Dataset Information

Early parasite clearance following artemisinin-based combination therapy among Ugandan children with uncomplicated Plasmodium falciparum malaria.

ABSTRACT: Artemisinin-based combination therapy (ACT) is widely recommended as first-line therapy for uncomplicated Plasmodium falciparum malaria worldwide. Artemisinin resistance has now been reported in Southeast Asia with a clinical phenotype manifested by slow parasite clearance. Although there are no reliable reports of artemisinin resistance in Africa, there is a need to better understand the dynamics of parasite clearance in African children treated with ACT in order to better detect the emergence of artemisinin resistance.Data from a cohort of Ugandan children four to five years old, enrolled in a longitudinal, randomized, clinical trial comparing two leading ACT, artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP), were analysed. For all episodes of uncomplicated P. falciparum malaria over a 14-month period, daily blood smears were performed for three days following the initiation of therapy. Associations between pre-treatment variables of interest and persistent parasitaemia were estimated using multivariate, generalized, estimating equations with adjustment for repeated measures in the same patient.A total of 202 children were included, resulting in 416 episodes of malaria treated with AL and 354 episodes treated with DP. The prevalence of parasitaemia on days 1, 2, and 3 following initiation of therapy was 67.6, 5.6 and 0% in those treated with AL, and 52.2, 5.7 and 0.3% in those treated with DP. Independent risk factors for persistent parasitaemia on day 1 included treatment with AL vs DP (RR?=?1.34, 95% CI 1.20-1.50, p?20,000/?L vs <4,000/?L (RR?=?3.37, 95% CI 2.44-4.49, p?

SUBMITTER: Muhindo MK

PROVIDER: S-EPMC3909240 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Early parasite clearance following artemisinin-based combination therapy among Ugandan children with uncomplicated Plasmodium falciparum malaria.

Muhindo Mary K MK Kakuru Abel A Jagannathan Prasanna P Talisuna Ambrose A Osilo Emmanuel E Orukan Francis F Arinaitwe Emmanuel E Tappero Jordan W JW Kaharuza Frank F Kamya Moses R MR Dorsey Grant G

Malaria journal 20140128

<h4>Background</h4>Artemisinin-based combination therapy (ACT) is widely recommended as first-line therapy for uncomplicated Plasmodium falciparum malaria worldwide. Artemisinin resistance has now been reported in Southeast Asia with a clinical phenotype manifested by slow parasite clearance. Although there are no reliable reports of artemisinin resistance in Africa, there is a need to better understand the dynamics of parasite clearance in African children treated with ACT in order to better de ...[more]

PMID: 24468007

Similar Datasets

Project description:BackgroundArtemisinin-resistant Plasmodium falciparum has been reported in Pailin, western Cambodia, detected as a slow parasite clearance rate in vivo. Emergence of this phenotype in western Thailand and possibly elsewhere threatens to compromise the effectiveness of all artemisinin-based combination therapies. Parasite genetics is associated with parasite clearance rate but does not account for all variation. We investigated contributions of both parasite genetics and host factors to the artemisinin-resistance phenotype in Pursat, western Cambodia.MethodsBetween June 19 and Nov 28, 2009, and June 26 and Dec 6, 2010, we enrolled patients aged 10 years or older with uncomplicated falciparum malaria, a density of asexual parasites of at least 10,000 per μL of whole blood, no symptoms or signs of severe malaria, no other cause of febrile illness, and no chronic illness. We gave participants 4 mg/kg artesunate at 0, 24, and 48 h, 15 mg/kg mefloquine at 72 h, and 10 mg/kg mefloquine at 96 h. We assessed parasite density on thick blood films every 6 h until undetectable. The parasite clearance half-life was calculated from the parasite clearance curve. We genotyped parasites with 18 microsatellite markers and patients for haemoglobin E, α-thalassaemia, and a mutation of G6PD, which encodes glucose-6-phosphate dehydrogenase. To account for the possible effects of acquired immunity on half-life, we used three surrogates for increased likelihood of exposure to P falciparum: age, sex, and place of residence. This study is registered with ClinicalTrials.gov, number NCT00341003.FindingsWe assessed 3504 individuals from all six districts of Pursat province seeking treatment for malaria symptoms. We enrolled 168 patients with falciparum malaria who met inclusion criteria. The geometric mean half-life was 5·85 h (95% CI 5·54-6·18) in Pursat, similar to that reported in Pailin (p=0·109). We identified two genetically different parasite clone groups: parasite group 1 (PG1) and parasite group 2 (PG2). Non-significant increases in parasite clearance half-life were seen in patients with haemoglobin E (0·55 h; p=0·078), those of male sex (0·96 h; p=0·064), and in 2010 (0·68 h; p=0·068); PG1 was associated with a significant increase (0·79 h; p=0·033). The mean parasite heritability of half-life was 0·40 (SD 0·17).InterpretationHeritable artemisinin resistance is established in a second Cambodian province. To accurately identify parasites that are intrinsically susceptible or resistant to artemisinins, future studies should explore the effect of erythrocyte polymorphisms and specific immune responses on half-life variation.FundingDivision of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health.

Project description:BackgroundArtemisinin-based combination therapies are the recommended first-line treatments of falciparum malaria in all countries with endemic disease. There are recent concerns that the efficacy of such therapies has declined on the Thai-Cambodian border, historically a site of emerging antimalarial-drug resistance.MethodsIn two open-label, randomized trials, we compared the efficacies of two treatments for uncomplicated falciparum malaria in Pailin, western Cambodia, and Wang Pha, northwestern Thailand: oral artesunate given at a dose of 2 mg per kilogram of body weight per day, for 7 days, and artesunate given at a dose of 4 mg per kilogram per day, for 3 days, followed by mefloquine at two doses totaling 25 mg per kilogram. We assessed in vitro and in vivo Plasmodium falciparum susceptibility, artesunate pharmacokinetics, and molecular markers of resistance.ResultsWe studied 40 patients in each of the two locations. The overall median parasite clearance times were 84 hours (interquartile range, 60 to 96) in Pailin and 48 hours (interquartile range, 36 to 66) in Wang Pha (P<0.001). Recrudescence confirmed by means of polymerase-chain-reaction assay occurred in 6 of 20 patients (30%) receiving artesunate monotherapy and 1 of 20 (5%) receiving artesunate-mefloquine therapy in Pailin, as compared with 2 of 20 (10%) and 1 of 20 (5%), respectively, in Wang Pha (P=0.31). These markedly different parasitologic responses were not explained by differences in age, artesunate or dihydroartemisinin pharmacokinetics, results of isotopic in vitro sensitivity tests, or putative molecular correlates of P. falciparum drug resistance (mutations or amplifications of the gene encoding a multidrug resistance protein [PfMDR1] or mutations in the gene encoding sarco-endoplasmic reticulum calcium ATPase6 [PfSERCA]). Adverse events were mild and did not differ significantly between the two treatment groups.ConclusionsP. falciparum has reduced in vivo susceptibility to artesunate in western Cambodia as compared with northwestern Thailand. Resistance is characterized by slow parasite clearance in vivo without corresponding reductions on conventional in vitro susceptibility testing. Containment measures are urgently needed. (ClinicalTrials.gov number, NCT00493363, and Current Controlled Trials number, ISRCTN64835265.)

Project description:BackgroundMalaria is a major public health problem in endemic countries including Sudan, where about 75% of populations are at risk. Due to widespread of chloroquine-resistant strains of Plasmodium falciparum, artemisinin-based combination therapy (ACT) is currently treatment of choice for malaria in the vast majority of malaria-endemic countries. This systematic review and meta-analysis is performed to obtain an overall stronger evidence of the outcomes of ACT in the treatment of uncomplicated falciparum malaria from the existing literature in Sudan.MethodsThe preferred reporting items for systematic review and meta-analysis statement were used to select studies to be included in this review. A computerized systematic strategy was adopted to search articles from PubMed, Google Scholar and Science Direct databases. Unpublished materials were also included. Open Meta-Analyst software was used to perform the meta-analysis. Random effects model was used to combine the included studies and the heterogeneity of studies was assessed using Cochrane Q and I2 (χ2 = 73.05, df (19), P < 0.001 and I2 = 73.99).ResultsTwenty studies fulfilled the inclusion criteria (ACT in the treatment of uncomplicated falciparum malaria) and were included in the final analysis with a total number of 4070 participants. Malaria treatment outcome was assessed using World Health Organization guidelines. Adequate clinical and parasitological response was used to assess treatment success at the 28th day. Treatment success of all combined studies was 98% [(95% CI 97.2-98.8%), P < 0.001]. Treatment success was higher in malaria patients treated with artemether + lumefantrine (AL) than patients treated with artesunate + sulfadoxine-pyrimethamine (AS + SP) (98.9% (95% CI 98.4-99.4%) vs 97.1% (95% CI 95.5-98.6%), P < 0.001). Eleven studies reported adverse drug reactions (ADRs) to ACT (184 participants out of 3957 (4.65%). The ADRs were mild and resolved spontaneously. There was no severe ADRs or deaths.ConclusionBased on this review, the overall malaria treatment success was high (98%). AL regimen showed higher efficacy compared to AS + SP. The overall regimens were associated with mild low rates ADRs.

Project description:BackgroundArtemisinin-based combination therapy (ACT) is the first-line treatment for uncomplicated malaria in Ghana. Artemisinin (ART) tolerance in Plasmodium falciparum has arisen in Southeast Asia and recently, in parts of East Africa. This is ascribed to the survival of ring-stage parasites post treatment. The present study sought to assess and characterize correlates of potential ART tolerance based on post-treatment parasite clearance, ex vivo and in vitro drug sensitivity, and molecular markers of drug resistance in P. falciparum isolates from children with uncomplicated malaria in Ghana.MethodsSix months to fourteen years old children presenting with acute uncomplicated malaria (n = 115) were enrolled in two hospitals and a Health Centre in Ghana's Greater Accra region and treated with artemether-lumefantrine (AL) according to body weight. Pre- and post-treatment parasitaemia (day 0 and day 3) was confirmed by microscopy. The ex vivo ring-stage survival assay (RSA) was used to detect percent ring survival while the 72 h SYBR Green I assay was used to measure the 50% inhibition concentration (IC50s) of ART and its derivatives and partner drugs. Genetic markers of drug tolerance /resistance were evaluated using selective whole genome sequencing.ResultsOf the total of 115 participants, 85 were successfully followed up on day 3 post-treatment and 2/85 (2.4%) had parasitaemia. The IC50 values of ART, artesunate (AS), artemether (AM), dihydroartemisinin (DHA), amodiaquine (AQ), and lumefantrine (LUM) were not indicative of drug tolerance. However, 7/90 (7.8%) pre-treatment isolates had > 10% ring survival rates against DHA. Of the four isolates (2 RSA positive and 2 RSA negative) with high genomic coverage, P. falciparum (Pf) kelch 13 K188* and Pfcoronin V424I mutations were only present in the two RSA positive isolates with > 10% ring survival rates.ConclusionsThe observed low proportion of participants with day-3 post-treatment parasitaemia is consistent with rapid ART clearance. However, the increased rates of survival observed in the ex vivo RSA against DHA, maybe a pointer of an early start of ART tolerance. Furthermore, the role of two novel mutations in PfK13 and Pfcoronin genes, harboured by the two RSA positive isolates that had high ring survival in the present study, remains to be elucidated.

Dataset Information

Early parasite clearance following artemisinin-based combination therapy among Ugandan children with uncomplicated Plasmodium falciparum malaria.

Publications

Early parasite clearance following artemisinin-based combination therapy among Ugandan children with uncomplicated Plasmodium falciparum malaria.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets