View clinical trials related to Plasmodium Vivax Malaria.
Filter by:In this area of Greater Mekong Subregion (GMS), vivax malaria is the most common kind of malaria. It can stay very long in the liver, and come out later to make another episode of illness. This can happen many times even without a mosquito bite. Only 8-aminoquinoline drugs can kill the liver forms of the malaria parasite. One of these drugs is called primaquine, and it has been used all over the world for a long time. There is now a new formulation of this 8-aminoquinoline drug called tafenoquine that can also treat the malaria in the liver. The main benefit of this drug is that it is a single dose, which makes much convenient for the patients as well as for the malaria control program than conventional 14 days of primaquine. Recent research suggests that ACT (Artemisinin Combination Therapy) may antagonise the efficacy of tafenoquine (Baird et al. 2020 ASTMH Annual Meeting) . This could prevent the use of tafenoquine in areas with chloroquine resistant P. vivax parasites where national malaria programmes recommend ACTs for vivax malaria. Also, currently recommended tafenoquine dose is sub-optimal: 300 mg dose proved significantly inferior to low dose primaquine in a meta-analysis of the phase 3 studies when restricted to the Southeast Asian region (Llanos-Cuentas et al. 2019 NEJM; Watson et al. 2022a Elife). A tafenoquine dose of 450mg is predicted to provide >90% of the maximal effect. The objective of this research is to find out whether 450 mg dose of tafenoquine can be combined effectively with ACT providing a short course treatment for P. vivax malaria.
This study assesses the effectiveness of reactive focal mass drug administration (rfMDA), targeting both village and forest working populations, compared to control for reducing the health promotion hospital-level (sub-district) incidence and prevalence of P. falciparum and P. vivax within five provinces in Thailand.
Tafenoquine was recently approved by regulatory authorities in the USA and Australia. Tafenoquine is an alternative radical curative treatment to primaquine acting against the dormant liver stage of Plasmodium vivax (the hypnozoite). Tafenoquine (an 8-aminoquinoline) has the substantial advantage of single dosing as compared to a 14-day course of primaquine to achieve radical cure. The recommended tafenoquine dose is 300 mg, which was shown to be significantly worse in radical curative efficacy to a total primaquine dose of 3.5 mg/kg in Southeast Asia. The cure rate of tafenoquine 300 mg in Southeast Asian study sites was only 74%. The comparator 3.5 mg/kg total primaquine dose is the standard and most commonly used dose globally, but in Southeast Asia and the Western Pacific, higher doses of primaquine are needed for radical cure. This study aims to determine the optimal dose of tafenoquine in Southeast Asia.
This study assesses the effectiveness and feasibility of enhanced reactive case detection (RACD) targeting high-risk villages and forest workers for reducing Plasmodium falciparum and Plasmodium vivax transmission in southern Lao Peoples Democratic Republic. The authors hypothesize that enhanced community-based RACD will be more effective than standard of care case management and RACD at reducing P. falciparum and P. vivax confirmed case incidence and parasite prevalence over an 18-month period in Lao Peoples Democratic Republic.
This will be a Proof-of-concept / Phase IIa, open label study to examine the efficacy of DSM265 in uncomplicated Plasmodium vivax and Plasmodium falciparum blood-stage malaria in adult patients. A minimum of two cohorts (20 patients) and a maximum of 6 cohorts (60 patients, 3 dose levels) will be tested. The starting dose of DSM265 for the first P. vivax and P. falciparum cohorts will be 400 mg. This dose is expected to show complete clearance of parasites by microscopy by Day 7 and a decrease in recrudescence rate assessed at Day 14 (success criteria for dose de-escalation and continuation of the study).
The purpose of this study is to assess the effectiveness of different malaria control strategies in the first year of life. The effectiveness of delivering an intermittent screening and treatment programme with dihydroartemisinin-piperaquine (DHP), linked to local immunization programmes, will be compared to the current practice of passive case detection of malaria. This study has two objectives: 1. To assess the effectiveness of intermittent screening and treatment with dihydroartemisinin-piperaquine (DHP) administered at 2, 3, 4 and 9 months of age compared with the current practice of passive detection and treatment for malaria in an area with high drug resistance levels to both P. falciparum and P. vivax. 2. To evaluate the safety, efficacy and population pharmacokinetics of DHP in children under 1 year of age.
This is a study of drug effectiveness for 2 treatments of vivax malaria, which is one of the two main types of malaria in Viet Nam. There are two important drugs used in Viet Nam for treating vivax malaria, Chloroquine and Artemisinin. Sometimes, when medicines are used for many years they become less effective at treating a disease, especially when they are not used at adequate doses according to national guidelines or when counterfeit drugs are available in the market. The purpose of this study is to check that Chloroquine and Artemisinin, are still effective for patients in Viet Nam. Participants in this study will be treated with either Dihydroartemisinin-Piperaquine (DHA-PPQ) or Chloroquine (CQ) for 3 days. Both drugs are recommended by the national guidelines to treat vivax malaria. The investigators would like to know if both of these treatments are equally effective so half of the patients in the study will be treated with DHA-PPQ and the other half will be treated with CQ. This way the investigators can compare the drugs to find out if one is better than the other. Participants will be followed for 3 days in hospital, then regularly by follow-up visits until the 63rd day. Tests will be done to determine the amount of drug and malaria parasites in the participant's body and how the blood cells react to the malaria. The parasite will be tested to determine what type it is and how it reacts to the treatment. The results of the study will be used to inform malaria treatment guidelines in Viet Nam.
The current treatment recommendations for P. vivax in pregnant and non-pregnant individuals are to use chloroquine; in non-pregnant patients this is followed by primaquine to prevent relapse. As primaquine can not be used in pregnant women, these women remain at risk of relapse. As there is increasing concern about chloroquine resistant P. vivax in this region, there is a need to identify alternative treatment options. The artemisinin combination therapies are recommended for use against P. falciparum infections in pregnant women after the 1st trimester; additional data are needed to support the use of these drugs against P. vivax.
The purpose of this study is to demonstrate that volunteers can be safely and reproducibly infected with Plasmodium vivax (P. vivax) by the bites of experimentally infected Anopheles dirus (An. dirus) mosquitoes carrying P. vivax sporozoites in their salivary glands.
This study, conducted at Johns Hopkins University Center for Immunization Research in Washington DC, will test the safety and immune response of healthy volunteers to two experimental malaria vaccines. Malaria is a disease of red blood cells caused by a parasite that spreads from person to person by mosquitoes. It affects people of all ages, but is particularly severe in children. Patients may have a high fever, chills and muscle aches. They sometimes can have severe complications that may even result in death. The vaccines in this study are called "transmission blocking" vaccines. These vaccines stimulate the person's immune system to produce antibodies against malaria. When a mosquito bites a vaccinated person, it ingests some of the person's blood. The antibodies in the ingested blood stop the malaria parasite from developing inside the mosquito. The mosquito would not be able to transmit malaria to other people. PpPfs25/ISA51 (Vaccine A) stimulates production of antibodies against the malaria parasite Plasmodium falciparum, and ScPvs25/ISA51 (Vaccine B) stimulates antibodies against the malaria parasite Plasmodium vivax. The vaccines also contain a substance called Montanide ISA51, which boosts the immune response to the vaccine. Healthy volunteers between 18 and 50 years of age may be eligible for this study. Candidates are screened with a medical history, physical examination, and blood and urine tests. Women who are able to become pregnant have a urine pregnancy test before each immunization. Participants are randomly assigned to receive two injections, spaced 4 months apart, of either Vaccine A or Vaccine B at one of three doses-high, medium, or low. Two subjects in each dose group additionally serve as "controls" and receive only Montanide ISA51 mixed with saline. The vaccine is injected into the muscle of the upper arm. Subjects are monitored for 30 minutes after each injection for possible side effects and take home a diary card to record their temperature and any symptoms that may appear over the next 13 days. A blood sample is drawn before and on several occasions after each vaccination to check the subject's health and to evaluate the immune response to the vaccine. At 1, 3, 7, 14, and 21 days after each vaccination, participants come to the clinic for a check of vital signs (temperature, pulse, respiration, and blood pressure), brief physical examination, and history of symptoms since the previous visit.