Studies on gestational malaria and placental malaria have been scarce in malaria-endemic areas of the Western Hemisphere. To describe the histopathology of placental malaria in Colombia, a longitudinal descriptive study was conducted. In this study, 179 placentas were studied by histologic analysis (112 with gestational malaria and 67 negative for malaria). Placental malaria was confirmed in 22.35%, 50.0% had previous infections, and 47.5% had acute infections. Typical malaria-associated changes were observed in 37%. The most common changes were villitis, intervillitis, deciduitis, increased fibrin deposition, increased syncytial knots, mononuclear (monocytes/macrophages and lymphocytes), polymorphonuclear cell infiltration, and trophozoites in fetal erythrocytes. No association was found between type of placental changes observed and histopathologic classification of placental malaria. The findings are consistent with those reported for placental malaria in other regions. Plasmodium vivax was the main parasite responsible for placental and gestational malaria, but its role in the pathogenesis of placental malaria was not conclusive.

Background: The frequency of pregnancy-associated malaria is increasingly being documented in American countries. In Colombia, with higher frequency ofPlasmodium vivaxoverPlasmodium falciparuminfection, recent reports confirmed gestational malaria as a serious public health problem. Thick smear examination is the gold standard to diagnose malaria in endemic settings, but in recent years, molecular diagnostic methods have contributed to elucidate the dimension of the problem of gestational malaria. The study was aimed at exploring the prevalence of gestational, placental and congenital malaria in women who delivered at the local hospitals of north-west Colombia, between June 2008 and April 2011.Methods: A group of 129 parturient women was selected to explore the prevalence of gestational, placental and congenital malaria in a descriptive, prospective and transversal (prevalence) design. Diagnosis was based on the simultaneous application of two independent diagnostic tests: microscopy of thick blood smears and a polymerase chain reaction assay (PCR).Results: The prevalence of gestational malaria (thick smear /PCR) was 9.1%/14.0%; placental malaria was 3.3%/16.5% and congenital malaria was absent. A history of gestational malaria during the current pregnancy was significantly associated with gestational malaria at delivery.Plasmodium vivaxcaused 65% of cases of gestational malaria, whereasP. falciparumcaused most cases of placental malaria.Conclusions: Gestational and placental malaria are a serious problem in the region, but the risk of congenital malaria is low. A history of malaria during pregnancy may be a practical indicator of infection at delivery.

Objective: Evaluate the frequency of failure of eight treatments for non-complicated malaria caused byPlasmodium falciparumin patients from Turbo (Urabá region), El Bagre and Zaragoza (Bajo Cauca region), applying the 1998 protocol of the World Health Organization (WHO). Monotherapies using chloroquine (CQ), amodiaquine (AQ), mefloquine (MQ) and sulphadoxine-pyrimethamine (SP), and combinations using chloroquine-sulphadoxine-pyrimethamine (CQ-SP), amodiaquine-sulphadoxine-pyrimethamine (AQ-SP), mefloquine-sulphadoxine-pyrimethamine (MQ-SP) and artesunate-sulphadoxine-pyrimethamine (AS-SP), were examined.Methodology: A balanced experimental design with eight groups. Samples were selected based on statistical and epidemiological criteria. Patients were followed for 21 to 28 days, including seven or eight parasitological and clinical evaluations, with an active search for defaulting patients. A non-blinded evaluation of the antimalarial treatment response (early failure, late failure, adequate response) was performed.Results: Initially, the loss of patients to follow-up was higher than 40%, but the immediate active search for the cases and the monetary help for transportation expenses of patients, reduced the loss to 6%. The treatment failure was: CQ 82%, AQ 30%, MQ 4%, SP 24%, CQ-SP 17%, AQ-SP 2%, MQ-S-P 0%, AS-SP 3%.Conclusion: The characteristics of an optimal epidemiological monitoring system of antimalarial treatment response in Colombia are discussed. It is proposed to focus this on early failure detection, by applying a screening test every two to three years, based on a seven to 14-day follow-up. Clinical and parasitological assessment would be carried out by a general physician and a field microscopist from the local hospital, with active measures to search for defaulter patients at follow-up.

Introducción: en Colombia se ignora la frecuencia de malarias gestacional (MG), congénita (MC) y placentaria (MP) y la mortalidad asociada a ellas, así como el cuadro clínico de la MG. Objetivos: calcular la prevalencia e incidencia de MG, MP y MC, la mortalidad por MG y MC, y describir y comparar entre mujeres con y sin MG, los síntomas, signos y las características de la MG. Metodología: estudio descriptivo con componente longitudinal (cohorte) y transversal, con gestantes de 15 a 44 años, sus placentas e hijos. Las gestantes se captaron en las consultas prenatales y salas de parto de tres municipios de Urabá (Antioquia, Colombia), entre 2005 y 2007. Resultados: se captaron 2117 gestantes: a) cohorte: n=1927 mujeres con mínimo dos exámenes de gota gruesa; b) grupo transversal: n=190 mujeres con solo un examen de gota gruesa (en consulta prenatal o en parto). Hubo 220 casos de MG. Según la gota gruesa para Plasmodium las frecuencias fueron: prevalencia MG: 10,39%; proporción de incidencia MG: 9,28%; tasa de incidencia de MG: 9,01 por 100 mujeres/semana; proporción MC: 2,7%; prevalencia de MP: 11,7%. P. vivax causó 76% de MG, P. falciparum 22%, ambas especies 2%. Los síntomas y signos hallados en las gestantes con MG concordaron con los referidos para gestantes y no gestantes. No hubo muertes entre las 220 gestantes que presentaron malaria ni entre los cinco niños que presentaron MC. Conclusiones: las frecuencias de MG, MC y MP indican que esas entidades son problemas de salud pública en la población de gestantes y neonatos de Urabá.

A large-scale study was set up in order to study the epidemiology, clinical aspects, and immunopathology of gestational and placental malaria in north-west Colombia. In this region, recent reports using a qPCR technique, confirmed frequencies of infection, by Plasmodium falciparum or Plasmodium vivax, up to 45%. Given the high rates of infection observed both in mother and placenta, a first exploratory study was proposed in order to characterize the effect on the inflammation status, tissue damage and hypoxia in Plasmodium spp. infected placentas.

ANTECEDENTES: La malaria gestacional es causa importante de morbi-mortalidad materno-infantil y puede transcurrir con parasitemias no detectadas con microscopía; además, por la diversidad genética parasitaria, es común encontrar infecciones policlonales. OBJETIVOS: Conocer la frecuencia de infecciones submicroscópicas (ISM) y/o policlonales (IP) durante la gestación y analizar el impacto que tienen en la presentación clínica y el desarrollo de inmunidad y sus consecuencias en la madre y el producto de gestación. METODOLOGÍA: Se hizo búsqueda en Medline con los términos (MeSH) "pregnancy", "malaria", "PCR", "microscopy", "genotype", "clones". Se seleccionaron los estudios que diagnosticaron la infección por microscopía y PCR. RESULTADOS: Se incluyeron 16 estudios, todos realizados en África. El promedio ponderado (PP) de ISM en el total de mujeres fue del 36% y según fuese la infección microscópica (IM), submicroscópica o negativa, los PP de anemia materna y bajo peso al nacer (BPN) fueron 51%, 42% y 33% y 19%, 16% y 11%, respectivamente. Con referencia al grupo sin infección, los riesgos (OR) fueron: a) para anemia materna 2,12 en IM y 1,48 en ISM; b) para BPN 1,89 en IM y 1,56 en ISM. El PP de IP fue 75% y el promedio de clones por muestra fue tres. CONCLUSIONES: Las ISM y policlonales con P. falciparum son muy comunes durante la gestación, pero poco estudiadas y su impacto debe evaluarse en cada región, porque depende de la intensidad y estabilidad de la transmisión, la edad y paridad maternas, entre otras variables, que son influenciadas por las condiciones socioeconómicas y ambientales específicas.