Treatment Of Falciparum Malaria Research Articles

The effect of single low-dose primaquine treatment for uncomplicated Plasmodium falciparum malaria on haemoglobin levels in Ethiopia: a longitudinal cohort study

BackgroundTo interrupt residual malaria transmission and achieve successful elimination of Plasmodium falciparum in low-transmission settings, the World Health Organization (WHO) recommends the administration of a single dose of 0.25 mg/kg (or 15 mg/kg for adults) primaquine (PQ) combined with artemisinin-based combination therapy (ACT), without glucose-6-phosphate dehydrogenase (G6PD) testing. However, due to the risk of haemolysis in patients with G6PD deficiency (G6PDd), PQ use is uncommon. Thus, this study aimed to assess the safety of a single low dose of PQ administered to patients with G6PD deficiency.MethodsAn observational cohort study was conducted with patients treated for uncomplicated P. falciparum malaria with either single-dose PQ (0.25 mg/kg) (SLD PQ) + ACT or ACT alone. Microscopy-confirmed uncomplicated P. falciparum malaria patients visiting public health facilities in Arjo Didessa, Southwest Ethiopia, were enrolled in the study from September 2019 to November 2022. Patients with uncomplicated P. falciparum malaria were followed up for 28 days through clinical and laboratory diagnosis, such as measurements of G6PD levels and haemoglobin (Hb) concentrations. G6PD levels were measured by a quantiative CareSTART™ POCT S1 biosensor machine. Patient interviews were also conducted, and the type and frequency of clinical complaints were recorded. Hb data were taken on days (D) 7, 14, 21, and 28 following treatment with SLD-PQ + ACT or ACT alone.ResultsA total of 249 patients with uncomplicated P. falciparum malaria were enrolled in this study. Of these, 83 (33.3%) patients received ACT alone, and 166 (66.7%) received ACT combined with SLD-PQ treatment. The median age of the patients was 20 (IQR 28–15) years. G6PD deficiency was found in 17 (6.8%) patients, 14 males and 3 females. There were 6 (7.2%) and 11 (6.6%) phenotypic G6PD-deficient patients in the ACT alone and ACT + SLD-PQ arms, respectively. The mean Hb levels in patients treated with ACT + SLD-PQ were reduced by an average of 0.45 g/dl (95% CI = 0.39 to 0.52) in the posttreatment phase (D7) compared to a reduction of 0.30 g/dl (95% CI = 0.14 to − 0.47) in patients treated with ACT alone (P = 0.157). A greater mean Hb reduction was observed on day 7 in the G6PDd ACT + SLD-PQ group (− 0.60 g/dL) than in the G6PDd ACT alone group (− 0.48 g/dL); however, there was no statistically significant difference (P = 0.465). Overall, D14 losses were 0.10 g/dl (95% CI = − 0.00 to 0.20) and 0.05 g/dl (95% CI = − 0.123 to 0.22) in patients with and without SLD-PQ, respectively (P = 0.412).ConclusionsThis study’s findings indicate that using SLD-PQ in combination with ACT is safe for uncomplicated P. falciparum malaria regardless of the patient's G6PD status in Ethiopian settings. Caution should be taken in extrapolating this finding in other settings with diverse G6DP phenotypes.

Efficacy and safety of artemether-lumefantrine for the treatment of uncomplicated falciparum malaria in mainland Tanzania, 2019

BackgroundArtemisinin-based combination therapy (ACT) has been a major contributor to the substantial reductions in global malaria morbidity and mortality over the last decade. In Tanzania, artemether-lumefantrine (AL) was introduced as the first-line treatment for uncomplicated Plasmodium falciparum malaria in 2006. The World Health Organization (WHO) recommends regular assessment and monitoring of the efficacy of the first-line treatment, specifically considering that artemisinin resistance has been confirmed in the Greater Mekong sub-region. This study's main aim was to assess the efficacy and safety of AL for treating uncomplicated P. falciparum malaria in Tanzania.MethodsThis was a single-arm prospective antimalarial drug efficacy trial conducted in four of the eight National Malaria Control Programme (NMCP) sentinel sites in 2019. The trial was carried out in outpatient health facilities in Karume-Mwanza region, Ipinda-Mbeya region, Simbo-Tabora region, and Nagaga-Mtwara region. Children aged six months to 10 years with microscopy confirmed uncomplicated P. falciparum malaria who met the inclusion criteria were recruited based on the WHO protocol. The children received AL (a 6-dose regimen of AL twice daily for three days). Clinical and parasitological parameters were monitored during follow-up over 28 days to evaluate drug efficacy.ResultsA total of 628 children were screened for uncomplicated malaria, and 349 (55.6%) were enrolled between May and September 2019. Of the enrolled children, 343 (98.3%) completed the 28-day follow-up or attained the treatment outcomes. There were no early treatment failures; recurrent infections during follow-up were common at two sites (Karume 29.5%; Simbo 18.2%). PCR-corrected adequate clinical and parasitological response (ACPR) by survival analysis to AL on day 28 of follow-up varied from 97.7% at Karume to 100% at Ipinda and Nagaga sites. The commonly reported adverse events were cough, skin pallor, and abdominal pain. The drug was well tolerated, and no serious adverse event was reported.ConclusionThis study showed that AL had adequate efficacy and safety for the treatment of uncomplicated falciparum malaria in Tanzania in 2019. The high recurrent infections were mainly due to new infections, highlighting the potential role of introducing alternative artemisinin-based combinations that offer improved post-treatment prophylaxis, such as artesunate-amodiaquine (ASAQ).

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.

Efficacy of artesunate-amodiaquine for treatment of uncomplicated Plasmodium falciparum malaria in mainland Tanzania

BackgroundDiversification of artemisinin-based combination therapy (ACT) is suggested as one of the strategies that can be used to contain artemisinin resistance. Artesunate-amodiaquine (ASAQ) is one of the artemisinin-based combinations that can be used in the diversification strategy as an alternative first-line treatment for uncomplicated malaria in mainland Tanzania. There is however limited data on the efficacy of ASAQ in mainland Tanzania. This study assessed the efficacy of ASAQ for treatment of uncomplicated Plasmodium falciparum malaria in selected sentinel sites for therapeutic efficacy studies in mainland Tanzania.MethodsBetween December 2018 and March 2020, children aged between 6 months and 10 years, attending at Nagaga, Mkuzi, and Mlimba primary health facilities, and with suspected uncomplicated malaria infection were screened for eligibility to participate in the study. Malaria infection was screened using microscopy. Children with uncomplicated P. falciparum monoinfection and who fulfilled all other inclusion criteria, and had none of the exclusion criteria, according to the World Health Organization (WHO) guidelines, were treated with ASAQ. Follow-up visits were scheduled on days 0, 1, 2, 3, 7, 14, 21, and 28 or on any day of recurrent infection for clinical and laboratory assessment. Polymerase chain reaction (PCR)-corrected cure rate on day 28 was the primary outcome.ResultsA total of 264 children, 88 in each of the three study sites (Mlimba, Mkuzi and Nagaga health facilities) were enrolled and treated with ASAQ. The ASAQ PCR-corrected cure rate was 100% at all the three study sites. None of the participants had early treatment failure or late clinical failure. Furthermore, none of the participants had a serious adverse event.ConclusionASAQ was highly efficacious for the treatment of uncomplicated P. falciparum malaria in mainland Tanzania, therefore, it can be deployed as an alternative first-line treatment for uncomplicated malaria as part of diversification strategy to contain the spread of partial artemisinin resistance in the country.

Trio fluorophore-based phenotypic assay for the detection of artemisinin-induced growth-arrested Plasmodium falciparum in human erythrocytes

Artemisinin combination therapy remains effective for the treatment of falciparum malaria. However, Plasmodium falciparum can escape the effects of artemisinin by arresting their growth. The growth-arrested parasites cannot be distinguished from nonviable parasites with standard microscopy techniques due to their morphological similarities. Here, we demonstrated the efficacy of a new laboratory assay that is compatible with the artemisinin susceptibility test. As a result of the differential cell permeabilities of two DNA-binding fluorophores, growth-arrested P. falciparum can be distinguished from parasites killed by artemisinin, since the latter lose cell membrane permeability. This fluorescence-based assay increased the sensitivity and specificity of the ring survival assay in the assessment of artemisinin susceptibility. When combined with a third fluorophore-conjugated anti-human leukocyte antibody, this trio fluorophore assay became more useful in identifying growth-arrested parasites in mock human blood samples. This novel assay is a simple and rapid technique for monitoring artemisinin resistance with greater sensitivity and accuracy compared with morphology-based observations under a light microscope.

Efficacy and safety of Artemisinin Combination Therapy for the treatment of uncomplicated Plasmodium falciparum malaria across international borders of India

Background & objectives: Malaria due to Plasmodium falciparum (Pf) remains a major public threat in India. Artemisinin-based combination therapy (ACT) has been the country’s first-line drug for uncomplicated Pf malaria. In 2013-2014, Artesunate plus sulfadoxine (AS+SP) was replaced by Artemether Lumefantrine (AL) as the first- line antimalarial in North East (NE) states of the country which are endemic for Pf malaria. Regular monitoring of antimalarial drugs is of utmost importance to achieve the goal of elimination. This study aimed to assess the efficacy and safety of ACT for treating uncomplicated Pf malaria in the NE states of India. Methods: A prospective study of 28-day follow-up was conducted to monitor the efficacy and safety of AL from 2018-2019 in four districts, Udalgiri, Meghalaya, Lawngtlai, and Dhalai of NE, India. The clinical and parasitological response and the polymorphism analysis of the Pfdhps, P/dhfr, and Pfkelch 13 gene were evaluated. Results: A total of 234 patients were enrolled in the study out of 216 patients who completed the follow-up to 28 days. One-hundred percent adequate clinical and parasitological responses (ACPR) were observed with polymerase chain reaction (PCR) correction. The genotype results suggest no recrudescence in the treatment-failure patients. The classical single nucleotide polymorphisms (SNP) in the Pfdhfr gene was S108N (94.9%), followed by C59R (91.5%), whereas, in the Pfdhps gene, the common SNP was A437G (79.6%), followed by S3436A. No associated or validated mutations were found in the propeller region of the PfKelch13 gene. Interpretation & conclusion: AL was efficacious and safe in uncomplicated P. falciparum malaria in North East India. In contrast, mutations in the genes responsible for sulfadoxine and pyrimethamine resistance have been fixed in northeast India’s population.

Prevalence of polymorphisms in marker genes associated with antimalarial drug resistance in Plasmodium falciparum following 10 years of artemisinin-based combination therapy implementation in urban Kolkata.

Resistance to antimalarial drugs is one of the major challenges for malaria elimination. In India, artemisinin combination therapy (artesunate-sulfadoxin pyrimethamine) was introduced in place of chloroquine (CQ) for the treatment of uncomplicated falciparum malaria in 2010. Periodical monitoring of polymorphisms in antimalarial drug resistance marker genes will be useful for assessing drug pressure, mapping and monitoring of drug resistance status; and will be helpful for searching alternative treatments. This study was conducted to study the polymorphisms in antimalarial drug resistance marker genes among clinical Plasmodium falciparum isolates collected from Kolkata after 10 years of artemisinin-based combination therapie (ACT) implementation. Blood samples were collected from P. falciparum mono-infected patients and polymorphisms in P. falciparum CQ resistance transporter (pfcrt), P. falciparum multidrug resistance (pfmdr-1), P. falciparum dihydrofolate reductase (pfdhfr), P. falciparum dihydropteroate synthetase (pfdhps), pfATPase6 and pfK-13 propeller genes were analysed by polymerase chain reaction and DNA sequencing. In pfcrt gene, C72S, and K76T mutation was recorded in 100% isolates and no mutations was detected in any of the targeted codons of pfmdr-1 gene. A double mutant pfcrt haplotype SVMNT and wildtype haplotype NYD in pfmdr-1 were prevalent in 100% of study isolates. Triple mutant pfdhfr-pfdhps haplotype ANRNI-SGKAA was recorded. No polymorphism in pfK13 gene was documented in any of the isolates. Observed wild codon N86 along with Y184 and D1246 of pfmdr-1 gene might be an indication of the reappearance of CQ sensitivity. The absence of quadruple and quintuple haplotypes in pfdhfr-pfdhps gene along with the wild haplotype of pfK13 is evidence of ACT effectivity. Hence, similar studies with large sample size are highly suggested for monitoring the drug resistance status of P. falciparum.

Genetic characteristics of P. falciparum parasites collected from 2012 to 2016 and anti-malaria resistance along the China-Myanmar border.

The therapeutic efficacy studies of DHA-PIP for uncomplicated Plasmodium falciparum patients were implemented from 2012 to 2016 along China (Yunnan province)-Myanmar border, which verified the high efficacy of DHA-PIP. With the samples collected in these studies, the genetic characteristics of P. falciparum parasites based on in vivo parasite clearance time (PCT) was investigated to explore if these parasites had developed resistance to DHA and PIP at molecular level. The genetic characteristics were investigated based on K13 genotypes, copy numbers of genes pfpm2 and pfmdr1, and nine microsatellite loci (Short Tandem Repeats, STR) flanking the K13 gene on chromosome 13. The PCT 50s were compared based on different K13 genotypes, sites, periods and copy numbers. In the NW (North-West Yunnan province bordering with Myanmar) region, F446I was the main K13 genotype. No significant differences for PCT 50s presented among three K13 genotypes. In SW (South-West Yunnan province bordering with Myanmar) region, only wild K13 genotype was detected in all parasite isolates whose PCT 50s was significantly longer than those in NW region. For the copy numbers of genes, parasite isolates containing multiple copies of pfmdr1 gene were found in both regions, but only single copy of pfpm2 gene was detected. Though the prevalence of parasite isolates with multiple copies of pfmdr1 gene in SW region was higher than that in NW region, no difference in PCT 50s were presented between isolates with single and multiple copies of pfmdr1 gene. The median He values of F446I group and Others (Non-F446I K13 mutation) group were 0.08 and 0.41 respectively. The mean He values of ML group (Menglian County in SW) and W (wild K13 genotype in NW) group were 0 and 0.69 respectively. The mean Fst values between ML and W groups were significantly higher than the other two K13 groups. P. falciparum isolates in NW and SW regions had very different genetic characteristics. The F446I was hypothesized to have independently appeared and spread in NW region from 2012 and 2016. The high susceptibility of PIP had ensured the efficacy of DHA-PIP in vivo. Multiple copy numbers of pfmdr1 gene might be a potential cause of prolonged clearance time of ACTs drugs along China-Myanmar border. Trial registration: ISRCTN, ISRCTN 11775446. Registered 17 April 2020-Retrospectively registered, the registered name was Investigating resistance to DHA-PIP for the treatment of Plasmodium falciparum malaria and chloroquine for the treatment of Plasmodium vivax malaria in Yunnan, China. http://www.isrctn.com/ISRCTN11775446.

Screening for K13-Propeller Mutations Associated with Artemisinin Resistance in Plasmodium falciparum in Yambio County (Western Equatoria State, South Sudan).

Artemisinin-combined treatments are the recommended first-line treatment of Plasmodium falciparum malaria, but they are being threatened by emerging artemisinin resistance. Mutations in pfk13 are the principal molecular marker for artemisinin resistance. This study characterizes the presence of mutations in pfk13 in P. falciparum in Western Equatoria State, South Sudan. We analyzed 468 samples from patients with symptomatic malaria and found 15 mutations (8 nonsynonymous and 7 synonymous). Each mutation appeared only once, and none were validated or candidate markers of artemisinin resistance. However, some mutations were in the same or following position of validated and candidate resistance markers, suggesting instability of the gene that could lead to resistance. The R561L nonsynonymous mutation was found in the same position as the R561H validated mutation. Moreover, the A578S mutation, which is widespread in Africa, was also reported in this study. We found a high diversity of other pfk13 mutations in low frequency. Therefore, routine molecular surveillance of resistance markers is highly recommended to promptly detect the emergence of resistance-related mutations and to limit their spread.

Evidence Based Optimal Dosing of Intravenous Artesunate in Children with Severe Falciparum Malaria.

The majority of deaths from malaria are in young African children. Parenteral artesunate (ARS) is the first-line treatment for severe falciparum malaria. Since 2015, the World Health Organization has recommended individual doses of 3 mg/kg for children weighing < 20 kg. Recently, the US Food and Drug Administration (FDA) has challenged this recommendation, based on a simulated pediatric population, and argued for a lower dose in younger children (2.4 mg/kg). In this study, we performed population pharmacokinetic (PK) modeling of plasma concentration data from 80 children with severe falciparum malaria in the Democratic Republic of Congo who were given 2.4 mg/kg of ARS intravenously. Bayesian hierarchical modeling and a two-compartment parent drug-metabolite PK model for ARS were used to describe the population PKs of ARS and its main biologically active metabolite dihydroartemisinin. We then generated a virtual population representative of the target population in which the drug is used and simulated the total first-dose exposures. Our study shows that the majority of younger children given the lower 2.4 mg/kg dose of intravenous ARS do not reach the same drug exposures as older children above 20 kg. This finding supports withdrawal of the FDA's recent lower ARS dose recommendation as parenteral ARS is an extremely safe and well-tolerated drug and there is potential for harm from underdosing in this rapidly lethal infection.

Safety and efficacy of photodynamic therapy for the treatment of malaria in adults in Nigeria: Phase 2 trial

Background: This is the first randomized controlled trial assessing the efficacy and safety of photodynamic therapy in the treatment of uncomplicated falciparum Malaria in adults. The aim of the current study is to evaluate the use of photodynamic therapy as a possible novel treatment option.

Malaria in Pregnancy: Key Points for the Neonatologist.

In malaria-endemic regions, infection with the malaria parasite Plasmodium during pregnancy has been identified as a key modifiable factor in preterm birth, the delivery of low-birthweight infants, and stillbirth. Compared with their nonpregnant peers, pregnant persons are at higher risk for malaria infection. Malaria infection can occur at any time during pregnancy, with negative effects for the pregnant person and the fetus, depending on the trimester in which the infection is contracted. Pregnant patients who are younger, in their first or second pregnancy, and those coinfected with human immunodeficiency virus are at increased risk for malaria. Common infection prevention measures during pregnancy include the use of insecticide-treated bed nets and the use of intermittent preventive treatment with monthly doses of antimalarials, beginning in the second trimester in pregnant patients in endemic areas. In all trimesters, artemisinin-combination therapies are the first-line treatment for uncomplicated falciparum malaria, similar to treatment in nonpregnant adults. The World Health Organization recently revised its recommendations, now listing the specific medication artemether-lumefantrine as first-line treatment for uncomplicated malaria in the first trimester. While strong prevention and detection methods exist, use of these techniques remains below global targets. Ongoing work on approaches to treatment and prevention of malaria during pregnancy remains at the forefront of global maternal child health research.

A successful falciparum malaria treatment with hemodiafiltration in an African patient

Malaria is a serious infectious illness that has existed since ancient times. Despite its prevalence in Sub-Saharan Africa, it remains a global public health issue. However, Plasmodium falciparum causes the most severe and fatal form of malaria, accounting for almost 80% of global mortality. Malarial acute kidney injury (AKI) caused by malaria can progress rapidly. An early initiation to renal replacement therapy is advised because AKI induced by malaria may worsen fast. This paper report a successful severe malaria therapy with hemodiafiltration in the ICU of an African student studying in Turkey. The patient, whose blurring of consciousness increased and Glasgow coma scale (GCS) decreased GCS=8, was admitted to the anesthesiology and reanimation ICU. The patient was treated for 3 days with malaria medications and continuous renal replacement therapy (CRRT). Malaria persists everywhere, especially among nonimmunized people. AKI is common in malaria patients. Patients with severe malaria should be examined for renal involvement, including electrolyte abnormalities and fluid overload. Supportive treatment is recommended for oliguric AKI. If feasible, CRRT may help these patients.

Therapeutic efficacy of artesunate–amodiaquine and artemether–lumefantrine for the treatment of uncomplicated falciparum malaria in Chad: clinical and genetic surveillance

BackgroundArtesunate–amodiaquine (AS–AQ) and artemether–lumefantrine (AL) are the currently recommended first-and second-line therapies for uncomplicated Plasmodium falciparum infections in Chad. This study assessed the efficacy of these artemisinin-based combinations, proportion of day 3 positive patients, proportions of molecular markers associated with P. falciparum resistance to anti-malarial drugs and variable performance of HRP2-based malaria rapid diagnostic tests (RDTs).MethodsA single-arm prospective study assessing the efficacy of AS–AQ and AL at three sites (Doba, Kelo and Koyom) was conducted between November 2020 to January 2021. Febrile children aged 6 to 59 months with confirmed uncomplicated P. falciparum infection were enrolled sequentially first to AS–AQ and then AL at each site and followed up for 28 days. The primary endpoint was PCR-adjusted adequate clinical and parasitological response (ACPR). Samples collected on day 0 were analysed for mutations in pfkelch13, pfcrt, pfmdr-1, pfdhfr, pfdhps genes and deletions in pfhrp2/pfhrp3 genes.ResultsBy the end of 28-day follow-up, per-protocol PCR corrected ACPR of 97.8% (CI 95% 88.2–100) in Kelo and 100% in Doba and Kayoma were observed among AL treated patients. For ASAQ, 100% ACPR was found in all sites. All, but one patient, did not have parasites detected on day 3. Out of the 215 day 0 samples, 96.7% showed pfkelch13 wild type allele. Seven isolates carried nonsynonymous mutations not known to be associated artemisinin partial resistance (ART-R). Most of samples had a pfcrt wild type allele (79% to 89%). The most prevalent pfmdr-1 allele detected was the single mutant 184F (51.2%). For pfdhfr and pfdhps mutations, the quintuple mutant allele N51I/C59R/S108N + G437A/540E responsible for SP treatment failures in adults and children was not detected. Single deletion in the pfhrp2 and pfhrp3 gene were detected in 10/215 (4.7%) and 2/215 (0.9%), respectively. Dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, were observed in 5/215 (2.3%) isolates.ConclusionThe results of this study confirm that AS–AQ and AL treatments are highly efficacious in study areas in Chad. The absence of known pfkelch13 mutations in the study sites and the high parasite clearance rate at day 3 suggest the absence of ART-R. The absence of pfdhfr/pfdhps quintuple or sextuple (quintuple + 581G) mutant supports the continued use of SP for IPTp during pregnancy. The presence of parasites with dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, warrants the continued surveillance.Trial registration ACTRN12622001476729

­Pharmacokinetics of antimalarial drugs used to treat uncomplicated malaria in breastfeeding mother-infant pairs: An observational pharmacokinetic study

Background: Data surrounding the exposure of the breastfed infant to drugs and any associated risks are sparse. Drugs usually are transferred to milk in small quantities, and many have been used without obviously noticeable infant toxicity for many years – this lack of a ‘safety signal’ has further reduced the interest in studying mother-to-infant transfer of the drugs. In sub-Saharan Africa, pregnant women are at risk of Plasmodium falciparum infection, and one in four women have evidence of placental infection at the time of delivery. Artemisinin-based combination therapies (ACTs), primarily artemether-lumefantrine (AL), are the current first-line treatment for uncomplicated Plasmodium falciparum malaria, with the same dosing recommendations in breastfeeding women as those in the adult population. Dihydroartemisinin-piperaquine (DP) is routinely used as an alternative to AL in Uganda. However, lactation pharmacokinetics (PK) of ACTs are unknown. Pharmacokinetic characterization of anti-malarial transfer to breast milk and breastfed infants is crucial in understanding the potential consequences to the infant, in terms of therapeutic- and prophylactic effects as well as potential toxicity. Methods: This observational study will enroll 30 mother-infant pairs, and aims to characterize the breastmilk transfer of antimalarial medications (AL and DP) to infants when these ACTs are administered to mothers as part of treatment for uncomplicated malaria. In addition, we will assess the mental health of the breastfeeding mothers enrolled as well as the well-being of their children. PK samples of maternal blood, breastmilk and breastfeeding infant’s blood will be obtained at specific times points. Pharmacokinetic data will be analyzed using a population pharmacokinetic approach. Conclusions: We anticipate that findings from this research will guide to develop a PK model describing lumefantrine and piperaquine disposition and will provide a framework to foster other lactation pharmacokinetic studies in different disease areas.

Evolution of genetic markers for drug resistance after the introduction of dihydroartemisinin–piperaquine as first-line anti-malarial treatment for uncomplicated falciparum malaria in Indonesia

BackgroundDihydroartemisinin–piperaquine has been Indonesia’s first-line anti-malarial treatment since 2008. Annual therapeutic efficacy studies (TES) done in the last 12 years showed continued high treatment efficacy in uncomplicated Plasmodium falciparum malaria. Although these studies did not show evidence for artemisinin resistance, a slight increase in Late Treatment Failure was observed over time. It is highlight to explore the evolution of genetic markers for ACT partner drug resistance since adopting DHA–PPQ.MethodsDry blood spots were identified from a mass blood survey of uncomplicated falciparum malaria patients (N = 50) in Sumba from 2010 to 2018. Analysis of genotypic profile (N = 51) and a Therapeutic Efficacy Study (TES) from Papua (N = 142) from 2020 to 2021, 42-day follow-up. PCR correction using msp1, msp2, and glurp was used to distinguish recrudescence and reinfection. Parasite DNA from DBSs was used for genotyping molecular markers for antimalaria drug resistance, including in Pfk13, pfcrt, and pfmdr1, as well as gene copy number variation in pfpm2/3 and pfmdr1.ResultsThe study revealed the absence of SNPs associated with ART resistance and several novel SNPs such as L396F, I526V, M579I and N537S (4.25%). In Sumba, the mutant haplotype SDD of pfmdr1 was found in one-third of the isolates, while only 8.9% in Papua. None of the pfcrt mutations linked to piperaquine resistance were observed, but 71% of isolates had pfcrt I356L. Amplification of the pfpm2/3 genes was in Sumba (17.02%) and Papua (13.7%), while pfmdr1 copy number prevalence was low (3.8%) in both areas. For the TES study, ten recurrences of infection were observed on days 28, 35, and 42. Late parasitological failure (LPF) was observed in 10/117 (8.5%) subjects by microscopy. PCR correction revealed that all nine cases were re-infections and one was confirmed as recrudescence.ConclusionThis study revealed that DHA–PPQ is still highly effective against P. falciparum. The genetic architecture of the parasite P. falciparum isolates during 2010–2021 revealed single copy of Pfpm2 and pfmdr1 were highly prevalent. The slight increase in DHA–PPQ LTF alerts researchers to start testing other ACTs as alternatives to DHA–PPQ for baseline data in order to get a chance of achieving malaria elimination wants by 2030.Graphical

Micromolar Dihydroartemisinin Concentrations Elicit Lipoperoxidation in Plasmodium falciparum-Infected Erythrocytes.

Malaria is still the most important parasitic infectious disease. Numerous substances are known to have antimalarial activity; among them, artemisinin is the most widely used one, and artemisinin-based combination therapy (ACT) is recommended for the treatment of Plasmodium falciparum (P.f.) malaria. Antitumor, immunomodulatory, and other therapeutic applications of artemisinin are under extensive study. Several different mechanisms of action were proposed for dihydroartemisinin (DHA), the active metabolite of artemisinin, such as eliciting oxidative stress in target cells. The goal of this study is to monitor the generation of reactive oxygen species (ROS) and lipid peroxidation product 4-hydroxynonenal (4-HNE) by DHA in P.f.-infected human erythrocytes. Checking ROS and 4-HNE-protein adducts kinetics along the maturation of the parasite, we detected the highest level of 4-HNE in ring forms of P.f. due to DHA treatment. Low micromolar concentrations of DHA quickly induced levels of 4-HNE-adducts which are supposed to be damaging. Mass spectrometry identified the P.f. protein cysteine proteinase falcipain-1 as being heavily modified by 4-HNE, and plausibly, 4-HNE conjugation with vital P.f. proteins might contribute to DHA-elicited parasite death. In conclusion, significant 4-HNE accumulation was detectable after DHA treatment, though, at concentrations well above pharmacologically effective ranges in malaria treatment, but at concentrations described for antitumor activity. Thus, lipid peroxidation with consequent 4-HNE conjugation of functionally relevant proteins might be considered as a uniform mechanism for how DHA potentiates antimalarials' action in ACT and controls the progression of tumors.

Impact of Plasmodium falciparum infection on DNA methylation of circulating immune cells.

The regulation of immune cell responses to infection is a complex process that involves various molecular mechanisms, including epigenetic regulation. DNA methylation has been shown to play central roles in regulating gene expression and modulating cell response during infection. However, the nature and extent to which DNA methylation is involved in the host immune response in human malaria remains largely unknown. Here, we present a longitudinal study investigating the temporal dynamics of genome-wide in vivo DNA methylation profiles using 189 MethylationEPIC 850K profiles from 66 children in Burkina Faso, West Africa, sampled three times: before infection, during symptomatic parasitemia, and after malaria treatment. The results revealed major changes in the DNA methylation profiles of children in response to both Plasmodium falciparum infection and malaria treatment, with widespread hypomethylation of CpGs upon infection (82% of 6.8K differentially methylated regions). We document a remarkable reversal of CpG methylation profiles upon treatment to pre-infection states. These changes implicate divergence in core immune processes, including the regulation of lymphocyte, neutrophil, and myeloid leukocyte function. Integrative DNA methylation-mRNA analysis of a top differentially methylated region overlapping the pro-inflammatory gene TNF implicates DNA methylation of TNF cis regulatory elements in the molecular mechanisms of TNF regulation in human malaria. Our results highlight a central role of epigenetic regulation in mounting the host immune response to P. falciparum infection and in response to malaria treatment.

Efficacy and safety of pyronaridine–artesunate versus artemether–lumefantrine in the treatment of acute uncomplicated malaria in children in South-West Nigeria: an open-labelled randomized controlled trial

BackgroundIn Nigeria, declining responsiveness to artemether–lumefantrine (AL), the artemisinin-based combination therapy (ACT) of choice since 2005, has been reported. Pyronaridine–artesunate (PA) is a newer fixed-dose ACT recently prequalified by the WHO for the treatment of uncomplicated falciparum malaria. However, PA data from the Nigerian pediatric population is scarce. Therefore, the efficacy and safety of PA and AL using the WHO 28-day anti-malarial therapeutic efficacy study protocol in Ibadan, southwest Nigeria, were compared.MethodsIn an open-labelled, randomized, controlled clinical trial, 172 children aged 3–144 months with a history of fever and microscopically confirmed uncomplicated Plasmodium falciparum malaria were enrolled in southwest Nigeria. Enrollees were randomly assigned to receive PA or AL at standard dosages according to body weight for 3 days. Venous blood was obtained for hematology, blood chemistry, and liver function tests on days 0, 3, 7, and 28 as part of the safety evaluation.Results165 (95.9%) of the enrolled individuals completed the study. About half (52.3%; 90/172) of enrollees were male. Eighty-seven (50.6%) received AL, while 85 (49.4%) received PA. Day 28, adequate clinical and parasitological response for PA was 92.7% [(76/82) 95% CI 83.1, 95.9] and 71.1% [(59/83) 95% CI 60.4, 79.9] for AL (0.001). Fever and parasite clearance were similar in both groups. Two of six and eight of 24 parasite recurrences were observed among PA- and AL-treated children, respectively. PCR-corrected Day-28 cure rates for PA were 97.4% (76/78) and 88.1% (59/67) for AL (= 0.04) in the per-protocol population after new infections were censored. Hematological recovery at day 28 was significantly better among PA-treated patients (34.9% 2.8) compared to those treated with AL (33.1% 3.0) (0.002). Adverse events in both treatment arms were mild and similar to the symptoms of malaria infection. Blood chemistry and liver function tests were mostly within normal limits, with an occasional marginal rise.ConclusionPA and AL were well-tolerated. PA was significantly more efficacious than AL in both the PCR-uncorrected and PCR-corrected per-protocol populations during this study. The results of this study support the inclusion of PA in the anti-malarial treatment guidelines in Nigeria.Retrospective trial registrationClinicaltrials.gov: NCT05192265.

SERIOUS ANTIMALARIA RESISTANCE, GENETIC MARKERS OF KELCH 13, PLASMEPSINE 2 CNV ASSOCIATED WITH DIHYDROARTEMISININE - PIPERAQUINE RESISTANCE IN Plasmodium falciparum POPULATION IN MALARIA ENDEMIC ZONE OF DAKLAK PROVINCE, 2019 - 2020

Backgrounds: Dihydroartemisinin - piperaquine is a current frontline drug recommended in global by WHO for the treatment of Plasmodium falciparum malaria (WHO, 2015), but is now failing in Vietnam provinces where border Cambodia, and has emerged and spread. The purpose of this study was to evaluate efficacy and molecular markers of dihydroartemisinin - piperaquine failures in Daklak province. &#x0D; Methods: A study design of non - randomized controlled study design for the 42 day - course follow - up in vivo test, and the molecular markers analysis. &#x0D; Findings: The data showed that adequate clinical and parasitological response was sharply declined of 12,1%, late clinical failure of 51.5%, late parasitological failure of 36.4%, proportion of positive parasitemia at D3 is 37%, slope half - life of 5.36 hrs, and progressive parasite clearance PC50, PC75, PC 90, PC95, and PC99 were 13.24; 19.29; 25.69; 29.97 and 39.15 hrs, respectively. Molecular markers of C580Y Kelch mutation observed 100% (50/50) in the patients, increased of Plasmepsine 2 CNV of 72% (36/50), and both K13 and Plasmepsine 2 of 72% (36/50). &#x0D; Conclusions: The DHA - PPQ efficacy severely decreased of 12.1%, overall treatment failure of 87.9% with the prominent C580Y mutant plus increased Plasmepsine 2 copy number variation in delayed asexual P. falciparum parasite clearance. These obvious data need to urgently change antimalarial policy in DHA - PPQ resistance zones.