Effectiveness of Malaria Treatment in Mexico

• Status: Completed
• Trial end date: 2010-09-01
• Target enrollment: 0
• Participant gender: All

Summary

In the context of malaria elimination in the Americas, solid evidence is necessary of the effectiveness of anti-malarial control measures delivered to the affected individuals. In the Americas, most P. vivax infections are sensitive to Chloroquine (CQ) and Primaquine (PQ), and the most effective treatment worldwide comprises administration of a total dose of 25 milligrams (mg)/Kilogram (kg) weight of CQ distributed in three days and 3.5 mg/kg body weight of PQ administered during 14 days (T14). In Mexico, CQ and PQ have been administered since the late 50´s to treat malarious patients. In 1999 the National Malaria Control Program implemented an intermittent single doses treatment (ISD) as part of the overall strategy. After the blood sample was obtained for diagnosis of symptomatic patients, a single combined dose of CQ and PQ was administered, and after malaria infection confirmation, additional doses were administered monthly alternating each three months, during 3 years. Although, the number of malaria cases were reduced in most affected regions, in Southern México, many patients under ISD present recurrent blood infections, presumably relapse episodes were observed.

Working hypothesis: the administration of ISD is low effective to eliminate relapse episodes and its effectiveness depends on the coincidence of the relapse episodes and the administration of the medication), while the T14 is highly effective to eliminate P. vivax primary and relapse infections.

Objective: To determine the antimalarial drug effectiveness of the ISD and T14, based on CQ and PQ for the treatment of uncomplicated P. vivax infection (primary and recurrent blood infections) in Southern Mexico.

Methods: The study was carried out in malaria affected communities of Southern Mexico, following the WHO recommendations for clinical studies. Symptomatic patients diagnosed with P. vivax infection that meet the inclusion criteria, were invited to participate. After they accepted by informed consent, patients were semi-randomized and treated with either T14 (14-day treatment) or ISD (18 intermittent single doses of CQ-PQ). Clinical, parasitological, molecular and serological parameters were monitor over a 12-month follow up period to evaluate the treatment outcomes to cure blood infection and relapsing episodes. The study was conducted from February-2007 to October-2010. The results of this study will be used to assist the Ministry of Health of México in assessing the current national treatment guidelines for uncomplicated P. vivax malaria

• Phase: Phase 4
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: LILIA GONZALEZ CERON
• Collaborators: Centro Nacional de Vigilancia Epidemiológica y control de enfermedades (CENAVECE), Mexico; Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE), Mexico; Jurisdicción Sanitaria VII, Chiapas, México; Pan American Health Organization
• Treatments: Chloroquine; Chloroquine diphosphate; Primaquine

Criteria

Inclusion Criteria: Recommended by WHO, http://whqlibdoc.who.int/publications/2010/9789241547925_eng.pdf?ua=1

1. - Confirmed P. vivax mono- infection by microscopy

2. - Parasitemia, minimum of 500 asexual parasites per µl of blood.

3. - Presence of axillary temperature ≥ 37.5 or history of fever during the past 48 hours

4. - Ability to swallow oral medication

5. - Informed consent from the patient, or from the parent or guardian in the case of children under 7 years old, or both consents by participant and parent for individual´s age ranging within 7 and 18 years old.

6. - Ability and willingness to comply with the study protocol for the duration of the study and to comply with the study visit schedule.

7. -Patients living in accessible villages, desirable less than 1 hour far from our facility by car.

Exclusion Criteria:

1. - Mixed species infection with another plasmodium species

2. - Presence of signs of danger, or severe malaria, according to the definitions of WHO http://whqlibdoc.who.int/publications/2010/9789241547925_eng.pdf?ua=1

3. - if they presented signs of severe malnutrition or anemia

4. - had taken an anti-malaria treatment or had a malaria infection within the previous two months.

5. - Pregnant woman or positive pregnant test or breast feeding

6. - History of hypersensitivity to CQ or PQ

7. - Previous malaria attack within one year, identified at the malaria nominal record, sanitary jurisdiction VII of Chiapas, Mexico.

8. - had another cause for their fever or other chronic diseases as hypertension, diabetes, liver or kidney disease, etc.

9. - if they lived in communities at distances farther than one hour by motor vehicle from the facility.