Evaluating the Role of Chloroquine for Malaria Elimination

• Status: Completed
• Trial end date: 2015-06-01
• Target enrollment: 0
• Participant gender: Male

Summary

One of the proposed ideas for malaria elimination includes the use of drugs to interrupt malaria transmission by exhausting the human reservoir of infection. Theoretically, mass treatment of an entire population with a very effective and rapid-acting drug (for instance an ACT), followed by the administration of an effective prophylactic regime during a minimum of four weeks, so as to outlast the typical development period of Plasmodium parasites in Anopheline mosquitoes, could achieve the same objective. In this respect, chloroquine (CQ) would be an appropriate candidate. This drug exhibits two conditions that make it attractive for elimination campaigns: 1) It has been demonstrated to have an excellent safety profile, allowing for its use in all age groups including pregnant women and children; and 2) Its relatively long elimination half life (t1/2=1-2 months) can provide a long post-treatment prophylactic effect. Recent evidence suggests that CQ sensitivity may be returning in places where discontinuation has reduced the drug pressure to the parasite populations. In countries such as Malawi, P. falciparum seems to have regained full sensitivity to CQ, and molecular markers of antiCQ resistance have nearly disappeared. While this does not support the reintroduction of CQ as first line therapy, it does suggest that, if proven sensitive in a given area, it could play a prophylactic role in malaria elimination strategies when used in combination with other drugs or tools. Thus, we intend to evaluate the potential role of chloroquine in preventing infections during elimination campaigns by performing a randomized, single-blind, placebo-controlled trial in asymptomatic Mozambican adults.

Choosing asymptomatic parasitaemic adult males from a malaria-endemic area as our study population introduces limited risks when administering a drug with an uncertain efficacy (47% efficacious in 2001-2002). In malaria-endemic areas, this age group has a remarkably low risk of developing severe disease (irrespective of clinical symptoms), and it is foreseeable that parasitemia may be well tolerated, and in certain cases, spontaneously cleared from the individual's blood as a result of the immune system. In the unlikely event of any clinical symptomatology appearing throughout the follow-up, individuals will be examined by a study clinician and treated immediately with the country's first-line malaria treatment (artemether-lumefantrine, Coartem ®).

• Phase: Phase 2/Phase 3
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Centro de Investigacao em Saude de Manhica
• Treatments: Chloroquine; Chloroquine diphosphate

Criteria

Inclusion Criteria:

• Male individuals

• P. falciparum infection detected by microscopy (Minimum 250 parasites/microliter; Maximum 10.000parasites/microliter)

• Ability to swallow oral medication

• Ability and willingness to comply with the study protocol for the duration of the study and to comply with the study visit schedule; and

• Informed consent from the participant individual

Exclusion Criteria:

• Age <18 years

• Female individuals

• Axillary temperature >=37.5ºC

• Presence of any other co-existing clinical condition that in the opinion of the recruiting physician would not allow the individual to be considered a "healthy" asymptomatic carrier

• Regular medication which may interfere with antimalarial efficacy or antimalarial pharmacokinetics, such as Cotrimoxazole

• History of hypersensitivity reactions or contraindications to CQ

• Known HIV positive patients in treatment with antiretrovirals