Assessment of therapeutic response of Plasmodium falciparum to chloroquine and sulfadoxine-pyrimethamine in an area of low malaria transmission in Colombia.

Abstract

Abstract. Although chloroquine (CQ) resistance was first reported in Colombia in 1961 and sulfadoxine-pyrimethamine (SP) resistance in 1981, the frequency of treatment failures to these drugs in Colombia is unclear. A modified World Health Organization 14-day in vivo drug efficacy test for uncomplicated Plasmodium falciparum malaria in areas with intense malaria transmission was adapted to reflect the clinical and epidemiologic features of a low-intensity malaria transmission area in the Pacific Coast Region of Colombia. Patients Ն1 year of age with a parasite density Ն1,000 asexual parasites per microliter were enrolled in this study. Forty-four percent (24 of 54) of the CQ-treated patients were therapeutic failures, including 7 early treatment failures (ETFs) and 17 late treatment failures (LTFs). Four (6%) of 67 SP-treated patients were therapeutic failures (2 ETFs and 2 LTFs). Therapeutic failure in the CQ-treated group was associated with an age Ͻ15 years old (P Ͻ 0.01), but was not associated with initial parasite density, the presence of CQ or sulfa-containing drugs in urine, or a history of malaria. The high level of therapeutic failures to CQ detected in this study underscores the need and importance of drug efficacy evaluation in the development of a rational national antimalarial drug policy. The relatively low level of therapeutic failures to SP compared with other South American countries raises further questions regarding factors that might have prevented the rapid development of in vivo resistance to this drug combination.Despite attempts at eradication, malaria remains a major public health problem in Colombia. During 1997, 180,910 malaria cases were reported to the Ministry of Health, of which 36% were caused by Plasmodium falciparum. The administrative departments of Chocó, Valle, Cauca, and Nariño on the Pacific coast accounted for 45% of the P. falciparum malaria cases diagnosed in 1997 in Colombia.Since 1961, when chloroquine (CQ) resistance was first reported in Colombia, 1 several studies have confirmed CQ and sulfadoxine-pyrimethamine (SP) resistance both in vivo and in vitro. [2][3][4] In 1986, the National Malaria Control Program recommended a combination of CQ plus SP with a single-dose of primaquine (as a gametocidal agent) for the treatment of uncomplicated P. falciparum infection in areas without CQ resistance, and amodiaquine plus SP and primaquine for areas with CQ resistance. Although the national treatment policy differentiates areas with and without resistance to CQ, few studies have attempted to elucidate the distribution and magnitude of CQ resistance in Colombia.The objective of our study was to determine the frequency of therapeutic failures to CQ and SP in patients with uncomplicated P. falciparum infection, using a 14-day in vivo test in an area of low intensity transmission in the northern Pacific coast of Colombia. At the same time, the study was used to train personnel from the Ministry of Health and regional malaria control programs from 3 Departments of Colombia in t...

Estudio piloto de la eficacia y de los efectos sobre los gametocitos del esquema artesunato-mefloquina-primaquina para la malaria por Plasmodium falciparum

“…Las tasas de curación con este medicamento han disminuido drásticamente con reportes de falla hasta de 97% en el departamento de Antioquia (7) y hasta 70% en la costa Pacífica (8). En 2006, Blair y colaboradores reportaron cifras de falla a todos los medicamentos usados como monoterapia: a la cloroquina de 82%, a la sulfadoxina-pirimetamina de 24,1%, a la amodiaquina de 30,3%, a la mefloquina de 4,4% y a las combinaciones cloroquina más sulfadoxinapirimetamina (17,2%), artesunato más sulfadoxina-pirimetamina (3,4%), amodiaquina más sulfadoxina-pirimetamina (2,2%).…”

Nuevas alternativas terapéuticas para el manejo de la malaria

“…Sin embargo, pareciera que éste no es el comportamiento de la respuesta terapéutica en todo el país y específicamente en la Costa Pacífica colombiana donde hay informes de alta falla terapéutica para esquemas de amodiaquina y sulfadoxina-pirimetamina (15 …”

Eficacia de la combinación amodiaquina más sulfadoxinapirimetamina y de la cloroquina para el tratamiento del paludismo en Córdoba, Colombia, 2006

“…En Colombia, los altos porcentajes (44% a 97%) de fallas terapéuticas encontrados en los estudios de eficacia de la cloroquina como monoterapia o en combinación con sulfadoxina-pirimetamina para el tratamiento del paludismo no complicado por P. falciparum, realizados entre 1997 y 2000 en la costa del Pacífico y en Antioquia (7)(8)(9)(10)(11), llevaron al Ministerio de Salud a cambiar, a partir del año 2000, el esquema de tratamiento de primera línea para P. falciparum por la combinación amodiaquina más sulfadoxina-pirimetamina (12), esquema actualmente vigente.…”