Active clinical trials for "Malaria, Vivax"

A clinical study to assess the safety and efficacy of alternative regimens of primaquine for radical cure of vivax malaria in glucose 6-phosphate dehydrogenase (G6PD) deficient. G6PD deficient patients with P. vivax monoinfection will be treated with either weekly or delayed one-week course of primaquine, and the currently recommended by national guideline, 12-week chloroquine regimen to compare treatment safety among groups. All groups will be actively monitored for hemolysis during treatment and will have six-month follow-up period to assess treatment efficacy.

Although Plasmodium vivax (P. vivax), one of the five malaria species causing parasites, has the widest geographical distribution, it is rare in sub-Saharan Africa due to the absence of a red blood cell receptor (Duffy antigen) in black Africans. Duffy-negative individuals are, for the most part, therefore refractory to P. vivax infection and the Duffy-negative phenotype is found at highest frequencies in Africa, whereas it is relatively rare elsewhere. P. vivax has however, been observed as single infections in up to 5% of Duffy-negative febrile patients in one health facility in Dschang, a region of low malaria transmission in Western highlands of Cameroon. Whereas in the littoral South West and Southern forest of Cameroon characterised by high malaria transmission, areas, there are contrasting molecular evidence of human P. vivax infection. While important, the significance is limited from an epidemiological point of view, concerning the source, transmission, distribution range of P. vivax. There is thus a challenge in the true estimation of malaria burden, as well as the attributable parasite species in infections occurring in the low transmission areas of Western Cameroon. As a consequence, our understanding of the local epidemiology of malaria in Western Cameroon warrants formal investigation. The current proposal is a multi-centre observational study. Its purpose is to characterise the malaria species composition and particularly exposure and burden of P. vivax across malaria endemic settings in Cameroon. It will use multiplex serological methods based on quantitative suspension array on finger-stick blood samples collected from febrile patients of ages 1-100 during two malaria transmission seasons in different eco-climatic regions in Cameroon.

The investigators are proposing a new malaria control strategy to reach the group of garimpeiros not reached by the usual actions of the health services. As it is a complex strategy, several evaluation mechanisms have been designed. The main characteristics of the research are: Access to the target population: our target population is represented by miners active and mobile in the south of the Guiana Shield, between Amapá (Brazil), French Guiana (France) and Suriname. To overcome the obstacles posed by the remoteness and clandestinity of the communities of interest, our intervention will take place in the logistical and support hubs (staging areas) of the miners, located in the border regions between the above territories. Thus, it will take advantage of their periodic mobility between these bases and the gold mining sites, and reach the target population where it can be easily accessed. The intervention will be combined and will include a common core (malaria health education activity) and two modules that will be offered to participants. Each participant (meeting the inclusion criteria) will be able to choose between participating to one or both modules. The common core of health education will focus on malaria: its causes, means of prevention, the main differences between P. falciparum and P. vivax disease, the importance of a complete treatment against any form of Plasmodium spp. Module A of the intervention will be treatment targeting asymptomatic individuals at risk of carrying P. vivax. The aim of this module is to prevent relapses and reduce the number of human hosts able to transmitthe parasite. Module B of the intervention will correspond to the provision, after appropriate training, of a Malakit self-test and self-treatment kit. The aim of this module is to provide access to quality diagnosis and treatment for episodes of symptoms consistent with malaria that occur in situations of extreme remoteness from health services. The purpose of this study is to evaluate a strategy that, if appropriate, can be implemented by health authorities in countries with residual malaria transmission in populations with characteristics similar to our study population. The investigators will therefore use a pragmatic approach so that the conclusions drawn can be transposed as easily as possible to real life, while at the same time putting great effort into the safety of the intervention. Thus, the study field workers who will administer the intervention will have a similar profile to health workers recruited by a large number of malaria control programmes, particularly in remote areas. In addition, monitoring will be simplified and monitoring data can be collected both through face-to-face visits and remotely administered questionnaires. The investigators chose to design many of the components of the intervention and study with a participatory approach. In order to generate the data necessary for health authorities to potentially take ownership of the intervention in the future, the study will evaluate two aspects of the intervention: effectiveness and implementation. First, the investigators want to evaluate the population-scale effectiveness ofthe intervention to reduce malaria transmission with a quasi-experimental approach. Secondly, the investigators will analyse the implementation of theintervention, and generate valuable knowledge for further implementation within local health services. This evaluation will be carried out through the components of the CUREMA study: the intervention itself, pre/post-intervention cross-sectional surveys, a nested cohort, the qualitative component and the modelling of epidemiological surveillance data. • The implementation of these components will have an expected duration of approximately 27 months, the start of inclusions is scheduled for September 2022.

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 is an open-label, single-centre, non-randomised, first-in-human Phase Ia study to assess the safety and immunogenicity of the Pvs25-IMX313 vaccine, administered in Matrix-M1 adjuvant.

This is a clinical trial to evaluate an experimental serological diagnostic technique intended to identify people at high risk of having dormant malaria parasites in their liver. The study is designed to evaluate the efficacy of serological screening vs. routine care for the prevention of recurrent P. vivax infections. A total of 960 schoolchildren will be randomized into the interventional or control arm.

This is a clinical study to assess the safety and feasibility of Plasmodium vivax (P. vivax) controlled blood-stage human malaria infection (CHMI), by inoculation using a newly created source of P. vivax malaria-infected blood. 25 healthy malaria-naïve UK volunteers, aged 18 - 50, will be recruited through the five phases of the study at the CCVTM, Oxford. Volunteers will undergo primary, secondary and tertiary P. vivax blood-stage challenges, which will be induced by injection of P. vivax infected blood. After the first challenge, the optimal dose for blood-stage CHMI will be selected and used for the second and third challenges. Through each challenge period, volunteers will have blood taken at regular intervals to measure the parasite growth, quantify the sexual parasite forms and assess the immune response to P. vivax infection. Transmission of P. vivax from volunteers to the Anopheline mosquito vectors will also be assessed. In each challenge, following diagnosis, volunteers will be treated with a standard antimalarial course of oral artemether-lumefantrine (Riamet), given over 60 hours. Volunteers who take part in this study will be involved in the trial for approximately 2 years, receiving each of the three challenges at intervals of approximately 5 (and up to 9) months. Volunteers will be followed for 3 months after their last challenge.

FLAME is an open-label cluster-randomized controlled trial that aims to determine the effectiveness of focal mass drug administration (fMDA) to reduce the incidence of Plasmodium vivax malaria in the Loreto Department in Peru. Standard interventions, including symptomatic and asymptomatic screening for malaria infections, provision of insecticide-treated bednets, and environmental transmission monitoring, will be compared to clusters of villages randomized to receive anti-malarial drugs.

The purpose of this prospective, observational study is to assess the operational feasibility of appropriate radical cure treatment for P. vivax malaria with tafenoquine or primaquine, in patients 16 year and older, after G6PD testing in Thailand. The study will be implemented in a phased manner, in the provinces of Yala and Mae Hong Son. The first phase will be at higher level health facilities (hospitals). An interim analysis will be conducted after 40 patients are enrolled in the study in order to decide whether the study could be extended to lower level HFs. If approved by the Independent Study Oversight Committee, the study will be implemented in lower level HFs (malaria clinics).Higher level HFs will continue to include patients in the study during this 2nd phase.Written informed consent / assent is required from all patients /guardians in the case of minors.

The proportion of malaria that is the Plasmodium vivax species is increasing in Indonesia. Reducing vivax malaria will require innovative solutions to cure both the blood and liver stages of the disease. This study will evaluate of the feasibility of implementing point-of-care glucose-6-phosphate dehydrogenase deficiency (G6PD) testing. This will be followed by high dose, short course primaquine treatment regimens for patients with vivax malaria, and combined with patient education, surveillance, and pharmacovigilance. We plan to implement the study at 6 health facilities across Indonesia using a staged before-and-after study, with a mixed method evaluation.