 64C > T) in the CYP2B6 gene among individuals in Southwest Nigeria: Implications for malaria treatment

Malaria remains a disease of major public health concern globally, with endemicity more pronounced in the sub-Saharan Africa while children below the age of five alongside pregnant women are the most affected groups. The artemisinin combination therapy (ACT) is the recommended first line treatment for Plasmodium falciparum malaria in Nigeria. However, Single nucleotide polymorphisms of the cytochrome P450 2B6 gene (known for the primary induction of artemisinin) can affect the enzyme function as it either enhances, decreases, or abolishes its enzymatic activities depending on the drug substrates. This study investigated the frequency of commonly observed CYP2B6 variants (516G > T {rs3745274}, 785A > G{rs2279343}, 64C > T {rs2279345}) and the association with malaria in a Yoruba population of Nigeria. Genotyping of CYP2B6 genetic polymorphisms was carried out among 200 children using PCR-RFLP protocol. Statistical package for social sciences (SPSS) was used in analyzing demographic and clinical data. Genotypic and Allelic frequencies were calculated, conformity with Hardy-Weinberg equilibrium and associations were tested for under three different genetic models using PLINK v1.90 and Haploview 4.2. We observed a minor allelic frequency (MAF) of 0.12, 0.375, 0.423 for 785A > G, 64C > T and 516G > T allelic variants respectively. The Three SNPs were not in linkage disequilibrium, the variants 785A > G and 516G > T were in conformity with Hardy-Weinberg equilibrium. The genotype distributions of 785A > G and 64C > T differed significantly across all malaria groups. Further analysis showed a statistically significant association of 785 A > G with malaria. The 785A > G variant under the dominant and additive genetic models reduced the risk of developing uncomplicated malaria (95% CI = 0.15–0.81, OR = 0.35, p = 0.0142) and severe malaria (95% CI = 0.20–0.97, OR = 0.44, p = 0.0439) from asymptomatic malaria. This finding indicates that the cytochrome p450 gene variant, 785A > G may confer protection against malaria development in addition to its drug metabolism functions. Further large-scale studies on CYP2B6 variants are recommended to explore the impact in malaria development or susceptibility.

Persistence of Residual Submicroscopic P. falciparum Parasitemia following Treatment of Artemether-Lumefantrine in Ethio-Sudan Border, Western Ethiopia.

The emergence of artemisinin-resistant parasites in Africa has had a devastating impact, causing most malaria cases and related deaths reported on the continent. In Ethiopia, artemether-lumefantrine (AL) is the first-line drug for the treatment of uncomplicated falciparum malaria. This study is one of the earliest evaluations of artemether-lumefantrine (AL) efficacy in western Ethiopia, 17 years after the introduction of this drug in the study area. This study aimed at assessing PCR- corrected clinical and parasitological responses at 28 days following AL treatment. Sixty uncomplicated falciparum malaria patients were enrolled, treated with standard doses of AL, and monitored for 28 days with clinical and parasitological assessments from September 15 to December 15, 2020. Microscopy was used for patient recruitment and molecular diagnosis of P. falciparum was performed by Var gene acidic terminal sequence (varATS) real-time PCR on dried blood spots collected from each patient from day 0 and on follow-up days 1, 2, 3, 7, 14, 21, and 28. MspI and msp2 genotyping was done to confirm occurrence of recrudescence. Data entry and analysis were done by using the WHO-designed Excel spreadsheet and SPSS version 20 for Windows. A P value of less or equal to 0.05 was considered significant. From a total of 60 patients enrolled in this efficacy study, 10 were lost to follow-up; the results were analyzed for 50 patients. All the patients were fever-free on day 3. The asexual parasite positivity rate on day 3 was zero. However; 60% of the patients were PCR positive on day 3. PCR positivity on day 3 was more common among patients <15 years old as compared with those ≥15 years old (AOR = 6.44, P = 0.027). Only two patients met the case definition of treatment failure. These patients were classified as a late clinical failure as they showed symptoms of malaria and asexual stages of the parasite detected by microscopy on day 14 of their follow-ups. Hence, the Kaplan-Meier analysis of PCR- corrected adequate clinical and parasitological response (ACPR) rate of AL among study participants was 96% (95% CI: 84.9-99). In seven patients, the residual submicroscopic parasitemia persists from day 0 to day 28 of the follow-up. In addition, 16% (8/50) of patients were PCR- and then turned PCR+ after day 7 of the follow-up. AL remains efficacious for the treatment of uncomplicated falciparum malaria in the study area. However, the persistence of PCR-detected residual submicroscopic parasitemia following AL might compromise this treatment and need careful monitoring.

Keystone Malaria Symposium 2022: a vibrant discussion of progress made and challenges ahead from drug discovery to treatment

Keystone Malaria Symposium 2022: a vibrant discussion of progress made and challenges ahead from drug discovery to treatment

In-vitro Activity of Medicinal Plant Crude Extract and In-vivo Toxicity Testing of Dichloromethane Root Extract of Citrus limon in laboratory Rabbits

Aims: To identify viable phytomedicines traditionally employed for the treatment of malaria in Kenya that could be developed into antimalarial agents.&#x0D; Study Design: Quantitative analysis of antiplasmodial activities and brine shrimp bioassays were carried out using standard procedures. The experiment was set in duplicate for each concentration of the drug and average IC50 determined.&#x0D; Place and Duration of Study: Seven indigenous plants: Achyranthes aspera, Heinsiacrinita, Bridelia cathartica, Citrus limon, Microglossapyrifolia, Vernoniaglabra and Carissa edulis obtained from Kilifi and Homa-Bay counties in Kenya were evaluated for their anti-Plasmodium falciparum potential. Collection of samples and analysis took about three months from April 2018.&#x0D; Methodology: Both Chemical and aqueous crude extraction methods were carried out to identify the most active extracts against P. Falciparum and then isolate pure active phytochemicals. Pure compounds were subjected to Nuclear Magnetic Resonance (NMR), Infra-Red (IR) and Mass Spectroscopy (MS) analyses for structure elucidation.&#x0D; Results: Four extracts (hexane, dichloromethane (DCM),methanoland water) of seven different species of plants were analyzed for their anti-plasmodial activities.W2 and D6 strains of Falciparum were tested. However, the three most active extracts were from Citrus lemon roots (DCM) with IC50 value of 7.017 µg/mL, C. edulis root (aqueous) with IC50 value of 8.054 µg/Ml and B. Cathertical eaves (methanol) with IC50 value of 15.647 µg/Ml. However, three pure compounds were obtained; suberosin IC5026.7 (Strain W2), 53.1 (Strain D6) and xanthyletin IC501580 (Strain W2) from C. limon (DCM) and spinasterol IC50 43.2 (Strain W2) from M. pyrifolia (hexane).&#x0D; Conclusion: The three different species of plants with most active compounds have demonstrated their potentiality in treatment for falciparum malaria. Structures of the isolated three compounds can be modelled to synthesis of anti- plasmodial drugs as they are active in vitro.

In vitro Antiplasmodial Activities of Crude Extracts and Compounds Derived from Selected Indigenous Medicinal Plants used Traditionally to Treat Malaria in Kenya

Aims: To identify viable phytomedicines traditionally employed for the treatment of malaria in Kenya that could be developed into antimalarial agents.&#x0D; Study Design: Quantitative analysis of antiplasmodial activities and brine shrimp bioassays were carried out using standard procedures. The experiment was set in duplicate for each concentration of the drug and average IC50 determined.&#x0D; Place and Duration of Study: Seven indigenous plants: Achyranthesaspera, Heinsiacrinita, Brideliacathartica, Citrus limon, Microglossapyrifolia, Vernoniaglabra and Carissa edulis obtained from Kilifi and Homa-Bay counties in Kenya were evaluated for their anti-Plasmodium falciparumpotential.Collection of samples and analysis took about three months.&#x0D; Methodology: Both Chemical and aqueous crude extraction methods were carried out to identify the most active extracts against P. Falciparum and thenisolatepureactive phytochemicals. Pure compounds were subjected to Nuclear Magnetic Resonance (NMR), Infra-Red (IR) and Mass Spectroscopy (MS) analyses for structure elucidation.&#x0D; Results: Four extracts of hexane, dichloromethane (DCM), methanol and water of seven different species of plants were analyzed for their anti-plasmodial activities.W2 and D6 strains of Falciparum were tested. However, the three most active extracts were from Citrus lemon roots (DCM) with IC50 value of 7.017 µg/mL, C. edulis root (aqueous) with IC50 value of 8.054 µg/Ml and B. Cathertica leaves (methanol) with IC50 value of 15.647 µg/Ml. However, three pure compounds were obtained; suberosinIC5026.7 (Strain W2), 53.1 (Strain D6) and xanthyletin IC501580 (Strain W2) from C. Limon (DCM) and spinasterolIC5043.2 (Strain W2) fromM. pyrifolia (hexane).&#x0D; Conclusion: The three different species of plants with most active compounds have demonstrated their potentiality in treatment for falciparum malaria. Structures of the isolated three compounds can be modelled to synthesise anti- plasmodial drugs as they are active in vitro.

Expert perspectives on the introduction of Triple Artemisinin-based Combination Therapies (TACTs) in Southeast Asia: a Delphi study

BackgroundTriple Artemisinin-based Combination Therapies (TACTs) are being developed as a response to artemisinin and partner drug resistance in Southeast Asia. However, the desirability, timing and practical feasibility of introducing TACTs in Southeast Asia is subject to debate. This study systematically assesses perspectives of malaria experts towards the introduction of TACTs as first-line treatment for uncomplicated falciparum malaria in Southeast Asia.MethodsA two-round Delphi study was conducted. In the first round, 53 malaria experts answered open-ended questions on what they consider the most important advantages, disadvantages, and implementation barriers for introducing TACTs in Southeast Asia. In the second round, the expert panel rated the relevance of each statement on a 5-point Likert scale.ResultsMalaria experts identified 15 advantages, 15 disadvantages and 13 implementation barriers for introducing TACTs in Southeast Asia in the first round of data collection. In the second round, consensus was reached on 13 advantages (8 perceived as relevant, 5 as not-relevant), 12 disadvantages (10 relevant, 2 not-relevant), and 13 implementation barriers (all relevant). Advantages attributed highest relevance related to the clinical and epidemiological rationale of introducing TACTs. Disadvantages attributed highest relevance related to increased side-effects, unavailability of fixed-dose TACTs, and potential cost increases. Implementation barriers attributed highest relevance related to obtaining timely regulatory approval, timely availability of fixed-dose TACTs, and generating global policy support for introducing TACTs.ConclusionsThe study provides a structured oversight of malaria experts’ perceptions on the major advantages, disadvantages and implementation challenges for introducing TACTs in Southeast Asia, over current practices of rotating ACTs when treatment failure is observed. The findings can benefit strategic decision making in the battle against drug-resistant malaria.

Artesunate\u2013amodiaquine and artemether\u2013lumefantrine for the treatment of uncomplicated falciparum malaria in Liberia: in vivo efficacy and frequency of molecular markers

BackgroundArtesunate–amodiaquine (ASAQ) and Artemether–lumefantrine (AL) are the recommended treatment for uncomplicated Plasmodium falciparum malaria in Liberia. Intermittent preventive treatment with sulfadoxine/pyrimethamine is also recommended for pregnant women. The therapeutic efficacy of Artesunate–amodiaquine and Artemether–lumefantrine, and the frequency of molecular markers associated with anti-malarial drug resistance were investigated.MethodsThe therapeutic efficacy of ASAQ and AL was evaluated using the standard World Health Organization protocol (WHO. Methods for Surveillance of Antimalarial Drug Efficacy. Geneva: World Health Organization; 2009. https://www.who.int/malaria/publications/atoz/9789241597531/en/). Eligible children were recruited and monitored clinically and parasitologically for 28 days. Polymorphisms in the Pfkelch 13, chloroquine resistance transporter (Pfcrt), multidrug resistance 1 (Pfmdr-1), dihydrofolate reductase (Pfdhfr), and dihydropteroate synthase (Pfdhps) genes and copy number variations in the plasmepsin-2 (Pfpm2) gene were assessed in pretreatment samples.ResultsOf the 359 children enrolled, 180 were treated with ASAQ (89 in Saclepea and 91 in Bensonville) and 179 with AL (90 in Sinje and 89 in Kakata). Of the recruited children, 332 (92.5%) reached study endpoints. PCR-corrected per-protocol analysis showed ACPR of 90.2% (95% CI: 78.6–96.7%) in Bensonville and 92.7% (95% CI: 83.4.8–96.5%) in Saclepea for ASAQ, while ACPR of 100% was observed in Kakata and Sinje for AL. In both treatment groups, only two patients had parasites on day 3. No artemisinin resistance associated Pfkelch13 mutations or multiple copies of Pfpm2 were found. Most samples tested had the Pfcrt 76 T mutation (80/91, 87.9%), while the Pfmdr-1 86Y (40/91, 44%) and 184F (47/91, 51.6%) mutations were less frequent. The Pfdhfr triple mutant (51I/59R/108 N) was the predominant allele (49.2%). For the Pfdhps gene, it was the 540E mutant (16.0%), and the 436A mutant (14.3%). The quintuple allele (51I/59R/108 N-437G/540E) was detected in only one isolate (1/357).ConclusionThis study reports a decline in the efficacy of ASAQ treatment, while AL remained highly effective, supporting the recent decision by NMCP to replace ASAQ with AL as first-line treatment for uncomplicated falciparum malaria. No association between the presence of the mutations in Pfcrt and Pfmdr-1 and the risk of parasite recrudescence in patients treated with ASAQ was observed. Parasites with signatures known to be associated with artemisinin and piperaquine resistance were not detected. The very low frequency of the quintuple Pfdhfr/Pfdhps mutant haplotype supports the continued use of SP for IPTp. Monitoring of efficacy and resistance markers of routinely used anti-malarials is necessary to inform malaria treatment policy.Trial registration ACTRN12617001064392.

Anti-Gametocyte Antigen Humoral Immunity and Gametocytemia During Treatment of Uncomplicated Falciparum Malaria: A Multi-National Study.

IntroductionUnderstanding the human immune response to Plasmodium falciparum gametocytes and its association with gametocytemia is essential for understanding the transmission of malaria as well as progressing transmission blocking vaccine candidates.MethodsIn a multi-national clinical efficacy trial of artemisinin therapies (13 sites of varying transmission over South-East Asia and Africa), we measured Immunoglobulin G (IgG) responses to recombinant P. falciparum gametocyte antigens expressed on the gametocyte plasma membrane and leading transmission blocking vaccine candidates Pfs230 (Pfs230c and Pfs230D1M) and Pfs48/45 at enrolment in 1,114 participants with clinical falciparum malaria. Mixed effects linear and logistic regression were used to determine the association between gametocyte measures (gametocytemia and gametocyte density) and antibody outcomes at enrolment.ResultsMicroscopy detectable gametocytemia was observed in 11% (127/1,114) of participants at enrolment, and an additional 9% (95/1,114) over the follow-up period (up to day 42) (total 20% of participants [222/1,114]). IgG levels in response to Pfs230c, Pfs48/45 and Pfs230D1M varied across study sites at enrolment (p < 0.001), as did IgG seroprevalence for anti-Pfs230c and D1M IgG (p < 0.001), but not for anti-Pfs48/45 IgG (p = 0.159). In adjusted analyses, microscopy detectable gametocytemia at enrolment was associated with an increase in the odds of IgG seropositivity to the three gametocyte antigens (Pfs230c OR [95% CI], p: 1.70 [1.10, 2.62], 0.017; Pfs48/45: 1.45 [0.85, 2.46], 0.174; Pfs230D1M: 1.70 [1.03, 2.80], 0.037), as was higher gametocyte density at enrolment (per two-fold change in gametocyte density Pfs230c OR [95% CI], p: 1.09 [1.02, 1.17], 0.008; Pfs48/45: 1.05 [0.98, 1.13], 0.185; Pfs230D1M: 1.07 [0.99, 1.14], 0.071).Conclusion Pfs230 and Pfs48/45 antibodies are naturally immunogenic targets associated with patent gametocytemia and increasing gametocyte density across multiple malaria endemic settings, including regions with emerging artemisinin-resistant P. falciparum.

A High efficacy of Artemether–Lumefantrine and Artesunate-Amodiaquine for the treatment of uncomplicated falciparum malaria in Massokory, Mondo and Dourbali provinces (Chad).

Artemether-Lumefantrine (AL) and Artesunate-Amodiaquine (ASAQ) are recommended for the treatment of uncomplicated malaria in Chad. The objective of this study was to evaluate the High efficacy of Artemether–Lumefantrine and Artesunate-Amodiaquine for the treatment of uncomplicated falciparum malaria in Massokory, Mondo and Dourbali provinces (Chad).The study was&nbsp; carried out in 2019, 1113 patients children &nbsp;aged from 6 to 60 months were randomly assigned treatment with Artemether-Lumefantrine and Artesunate-Amodiaquine and followed up for 28 days. Primary endpoint was the treatment efficacy over 28 days. The early treatment failure was (0.13%) in AL group and (0.17%) in ASAQ group. No early clinical failure was found. Adequate clinical and parasitological responses were significantly higher in Artesunate-Amodiaquine group (ASAQ) (99.82% versus (99.10%) in Artemether-Lumefantrine (AL) group, p = 0.0009). All treatments had a similar and good tolerability profile that confirm the high efficacy of the first- and the newly recommended alternative ACT for treatments for uncomplicated falciparum malaria in Chad. The high parasite density clearance suggests absence of suspected artemisinin resistance, defined as delayed parasite clearance &nbsp

Current status of 4-aminoquinoline resistance markers 18 years after cessation of chloroquine use for the treatment of uncomplicated falciparum malaria in the littoral coastline region of Cameroon

ABSTRACT The onset and rapid spread of chloroquine resistance and the introduction of amodiaquine for the treatment of uncomplicated malaria in Cameroon have influenced the proportion of Plasmodium falciparum sensitive and resistant alleles related to 4-aminoquinoline drugs. This study was undertaken to determine the prevalence of resistance markers to antimalarial 4-aminoquinolines in Douala in the Littoral Region, and Buea in the South West Region in June 2020. Dry blood spots were prepared from malaria microscopy positive cases and used for parasite DNA extraction by chelex-100 method. Plasmodium species identification was carried out by PCR amplification/agarose gel electrophoresis of 18srRNA. The Pfcrt and Pfmdr1 genes were amplified by PCR followed by restriction digestion. The prevalence of single nucleotide polymorphisms (SNPs) was compared between study sites and with previous studies carried out between 2003–2005 and 2009–2011 using the Chi square test. The results showed that Plasmodium falciparum was the dominant species occurring as mono-infections (84.6%). The wild type K76 allele of the Pfcrt gene was found in 74.9% of isolates while the wild N86, Y184 and D1246 alleles of the Pfmdr1 gene were found respectively in 87.2%, 89.6% and 100% of field isolates. The results showed a significant reduction in the mutant alleles compared to results obtained in 2003–2005 and 2009–2013. The KNYD haplotype was observed to be the most prevalent. The results indicated that there is a gradual erosion of the mutant Pfcrt and Pfmdr1 genotype and a gradual return to the sensitive P. falciparum genotype in Cameroon.

The Effect of Arthrospira Platensis on the Acute Toxicity of Artemeter Lumefantrine in Malaria Patients

Malaria has remained one of the leading causes of morbidity and mortality in most developing countries. This pathology is caused by the Plasmodium spp. Artemisinin-based combination therapy is recommended by current WHO guidelines for the treatment of uncomplicated falciparum malaria (ACT). -Linolenic acid, one of the necessary fatty acids, is abundant in the microscopic filamentous alga Arthrospira platensis, which is rich in proteins, vitamins, vital amino acids, and minerals (GLA). The current study was carried out to evaluate the effect of Arthrospira platensis on the liver and kidney toxicity induced by ACT. Malaria patients were randomized into two groups to receive therapeutic dose of either artemether-lumefantrine 20/120mg (group 1) or artemether-lumefantrine 20/120mg + Arthrospira platensis 8g daily (group2) as an adjunct therapy and follow-up for 7 days. After treatment their liver and kidney Biochemical parameters (ALT, AST, ALB, UREA, CREAT) were measured. Both pre and post treatment samples were analyzed and the results gotten compared with control group made up of malaria negative patients. Serum activity of selected biomarkers (ALT, AST, ALB, UREA) of malaria patients were seen to be statistically significant (P&lt;0.05) on D0 when compared to that of malaria negative patients. This study showed that Arthrospira platensis prevented the artemether-lumefantrine induced significant changes on the liver and kidney biochemical parameters analyzed. The results obtained from this study, indicate that Arthrospira platensis has a positive effect on the liver and kidney toxicity induced by ACT and hence could be administered together with ACT in malaria treatment. Keywords: Malaria, ACT, Toxicity, Arthrospira platensis, oxidative damage

Effectiveness of Artemether Lumefantrine and Dihydroartemisinin Piperaquine in Clearance of Gametocytes in Uncomplicated Plasmodium falciparum Malaria in Tiwi Kenya

Background: Over 80 countries worldwide have now implemented WHO recommendations to use Artemisinin-Based Combination Therapy as a first-line treatment for Plasmodium falciparum malaria. The sexual stage of P. falciparum is responsible for the transmission of malarial parasites to infectious mosquitoes. Studies on gametocytes are generally based on microscopic detection, which is not sensitive, and there is a need for more sensitive molecular techniques that can detect and quantify gametocytes at densities as low as 0.02 to 0.1 gametocytes per micro-litre. The objective of this study was to determine the clearance rates of gametocytes after AL and DHA&amp;P in uncomplicated P. falciparum and to compare the effectiveness of microscopy and reverse transcriptase-polymerase chain reaction in gametocyte detection. Methods: In a randomised controlled clinical trial of samples collected, gametocyte densities were quantified by microscopy by counting against 500 leukocytes in the thick smear converted to numbers of parasites per micro-litre by assuming a standard count of 800 leukocytes per micro-litre of blood after staining with 10% Giemsa stain and by reverse transcriptase-polymerase chain reaction using primers specific to the pfs25 gene. Results: There was no significant difference between the drug’s gametocyte clearance (p&lt;.082). The drugs cleared gametocytes in infected patients by day 28 as detected by microscopy. There was a significant difference in the detection of gametocytes by RT-PCR and microscopy (p&lt;.001). Conclusion: This study showed that Artemether-Lumefantrine and Dihydroartemisinin piperaquine have gametocytocidal effects on P. falciparum and the study on the clearance of gametocytes using both artemether-lumefantrine and Dihydroartemisinin piperaquine may be carried out using a larger sample size for policy implementation. The reverse transcriptase-polymerase chain reaction is more effective than microscopy in detecting low levels of gametocytes and the pfs25 gene can be used in the detection of gametocytes in the field to monitor the clearance of gametocytes.

Efficacy and safety of dihydroartemisinin\u2013piperaquine for the treatment of uncomplicated Plasmodium falciparum and Plasmodium vivax malaria in Papua and Sumatra, Indonesia

BackgroundDihydroartemisinin–piperaquine (DHA–PPQ) has been adopted as first-line therapy for uncomplicated falciparum malaria in Indonesia since 2010. The efficacy of DHA–PPQ was evaluated in 2 sentinel sites in Keerom District, Papua and Merangin District, Jambi, Sumatra from April 2017 to April 2018.MethodsClinical and parasitological parameters were monitored over a 42-day period following the World Health Organization standard in vivo protocol and subjects meeting the inclusion criteria were treated with DHA–PPQ once daily for 3 days, administered orally.ResultsIn Papua, 6339 subjects were screened through active and passive cases detection. Of the 114 falciparum and 81 vivax cases enrolled, 102 falciparum and 80 vivax cases completed the 42 day follow up, and 12 falciparum and 1 vivax cases were either lost to follow up or withdrawn. Kaplan–Meier analysis of microscopy readings of 102 falciparum cases revealed 93.1% (95% CI 86.4–97.2) as Adequate Clinical and Parasitological Response (ACPR). No delay in parasite clearance nor severe adverse reaction was observed. Recurrent parasites of Plasmodium falciparum were detected in 7 cases and categorized as late treatment failures (LTF) at days 21, 35, and 42 and one of which was reinfected by Plasmodium vivax at day 42. Two cases were confirmed as recrudescent infection and 4 were re-infection. The PCR-corrected DHA–PPQ efficacy for P. falciparum was 97.9% (95% CI 92.7–99.7). Of the 80 cases of P. vivax that were followed up, 71 cases were completely cured and classified as ACPR (88.8%, 95% CI 79.7–94.7) and 9 cases showed recurrent infection at days 35 and 42, and classified as LTF. In Sumatra, of the 751 subjects screened, 35 vivax subjects enrolled, 34 completed the 42 day follow up. Thirty-three cases were completely cured and classified as ACPR (97.1%, 95% CI 84.7–99.9) and 1 recurrent infection was observed and classified as LTF. No delay in parasite clearance nor severe adverse reaction was observed. Analysis of the Pfk13 gene in P. falciparum cases from Papua revealed no mutations associated with artemisinin resistance in the 20 SNPs previously reported. Analysis of the Pfpm2 gene at day 0 and day of recurrence in recrudescent cases revealed the same single copy number, whereas 3 of the 4 re-infection cases carried 2–3 Pfpm2 gene copy numbers.ConclusionTreatment of falciparum and vivax malaria cases with DHA–PPQ showed a high efficacy and safety.

Therapeutic efficacy of artemether-lumefantrine, artesunate-amodiaquine and dihydroartemisinin-piperaquine in the treatment of uncomplicated Plasmodium falciparum malaria in Sub-Saharan Africa: A systematic review and meta-analysis.

Sub-Saharan Africa has the highest burden of malaria in the world. Artemisinin-based combination therapies (ACTs) have been the cornerstone in the efforts to reduce the global burden of malaria. In the effort to facilitate early detection of resistance for artemisinin derivatives and partner drugs, WHO recommends monitoring of ACT's efficacy in the malaria endemic countries. The present systematic meta-analysis study summarises the evidence of therapeutic efficacy of the commonly used artemisinin-based combinations for the treatment of uncomplicated P. falciparum malaria in Sub-Saharan Africa after more than a decade since the introduction of the drugs. Fifty two studies carried out from 2010 to 2020 on the efficacy of artemether-lumefantrine or dihydro-artemisinin piperaquine or artesunate amodiaquine in patients with uncomplicated P. falciparum malaria in Sub-Saharan Africa were searched for using the Google Scholar, Cochrane Central Register of controlled trials (CENTRAL), PubMed, Medline, LILACS, and EMBASE online data bases. Data was extracted by two independent reviewers. Random analysis effect was performed in STATA 13. Heterogeneity was established using I2 statistics. Based on per protocol analysis, unadjusted cure rates in malaria infected patients treated with artemether-lumefantrine (ALU), artesunate-amodiaquine (ASAQ) and dihydroartemisinin-piperaquine (DHP) were 89%, 94% and 91% respectively. However, the cure rates after PCR correction were 98% for ALU, 99% for ASAQ and 99% for DHP. The present meta-analysis reports the overall high malaria treatment success for artemether-lumefantrine, artesunate-amodiaquine and dihydroartemisinin-piperaquine above the WHO threshold value in Sub-Saharan Africa.

Does Primaquine Become The First Line in the Treatment of Uncomplicated Malaria in Coming Days?

Background: Malaria is a major public health problem throughout human history, particularly in the tropical and subtropical countries. Primaquine, introduced in 1950, for preventing relapse and sterilizes infectious sexual plasmodia. Methods: A retrospective study was performed for 610 patients (250 were male and 360 were female), (all ages) to study the efficacy of Primaquine in the treatment of falciparum malaria after receiving this drug for five days. Results: Five hundred and ninety three patients (97.2 %) were completely recovered from malaria within 3 to 5 days after receiving Primaquine tablets. Conclusion: In our opinion Primaquine should become the first line as antimalarial drug soon later for uncomplicated malaria, because of its high efficiency against infections with Plasmodiumfalciparum and P.vivax active stages.

Challenges in the clinical development pathway for triple and multiple drug combinations in the treatment of uncomplicated falciparum malaria

The addition of a third anti-malarial drug matching the pharmacokinetic characteristics of the slowly eliminated partner drug in artemisinin-based combination therapy (ACT) has been proposed as new therapeutic paradigm for the treatment of uncomplicated falciparum malaria. These triple artemisinin-based combination therapy (TACT) should in theory more effectively prevent the development and spread of multidrug resistance than current ACT. Several clinical trials evaluating TACT—or other multidrug anti-malarial combination therapy (MDACT)—have been reported and more are underway. From a regulatory perspective, these clinical development programmes face a strategic dilemma: pivotal clinical trials evaluating TACT are designed to test for non-inferiority of efficacy compared to standard ACT as primary endpoint. While meeting the endpoint of non-inferior efficacy, TACT are consistently associated with a slightly higher frequency of adverse drug reactions than currently used ACT. Moreover, the prevention of the selection of specific drug resistance—one of the main reasons for TACT development—is beyond the scope of even large-scale clinical trials. This raises important questions: if equal efficacy is combined with poorer tolerability, how can then the actual benefit of these drug combinations be demonstrated? How should clinical development plans be conceived to provide objective evidence for or against an improved management of patients and effective prevention of anti-malarial drug resistance by TACT? What are the objective criteria to ultimately convince regulators to approve these new products? In this Opinion paper, the authors discuss the challenges for the clinical development of triple and multidrug anti-malarial combination therapies and the hard choices that need to be taken in the further clinical evaluation and future implementation of this new treatment paradigm.