Defining the Micro-epidemiology and Elimination Strategy of Falciparum Malaria in Areas of Artemisinin Resistance (TME)
The overall aim of this study is two fold:
- to pilot targeted chemo-elimination of plasmodium falciparum malaria in known areas of artemisinin resistance in South East Asia.
- to understand the micro-epidemiology of malaria in these areas; chiefly, the prevalence and importance to on-going transmission of sub-clinical p.f malaria infections.
Plasmodium Falciparum Malaria
Drug: malaria elimination using DP and low-dose primaquine
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Defining the Micro-epidemiology and Elimination Strategy of Falciparum Malaria in Areas of Artemisinin Resistance: Targeted Chemo-elimination to Eradicate Malaria in Areas of Suspected or Proven Artemisinin Resistance in Southeast Asia|
- prevalence of falciparum malaria measured by qPCR (quantitative real time polymerase chain reaction), 12 months after the first administration of treatment with dihydroartemisinin-piperaquine and primaquine. [ Time Frame: 12 months ] [ Designated as safety issue: No ]Percentage falls in asymptomatic malaria prevalence in the intervention villages vs control villages, as determined by highly sensitive qPCR, 12 months after the first administration of treatment with dihydroartemisinin-piperaquine and primaquine.
- Safety and acceptability of targeted malaria elimination [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]Safety and acceptability of targeted malaria elimination with dihydroartemisinin-piperaquine and low dose primaquine, evaluated by questionnaires filled out by participants or care givers.
- Effect on gametocyte carriage by targeted malaria elimination [ Time Frame: 12 months ] [ Designated as safety issue: No ]Effect on gametocyte carriage by targeted malaria elimination, measured by the proportions of gametocyte carriers over the 12 month period
- Characterize parasite carriage using highly sensitive techniques in four geographically separate sites where resistance to artemisinin has been documented [ Time Frame: 12 months ] [ Designated as safety issue: No ]Characterize parasite carriage using by molecular analysis of parasite genotypes, markers of resistance and parasite population genetic structure
|Study Start Date:||April 2013|
|Estimated Study Completion Date:||December 2016|
|Estimated Primary Completion Date:||June 2016 (Final data collection date for primary outcome measure)|
Experimental: malaria elimination using DP and low-dose primaquine
Two villages randomly allocated to intervention (chemo-elimination) at each of the 4 sites (population approximately 500 people in each village). In these villages the entire population will be invited to receive three, monthly rounds of treatment with dihydroartemisinin-piperaquine and primaqunine to kill malaria parasites. The micro-epidemiology of malaria will be studied and prevalence and patterns of transmission used for comparison. NB, in Cambodia there will be no intervention villages and all four villages will be used to study the micro-epidemiology of malaria transmission in the absence of malaria elimination.
Drug: malaria elimination using DP and low-dose primaquine
Treatment of all persons resident in the intervention villages including those who do not have malaria parasites as detected by rapid diagnostic test. This is to interrupt p.f malaria transmission by removing the reservoir of all potentially infectious people from the area.
No Intervention: Control villages
Two villages randomly allocated to control (no chemo-elimination) at each of the 4 sites (population approximately 500 people in each village). In these villages only the micro-epidemiology of malaria will be studied and prevalence and patterns of transmission used for comparison. NB, in Cambodia there will be no intervention villages and all four villages will be used to study the micro-epidemiology of malaria transmission in the absence of malaria elimination.
The spread of artemisinin resistance in Plasmodium falciparum, which compromises the therapeutic efficacy of artemisinin combination treatments (ACTs), is the greatest threat to current global initiatives to control and eliminate malaria and is considered the highest priority of the WHO Global Malaria Programme. If not eliminated, resistant parasites could spread across Asia to Africa, as happened with resistance to other antimalarials in the past.
Conventional descriptions of the epidemiology of malaria in low transmission settings suggest that malaria prevalences are low (<10%) and heterogeneous. Most or all infections are thought to be symptomatic so the focus of malaria control activities is on the identification and treatment of symptomatic individuals. We and others have shown recently that artemisinin resistant P. falciparum is prevalent in Western Cambodia, and that it is now also found along the Thailand-Myanmar border and Vietnam. We have recently developed highly sensitive quantitative PCR (qPCR) methods for parasite detection using >1mL of blood which are 5,000 times more sensitive than conventional microscopy, and 100 times more sensitive than currently used PCR.
We have studied villages along the Thai-Myanmar border which are typical for the region and are classified by conventional epidemiological techniques as low-transmission (5-20% malaria prevalence). Our studies suggest that the majority of the population is infected. In Pailin, Western Cambodia, in areas where the National Malaria Control Programme and WHO believe that malaria has been all but eliminated, we have also found very high rates (>80%) of sub-microscopic parasitaemia in patients with fever or history of fever who are RDT negative. Thus, there is a lot more asymptomatic malaria in low transmission settings than previously thought, suggesting that control and elimination activities need to be rethought.
This study is designed to conduct and evaluate the efficacy of pilot implementation of targeted chemo-elimination in selected areas with the goal of eliminating malaria in these regions. This differs from mass drug administration (MDA); it is a strategy used to identify specific areas where mass treatment is necessary, in this case to eliminate all malaria parasites. Elimination will be targeted at communities with significant levels of subclinical infection and transmission which will be identifiable in the future by comparing rates of positivity by RDT or microscopy from new population samples against our qPCR data, which shows the true falciparum prevalence.
The study will assess the feasibility, safety and acceptability of this strategy and its impact on the transmission of malaria and the progression of artemisinin resistance. In addition it will evaluate the contribution of low parasitaemia carriage to transmission of artemisinin resistant malaria. These pilot studies are a necessary prelude to future scale up and policy implementation.
Dihydroartemisinin-piperaquine (DP) is a highly efficacious and inexpensive ACT which is well tolerated by all age groups when used to treat uncomplicated multi-drug resistant falciparum malaria in South East Asia. Monthly DP treatments have proved highly effective and well tolerated. When used as part of a MDA strategy, the addition of a gametocytocidal drug contributes towards the goal of malaria elimination by adding a strong transmission blocking activity to the regimen. Primaquine (PQ), the only currently licensed 8-aminoquinoline, is relatively safe and very effective when used at a dose of 0.25 mg base/kg, and does not require G6PD screening. Thus, we propose to evaluate the potential of this strategy to eliminatie malaria focally in areas where artemisinin resistance in P. falciparum is prevalent using DP plus PQ.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01872702
|Contact: Nicholas J White, PhD||+66 (0)firstname.lastname@example.org|
|Contact: Arjen Dondorp, PhD||+66 (0)email@example.com|
|National Centre for Parasitology, Entomology and Malaria Control||Active, not recruiting|
|Phnom Penh, Cambodia, 372|
|Mahidol Oxford Clincal Research Unit, Myanmar||Active, not recruiting|
|Shoklo Malaria Research Unit||Recruiting|
|Mae Sot, Tak, Thailand|
|Contact: Francois Nosten, PhD firstname.lastname@example.org|
|Contact: Khin M Lwin, MD|
|Principal Investigator: Francois Nosten, PhD|
|Oxford University Clinical Research Unit - Vietnam||Recruiting|
|Ho Chi Minh city, Vietnam, Ward 1, District 5|
|Contact: Tran Tinh Hien, PhD +84 (8) 3923 7954 email@example.com|
|Principal Investigator: Tran T Hien, PhD|
|Principal Investigator:||Nicholas J White, PhD||University of Oxford|