Antecedentes. En Colombia existen pocos estudios que buscan encontrar diferencias clínicas y parasitológicas en la malaria causada por Plasmodium falciparum y Plasmodium vivax. Objetivo. Describir el perfil clínico y parasitológico de las malarias por Plasmodium falciparum y Plasmodium vivax no complicadas en Tierralta, Córdoba, Colombia. Materiales y métodos. Se evaluaron pacientes con paludismo no complicado por Plasmodium falciparum y Plasmodium vivax según los protocolos estandarizados por la Organización Panamericana de la Salud y se recolectó información clínica y parasitológica. De igual forma, se utilizó análisis multivariado por correspondencias múltiples para describir diferentes perfiles de pacientes con paludismo no complicado por estas dos especies antes de recibir tratamiento. Resultados. Se evaluaron 112 pacientes con edad entre 6 y 64 años, 59 (52.7%) con Plasmodium falciparum y 53 (47.3%) con Plasmodium vivax. Los síntomas más frecuentes fueron fiebre en 111 pacientes (99.1%; IC 95%: 81.5-100), sudoración en 105 (93.8%; IC 95%: 76.7-100) y dolor osteomuscular en 105 (93.8%; IC 95%: 76.7-100). Se presentaron con mayor frecuencia, y con diferencia significativa, en las infecciones por Plasmodium falciparum: diarrea en 18 pacientes (30.5%; IC 95%: 18.1-48.2); decaimiento en 49 (83%; IC 95%: 61.4-109.8); palidez palmar en 39 (66.1%; IC 95%: 47-90.4) y sequedad de mucosas en 12 (20.3%; IC 95%: 10.5-35.5). El escalofrío se presentó con mayor frecuencia en Plasmodium vivax (98.1%; IC 95%: 73.4-128.1). El análisis multivariado agrupó las variables en cuatro perfiles distintos de presentaciones clínicas así: 1) síntomas clínicos y su relación con el recuento parasitario, 2) características clínicas en relación con la edad y sexo, 3) antecedentes de malaria en relación con características demográficas y clínicas y 4) especie del parásito en relación con antecedentes, clínica y variables demográficas. Conclusión. Se identificaron algunas diferencias clínicas entre los enfermos con Plasmodium vivax y los enfermos con Plasmodium falciparum, y las variables estudiadas se agruparon en cuatro perfiles que permiten una variedad de interpretaciones.

Background. There are few studies in Colombia that have aimed at finding clinical and parasitological differences between Plasmodium falciparum and Plasmodium vivax malaria. Objective. To describe the clinical and parasitological profile of non-complicated malaria caused by Plasmodium falciparum and Plasmodium vivax in Tierralta, Cordoba, Colombia. Materials and Methods. Patients with non-complicated malaria caused by Plasmodium falciparum and Plasmodium vivax were evaluated according to standardized protocols recommended by the Pan American Health Organization. Both clinical and parasitological information was collected. A multiple correspondence multivariate analysis was used to describe the different profiles of patients suffering non-complicated malaria caused by these two species before the administration of the required treatment. Results. One hundred and twelve patients aged 6 to 64 were evaluated, 59 (52.7%) suffering Plasmodium falciparum malaria and 53 (47.3%), Plasmodium vivax malaria. The most frequent symptoms were fever in 111 (99.1%; 95% CI: 81.5- 100), sweating in 105 (93.8%; 95% CI: 76.7-100) and musculoskeletal pain in 105 (93.8%; IC 95%: 76.7-100). Regarding the Plasmodium falciparum infections there was a higher frequency, with significant difference, in the following clinical manifestations: diarrhea: 18 patients (30.5%; 95%: 18.1-48.2); asthenia: 49 patients (83%; 95% CI: 61.4-109.8); palmar pallor: 39 patients (66.1%; 95% CI: 47-90.4); mucosal dryness: 12 patients (20.3%; 95%CI: 10.5-35.5). The chills appeared with higher frequency in Plasmodium vivax malaria (98.1%; 95%CI: 73.4-128.1). The multivariate analysis grouped the variables into four different profiles of clinical presentations: Clinical symptoms and their relation to the parasite count; clinical characteristics in relation to age and sex; history of malaria regarding demographic and clinical characteristics; and parasite species in relation to historic, clinical and demographic variables. Conclusions. Some clinical differences between patients with Plasmodium vivax and patients with Plasmodium falciparum were identified and the studied variables were grouped into four profiles which allow for a variety of interpretations.

The present study developed and standardized an enzime-linked immunosorbent assay (ELISA) to detect Giardia antigen in feces using rabbit polyclonal antibodies. Giardia cysts were purified from human fecal samples by sucrose and percoll gradients. Gerbils (Meriones unguiculatus) were infected to obtain trophozoites. Rabbits were inoculated with either cyst or trophozoite antigens of 14 Colombian Giardia isolates to develop antibodies against the respective stages. The IgG anti-Giardia were purified by sequential caprylic acid and ammonium sulfate precipitation. A portion of these polyclonal antibodies was linked to alkaline phosphatase (conjugate). One hundred and ninety six samples of human feces, from different patients, were tested by parasitologic diagnosis: 69 were positive for Giardia cysts, 56 had no Giardia parasites, and 71 revealed parasites other than Giardia. The optimal concentration of polyclonal antibodies for antigen capture was 40 µg/ml and the optimal conjugate dilution was 1:100. The absorbance cut-off value was 0.24. The parameters of the ELISA test for Giardia antigen detection were: sensitivity, 100% (95% CI: 93.4-100%); specificity, 95% (95% CI: 88.6-97.6%); positive predictive value, 91% (95% CI: 81.4-95.9%); and negative predictive value, 100% (95% CI: 96.1-100%). This ELISA will improve the diagnosis of Giardia infections in Colombia and will be useful in following patients after treatment.