Resumen

MARTINEZ, Eddy et al. Recurrent parasitaemia in infections by Plasmodium vivax treated with chloroquine in the Amazon of Bolivia. Cuad. - Hosp. Clín. [online]. 2009, vol.54, n.2, pp. 108-117. ISSN 1652-6776.

A study was carried out of the efficacy of chloroquine in the treatment of the uncomplicated malaria by Plasmodium vivax. The work was carried out in the sentinel site of Riberalta, Beni wich is located in the Amazon region of Bolivia. The standardized methodology of PAHO/WHO was used for the evaluation in vivo of the antimalarial drug's efficacy. The study included sixty-three patients with malaria due to P. vivax, and all received treatment under strict supervision based in chloroquine 25mg base for kg, allocated in 3 days (first day 10mg/Kg, second and third days 7,5mg/Kg). Follow-up of the patients was carried out throughout 28 days, including both clinical and parasitological evaluations. Blood samples were collected to measure the chloroquine and desethylchloroquine levels and to genotyping malaria parasites. Out of 63 patients enrolled in the study 57 were successfully monitored throughout the entire 28 days. By microscopy, late recurrent parasitaemia was detected in 9 patients (15.5%), eight by day twenty-eight, and one in day twenty-one, the last one was excluded from the study by alcoholic. The patients received a second treatment based on chloroquine (same dosage), and in all cases the parasitaemia disappeared. One patient however, presented a new recurrence by day 28, and received combined therapy based on mefloquine (12mg/Kg day for 2 days) and artesunate (4mg/Kg day for 3 days), with a clinical and parasitological cure recorded. In 4 cases the recurrent parasitaemia was confirmed by PCR that also identified that the recurrent strains were the same that of the day 0 for all patients. Based on these results, Bolivian Ministry of Health and Sports, maintains the use of the chloroquine plus primaquine for the treatment of the infections for P. vivax. However, a second course of treatment with the same scheme was included, and in case of recurrent or persistent parasitaemia occurring afterthe second treatment (considering the possibility of chloroquine-resistance), an inclusion in the Bolivian Policy of Medicaments was made, as second line, the combined therapy based on mefloquine and artesunate, complemented with primaquine. Future studies are required to define the reasons for the recurrent parasitaemia by P. vivax in the Bolivian Amazon.

Palabras llave : Plasmodium vivax; recurrent parasitaemia; chloroquine-resistance; chloroquine; treatment; Amazon; Bolivia.