Active clinical trials for "Malaria, Vivax"

The purpose of this study is to learn more about vivax malaria in very young children, how the growth of children is affected by malaria infections, and how inherited traits protect children from getting malaria. Participants will be 266 children 24 months of age or younger who live in certain villages in East Sepik Province, Papua New Guinea, where malaria is very common. The study also will find out how malaria spreads in the area. By learning how and when a child develops resistance to vivax malaria, researchers can try to find ways to help people from getting it. And, they can get a better understanding of how inherited traits influence all types of malaria infections. In this study, the parent and child will be visited by the study team or health workers every week to check health and bednet use. Every 2 weeks, the study team will take a small blood sample to check for malaria and take measurements to study the child's growth. Participants will be followed for up to 2 years.

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.

An antimalarial drug efficacy trial was conducted for artemether-lumefantrine (AL) and chloroquine (CQ) in the three (3) municipalities (Bataraza, Brookes and Rizal) of Palawan. Study subjects are febrile individuals between > 6 months old and 59 years old with confirmed uncomplicated P. falciparum or P. vivax infections. Patients with P. falciparum was treated with Artemether-lumefantrine administered 3 days (Days 0, 1 and 2) according to body weight. Primaquine at 0.75 mg base/kg body weight single dose was given on Day 3. For Plasmodium vivax patients chloroquine were administered according to body weight at a total dose of 25 mg/kg over 3 days (10 mg/kg on Day 0; 10 mg/kg on Day 1 and 5 mg/kg on Day 2), and primaquine following the National Treatment Guidelines. During the period that this report covers, 84 and 75 patients met the inclusion criteria for Pf and Pv respectively. Clinical and parasitological parameters were monitored over a 28-day follow-up period for both drugs. The presence of only 1 Late Clinical Failure (LCF) of P. falciparum parasitemia out of 84 enrolled patients and 2 Late Parasitological Failure (LPF) of P. vivax patients out of 75 enrolled patients within the 28 days follow up suggest that both drugs are still efficacious.

Chloroquine (CQ) is officially used as a first-line drug of Plasmodium vivax malaria in the Philippines. In this study, the therapeutic efficacy of CQ for the treatment of uncomplicated P. vivax malaria in three (3) municipalities (Bataraza, Brooke's Point and Rizal) of Palawan was evaluated using the World Health Organization protocol with a follow-up of 28 days and additional 2 days (Day 31 and 34) for hemoglobin monitoring after primaquine treatment. Study subjects were febrile individuals between > 6 months old and 59 years old with confirmed uncomplicated P. vivax infections. Chloroquine was administered according to body weight at a total dose of 25 mg/kg over 3 days (10 mg/kg on Day 0; 10 mg/kg on Day 1 and 5 mg/kg on Day 2), and primaquine following the National Treatment Guidelines. During the 1 year period that this report covers, there were 8,305 individuals were screened.

This research is intended to study the efficacy of chloroquine (CQ) and primaquine (PQ) for Plasmodium vivax (P.vivax) infection, and also to study the recurrence rate among patients with P.vivax malaria on standard doses of CQ and PQ. For this study, PQ will be withheld for 28 days so as to study the efficacy of CQ alone. This study will assess whether CQ is still effective against P.vivax or whether there are resistant P.vivax strains in Bhutan.

This is a randomized, double-blind, controlled, which seeks to compare two groups of volunteers (naive and previously exposed to malaria) vaccinated with three doses of a synthetic derivative of the CS protein of Plasmodium vivax to determine their protective efficacy. Then volunteers will be subject to an infectious challenge (Controlled Human Malaria Infection) to assess the infectivity of gametocytes in the blood early stage of P. vivax in Anopheles albimanus mosquitoes.

The purpose of this study is to determine which, between weekly prophylaxis or malaria attack treatment, both by chloroquine, is the most appropriate way to protect women and foetus from P. vivax malaria infection during pregnancy.

Historically, Plasmodium vivax has been termed "benign" due to its non-life threatening clinical course and since the 1800's this view has been cultivated as demonstrated by the use of the term "benign tertian malaria" to describe the infection.However over the last 15 years, more severe P. vivax malaria is being reported, causing concern that severe P. vivax malaria is under diagnosed. The definition of severe P. vivax malaria borrows from P. falciparum and is primarily one of exclusion. Species PCR (polymerase chain reaction) is the only way to prove P. vivax mono-infection but is expensive and requires skilled staff and technology. In resource constrained settings, diagnostic testing is not available for detection of most non-malarial infections further affecting the ability to determine whether severe symptoms are due to P. vivax malarial infection or a concomitant one. Retrospective studies from India, Pakistan, Indonesia, Papua New Guinea and Sudan support the existence of severe P. vivax malaria. However, inconsistent methodologies, definitions of severity, and use of diagnostic tests to exclude concomitant infection do not allow for standardised assessments for severe P. vivax infection across studies. A review by Baird, highlighted that the risk of being classed as suffering from severe illness was only minimally higher in P. falciparum than in P. vivax, but was unable to combine the data as a meta-analysis. The primary reported symptoms for severe P. vivax included severe anaemia particularly in children, severe thrombocytopaenia, respiratory distress, neurological syndromes (coma or seizures), renal and hepatic failure. Prospective studies have shown similar results. Tjitra et al showed that 23% (675 of 2,937) patients admitted with microscopically diagnosed P. vivax infections in Papua, Indonesia had severe disease and that the risk of severe malaria was significantly higher when admitted with P. vivax than with P. falciparum. In studies from Papua New Guinea, few differences between the clinical presentation of P. falciparum and P. vivax were found in children with severe malaria. This appears to be similar in populations from Sudan, Pakistan and India. In contrast, in Thailand, anecdotal observations note a low prevalence of severe P. vivax infections. The WHO criteria to assess severe P. falciparum have been extrapolated to P. vivax. In the 2015 WHO malaria guidelines some criteria now account for P. vivax, such as removing a minimum parasitaemia when assessing for severe anaemia. Whilst these criteria may not be the most sensitive tool to define severe P. vivax infections, it is used for this purpose. It has been suggested that additional clinical information may be necessary to define truly severe P. vivax cases. In order to describe the characteristics of the severity of P. vivax infections in north-western Thailand, we will perform a retrospective review of annual reports of the outpatient database, the inpatient database and eligible inpatient medical records from 2001 to 2016. The WHO malaria guidelines and additional clinical information will be used to assess the severity of infection and thus, a rate of severe P. vivax can be determined.

This research is intended to study the efficacy of CQ alone for P.vivax infection and also to study the recurrence rate among patients with P.vivax on standard dose of CQ and PQ. For this study, PQ will be withheld for 28 days so as to study the efficacy of CQ alone since masking effect over one another was found when CQ is given with PQ. So the investigators are not sure whether the recurrence is due to resistance to CQ or CQ concentration in blood is below therapeutic level or it is due to PQ is in inadequate dose. From this study the investigators will get findings like may be CQ is still working for P.vivax or no longer working for P.vivax due to resistance developed by P.vivax parasites. So for P.vivax which is not responding to CQ therapy, the investigators will go for second line treatment with ACT in a similar fashion as it is given for P. falciparum infection in Bhutan. And if the investigators find CQ is still working for P.vivax infection, the next level of study will be to compare higher dose of PQ with standard dose of PQ ( as practiced now) in lieu of bringing down the relapse rates in P. vivax infection.