View clinical trials related to Malaria, Falciparum.
Filter by:This is an open label, multi-centre phase I/IIa sporozoite-challenge trial to assess the safety, immunogenicity and efficacy of two combination ChAd63-MVA heterologous prime-boost vaccination regimens. All volunteers recruited will be healthy, malaria naïve adults aged between 18 and 45 years. To determine the efficacy of each of two combinations of heterologous prime-boost immunisation strategies: 1. ChAd63-MVA ME-TRAP combined with ChAd63-MVA CS 2. ChAd63-MVA ME-TRAP combined with ChAd63-MVA CS and ChAd63-MVA AMA1 The study will be conducted at the University of Oxford's Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Oxford, UK and the Wellcome Trust Clinical Research Facility in Southampton, UK. The malaria challenge will take place at the insectary at Imperial College (Infection and Immunity Section) in London, UK.
Background: - Artemisinin-based combination therapies (ACTs) are the first-line treatments for malaria. ACTs are highly effective, but malaria caused by the Plasmodium falciparum parasite is becoming resistant to some ACTs. ACT-resistant malaria has shown up in some parts of Cambodia, but not yet in other parts of the country. This has been shown by treating patients with ACTs, checking the amount of parasites in the patient s blood every 6 hours, and calculating the rate of parasite clearance. The parasite clearance rate in response to ACTs is getting slower in western Cambodia and may be the first sign of ACT resistance. Researchers want to study how effective ACTs are in different regions of Cambodia. This study will look at the extent of ACT resistance and how widespread ACT-resistant malaria has become. Objectives: - To compare the prevalence of ACT-resistant malaria in western, northern and eastern Cambodia. Eligibility: - Individuals between 2 and 65 years of age who have uncomplicated Plasmodium falciparum malaria and have not taken any antimalarial drugs for their symptoms in the previous 7 days. Design: - Participants will be recruited from clinics and hospitals in three Cambodian provinces. - Participants will be informed about the study and their consent to participate in the study will be obtained. - A venous blood sample will be obtained from patients before treatment and used for laboratory experiments to measure parasite and patient factors that might affect the parasite clearance rate. - Participants with malaria will be treated with dihydroartemisinin-piperaquine (DHA-PPQ), the standard first-line treatment for malaria in Cambodia. - Treatment will be monitored with frequent blood samples obtained from a finger prick. The amount of malaria parasites in each blood sample will be counted and followed until they are no longer detectable. - Participants will have weekly follow-up visits for up to 9 weeks. Finger-prick blood samples will be taken at each visit to see if the parasites reappear after treatment with ACT.
The purpose of the study is to determine whether long lasting insecticidal nets and indoor residual insecticide spraying, alone or in combination, are effective for controlling insecticide resistant anopheles mosquitoes for malaria prevention.
In Afghanistan, studies over the past 15 years have shown a high degree of Plasmodium falciparum resistance to chloroquine. In 2003 the high failure rate of chloroquine against falciparum malaria led the national malaria treatment programme to switch its recommended first line drug treatment for uncomplicated Plasmodium falciparum malaria to artemisinin-based combination therapy (ACT) in the form of Artesunate/Sulphadoxine-Pyrimethamine (AS+SP). Second line drug treatment is oral quinine (7 days). For operational reasons, prior to recent studies (manuscript in preparation) there have been no molecular data on P. falciparum SP resistance markers from within the borders of Afghanistan. These studies have revealed early evidence of increasing SP resistance (resistance polymorphisms with double DHFR & triple DHPS mutations). The aim of this study is to conduct a focused, prospective study in Kunar for monitoring of the efficacy of the AS+SP combination in this province, along with molecular studies of isolates from recruited patients.
In a previous study (NL33904.091.10) the investigators challenged 24 volunteers after Chloroquine Prophylaxis Sporozoites (CPS) immunization with 45, 30 or 15 infected mosquito-bites respectively. The availability of this immunized cohort opens the unique opportunity to determine protection to a heterologous challenge for both of the protected and unprotected volunteers as the previous challenge infection might have served as immunological boost to the unprotected volunteers. In the current observational, proof of principle study, the investigators aim to investigate the protection on an individual basis of these previously immunized and challenged volunteers against a heterologous P. falciparum challenge.
The main purpose of this study is to compare artesunate-mefloquine combination therapy given for 2 and 3 days at the same total dose for the treatment of uncomplicated falciparum malaria.
In camps for displaced persons located along the Thai-Myanmar border, mefloquine and artesunate combination therapy has been used since 1992. In vivo efficacy of a 3 day regimen of mefloquine + artesunate (MAS3) has been monitored regularly since its introduction in 1992. In 2009 Carrara et al summarised the in vivo PCR-adjusted cure rates at Day 42 and Day 63 in patients treated with MAS3 between 1995 and 2005, as well as the in-vitro parasite susceptibility to MAS3 during that same period, and the changes in pfmdr1 copy numbers.The proportion of patients with parasitaemia persisting on day-2 increased significantly from 4.5% before 2001 to 21.9% after 2002 (p<0.001). Delayed parasite clearance was associated with increased risk of developing gametocytaemia (AOR = 2.29; 95% CI, 2.00-2.69, p = 0.002). MAS3 efficacy declined slightly but significantly (Hazards ratio 1.13; 95% CI, 1.07-1.19, p<0.001), although efficacy in 2007 remained well within acceptable limits: 96.5% (95% CI, 91.0-98.7). The proportion of infections caused by parasites with increased pfmdr1 copy number rose from 30% (12/40) in 1996 to 53% (24/45) in 2006 (p = 0.012, test for trend). Evidence of reduced susceptibility to artemisinins in Western Cambodia was first reported in January 2007. Artemisinin resistance was manifest by a marked slowing of parasite clearance. A more recent analysis of parasite clearance data collected prospectively in patients with uncomplicated hyperparasitaemic malaria has shown a progressive decline in parasite clearance rates over the last decade suggesting a decline following the same trajectory as in Western Cambodia but with a time lag of a few years. Surveillance data collected in 2011 have shown a dramatic and worrying decline in efficacy of MAS3, albeit in a small number of patients. This decline in efficacy of mefloquine + artesunate is likely to be attributable to reduced parasite susceptibility to mefloquine. The other fixed dose combinations available dihydroartemisinin-piperaquine (DP) is the best option to replace mefloquine-artesunate since it is thought that it remains effective in the presence of high pfmdr1 copy numbers. In addition DP is administered once daily and needs no special dietary modification to ensure adequate absorption. In this study it is hypothesised that efficacy of DP (estimated to be 95%) will be significantly higher than that of MAS3 (estimated to be 65%), therefore the investigators propose to conduct a randomised controlled trial between DP and MAS3 for the treatment of P.falciparum.
This study aims to assess the safety and effectiveness of four new candidate malaria vaccines; ChAd63 CS, ChAd63 ME-TRAP, MVA CS & MVA ME-TRAP. These vaccines consist of viruses (ChAd63 and MVA) which have been genetically modified so (i) they cannot replicate in humans and (ii) they include parts of the malaria parasite; Plasmodium falciparum (CS and ME-TRAP). The hope is that these vaccines will induce immune responses in vaccinees that are able to prevent malaria. This proposed study will compare how effective ChAd63-MVA CS is at preventing malaria infection in UK volunteers following malaria challenge compared to ChAd63-MVA ME-TRAP. The study will be conducted at the University of Oxford's Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Oxford, UK and the Wellcome Trust Clinical Research Facility in Southampton, UK. The malaria challenge will take place at the insectary at Imperial College (Infection and Immunity Section) in London, UK.
The purpose of the study is to obtain efficacy, safety and pharmacokinetic (PK) data following treatment with artemether-lumefantrine dispersible tablet in infants < 5 kg of body weight (BW) with uncomplicated falciparum malaria.
The primary trial objective is to determine the clinically effective dose of orally administered pyronaridine/artesunate (Pyramax®, PA) with a 3:1 ratio to treat adults with acute, symptomatic, uncomplicated P. falciparum malaria in South East Asia and Africa. Secondary trial objectives are to determine the safety of once-daily dosing for 3 days of PA and to explore possible ethnic differences in safety or efficacy.