Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Double Blind Randomized Controlled Trial to Assess the Efficacy and Safety of Low Dose Primaquine for Clearance of Gametocytes in Asymptomatic Individuals Infected With P. Falciparum in Burkina Faso
Brief Summary: Primaquine (PQ) is currently the only available drug that can clear mature transmission stages of P. falciparum parasites. PQ was previously shown to clear gametocytes that persist after artemisinin-combination therapy. However, there are safety concerns about the use of PQ at the currently recommended dose of 0.75mg/kg in individuals who are glucose-6-phosphate dehydrogenase (G6PD) deficient. PQ causes transient but significant haemolysis in G6PD deficient individuals; this side-effect is dose dependent. There are indications that a lower dosing of PQ may effectively reduce gametocyte carriage but the lowest efficacious dose for gametocyte clearance is currently unknown. Recently, the World Health Organization changed their recommendation to a low dose of primaquine, 0.25mg/kg. However, there is no direct evidence on the extent to which (low dose) PQ prevents malaria transmission to mosquitoes and what the lowest efficacious dose is.

In the current study we aim to identify the lowest efficacious dose of PQ in individuals with normal G6PD function. Children with asymptomatic malaria and normal G6PD enzyme function will be randomized to treatment with artemether-lumefantrine alone or in combination with low doses of PQ. All enrolled individuals will receive a full three-day course of AL, and will be randomized to receive a dose of primaquine or placebo with their fifth dose of AL. Efficacy will be determined based on gametocyte carriage during follow-up, measured by molecular methods. For a subset of participants with patent gametocytes, primaquine effect on infectivity to mosquitoes will be assessed by membrane feeding assays


Options:
A: Inclusion Criteria:

* Age \>/= 1 year and \</= 10 years
* Weight over 10kg
* Fever \>38 degrees C (tympanic) or history of fever in the last 24 hours
* P. falciparum parasitaemia \<500 000/µl
* Normal G6PD enzyme function

Exclusion Criteria:

* Enrolled in another study
* Evidence of severe illness/ danger signs
* Known allergy to study medications
* Haemoglobin \< 8g/dL)
* Started menstruation
* Pregnancy or breastfeeding
* Primaquine taken within the last 4 weeks
* Blood transfusion within the last 90 days
* Non-falciparum malaria co-infection
B: Inclusion Criteria:

1. Age \> 2 years and \<15 years
2. Weight over 10kg
3. P. falciparum parasitaemia \>1,000 parasites and \<200,000 parasites/µl
4. P. falciparum gametocytes detected by microscopy
5. Normal G6PD enzyme function
6. Informed consent by legally acceptable representative

Exclusion Criteria:

1. Enrolled in another study
2. Fever or history of fever in the last 24 hours
3. Evidence of severe illness/ danger signs
4. Known allergy to study medications
5. Hb \< 8g/dL
6. Started menstruation
7. Pregnancy or breastfeeding
8. Antimalarials taken within the last 2 days
9. Primaquine taken within the last 4 weeks
10. Blood transfusion within the last 90 days
11. Non-falciparum malaria co-infection
C: Inclusion criteria:

* Acute, uncomplicated P.falciparum malaria, microscopically confirmed infection.
* Temperature at screening of 37.5oC or over or confirmed history of fever within previous 24-hours.
* Weight 7.5kg or over , no upper weight limit.
* Screening haemoglobin (Hb) of 7g/dl, or more or haematocrit of 25% or over(if Hb not available at screening).
* Willingness to comply with the study visits and procedures, as outlined in the informed consent form.
* Written or oral witnessed consent obtained from subject, parent or guardian.
* Assent is given by a child aged 12 to \<18years, in addition to the consent of their parent or guardian.

Exclusion criteria:

* Features of severe/complicated falciparum malaria.
* Hypersensitivity to active substances (chlorproguanil, dapsone, artesunate), or excipients of the investigational products.
* Known allergy to biguanides, sulphones, sulphonamides or artemisinin derived products.
* Known history of G6PD deficiency.
* Infants with a history of hyperbilirubinaemia during the neonatal period.
* Evidence of any concomitant infection at the time of presentation (including P. vivax, P. ovale and P. malariae).
* Use of concomitant medications that may induce haemolysis or haemolytic anaemia from the WHO (World Health Organization) list of essential drugs.
* Any other underlying disease that may compromise the diagnosis and the evaluation of the response to the study medication (including clinical symptoms of immunosuppression, tuberculosis, bacterial infection; cardiac or pulmonary disease).
* Malnutrition, defined as a child whose weight-for-height is below -3 standard deviations or less than 70% of the median of the NCHS/WHO normalised reference values
* Treatment within the past three months with mefloquine or mefloquine-sulphadoxine-pyrimethamine; twenty-eight days with sulphadoxine/pyrimethamine, sulfalene/pyrimethamine, lumefantrine or artemether/lumefantrine, amodiaquine, atovaquone or atovaquone/proguanil, halofantrine; 14-days with chlorproguanil/dapsone, or 7-days with quinine (full course), proguanil, artemisinin, tetracycline doxycycline or clindamycin.
* Positive sulphadoxine/pyrimethamine urine screen for 'unknown' antimalarial drug use in prior 28-days.
* Use of an investigational drug within 30 days or 5 half-lives whichever is the longer.
* Previous participation in this study.
* Female subjects of child-bearing potential who have had a positive pregnancy test at enrolment, or do not give their consent to take a pregnancy test.
* Female subjects who will be breast-feeding an infant for the duration of the study.
D: Inclusion Criteria:

* age ≥ 4 years old
* parasite count ≥ 1,000 asexual parasites/µL
* normal glucose-6-phosphate dehydrogenase enzyme level based on qualitative test (Trinity Biotech® no 203, USA)
* hemoglobin level ≥ 8 gr/dL as measured by Hemoque® apparatus;
* have the ability to return for 42-day-follow up and
* willingness to sign the informed-consent form.

Exclusion Criteria:

* are infected with other r plasmodium species
* have only gametocytes of P. falciparum;
* are pregnant - measured by positive result on HCG urine test and/or breastfeeding women
* present signs of pitting edema on both legs as a sign of malnutrition
* have complicated or severe malaria, other chronic diseases or history of drug allergies.

Answer: B