Performance of the hematology analyzer XN-31 prototype in the detection of Plasmodium infections in an endemic region of Colombia.

Early and accurate diagnosis is critical in reducing the morbidity and mortality associated with malaria. Microscopy (MI) is the current diagnostic gold standard in the field; however, it requires expert personnel, is time-consuming, and has limited sensitivity. Although rapid diagnostic tests for antigen detection (RDTs) are an alternative to diagnosis, they also have limited sensitivity and produce false positive results in detecting recent past infection. The automated hematology analyzer XN-31 prototype (XN-31p) (Sysmex Corporation, Kobe, Japan) is able to identify plasmodium-infected erythrocytes, count parasitemia and perform complete blood-cell counts within one minute. The performance of the XN-31p in diagnosing malaria was evaluated and compared with real-time polymerase chain reaction (qPCR), MI and RDT in an endemic area of Colombia where Plasmodium falciparum and Plasmodium vivax are present. Acute febrile patients were enrolled from July 2018 to April 2019 in Quibdó, Colombia. Malaria diagnoses were obtained from MI and RDT in the field and later confirmed by qPCR. Venous blood samples in EDTA were processed with an XN-31p in the field. Sensitivity, specificity, positive/negative predictive values, and the likelihood ratios of positive and negative tests were calculated with respect to the results from qPCR, MI and RDT. The intraclass correlation coefficient (ICC) and Bland-Altman plot were used to evaluate the concordance in the parasitemia with respect to MI. A total of 1,754 subjects were enrolled. The mean age was 27.0 years (IQR 14-44); 89.6% were Afro-Colombians, 94.3% lived in urban areas and 0.91% were pregnant. With respect to qPCR, the XN-31p showed a sensitivity of 90% (95% CI 87.24-92.34) and a specificity of 99.83% (95% CI 99.38-99.98) in detecting Plasmodium spp.; both parameters were equivalent to those for MI and RDT. Using MI as the reference, the XN-31p showed a sensitivity of 98.09% (95% CI 96.51-99.08), a specificity of 99.83% (95% CI 99.4-99.98), an ICC of 0.85 (95% CI 0.83-0.87) and an average difference of - 3096 parasites/µL when compared with thick-smear MI and an ICC of 0.98 (95% CI 0.97-0.98) and an average difference of - 0.0013% when compared with thin-smear MI. The XN-31p offers a rapid and accurate alternative method for diagnosing malaria in clinical laboratories in areas where P. falciparum and P. vivax cocirculate.

Associated factors to self-medication with drugs related to COVID-19 in health science students from a peruvian city / Factores asociados a la automedicación con fármacos relacionados a COVID-19 en estudiantes de ciencias de la salud de una ciudad peruana

Objectives: To determine the factors associated with self-medication with drugs related to COVID-19 in health sciences students. Materials and methods: Observational, analytical, cross-sectional study in students of the health sciences of Tacna-Peru. Through a virtual survey, socio-educational variables, practices, self-medication characteristics and exposure to COVID-19 were recognized. The result was self-medication in the last 3 months with at least 1 in 14 drugs. The prevalence ratios were calculated using generalized linear models. Results: Of the 718 students, 51.3% live on self-medication. 62.2% self-medicated because they presented the highest number of respiratory symptoms and the drugs used more antipyretics, analgesics and corticosteroids. Students with a sentimental partner (PR: 1.33; 95% CI: 1.16-1.53), from a private university (PR: 1.36; 95% CI: 1.10- 1.69), that the priests in his family have a picnic a few times (PR: 2.34, 95% CI: 1.58-3.47) and in which a program sized for COVID-19 (PR : 1.47, 95% CI: 1.14-1.89). Conclusion: We found a high prevalence of self-medication. Most of them have self-medication that has a sentimental partner, from a private university, that their priests or relatives are on selfpicnic and that they have a size problem due to COVID-19, which they could use to promote the rational use of medications.

Objetivos: Determinar los factores asociados a la automedicación con fármacos relacionados con COVID-19 en estudiantes de ciencias de la salud. Material y métodos: Estudio observacional, analítico transversal, en estudiantes de ciencias de la salud de Tacna-Perú. Mediante un cuestionario virtual se recolectaron variables socioeducativas, prácticas, características de automedicación y exposición a COVID-19. El resultado fue automático en los últimos 3 meses con al menos 1 de 14 fármacos. Se calcularon las razones de prevalencia mediante los modelos lineales generalizados. Resultados:De los 718 estudiantes, el 51,3% se había automedicado. 62,2% se automedicó por presentar dos o más síntomas respiratorios siendo los fármacos más utilizados los antipiréticos, analgésicos y corticoides. Tuvieron mayor frecuencia de automedicación los estudiantes con pareja sentimental (RP: 1,33; IC95%: 1,16-1,53), de una universidad particular (RP: 1,36; IC95%: 1,10-1,69 ), que sus padres o familiares se automediquen algunas veces o siempre (RP: 2,34; IC95%: 1,58­3,47) y en los que se realizaron una prueba de tamizaje para COVID-19 (RP: 1, 47; IC95%: 1,14-1,89). Conclusiones:Encontramos una alta prevalencia de automedicación. Tuvieron mayor frecuencia de automedicación quienes tenían una pareja sentimental, proceden de una universidad particular, que sus padres o familiares se automediquen y en quienes se realizaron una prueba de tamizaje para COVID-19, lo cual podría ser utilizado para promover el uso racional de medicamentos .

Relaxation with heat and procedural information to diminish anxiety in presurgical patients of hernia surgery.

Presurgical anxiety has been associated with postsurgical pain and complications, therefore we decided to compare two psychological interventions in order to reduce presurgical anxiety-state and pain in patients undergoing hernia surgery. Patients undergoing the presurgical consultation for hernia repair (umbilical or inguinal), were invited. The group of procedural information consisted in administering an informative brochure after the presurgical consultation, while the relaxation with heat group (RWH) consisted in giving a heat pack to the patients while asking them to think in the benefits of the surgery and instructions of relaxation were given, this was performed at the operating theater before surgery. Anxiety-state and pain levels were measured after presurgical consultation and a day after just before surgery. Ninety-five patients were included in 3 groups of study (control = 36, procedural information = 31 and RWH = 28); when we included only those individuals with moderate or high anxiety at the presurgical consultation, we found that procedural information (-4.72 ± 6.10) and RWH diminished anxiety (-9.29 ± 6.91) but only RWH group reached statistical significance when compared with control group (-9.29 ± 6.91 vs -0.56 ± 9.82, p = 0.007). In conclusion, RWH produced a significantly higher reduction of anxiety-state before hernia surgery.

Novel antimalarial chloroquine- and primaquine-quinoxaline 1,4-di-N-oxide hybrids: Design, synthesis, Plasmodium life cycle stage profile, and preliminary toxicity studies.

Emergence of drug resistance and targeting all stages of the parasite life cycle are currently the major challenges in antimalarial chemotherapy. Molecular hybridization combining two scaffolds in a single molecule is an innovative strategy for achieving these goals. In this work, a series of novel quinoxaline 1,4-di-N-oxide hybrids containing either chloroquine or primaquine pharmacophores was designed, synthesized and tested against both chloroquine sensitive and multidrug resistant strains of Plasmodium falciparum. Only chloroquine-based compounds exhibited potent blood stage activity with compounds 4b and 4e being the most active and selective hybrids at this parasite stage. Based on their intraerythrocytic activity and selectivity or their chemical nature, seven hybrids were then evaluated against the liver stage of Plasmodium yoelii, Plasmodium berghei and Plasmodium falciparum infections. Compound 4b was the only chloroquine-quinoxaline 1,4-di-N-oxide hybrid with a moderate liver activity, whereas compound 6a and 6b were identified as the most active primaquine-based hybrids against exoerythrocytic stages, displaying enhanced liver activity against P. yoelii and P. berghei, respectively, and better SI values than primaquine. Although both primaquine-quinoxaline 1,4-di-N-oxide hybrids slightly reduced the infection of mosquitoes, they inhibited sporogony of P. berghei and compound 6a showed 92% blocking of transmission. In vivo liver efficacy assays revealed that compound 6a showed causal prophylactic activity affording parasitaemia reduction of up to 95% on day 4. Absence of genotoxicity and in vivo acute toxicity were also determined. These results suggest the approach of primaquine-quinoxaline 1,4-di-N-oxide hybrids as new potential dual-acting antimalarials for further investigation.

Anti-plasmodial effect of plant extracts from Picrolemma huberi and Picramnia latifolia.

BACKGROUND: Malaria is an infectious disease caused by parasites of the genus Plasmodium, of which Plasmodium vivax and Plasmodium falciparum are the major species that cause the disease in humans. As there are relatively few alternatives for malaria treatment, it is necessary to search for new chemotherapeutic options. Colombia possesses a great diversity of plants, which are potential sources of new compounds of medical interest. Thus, in this study the antiplasmodial effect of extracts from two species of plants from the families Simaroubaceae and Picramniaceae (Picramnia latifolia and Picrolemma huberi) was evaluated in vitro and in vivo. These plants were chosen because they contain secondary metabolites with interesting medicinal effects. RESULTS: The ethanolic extracts of both species were highly active with IC50: 1.2 ± 0.19 µg/mL for P. latifolia and IC50: 0.05 ± 0.005 µg/mL for P. huberi. The P. latifolia extract had a stage specific effect on trophozoites and inhibited parasite growth in vivo by 52.1 ± 3.4%, evaluated at 1000 mg/kg in Balb/c mice infected with Plasmodium berghei. On the other hand, evaluated at 150 mg/kg body weight in the same murine model, the ethanolic extract from P. huberi had an antiplasmodial effect in all the asexual intraerythrocytic stages of P. falciparum FCR3 and inhibited the parasitic growth in 93 ± 32.9%. CONCLUSIONS: This is the first report of anti-malarial activity for these two species of plants. Thus, P. latifolia and P. huberi are potential candidates for the development of new drugs for treating malaria.

Huberine, a New Canthin-6-One Alkaloid from the Bark of Picrolemma huberi.

A new alkaloid, Canthin-6-one, Huberine (1), together with three known compounds including 1-Hydroxy-canthin-6-one (2), Canthin-6-one (3) and stigma sterol (4), were isolated from the stem bark of Picrolemma huberi. The isolation was achieved by chromatographic techniques and the purification was performed on a C18 column using acetonitrile/water (90:10, v/v) with 0.1% formic acid as the mobile phase. The structural elucidation was performed via spectroscopic methods, notably 1D- and 2D-NMR, UV, IR, MS and HRMS. The antiplasmodial activity of the compounds was studied.

Antiplasmodial and Cytotoxic Activity of Raw Plant Extracts as Reported by Knowledgeable Indigenous People of the Amazon Region (Vaupés Medio in Colombia).

The in vitro antiplasmodial activity of 122 raw extracts prepared in ethanol and water from 35 medicinal plants reported by the Cubeo indigenous village of the Amazon region (Vaupés Medio in Colombia) was evaluated for efficacy against 3D7 (sensitive to chloroquine) and FCR-3 (resistant to chloroquine) Plasmodium falciparum strains. Five percent of these extracts presented a significant antiplasmodial activity (< 5 µg/mL) and 83 % of them were not cytotoxic. These findings highlight the importance of investigating traditional medicinal plants implemented by these ancestral communities of the Amazon region as well as their potential to become a source of new drugs against malaria.

Diez años de eficacia terapéutica de la cloroquina en malaria no complicada por Plasmodium vivax , Turbo, Antioquia, años 2002 y 2011 / Ten years of chloroquine efficacy for uncomplicated Plasmodium vivax malaria treatment, Turbo, Antioquia, 2002 and 2011

Introducción. La eficacia terapéutica de los antipalúdicos debe ser vigilada permanentemente debido al problema de resistencia. En Colombia existen pocos estudios que evalúen la eficacia de la cloroquina en la malaria no complicada por Plasmodium vivax . Objetivo. Evaluar la respuesta terapéutica de la cloroquina en el tratamiento del paludismo no complicado por P. vivax en el año 2011 en Turbo, Antioquia, y comparar estos resultados con los del estudio realizado en el año 2002 en el mismo municipio. Materiales y métodos. Se llevaron a cabo dos estudios en los que se incluyeron 152 participantes (50 en el año 2002 y 102 en el año 2011), todos mayores de cinco años, con malaria no complicada e infección simple por P. vivax , según los criterios de la Organización Mundial de la Salud (OMS). Se evaluó la eficacia terapéutica de la cloroquina, según los protocolos vigentes de la Organización Panamericana de la Salud (1998) y la OMS (2009); se dio tratamiento estándar supervisado con 1.500 mg de cloroquina en tres días y se hizo seguimiento clínico y parasitológico los días 0, 1, 2, 3, 7, 14 y 21 en el año 2002 y, además, el día 28 en el año 2011. Al finalizar el seguimiento se suministró primaquina a una dosis diaria de 0,25 mg/kg durante 14 días en todos los participantes. Resultados. Los resultados clínico y parasitológicos fueron adecuados en el 100 % de los participantes de ambos estudios. Conclusiones. La cloroquina continúa siendo eficaz para el tratamiento de la malaria no complicada por P. vivax en Turbo, Antioquia.

Introduction: The therapeutic efficacy of antimalarial drugs should be monitored continuously because of the emergence of drug resistance. In Colombia, there are few studies evaluating the efficacy of chloroquine in uncomplicated malaria by Plasmodium vivax . This study evaluated the therapeutic efficacy of chloroquine at two different times, with an interval of ten years, in the same municipality. Objective: To evaluate the therapeutic response to chloroquine for the treatment of uncomplicated P. vivax malaria in Turbo, Antioquia, in 2002, and to compare these results with those observed in 2011 in the same municipality. Materials and methods: Two studies included 152 volunteers (50 in 2002 and 102 in 2011), older than 5 years old, with uncomplicated malaria according to the World Health Organization (WHO) criteria and simple infection with P. vivax. The efficacy of chloroquine, according to the current standard treatment of the Pan American Health Organization (PAHO) (1998) and WHO (2009), was monitored with 1,500 mg of chloroquine in 3 days and was followed clinically and parasitologically on days 0, 1, 2, 3, 7, 14 and 21 in 2002, and also on day 28 in 2011. At the end of the follow-up a dose of 0.25 mg/kg/day of primaquine was administered to each patient for 14 days. Results: A hundred percent of the volunteers had adequate clinical and parasitological response in both studies. Conclusions: Chloroquine continues to be highly effective for the treatment of uncomplicated P. vivax malaria in Turbo, Antioquia, Colombia.

[Ten years of chloroquine efficacy for uncomplicated Plasmodium vivax malaria treatment, Turbo, Antioquia, 2002 and 2011]. / Diez años de eficacia terapéutica de la cloroquina en malaria no complicada por Plasmodium vivax, Turbo, Antioquia, años 2002 y 2011.

INTRODUCTION: The therapeutic efficacy of antimalarial drugs should be monitored continuously because of the emergence of drug resistance. In Colombia, there are few studies evaluating the efficacy of chloroquine in uncomplicated malaria by Plasmodium vivax . This study evaluated the therapeutic efficacy of chloroquine at two different times, with an interval of ten years, in the same municipality. OBJECTIVE: To evaluate the therapeutic response to chloroquine for the treatment of uncomplicated P. vivax malaria in Turbo, Antioquia, in 2002, and to compare these results with those observed in 2011 in the same municipality. MATERIALS AND METHODS: Two studies included 152 volunteers (50 in 2002 and 102 in 2011), older than 5 years old, with uncomplicated malaria according to the World Health Organization (WHO) criteria and simple infection with P. vivax. The efficacy of chloroquine, according to the current standard treatment of the Pan American Health Organization (PAHO) (1998) and WHO (2009), was monitored with 1,500 mg of chloroquine in 3 days and was followed clinically and parasitologically on days 0, 1, 2, 3, 7, 14 and 21 in 2002, and also on day 28 in 2011. At the end of the follow-up a dose of 0.25 mg/kg/day of primaquine was administered to each patient for 14 days. RESULTS: A hundred percent of the volunteers had adequate clinical and parasitological response in both studies. CONCLUSIONS: Chloroquine continues to be highly effective for the treatment of uncomplicated P. vivax malaria in Turbo, Antioquia, Colombia.

Dynamics of Plasmodium falciparum parasitemia regarding combined treatment regimens for acute uncomplicated malaria, Antioquia, Colombia.

Selecting suitable anti-malarial treatment represents one of the best tools for reducing morbidity and mortality caused by this disease. Sexual and asexual parasite dynamics were thus evaluated in patients involved in antimalarial drug efficacy studies by using combined treatment with and without artemisinin derivatives for treating uncomplicated acute Plasmodium falciparum malaria in Antioquia, Colombia. All treatment doses were supervised and administered according to patients' weight; sexual and asexual parasitemia were evaluated during 28- or 42-days follow-up in 468 patients. Artemisinin-based combination therapy showed greater parasiticidal ability, showing a mean asexual parasitemia survival rate of one day and mean gametocyte survival rate of 1-2 days. Sexual and asexual parasitemias were eliminated more quickly and effectively in the group receiving artemisinin-based combination therapy. Adding 45 mg of primaquine to treatment with artesunate and mefloquine reduced gametocyte and asexual parasite survival by one day.

Estudio piloto de la eficacia y de los efectos sobre los gametocitos del esquema artesunato-mefloquina-primaquina para la malaria por Plasmodium falciparum / Therapeutic efficacy of a regimen of artesunate-mefloquine-primaquine treatment for Plasmodium falciparum malaria and treatment effects on gametocytic development

Introducción. El tratamiento de la malaria por P. falciparum requiere de un esquema seguro, eficaz y de impacto en la transmisión. En 2006, se implementó en Antioquia el esquema artesunato-mefloquina y se adicionó primaquina para eliminar los gametocitos. Objetivo. Evaluar la eficacia y acción gametocida de los esquemas artesunato-mefloquina-primaquina y artesunato-mefloquina en pacientes con malaria no complicada por P. falciparum de Turbo, Antioquia. Materiales y métodos. Ensayo clínico aleatorio; los tratamientos se suministraron de forma supervisada y se realizó seguimiento clínico-parasitológico en los días 1, 2, 3, 7, 14, 21, 28, 35, y 42, para evaluar la respuesta según el protocolo OMS-2003 modificado. Resultados. Entre abril de 2007 y febrero de 2008, 50 pacientes fueron reclutados; los resultados mostraron una eficacia de 100% (IC95% 86,3%-100%) para el esquema artesunato-mefloquina (con/sin primaquina); la parasitemia y la fiebre fueron eliminadas completamente al tercer día de tratamiento en todos los pacientes. La eliminación de gametocitos fue mayor con el uso de primaquina; al tercer día de seguimiento, el 92% (IC95% 74%-99%) de los pacientes que recibieron primaquina no tuvieron gametocitos, en comparación con 78,3% (IC95% 59%-93%) de pacientes del grupo artesunato-mefloquina. Además, el esquema artesunato-mefloquina-primaquina eliminó la gametocitemia una semana antes que el esquema sin primaquina. Conclusión. Se recomienda el uso del esquema artesunato-mefloquina para la malaria por P. falciparum por su alta eficacia y se sugieren futuras evaluaciones del beneficio de la PQ en la reducción de la densidad y prevalencia de gametocitos.

Introduction. The treatment of Plasmodium falciparum malaria requires a safe and effective therapeutic treatment regimen, which in turn has high impact on the transmission. In 2006, an artesunate (AS)-mefloquine (MQ) treatment program was implemented in Antioquia. In addition, primaquine (PQ) was added to eliminate malaria gametocytes in the bloodstream. Objective. The efficacy and gametocytocidal activity was evaluated for two treatment regimens, AS-MQ-PQ and AS-MQ, in patients with uncomplicated P. falciparum malaria. Materials and methods. Between April 2007 and February 2008, 50 patients were recruited for the trial in Turbo, Antioquia. A randomized clinical trial was conducted. Treatment compliance was supervised, with a clinical and parasitological assessment on days 1, 2, 3, 7, 14, 21, 28, 35, and 42 to evaluate response rate according to the WHO 2003 protocol. Results. Clinical response and parasite elimination efficacy of AS-MQ (with or without PQ) was 100% (95% CI 86.3%-100%), and parasitemia and fever were absent on day 3 of treatment in all patients. Gametocyte elimination was superior when PQ was used--92% (95% CI: 74%-99%) of patients who received PQ had no gametocytes on day 3, compared to 78.3% (95% CI: 59%-93%) of patients who only received AS-MQ. Furthermore, circulating gametocytes were eliminated on average one week faster when the AS-MQ-PQ treatment scheme was used compared to the scheme without PQ. Conclusion. These studies recommend the use of AS-MQ to treat P. falciparum malaria given its good therapeutic efficacy. However, further assessment is suggested concerning the benefit of adding PQ to this treatment scheme.

[Therapeutic efficacy of a regimen of artesunate-mefloquine-primaquine treatment for Plasmodium falciparum malaria and treatment effects on gametocytic development]. / Estudio piloto de la eficacia y de los efectos sobre los gametocitos del esquema artesunato-mefloquina-primaquina para la malaria por Plasmodium falciparum.

INTRODUCTION: The treatment of Plasmodium falciparum malaria requires a safe and effective therapeutic treatment regimen, which in turn has high impact on the transmission. In 2006, an artesunate (AS)-mefloquine (MQ) treatment program was implemented in Antioquia. In addition, primaquine (PQ) was added to eliminate malaria gametocytes in the bloodstream. OBJECTIVE: The efficacy and gametocytocidal activity was evaluated for two treatment regimens, AS-MQ-PQ and AS-MQ, in patients with uncomplicated P. falciparum malaria. MATERIALS AND METHODS: Between April 2007 and February 2008, 50 patients were recruited for the trial in Turbo, Antioquia. A randomized clinical trial was conducted. Treatment compliance was supervised, with a clinical and parasitological assessment on days 1, 2, 3, 7, 14, 21, 28, 35, and 42 to evaluate response rate according to the WHO 2003 protocol. RESULTS: Clinical response and parasite elimination efficacy of AS-MQ (with or without PQ) was 100% (95% CI 86.3%-100%), and parasitemia and fever were absent on day 3 of treatment in all patients. Gametocyte elimination was superior when PQ was used--92% (95% CI: 74%-99%) of patients who received PQ had no gametocytes on day 3, compared to 78.3% (95% CI: 59%-93%) of patients who only received AS-MQ. Furthermore, circulating gametocytes were eliminated on average one week faster when the AS-MQ-PQ treatment scheme was used compared to the scheme without PQ. CONCLUSION: These studies recommend the use of AS-MQ to treat P. falciparum malaria given its good therapeutic efficacy. However, further assessment is suggested concerning the benefit of adding PQ to this treatment scheme.

Deficiencia de glucosa 6-fostato deshidrogenasa en hombres sanos y en pacientes maláricos; Turbo (Antioquia, Colombia) / Deficiency of glucose-6-phosphate dehydrogenase in healthy men and malaria patients; Turbo (Antioquia, Colombia)

INTRODUCCIÓN: En América Latina la deficiencia de glucosa 6-fosfato deshidrogenasa (d-G6PD) ha sido poco estudiada y en Colombia solo conocemos tres publicaciones antiguas. Urge conocer más la prevalencia de d-G6PD, sobre todo ahora que el tratamiento de la malaria vivax plantea aumentar la dosis diaria o total de primaquina. OBJETIVO: Medir la prevalencia de d-G6PD en poblaciones masculina sana y de enfermos con malaria por Plasmodium vivax, en Turbo (Urabá, departamento de Antioquia, Colombia). METODOLOGÍA: Encuestas de prevalencia, para evaluar la G6PD en dos poblaciones de Turbo (Antioquia): hombres sanos; hombres y mujeres con malaria vivax. Se trabajó con muestras diseñadas con criterios estadístico-epidemiológicos. La actividad enzimática se midió con el método normalizado de Beutler para valorar la G6PD en hemolizados. RESULTADOS: Entre los hombres sanos (n = 508), el intervalo de confianza 95 por ciento para el promedio (IC95 por ciento) estuvo entre 4,15 y 4,51 UI/g hemoglobina y 14,8 por ciento presentaron valores por debajo del "límite normal" de < 2,29 UI/g hemoglobina (prevalencia de d-G6PD). Entre los hombres con malaria (n = 206) el IC95 por ciento fue 3,81 a 4,16 UI/g hemoglobina y entre las mujeres palúdicas fue 3,86 a 4,20 UI/g hemoglobina. Los promedios masculinos (sanos vs. maláricos) fueron estadísticamente diferentes (p = 0,028). Únicamente 9,5 por ciento (13/137) de los enfermos con paludismo, todos de sexo masculino, presentaron d-G6PD. CONCLUSIONES: la d-G6PD es relativamente alta (14,8 por ciento) en la población masculina sana de Turbo y en los enfermos maláricos por P. vivax (9,5 por ciento, todos hombres).

Efficacy of three chloroquine-primaquine regimens for treatment of Plasmodium vivax malaria in Colombia.

Plasmodium vivax malaria is an important cause of morbidity in Central and South America. In Colombia, this is the most prevalent malaria infection, representing 75% of the reported cases. To define the efficacy of the chloroquine and primaquine regimen to eliminate hypnozoites and prevent relapses, we conducted a random controlled clinical trial of three primaquine regimens in an open-label study. We evaluated the anti-relapse efficacy of total primaquine doses of 45, 105, and 210 mg administered at a dosage of 15 mg/day in 210 adults with P. vivax infection from the northwestern region of Colombia. Cure rates for blood-stage P. vivax malaria by day 28 of follow-up were 100% in all groups. Post-treatment reappearance of parasitemia during the six months of follow-up was 45%, 36.6% and 17.6%, respectively, for each group. When compared with other groups, administration of 210 mg was a significant protection factor for reappearance of parasitemia in a malaria-endemic area.

Therapeutic efficacy test in malaria falciparum in Antioquia, Colombia.

OBJECTIVE: Evaluate the frequency of failure of eight treatments for non-complicated malaria caused by Plasmodium falciparum in 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.