Use Of Artemisinin-based Combination Therapy Research Articles

Molecular markers of artemisinin resistance during falciparum malaria elimination in Eastern Myanmar

BackgroundArtemisinin resistance in Plasmodium falciparum threatens global malaria elimination efforts. To contain and then eliminate artemisinin resistance in Eastern Myanmar a network of community-based malaria posts was instituted and targeted mass drug administration (MDA) with dihydroartemisinin-piperaquine (three rounds at monthly intervals) was conducted. The prevalence of artemisinin resistance during the elimination campaign (2013–2019) was characterized.MethodsThroughout the six-year campaign Plasmodium falciparum positive blood samples from symptomatic patients and from cross-sectional surveys were genotyped for mutations in kelch-13—a molecular marker of artemisinin resistance.ResultThe program resulted in near elimination of falciparum malaria. Of 5162 P. falciparum positive blood samples genotyped, 3281 (63.6%) had K13 mutations. The prevalence of K13 mutations was 73.9% in 2013 and 64.4% in 2019. Overall, there was a small but significant decline in the proportion of K13 mutants (p < 0.001). In the MDA villages there was no significant change in the K13 proportions before and after MDA. The distribution of different K13 mutations changed substantially; F446I and P441L mutations increased in both MDA and non-MDA villages, while most other K13 mutations decreased. The proportion of C580Y mutations fell from 9.2% (43/467) before MDA to 2.3% (19/813) after MDA (p < 0.001). Similar changes occurred in the 487 villages where MDA was not conducted.ConclusionThe malaria elimination program in Kayin state, eastern Myanmar, led to a substantial reduction in falciparum malaria. Despite the intense use of artemisinin-based combination therapies, both in treatment and MDA, this did not select for artemisinin resistance.

Therapeutic efficacy of generic artemether–lumefantrine in the treatment of uncomplicated malaria in Ghana: assessing anti-malarial efficacy amidst pharmacogenetic variations

BackgroundDespite efforts made to reduce morbidity and mortality associated with malaria, especially in sub-Saharan Africa, malaria continues to be a public health concern that requires innovative efforts to reach the WHO-set zero malaria agenda. Among the innovations is the use of artemisinin-based combination therapy (ACT) that is effective against Plasmodium falciparum. Generic artemether–lumefantrine (AL) is used to treat uncomplicated malaria after appropriate diagnosis. AL is metabolized by the cytochrome P450 family of enzymes, such as CYP2B6, CYP3A4 and CYP3A5, which can be under pharmacogenetic influence. Pharmacogenetics affecting AL metabolism, significantly influence the overall anti-malarial activity leading to variable therapeutic efficacy. This study focused on generic AL drugs used in malarial treatment as prescribed at health facilities and evaluated pharmacogenomic influences on their efficacy.MethodsPatients who have been diagnosed with malaria and confirmed through RDT and microscopy were recruited in this study. Blood samples were taken on days 1, 2, 3 and 7 for parasite count and blood levels of lumefantrine, artemisinin, desbutyl-lumefantrine (DBL), and dihydroartemisinin (DHA), the active metabolites of lumefantrine and artemether, respectively, were analysed using established methods. Pharmacogene variation analysis was undertaken using iPLEX microarray and PCR–RFLP.ResultsA total of 52 patients completed the study. Median parasite density from day 1 to 7 ranged from 0–2666/μL of blood, with days 3 and 7 recording 0 parasite density. Highest median plasma concentration for lumefantrine and desbutyl lumefantrine, which are the long-acting components of artemisinin-based combinations, was 4123.75 ng/mL and 35.87 ng/mL, respectively. Day 7 plasma lumefantrine concentration across all generic ACT brands was ≥ 200 ng/mL which potentially accounted for the parasitaemia profile observed. Monomorphism was observed for CYP3A4 variants, while there were observed variations in CYP2B6 and CYP3A5 alleles. Among the CYP3A5 genotypes, significant differences in genotypes and plasma concentration for DBL were seen on day 3 between 1/*1 versus *1/*6 (p = 0.002), *1/*3 versus *1/*6 (p = 0.006) and *1/*7 versus *1/*6 (p = 0.008). Day 7 plasma DBL concentrations showed a significant difference between *1/*6 and *1/*3 (p = 0.026) expressors.ConclusionsThe study findings show that CYP2B6 and CYP3A5 pharmacogenetic variations may lead to higher plasma exposure of AL metabolites.

Efficacy and safety of artemether-lumefantrine for the treatment of uncomplicated falciparum malaria in mainland Tanzania, 2018

BackgroundThe use of artemisinin-based combination therapy (ACT) is recommended by the World Health Organization for the treatment of uncomplicated falciparum malaria. Artemether-lumefantrine (AL) is the most widely adopted first-line ACT for uncomplicated malaria in sub-Saharan Africa (SSA), including mainland Tanzania, where it was introduced in December 2006. The WHO recommends regular assessment to monitor the efficacy of the first-line treatment specifically considering that artemisinin partial resistance was reported in Greater Mekong sub-region and has been confirmed in East Africa (Rwanda and Uganda). The main aim of this study was to assess the efficacy and safety of AL for the treatment of uncomplicated falciparum malaria in mainland Tanzania.MethodsA single-arm prospective anti-malarial drug efficacy trial was conducted in Kibaha, Mlimba, Mkuzi, and Ujiji (in Pwani, Morogoro, Tanga, and Kigoma regions, respectively) in 2018. The sample size of 88 patients per site was determined based on WHO 2009 standard protocol. Participants were febrile patients (documented axillary temperature ≥ 37.5 °C and/or history of fever during the past 24 h) aged 6 months to 10 years. Patients received a 6-dose AL regimen by weight twice a day for 3 days. Clinical and parasitological parameters were monitored during 28 days of follow-up to evaluate the drug efficacy and safety.ResultsA total of 653 children were screened for uncomplicated malaria and 349 (53.7%) were enrolled between April and August 2018. Of the enrolled children, 345 (98.9%) completed the 28 days of follow-up or attained the treatment outcomes. There were no early treatment failures, but recurrent infections were higher in Mkuzi (35.2%) and Ujiji (23%). By Kaplan–Meier analysis of polymerase chain reaction (PCR) uncorrected adequate clinical and parasitological response (ACPR) ranged from 63.4% in Mkuzi to 85.9% in Mlimba, while PCR-corrected ACPR on day 28 varied from 97.6% in Ujiji to 100% in Mlimba. The drug was well tolerated; the commonly reported adverse events were cough, runny nose, and abdominal pain. No serious adverse event was reported.ConclusionThis study showed that AL had adequate efficacy and safety for the treatment of uncomplicated falciparum malaria. The high number of recurrent infections were mainly due to new infections, indicating the necessity of utilizing alternative artemisinin-based combinations, such as artesunate amodiaquine, which provide a significantly longer post-treatment prophylactic effect.

Drug selection pressure and fitness cost for artemether-resistant Plasmodium berghei ANKA parasites in vivo

The clinical use of artemisinin-based combination therapies is threatened by increasing failure rates due to the emergence and spread of multiple drug resistance genes in most human Plasmodium strains. The aim of this study was to generate artemether-resistant (AMR) parasites from Plasmodium berghei ANKA (AMS), and determine their fitness cost. Artemether resistance was generated by increasing drug pressure doses gradually for 9 months. Effective doses (ED50 and ED90) were determined using the 4-day suppressive test, and the indices of resistance (I) at 50% and 90% (I50 and I90) were determined using the ratio of either ED50 or ED90 of AMR to AMS, respectively. The stability of the AMR parasites was evaluated by: five drug-free passages (5DFPs), 3 months of cryopreservation (CP), and drug-free serial passages (DFSPs) for 4 months. Analysis of variance was used to compare differences in growth rates between AMR and AMS with 95% confidence intervals. ED50 and ED90 of AMS were 0.61 and 3.43 mg/kg/day respectively. I50 and I90 after 20 cycles of artemether selection pressure were 19.67 and 21.45, respectively; 5DFP values were 39.16 and 15.27, respectively; 3-month CP values were 29.36 and 10.79, respectively; and DFSP values were 31.34 and 12.29, respectively. The mean parasitaemia value of AMR (24.70% ± 3.60) relative to AMS (37.66% ± 3.68) at Day 7 post infection after DFSPs revealed a fitness cost of 34.41%. A moderately stable AMRP. berghei line was generated. Known and unknown mutations may be involved in modulating artemether resistance, and therefore molecular investigations are recommended.

[Influence of white blood cells count on parasite density in Malaria in children aged 6 to 59 months in Benin].

For many years, the treatment of malaria was based on clinical presumptive diagnosis, making its differential diagnosis with other causes of hyperthermia difficult. This drug pressure has led to the emergence of Plasmodium strains resistant to the most commonly used antimalarial drugs. This is why in 2004, the health authorities decided to revise the policy of malaria management by adopting a new strategy based on the rational use of artemisininbased combination therapies after the biological confirmation of suspected malaria cases. The biological diagnosis is an essential part of malaria management. The gold standard technique for diagnosis is the thick drop combined with the calculation of parasite density (PD), which is determined on the basis of the number of parasites counted in a microscopic field against a proposed standard number of leukocytes. The number of leukocytes used to calculate the parasite density should ideally be the actual number of leukocytes in the patient per cubic millimetre of blood. However, in the absence of the availability of a blood count at the time of the thick drop, an average number of 8 000 leukocytes/mm3 was used by the World Health Organisation (WHO) to estimate the parasite density. Nonetheless, in Benin the average number of leukocytes adopted by the National Malaria Control Programme (PNLP) is 6 000/mm3. The aim of our study was to determine the impact of the leukocyte count on the calculation of the parasite density in cases of uncomplicated malaria. The study was a cross-sectional study with an analytical aim and took place in 2 hospitals in Benin, the Klouékanmey zone hospital in the south of Benin and the Djougou health centre in the north. It involved a population of 476 children aged between 6 and 59 months who were seen in consultation and in whom the clinical diagnosis of simple Plasmodium falciparum malaria was suspected. Children aged between 6 and 59 months, weighing at least 5 kg, with an axillary temperature ≥ 37.5°C at the time of consultation or a history of fever in the last 24 hours or other symptoms pointing to the diagnosis of malaria were included. Infestation was mono-specific for Plasmodium falciparum. Informed consent was required from the child's parents or guardian. The criteria for non-inclusion in our study were the presence of at least one sign of malaria severity, signs of severe malnutrition or a febrile state related to underlying infectious diseases other than malaria. Thick blood count and haemogram were systematically performed in all included children. Parasite density was calculated according to 3 methods, first using a weighted leukocyte count of 6 000/mm3 recommended by the Benin National Malaria Control Programme (PNLP), then a leukocyte count of 8 000/mm3 recommended by the World Health Organisation and finally the patient's actual leukocyte count obtained from the blood count. It should be noted that these different samples were respectively taken on the day of inclusion in compliance with the conditions of the pre-analytical phase in force in our medical biology laboratory. At the end of our study, 313 children, i.e. 65.76% of our study population had a positive white blood cell count with a positivity rate of 62.14% in Djougou, i.e. 174 children, and 70.9% in Klouékanmey, i.e. 139 children. The average leukocyte count in these children was 11,580/mm3. Among them, 205 children had an abnormal white blood cell count, i.e. 17 cases of leukopenia (5.43%) and 188 cases of hyperleukocytosis (60.06%). Using successively the average number of 6 000 leukocytes/mm3 proposed by the Benin PNLP and that of 8 000 leukocytes/mm3 proposed by the WHO, the average parasite densities were respectively 47,943 and 63,936 trophozoïtes/µl against 92,290 trophozoïtes/µl when the real number of leukocytes of the patients was used for the calculation of the PD. By using an average of 6 000 leukocytes/mm3 for PD calculation, 60% of the calculated PDs were underestimated and 6% were overestimated. Using an average of 8 000 leukocytes/mm3 resulted in 49% of PD being underestimated and 15% being overestimated. The difference between the three calculation methods was considered statistically significant (p value <0.05). The use of 6 000 or 8 000 coefficients for the estimation of parasitaemia could lead to a significant underestimation of the parasite load.

Polymorphism analysis of drug resistance markers in Plasmodium falciparum isolates from Benin

Like most countries in sub-Saharan African countries, Benin continues to bear a heavy malaria burden. In 2014, the National Malaria Control Programme (NMCP) changed its treatment policy, and recommended the use of artemisinin-based combination therapy (ACT) as first-line treatment for uncomplicated Plasmodium falciparum cases. The study presented here was conducted to investigate the impact of current antimalarial drug resistance on the country. Molecular surveillance targeting the Pfcrt, Pfmdr1, Pfkelch13, dhfr, and dhps genes was carried out on samples from patients positive for P. falciparum malaria by microscopy, LAMP and PCR diagnostic test. Molecular analysis was performed using targeted amplicon deep sequencing (TADS). In addition, the frequency of parasites with dual deletion of the histidine-rich protein 2 and 3 genes (pfhrp2 and pfhrp3), known to be responsible of the performance of HRP-based malaria rapid diagnostic tests (HRP-RDT), was estimated. Fifty-three falciparum samples collected at the Saint Jean de Dieu hospital in Tanguiéta, Benin, were tested. No Pfkelch13 validated or candidate artemisinin partial resistant variants were identified. A marked prevalence of Asn51Ile (N51I), Cys59Arg (C59R), and Ser108Asn (S108N) mutant alleles was found in the dhfr gene, representing the most frequent genotype (64%). Five-point mutations were detected in dhps, Ile431Val (I431V), Ser436Ala (S436A), Ala437Gly (A437G), Ala581Gly (A581G), Ala613Ser (A613S) of which the third was the most common (92%). No mutation was identified in dhps Lys540Glu (K540E). The quintuple mutant genotype resulting from the combination of the dhfr triple mutant (51I/59R/108N) with the dhps double mutant 436A/437G was detected at a frequency of 30%. Low levels of mutations in Pfcrt and no mutation at codon 86 in the Pfmdr1 DNA fragment were observed, whereas a high level of Tyr184Phe (Y184F) polymorphism in the Pfmdr1 gene was found. These results could be indicative, over a decade after the implementation of ACT therapy, of the return of chloroquine-sensitive but artemether-lumefantrine resistant falciparum genotypes in Benin. There was no evidence of HRP2 and HRP3 deletions. Data from the present study support the need for routine monitoring of molecular markers of antimalarial drug resistance as part of surveillance activities aimed to make informed treatment policy decisions at the national level.

Shifts in the clinical epidemiology of severe malaria after scaling up control strategies in Mali.

A decrease in malaria incidence following implementation of control strategies such as use of artemisinin-based combination therapies, insecticide-impregnated nets, intermittent preventive treatment during pregnancy and seasonal malaria chemoprevention (SMC) has been observed in many parts of Africa. We hypothesized that changes in malaria incidence is accompanied by a change in the predominant clinical phenotypes of severe malaria. To test our hypothesis, we used data from a severe malaria case-control study that lasted from 2014-2019 to describe clinical phenotypes of severe forms experienced by participants enrolled in Bandiagara, Bamako, and Sikasso, in Mali. We also analyzed data from hospital records of inpatient children at a national referral hospital in Bamako. Among 97 cases of severe malaria in the case-control study, there was a predominance of severe malarial anemia (49.1%). The frequency of cerebral malaria was 35.4, and 16.5% of cases had a mixed clinical phenotype (concurrent cerebral malaria and severe anemia). National referral hospital record data in 2013-15 showed 24.3% of cases had severe malarial anemia compared to 51.7% with cerebral malaria. In the years after SMC scale-up, severe malarial anemia cases increased to 30.1%, (P = 0.019), whereas cerebral malaria cases decreased to 45.5% (P = 0.025). In addition, the predominant age group for each severe malaria phenotype was the 0-1-year-olds. The decrease in malaria incidence noted with the implementation of control strategies may be associated with a change in the clinical expression patterns of severe malaria, including a potential shift in severe malaria burden to age groups not receiving seasonal malaria chemoprevention.

Stakeholder perceptions on the deployment of multiple first-line therapies for uncomplicated malaria: a qualitative study in the health district of Kaya, Burkina Faso

BackgroundIn Burkina Faso, malaria remains the first cause of medical consultation and hospitalization in health centres. First-line case management of malaria in the country’s health facilities is based on the use of artemisinin-based combination therapy (ACT). To optimize the use of these anti-malarial drugs in the perspective of mitigating the emergence of artemisinin resistance, which is a serious threat to malaria control and elimination, a pilot programme using multiple first-line therapies (MFTs) [three artemisinin-based combinations—pyronaridine–artesunate, dihydroartemisinin–piperaquine and artemether-lumefantrine] has been designed for implementation. As the success of this MFT pilot programme depends on the perceptions of key stakeholders in the health system and community members, the study aimed to assess their perceptions on the implementation of this strategy.MethodsSemi-structured interviews, including 27 individual in-depth interviews and 41 focus groups discussions, were conducted with key stakeholders including malaria control policymakers and implementers, health system managers, health workers and community members. Volunteers from targets stakeholder groups were randomly selected. All interviews were recorded, transcribed and translated. Content analysis was performed using the qualitative software programme QDA Miner.ResultsThe interviews revealed a positive perception of stakeholders on the implementation of the planned MFT programme. They saw the strategy as an opportunity to strengthen the supply of anti-malarial drugs and improve the management of fever and malaria. However, due to lack of experience with the products, health workers and care givers expressed some reservations about the effectiveness and side-effect profiles of the two anti-malarial drugs included as first-line therapy in the MFT programme (pyronaridine–artesunate, dihydroartemisinin–piperaquine). Questions were raised about the appropriateness of segmenting the population into three groups and assigning a specific drug to each group.ConclusionThe adherence of both populations and key stakeholders to the MFT implementation strategy will likely depend on the efficacy of the proposed drugs, the absence of, or low frequency of, side-effects, the cost of drugs and availability of the different combinations.

Reduction in Plasmodium falciparum Pfk13 and pfg377 allele diversity through time in southern Vietnam

BackgroundPlasmodium falciparum has acquired resistance to artemisinin in Southeast Asia, with mutations in the P. falciparum Kelch-13 (Pfk13) gene associated with the resistance phenotype. The widespread use of Artemisinin-based combination therapy (ACT)s in Southeast Asia has led to the selection and spread of parasites carrying mutations in Pfk13. We characterised the allele diversity of Pfk13 and pfg377, an artemisinin-resistance neutral polymorphic gene, in parasite DNA extracted human blood from in southern Vietnam in 2003, 2012, 2015 and 2018.MethodThis study was conducted in Bu Gia Map commune, Binh Phuoc province, Vietnam, from May 2018 to January 2019. Twenty-four samples from 2018 to 2019, 30 from 2003, 24 from 2012 and 32 from 2015 were analysed. Malaria-infected human blood was collected by finger-prick and used for molecular analysis. A nested-PCR targeting the small subunit ribosomal RNA gene was used for Plasmodium species identification, followed by amplification and nucleotide sequencing of Pfk13 and region 3 of pfg377. Archived blood samples collected in the same region in 2012 and 2015 were also analysed as above for comparison.ResultsThe genetic diversity of Pfk13 and pfg377 was lower in 2018–2019 compared to 2012 and 2015. The number of distinct Pfk13 mutants decreased from three in 2012 and 2015, P553L, V568G and C580Y, to one, C580Y in 2018–2019. In 2018–2019, the frequency of C580Y mutant strains was 71% (17/24 isolates). All samples were wild type in 2003. In 2012 and 2015, there were single-strain infections as well as co-infections with two mutant strains or with mutant and wild strains, whereas there were no co-infections in 2018. pfg377 allele diversity decreased from five alleles in 2012 to two alleles in 2018–2019.ConclusionThe genetic diversity of P. falciparum was reduced at the two genetic loci surveyed in this study, Pfk13 and pfg377. In the case of the former gene, we observed an increase in the prevalence of parasites carrying the C580Y gene, known to confer reduced susceptibility to ACTs. The reduction in the diversity of pfg377 may be linked to the clonal expansion of parasite strains carrying the C580Y mutation, leading to an overall reduction in parasite genetic diversity across the population.

The Effect of Arthrospira platensis (Phormidiaceae) 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. Current World Health Organization (WHO) guidelines for the treatment of uncomplicated falciparum malaria recommends the use of artemisinin-based combination therapy (ACT). Arthrospira platensis is a microscopic filamentous alga that is rich in proteins, vitamins, essential amino acids, minerals and essential fatty acids like -linolenic acid (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 20/120 mg (group 1) or artemether-lumefantrine 20/120 mg + Arthrospira platensis 8 g daily (group 2) as an adjunct therapy and follow-up for 7 days (D). After treatment, the activity levels/concentrations of liver and kidney biochemical markers (ALT, AST, ALB, UREA, CREAT) were analyzed. 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 statistically significant (P&lt;0.05) on D0 when compared to that of malaria negative patients. The serum activity of CREAT though not statistically significant (P&gt;0.05), increased compared to malaria negative patients. The serum level of ALT, AST, UREA and CREAT increased from D0 to D3 and decreased on D7 after treatment while ALB decreased from D0 to D3 and increased on D7 in both groups when compared with the negative control group. The concentration of these biochemical markers varied across the groups from D0 to D7. 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.

Artemisinin-Based Combination Therapy Synergized with Medicinal Plants to Induce Musculotoxic Effects.

Introduction Multivisceral, neurological, hepatic, and renal damage has been witnessed following the use of artemisinin-based combination therapy (ACT) and herbal medicine. These multiple organ damages make us think of muscle damage. The objective was to study the myotoxicity of the combination of ACTs with medicinal plants. Materials and Methods Muscle cells (RD cells) were brought into contact with preparations of antimalarial drugs and/or antimalarial herbs. The following drugs were used: artesunate 100 mg/amodiaquine 270 mg (ASAQ) and artemether 80 mg/lumefantrine 480 mg (AL); plant Sida acuta (PSA) and plant Enantia polycarpa (PEP) at 10 µg/ml. After 5 days of incubation, the cells were counted by using a hemocytometer with trypan blue solution. Results Artesunate/amodiaquine caused a significant drop in the number of muscle cells, compared to the control, between D2 and D4 (p < 0.001). There was also a significant difference between the control and artemether/lumefantrine between D2 (p < 0.01) and D4 (p < 0.001) and between the control and the Sida acuta plant, on D2 (p < 0.001), D4 (p < 0.001), and D5 (p < 0.05). In tubes treated with ASAQ and Sida acuta, cell mortality was over 30%. Finally, statistically significant cell destruction in the tubes treated with the combination of antimalarial drugs and traditional plants compared to those of the control was observed from D2 (p < 0.001). Conclusion Artemisinin-based combination therapy remains effective and well tolerated. But its combination with medicinal plants induced myotoxic effects. This toxicity would appear to be of the additive type. Further studies should be able to better elucidate the mechanism of this toxicity.

Targeted deep amplicon sequencing of antimalarial resistance markers in Plasmodium falciparum isolates from Cameroon

BackgroundRecent studies showed the first emergence of the R561H artemisinin-associated resistance marker in Africa, which highlights the importance of continued molecular surveillance to assess the selection and spread of this and other drug resistance markers in the region. MethodIn this study, we used targeted amplicon deep sequencing of 116 isolates collected in two areas of Cameroon to genotype the major drug resistance genes, k13, crt, mdr1, dhfr, and dhps, and the cytochrome b gene (cytb) in Plasmodium falciparum. ResultsNo confirmed or associated artemisinin resistance markers were observed in Pfk13. In comparison, both major and minor alleles associated with drug resistance were found in Pfcrt, Pfmdr1, Pfdhfr, and Pfdhps. Notably, a high frequency of other nonsynonymous mutations was observed across all the genes, except for Pfcytb, suggesting continued selection pressure. ConclusionsThe results from this study supported the continued use of artemisinin-based combination therapy and administration of sulfadoxine-pyrimethamine for intermittent preventive therapy in pregnant women, and for seasonal chemoprevention in these study sites in Cameroon.

Towards one standard treatment for uncomplicated Plasmodium falciparum and Plasmodium vivax malaria: Perspectives from and for the Peruvian Amazon

Malaria continues to wreak havoc in the Peruvian Amazon. Lengthy research efforts have brought important lessons on its particular epidemiology: the heterogeneous levels of transmission, the large reservoir of both asymptomatic and submicroscopic infections, the co-transmission of Plasmodium vivax and Plasmodium falciparum in the same areas, and the limitations of current diagnostics. Based on these features, the national elimination program could greatly benefit from simplified standard treatment, with the use of artemisinin-based combination therapy and even shorter schemes of primaquine maintaing the total dosing. It is acknowledged that there is some uncertainty regarding the true prevalence of glucose-6-phosphate dehydrogenase deficiency (G6PD) and genetic polymorphisms related to cytochrome P-450 isozyme 2D6 functioning. Once we have a better understanding, tafenoquine, whether or not in combination with a rapid G6PD enzyme test, may become a future pathway to eliminate the otherwise hidden reservoir of the P. vivax hypnozoite through one standard Plasmodium treatment.

Self-Diagnosis and Self-Treatment of Malaria in Hard-to-Reach and Mobile Populations of the Amazon: Results of Malakit, a Multicentric Intervention Research Project. Towards a Paradigm Shift?

Background: Illegal gold miners are currently a key reservoir for malaria in French Guiana (FG), with a risk of emergence of resistance linked to improper use of artemisinin-based combination therapy (ACT). The remoteness of the mines and regulatory issues hinder their access to health care. Methods: An intervention researched project (Malakit) implemented in FG borders with Brazil and Suriname aimed at determining the effectiveness of distributed kits for self-diagnosis and self-treatment to illegal gold miners, after training, at strategic border staging areas. Evaluation relied on questionnaires at inclusion and follow-up visits, and pre/post intervention surveys. The primary outcome was the proportion of persons reporting a use of certified ACT after a positive malaria diagnosis. The secondary outcomes assessed antimalarial adherence, kit use and impact on malaria epidemiology. Findings: The proportion of patients reporting a use of certified ACT after a positive diagnosis increased after the intervention (OR 1.8, 95%CI [1.1-3.0]). From April 2018 to March 2020, 3,733 persons participated in the intervention. The kit was used correctly by 71.7% [65.8-77.7] of the 223 persons reporting having used a malakit during the follow-up visits. The intervention could have accelerated the decline in malaria incidence in the region by 42.9%. InterpretationThis innovative international project showed that people with low education can correctly self-manage their malaria symptoms. This strategy could be integrated in the malaria control programs of the countries involved and considered in other regions with residual malaria in remote areas. Funding: This project was funded by the European Union, the Global Fund, PAHO, Brazil MoH, Cayenne Hospital and FG Health Regional Agency. Declaration of Interest: Any authors declare to have no conflict of interest. Ethical Approval: Each participant gave a written consent after clear and appropriate information. Ethics approvals were obtained from countries where the project was implemented (Table 1). The project was the subject of a Normal CNIL Declaration on 24 May 2018 (Declaration Number 2188949 v 0) for data analysis according to the General Data Protection Regulation (European Union Regulation 2016/679).

Toxicological effect of Artemisinin-Based Combination Therapies plus Paracetamol in malaria patients.

Following the paucity of safety reports in the use of Artemisinin-Based Combination Therapies (ACTs) plus paracetamol, the study assessed safety potential of artemether-lumefantrine (ALP), artesunate-amodiaquine (AAP), artesunate-mefloquine (AMP), artesunate-sulphadoxine-pyrimethamine (ASPP) and dihydroartemisinin-piperaquine (DHPP) combination with paracetamol in malaria patients. ACTs and paracetamol were administered concomitantly in conventional doses/regimen to randomly selected patients. Blood samples were collected from the ante-cubital vein before and after completion of therapies. Toxicity markers such as weights, glucose, lipids, renal electrolytes, liver enzymes and haematological indices were assessed using standard protocols. The total numbers of participants were 57 patients. Male to female ratio was 1:1.1. Mean body weight and ages were 59.19 ± 1.39 kg and 42.86 ± 1.32 years respectively. The mean temperatures prior to and after therapy were 37.49 ± 1.02 °C and 37.50 ± 0.17 °C respectively. Mean parasitaemia before the commencement of therapy was 6282 ± 21.01 parasites/μl. Out of thirty-seven toxicological indices evaluated, twenty-four were significantly altered by ACTs plus paracetamol (P < 0.05). Increased serum toxicity markers due to the drug combinations were glucose (AAP, AMP), urea (ALP, ASPP), bicarbonate ion (ALP, AAP, AMP, ASPP), chloride ion (ALP, AAP, AMP), creatinine (ALP, AAP, AMP, ASPP), alkaline phosphatase (ALP, AAP), aspartate aminotransferase and alanine aminotransferase (ALP, AAP, AMP, ASPP, DHPP), total protein (AMP, DHPP) and albumin (AMP, DHPP). Decreased serum toxicity markers due to the drugs were glucose (ALP, ASPP, DHPP), urea (AMP), bicarbonate ion (DHPP), chloride ion (ASPP, DHPP), creatinine (DHPP), alkaline phosphatase (AMP, ASPP, DHPP), total protein (ALP, AAP, and ASPP) and albumin (ALP, AAP, ASPP). Altered haematological indices were white blood cells, red blood cells, mean cell haemoglobin and platelets. Since ACTs plus paracetamol altered human system, discrete selection is essential in managing uncomplicated malaria most especially in patients with co-morbid conditions.

Pattern of anti-malarial drugs and artemether combination therapy adherence in an institution based medical centre, Nigeria

The change in policy guidelines for treating uncomplicated malaria became necessary because the therapeutic efficacy of chloroquine and SP had deteriorated. Hence compliance is a necessity to enable effective check on malaria. This work was carried out to evaluate antimalaria drug prescription and to update its usage in line with WHO guideline on Artemeter Combination therapy in a university based medical center. We utilized descriptive, cross-sectional, retrospective study of antimalaria prescriptions purposely carried out among male and female outpatients with mean age of 22.4±2.8 at a University health facility. This comprised all outpatients prescriptions that contained at least one antimalarial drug filed from October 2018 to September 2019. Systematic sampling was used to select the prescriptions. Based on the total number of 1250 prescriptions containing at least one antimalarial drug, a sampling interval of 5 was calculated and simple balloting was used for the first pick. A total number of two hundred and fifty (250) prescriptions containing at least one antimalarial drug were selected for the study. Out of 250 antimalaria prescriptions, usage of ACT class of Artemeter lumefantrine, Artemeter Amodiaquine and Artemeter Piparaqiune were recorded at 45.6%, 10.4% and 9.6% respectively. Triple combination Artemeter lumefantrine and Sulphadoxine-Pyrimethamine was recorded at 20.4% while Sulphadoxine-Pyrimethamine was recorded at 4%. Combination of antimalarial drugs with antibiotics was recorded at 31.2%. This study showed compliance with National Antimalarial Treatment Guideline for the treatment of malaria infection as it regards the use of artemisinin-based combination therapy. The frequency usage of artemeter lumefantrine was proceeding among other ACTs. The frequency in co-prescription of antibiotics with anti-malaria should be guarded to comply with WHO recommendation.

Trends in health workers\u2019 compliance with outpatient malaria case-management guidelines across malaria epidemiological zones in Kenya, 2010\u20132016

BackgroundHealth workers' compliance with outpatient malaria case-management guidelines has been improving, specifically regarding the universal testing of suspected cases and the use of artemisinin-based combination therapy (ACT) only for positive results (i.e., ‘test and treat’). Whether the improvements in compliance with ‘test and treat’ guidelines are consistent across different malaria endemicity areas has not been examined.MethodsData from 11 national, cross-sectional, outpatient malaria case-management surveys undertaken in Kenya from 2010 to 2016 were analysed. Four primary indicators (i.e., ‘test and treat’) and eight secondary indicators of artemether-lumefantrine (AL) dosing, dispensing, and counselling were measured. Mixed logistic regression models were used to analyse the annual trends in compliance with the indicators across the different malaria endemicity areas (i.e., from highest to lowest risk being lake endemic, coast endemic, highland epidemic, semi-arid seasonal transmission, and low risk).ResultsCompliance with all four ‘test and treat’ indicators significantly increased in the area with the highest malaria risk (i.e., lake endemic) as follows: testing of febrile patients (OR = 1.71 annually; 95% CI = 1.51–1.93), AL treatment for test-positive patients (OR = 1.56; 95% CI = 1.26–1.92), no anti-malarial for test-negative patients (OR = 2.04; 95% CI = 1.65–2.54), and composite ‘test and treat’ compliance (OR = 1.80; 95% CI = 1.61–2.01). In the low risk areas, only compliance with test-negative results significantly increased (OR = 2.27; 95% CI = 1.61–3.19) while testing of febrile patients showed declining trends (OR = 0.89; 95% CI = 0.79–1.01). Administration of the first AL dose at the facility significantly increased in the areas of lake endemic (OR = 2.33; 95% CI = 1.76–3.10), coast endemic (OR = 5.02; 95% CI = 2.77–9.09) and semi-arid seasonal transmission (OR = 1.44; 95% CI = 1.02–2.04). In areas of the lowest risk of transmission and highland epidemic zone, none of the AL dosing, dispensing, and counselling tasks significantly changed over time.ConclusionsThere is variability in health workers' compliance with outpatient malaria case-management guidelines across different malaria-risk areas in Kenya. Major improvements in areas of the highest risk have not been seen in low-risk areas. Interventions to improve practices should be targeted geographically.

Global estimation of anti-malarial drug effectiveness for the treatment of uncomplicated Plasmodium falciparum malaria 1991\u20132019

BackgroundAnti-malarial drugs play a critical role in reducing malaria morbidity and mortality, but their role is mediated by their effectiveness. Effectiveness is defined as the probability that an anti-malarial drug will successfully treat an individual infected with malaria parasites under routine health care delivery system. Anti-malarial drug effectiveness (AmE) is influenced by drug resistance, drug quality, health system quality, and patient adherence to drug use; its influence on malaria burden varies through space and time.MethodsThis study uses data from 232 efficacy trials comprised of 86,776 infected individuals to estimate the artemisinin-based and non-artemisinin-based AmE for treating falciparum malaria between 1991 and 2019. Bayesian spatiotemporal models were fitted and used to predict effectiveness at the pixel-level (5 km × 5 km). The median and interquartile ranges (IQR) of AmE are presented for all malaria-endemic countries.ResultsThe global effectiveness of artemisinin-based drugs was 67.4% (IQR: 33.3–75.8), 70.1% (43.6–76.0) and 71.8% (46.9–76.4) for the 1991–2000, 2006–2010, and 2016–2019 periods, respectively. Countries in central Africa, a few in South America, and in the Asian region faced the challenge of lower effectiveness of artemisinin-based anti-malarials. However, improvements were seen after 2016, leaving only a few hotspots in Southeast Asia where resistance to artemisinin and partner drugs is currently problematic and in the central Africa where socio-demographic challenges limit effectiveness. The use of artemisinin-based combination therapy (ACT) with a competent partner drug and having multiple ACT as first-line treatment choice sustained high levels of effectiveness. High levels of access to healthcare, human resource capacity, education, and proximity to cities were associated with increased effectiveness. Effectiveness of non-artemisinin-based drugs was much lower than that of artemisinin-based with no improvement over time: 52.3% (17.9–74.9) for 1991–2000 and 55.5% (27.1–73.4) for 2011–2015. Overall, AmE for artemisinin-based and non-artemisinin-based drugs were, respectively, 29.6 and 36% below clinical efficacy as measured in anti-malarial drug trials.ConclusionsThis study provides evidence that health system performance, drug quality and patient adherence influence the effectiveness of anti-malarials used in treating uncomplicated falciparum malaria. These results provide guidance to countries’ treatment practises and are critical inputs for malaria prevalence and incidence models used to estimate national level malaria burden.

Antiplasmodial Combined Formulation of Artemisinin with Peschiera fuchsiaefolia Bis-Indole Alkaloids

Antimalarial agents used as monotherapy are increasingly ineffective due to the emergence of Plasmodium resistant strains. Artemisinin (Arte), extracted from Artemisia annua, presents a good efficiency against the Plasmodium strains and is currently used to treat malaria. To avoid the appearance of new resistant strains to artemisinin, the use of Artemisinin-based Combination Therapy (ACT) with another antimalaria agent was recommended by WHO to provide an effective cure and delayed resistance. Although combined formulations of various drugs with Artemisinin have been developed, their release is immediate, and they require multiple doses with side detrimental effects and effectiveness still desired. To improve its efficiency, controlled release formulations were developed to ensure long-term antiplasmodial activity by associating Artemisinin with a natural antimalarial agent extracted from Peschiera fuchsiaefolia (Pf). The Pf extract (containing mostly low soluble alkaloids) was complexed with carboxymethylcellulose to improve its solubility and stability. Two formulation types are reported. As bilayer tablet dosage form, the kinetic release pattern was an immediate release of Artemisinin, followed by a slow sustained release of Pf for 12 h. As monolithic tablet, the release profile shows a simultaneous sustained release of the two active agents, about of 10 h for Arte and 12 h for Pf.

Systematic review of artemisinin embryotoxicity in animals: Implications for malaria control in human pregnancy

Pregnant women are one of the most susceptible and vulnerable groups to malaria, the most important parasitic disease worldwide. Artemisinin-based combination therapies (ACTs) are recommended for the treatment of uncomplicated malaria in all population groups including pregnant women. However, due to the embryotoxicity observed in animal studies, ACTs have long been contraindicated during the first trimester in pregnant women. Despite the safety concerns raised in pre-clinical studies, recent findings on ACTs's use in pregnant women appear to be reassuring regarding safety and have prompted a revision of malaria treatment guidelines for first trimester of pregnancy. To contribute to the risk-benefit assessment of ACTs, we conducted a systematic literature review of animal studies published between 2007 and 2019, which evaluated the embryotoxic effects of artemisinin and its derivatives among pregnant mammals. Eighteen experimental studies fitted the inclusion criteria. These studies confirmed and further characterized the severe embryolethal and embryotoxic dose-dependent effects of artemisinin and its derivatives when administered during the organogenesis period in rats, rabbits and monkeys. Timing of administration and dosage of the drug were found to be key factors in the appearance of embryo damage. Overall, the translation of the findings of artemisinin derivatives use in animal studies to pregnant women remains disturbing. Thus, a policy change in the use of ACTs during the first trimester in pregnant women for the treatment of uncomplicated malaria does not seem pertinent and if implemented, it should be accompanied by solid pharmacovigilance systems, which are challenging to establish in malaria endemic countries.