Is there added value from using three serial samples when surveying the occurrence of intestinal parasites in children?

BACKGROUND: Surveys for intestinal parasitic infections (IPIs) often involve samples from three sampling dates analysed by various microscopy techniques. However, analysis of three samples per individual is a huge burden on time and resources. We compared the value from analysing three or fewer samples. METHODS: In this cross-sectional study, three faecal samples were collected every other day from 332 children from two locations in Guantanamo province, Cuba. Samples were analysed by wet mount with Lugol stain, Willis flotation method and Kato-Katz thick smear. RESULTS: Most parasites were detected by wet mount, although helminth eggs not found by wet smear were detected by the Willis flotation method (in particular) and Kato-Katz smear. Blastocystis spp. was the most commonly detected parasite (about 65%), then Giardia duodenalis and then Entamoeba spp. Although analysis of two stool samples significantly increased occurrence data for Blastocystis, this was not so for the other parasites. For none of the protozoan parasites were results from analysing three samples significantly higher than results from analysing just two samples. CONCLUSIONS: Analysing two faecal samples by wet mount and the Willis flotation method provides useful data for estimating the prevalence of IPIs in relatively high prevalence settings. Analysing further samples provides limited additional information and adds an extra burden in terms of time and resources.

Conocimientos, percepciones y prácticas de médicos de atención primaria en Ecuador sobre la infección por Angiostrongylus cantonensis / Knowledge, perceptions and practice of primary healthcare doctors in Ecuador on Angiostrongylus cantonensis infection

Introducción: La angiostrongiliasis humana presenta un amplio espectro clínico: desde una infección asintomática a meningitis eosinofílica, meningoencefalitis eosinofílica y angiostrongiliasis ocular. Objetivo: Determinar los conocimientos, percepciones y prácticas en relación con la infección por Angiostrongylus cantonensis que poseen médicos de atención primaria de la República del Ecuador. Métodos: Se realizó un estudio observacional descriptivo. Se diseñó, validó y aplicó una encuesta sobre conocimientos, percepciones y prácticas a 163 médicos de atención primaria de las provincias Napo y Guayas, entre los meses de noviembre y diciembre de 2017. La información obtenida se almacenó en una base de datos Microsoft Access y se realizó un análisis de frecuencias a las respuestas dadas a cada una de las preguntas. Resultados: Se encontraron conocimientos insuficientes, percepciones inadecuadas y prácticas incorrectas en relación con la angiostrongiliasis. Conclusiones: Estos resultados orientan hacia la implementación de un programa de intervención educativa en médicos de atención primaria con el fin de atenuar las deficiencias encontradas, para incidir de forma positiva en comunidades donde existe la presencia de hospederos intermediarios y definitivos infectados y un riesgo potencial de infección.

Introduction: Human angiostrongyliasis presents a broad clinical spectrum, which ranges from asymptomatic infection to eosinophilic meningitis, eosinophilic meningoencephalitis, and ocular angiostrongyliasis. Objective: To determine the knowledge, perceptions, and practice of primary healthcare doctors in the Republic of Ecuador regarding Angiostrongylus cantonensis infection. Methods: It was conducted a descriptive observational study. A survey on knowledge, perceptions, and practice was designed, validated, and applied to 163 primary healthcare doctors from Napo and Guayas provinces between November and December 2017. The information obtained was stored in a Microsoft Access 2016 database, and a frequency analysis was performed to the answers provided to every question. Results: Insufficient knowledge, inadequate perceptions, and incorrect practice regarding angiostrongyliasis were found. Conclusions: The results evidenced the need to implement an educational intervention program to primary healthcare doctors aimed at reducing the deficiencies found to have a positive impact on the communities where the intermediate and definitive hosts and a potential infection risk exist.

Frecuencia de infección por cestodos en el Laboratorio Nacional de Referencia de Parasitismo Intestinal-IPK, Cuba, 2010-2018 / Frequency of cestode infection at the Intestinal Parasitic Disease National Reference Laboratory of Pedro Kourí Institute in Cuba, 2010-2018

Introdución: Los cestodos son helmintos parásitos del humano y de animales, con complejos ciclos de vida. En las infecciones por los cestodos no existen programas de desparasitación masiva implementados para disminuir la carga parasitaria de estos a nivel mundial, dada la baja prevalencia que se informa en estudios epidemiológicos. Existen pocos trabajos sobre la epidemiología y la detección de estas infecciones en la literatura internacional. Objetivo: Describir la frecuencia de infección de cestodos y sus características epidemiológicas. Métodos: Estudio descriptivo y retrospectivo, realizado entre el 3 de enero de 2010 y 28 de diciembre de 2018. Se analizaron todas las muestras de heces, parásitos adultos y metacestodos enviadas de la red de Salud al Laboratorio Nacional de Referencia de Parasitismo Intestinal-IPK. El universo de estudio estuvo constituido por 9833 muestras, que fueron enviadas mayoritariamente de la provincia La Habana. Resultados: La infección por Inermicapsifer madagascariensis predominó en niños menores de 5 años (69,6 por ciento; IC 95 por ciento: 47,1-86,8). La infección intestinal por Taenia spp. se diagnosticó prinipalmente en pacientes entre 15 y 65 años de edad (88,2 por ciento; IC95 por ciento: 63,6-98,5). De los 47 casos positivos a la infección por cestodos, 24 pertenecieron al sexo femenino (51,1 por ciento; IC95 por ciento: 35,7-66,4) y 23 al sexo masculino (48,9 por ciento; IC95 por ciento: 33,6-64,3). No hubo diferencias significativas entre la infección por Inermicapsifer madagascariensis y Taenia spp. y el sexo de los pacientes (p˃ 0,05). Conclusiones: Aunque la frecuencia de infección de las cestodiosis detectadas es baja, estos resultados pudieran ser útiles para un control integrado de las principales cestodioisis en los diferentes grupos etarios(AU)

Introduction: Cestodes are helminths of complex life cycles which may infect animals and humans. No mass deworming programs are in place to reduce the worldwide parasite load of cestodes, given the low prevalence reported by epidemiological research. Few studies are available in the international literature about the epidemiology and detection of these infections. Objective: Describe the frequency of cestode infection and its epidemiological characteristics. Methods: A retrospective descriptive study was conducted from 3 January 2010 to 28 December 2018. Evaluation was performed of all the samples of fecal matter, adult parasites and metacestodes submitted by the health care network to the Intestinal Parasitic Disease National Reference Laboratory at Pedro Kourí Institute. The study universe was 9 833 samples, mostly received from the province of Havana. Results: Inermicapsifer madagascariensis infection prevailed among children aged under 5 years (69.6 percent; CI 95 percent: 47.1-86.8). Taenia sp. intestinal infection was mainly diagnosed in patients aged 15-65 years (88.2 percent; CI 95 percent: 63.6-98.5). Of the 47 cestode infection positive cases, 24 were female (51.1 percent; CI 95 percent: 35.7-66.4) and 23 were male (48.9 percent; CI 95 percent: 33.6-64.3). No significant differences were found between Inermicapsifer madagascariensis and Taenia sp. infection and the sex of patients (p˃ 0.05). Conclusions: Although the frequency of cestode infection detected is low, these results could be useful for an integrated control of the main cestode infections affecting the different age groups(AU)

Molecular Characterization and Risk Factors of Giardia duodenalis among School Children from La Habana, Cuba.

Giardia duodenalis is considered the most common protozoan infecting humans worldwide. Molecular characterization of G. duodenalis isolates has revealed the existence of eight groups (assemblages A to H) which differ in their host distribution. A cross-sectional study was conducted in 639 children from La Habana between January and December 2013. Two assemblage-specific PCRs were carried out for the molecular characterization. The overall prevalence of Giardia infection was 11.9%. DNA from 63 of 76 (82.9%) samples was successfully amplified by PCR-tpi, while 58 from 76 (76.3%) were detected by PCRE1-HF. Similar results by both PCRs were obtained in 54 from 76 samples (71%). According to these analyses, assemblage B and mixed assemblages A + B account for most of the Giardia infections in the cohort of children tested. Our current study identified assemblage B as predominant genotype in children infected with Giardia. Univariate analysis indicated that omission of washing hands before eating and keeping dogs at home were significant risk factors for a Giardia infection. In the future, novel molecular tools for a better discrimination of assemblages at the subassemblages level are needed to verify possible correlations between Giardia genotypes and symptomatology of giardiasis.

Evaluación de la calidad del diagnóstico de la malaria por microscopía óptica en laboratorios provinciales de la República de Angola / Evaluation of the quality of malaria diagnosis by optical microscopy in provincial laboratories of the Republic of Angola

INTRODUCCIÓN: la malaria continúa siendo uno de los más importantes problemas de la salud pública a nivel mundial y afecta severamente al continente africano. OBJETIVO: evaluar el nivel de conocimientos teóricos y prácticos en el diagnóstico de la malaria de un grupo de técnicos dedicados a esta actividad. MÉTODOS: entre los años 2010 y 2012, se realizó un estudio cuasi experimental de evaluación en la red de salud, en 14 laboratorios provinciales de las 18 provincias de la República Angola, donde se entrenaron 243 técnicos que realizan habitualmente el diagnóstico de la malaria. Se hicieron entrenamientos de 10 días (70 horas) cumplimentando un programa que incluyó clases prácticas y teóricas, y sus respectivas evaluaciones inicial y final. RESULTADOS: después de los entrenamientos en cada una de las 14 provincias evaluadas la frecuencia de los técnicos desaprobados en la evaluaciones teóricas y prácticas disminuyó significativamente, (p<0,01). CONCLUSIONES: este es el primer trabajo realizado en Angola donde se demuestra una mejoría cualitativa y cuantitativa tanto en los conocimientos teóricos y habilidades prácticas de los técnicos después de un entrenamiento y readiestramiento, y constituye el primer paso de un esfuerzo encaminado para mejorar el diagnóstico de la malaria en el país(AU)

INTRODUCTION: malaria continues to be one of the main public health problems worldwide, severely affecting the African continent. OBJECTIVE: evaluate the level of theoretical and practical competence in the diagnosis of malaria achieved by a group of technicians engaged in this activity. METHODS: an evaluative quasi-experimental study was conducted from 2010 to 2012 in 14 provincial laboratories from the 18 provinces of the Republic of Angola, where 243 technicians received training in the field of malaria diagnosis. Training extended for 10 days (70 hours) based on a syllabus which included theoretical and practical lessons as well as an initial and a final evaluation. RESULTS: a post-training evaluation conducted in 14 provinces showed a significant decrease in the number of technicians failing their theoretical and practical tests (p<0.01). CONCLUSIONS: this is the first evaluation carried out in Angola in which qualitative and quantitative improvement is observed both in the theoretical knowledge and the practical skills of technicians after receiving training or retraining. It is also a first step in an effort to improve the quality of malaria diagnosis in the country(AU)

Impact of periodic selective mebendazole treatment on soil-transmitted helminth infections in Cuban schoolchildren.

OBJECTIVE: To evaluate the impact of periodic selective treatment with 500 mg mebendazole on soil-transmitted helminth (STH) infections in Cuban schoolchildren. METHODS: We followed up a cohort of 268 STH-positive schoolchildren, aged 5-14 years at baseline, at six-month intervals for two years and a final follow-up after three years. Kato-Katz stool examination was used to detect infections with Ascaris lumbricoides, Trichuris trichiura and hookworm. Common risk factors related to STHs were assessed by parental questionnaire. RESULTS: A significant reduction in the number of STH infections was obtained after three years with the highest reduction for T. trichiura (87.8%) and the lowest for hookworm (57.9%). After six months, cure rates (CRs) were 76.9% for A. lumbricoides, 67.4% for T. trichiura and 44.4% for hookworm. After two treatment rounds, more than 75% of all STH-positive children at baseline were cured, but with important differences between STH species (95.2% for A. lumbricoides, 80.5% for T. trichiura and 76.5% for hookworm). At the end of the study, these cumulative CRs were almost 100% for all three STHs. Risk factors for STHs were sex, sanitary disposal and habit of playing in the soil. CONCLUSIONS: Our results indicate that periodic selective treatment with 500 mg mebendazole is effective in reducing the number of STH infections in Cuban schoolchildren. Although important differences were found between helminth species, two rounds of treatment appeared sufficient to obtain substantial reductions.

Angiostrongylus cantonensis: un parásito emergente en Ecuador / Angiostrongylus cantonensis: an emerging parasite in Ecuador

Introducción: en 2008 se notificó por primera vez la presencia de Angiostrongylus cantonensis en Ecuador, así como los primeros casos de una enfermedad emergente causada por sus larvas, la meningitis eosinofilica. Métodos: se realizó una revisión de la literatura básica y actualizada sobre aspectos generales de Angiostrongylus cantonensis en el mundo y particulares en Ecuador, que incluyó los hallazgos parasitológicos, clínicos y malacológicos relacionados con la enfermedad. Resultados: se informan los hallazgos iniciales acerca de la aparición del parásito en Ecuador, así como la amplia distribución geográfica de sus hospederos intermediarios en el territorio nacional. Además, se notifican los brotes de meningitis eosinofilica por Angiostrongylus cantonensis y un caso de angiostrongyliosis ocular, informados oficialmente por el Ministerio de Salud Pública. Conclusiones: Angiostrongylus cantonensis es un parásito emergente en Ecuador, cuyo diagnóstico en la actualidad es clínico y epidemiológico, de ahí la importancia de contar con métodos de laboratorio que lo oriente. Por otra parte, es importante que se promuevan campañas de promoción y prevención de salud que contribuyan a romper la cadena de transmisión de la enfermedad.

Introduction: the presence of Angiostrongylus cantonensis and the first cases of eosinophilic meningitis, an emerging disease caused by its larvae, were first reported in Ecuador in the year 2008. Methods: a review was conducted of the basic and current bibliography on general aspects of Angiostrongylus cantonensis both worldwide and in Ecuador, including parasitological, clinical and malacological findings. Results: initial findings are reported about the emergence of the parasite in Ecuador, as well as the broad geographic distribution of its intermediate hosts in the national territory. Information is also provided about outbreaks of eosinophilic meningitis due to Angiostrongylus cantonensis and a case of ocular angiostrongylosis, based on official reports by the Ministry of Public Health. Conclusions: Angiostrongylus cantonensis is an emerging parasite in Ecuador whose diagnosis is currently based on clinical and epidemiological findings. Hence the importance of developing relevant laboratory methods. On the other hand, it is important to foster health promotion and prevention campaigns aimed at stopping the transmission of the disease.

Fascioliasis and intestinal parasitoses affecting schoolchildren in Atlixco, Puebla State, Mexico: epidemiology and treatment with nitazoxanide.

BACKGROUND: The Atlixco municipality, Puebla State, at a mean altitude of 1840 m, was selected for a study of Fasciola hepatica infection in schoolchildren in Mexico. This area presents permanent water collections continuously receiving thaw water from Popocatepetl volcano (5426 m altitude) through the community supply channels, conforming an epidemiological scenario similar to those known in hyperendemic areas of Andean countries. METHODOLOGY AND FINDINGS: A total of 865 6-14 year-old schoolchildren were analyzed with FasciDIG coproantigen test and Lumbreras rapid sedimentation technique, and quantitatively assessed with Kato-Katz. Fascioliasis prevalences ranged 2.94-13.33% according to localities (mean 5.78%). Intensities were however low (24-384 epg). The association between fascioliasis and the habit of eating raw vegetables was identified, including watercress and radish with pronouncedly higher relative risk than lettuce, corncob, spinach, alfalfa juice, and broccoli. Many F. hepatica-infected children were coinfected by other parasites. Entamoeba histolytica/dispar, Giardia intestinalis, Blastocystis hominis, Hymenolepis nana and Ascaris lumbricoides infection resulted in risk factors for F. hepatica infection. Nitazoxanide efficacy against fascioliasis was 94.0% and 100% after first and second treatment courses, respectively. The few children, for whom a second treatment course was needed, were concomitantly infected by moderate ascariasis burdens. Its efficacy was also very high in the treatment of E. histolytica/E. dispar, G. intestinalis, B. hominis, H. nana, A. lumbricoides, Trichuris trichiura, and Enterobius vermicularis. A second treatment course was needed for all children affected by ancylostomatids. CONCLUSIONS: Fascioliasis prevalences indicate this area to be mesoendemic, with isolated hyperendemic foci. This is the first time that a human fascioliasis endemic area is described in North America. Nitazoxanide appears as an appropriate alternative to triclabendazole, the present drug of choice for chronic fascioliasis. Its wide spectrum efficacy against intestinal protozooses and helminthiasis, usually coinfecting liver fluke infected subjects in human endemic areas, represents an important added value.

Parasitosis intestinales en pacientes con epilepsia de origen desconocido / Intestinal parasitosis found in patients with epilepsy of unknown etiology

Introducción: la epilepsia es una alteración del sistema nervioso central que afecta a un estimado de 50 millones de personas en el mundo, de los cuales 85 porciento vive en países en desarrollo. Alrededor de 20 porciento de las epilepsias son de difícil control o refractarias. En Cuba no existen antecedentes de estudios acerca del comportamiento de las parasitosis intestinales en estos pacientes, por lo cual se decidió realizar la presente investigación en un grupo de pacientes con epilepsia de origen desconocido del Instituto de Neurología y Neurocirugía de La Habana. Objetivos: determinar la prevalencia y las manifestaciones clínicas de las parasitosis intestinales, y relacionar estas infecciones con la existencia de epilepsia refractaria a los fármacos antiepilépticos. Métodos: se aplicó un cuestionario y se recogió una muestra de heces por cada paciente, se realizaron técnicas de diagnóstico coproparasitológico, como son el examen directo, el método de concentración de Willis y el procedimiento cuantitativo de Kato Katz

Introduction: the epilepsy is an alteration of the central nervous system (CNS) which roughly affects 50 millions of persons worldwide; almost 85 percent of them live in developing countries. Approximately 20 percent of epilepsies are difficult to control or they are called refractory epilepsies. Taking into account the lack of Cuban reports about the behavior of intestinal parasitic infections in these patients, it was decided to carry out this research study in a group of epileptic patients with unknown etiology, from the Institute of Neurology and Neurosurgery in Havana. Objectives: to determine the prevalence and the clinical manifestations of intestinal parasitic infections, and the possible association of these infections with epilepsy refractory to the antiepileptic drugs. Methods: a questionnaire was applied and one fecal sample was taken per patient. Various parasitological techniques were implemented, including direct wet mount, Willis concentration technique, and Kato Katz quantitative procedure

Aplicación de herramientas serológicas y moleculares para el diagnóstico de coriorretinitis por Toxoplasma gondii / Application of serological and molecular tools for diagnosis of chorioretinitis caused by Toxoplasma gondii

Introducción: Toxoplasma gondii, agente causal de la toxoplasmosis, es un protozoario intracelular obligado que puede afectar al globo ocular, siendo la causa más común de uveítis posterior. Objetivo: determinar la utilidad de las técnicas serológicas y moleculares para el diagnóstico de la toxoplasmosis ocular en pacientes con uveítis. Métodos: se diseñó un estudio de corte transversal para comparar un grupo de pacientes afectados por coriorretinitis toxoplásmica y otro con signos sugestivos de coriorretinitis no toxoplásmica. En ambos grupos se utilizaron métodos serológicos como la inmunofluorescencia indirecta y la prueba de inmunoensayo enzimático (ELISA), y la reacción en cadena de la polimerasa para el diagnóstico de la toxoplasmosis ocular. Resultados: las técnicas serológicas permitieron detectar los anticuerpos IgG anti-Toxoplasma en 100 % de los pacientes con coriorretinitis toxoplásmica, de ellos fueron positivos a los anticuerpos IgM solo 3 pacientes y 1 tuvo un resultado débil a la avidez IgG. La reacción en cadena de la polimerasa detectó el ADN de Toxoplasma gondii en 15 de los 47 pacientes para una sensibilidad de 31,9 %. Conclusiones: se reporta la detección de anticuerpos anti-Toxoplasma, en todos los casos de coriorretinitis toxoplásmica a través de los métodos serológicos, aunque la técnica más sensible fue la inmunofluorescencia indirecta. Se empleó la detección molecular del ADN de Toxoplasma gondii en pacientes con toxoplasmosis ocular, por primera vez en Cuba. Los resultados permiten sugerir el uso de técnicas serológicas y moleculares que ayuden a confirmar el diagnóstico de infección por Toxoplasma en pacientes con coriorretinitis.

Introduction: Toxoplasma gondii, the causative agent of toxoplasmosis, is an intracellular protozoan that can affect the eye, and be the most common cause of posterior uveitis. Objective: to determine the usefulness of serological and molecular techniques for the diagnosis of ocular toxoplasmosis in patients with uveitis. Methods: a cross-sectional study was designed in order to compare a group of patients with toxoplasmic retinochoroiditis and another affected by non-toxoplasmic retinochoroiditis. In both groups serological methods such as indirect immunofluorescence assay, immunoassay (ELISA), and the polymerase chain reaction were used for the diagnosis of ocular toxoplasmosis. Results: serological techniques allowed detecting anti-Toxoplasma IgG antibodies in 100 % of patients with toxoplasmic retinochoroiditis, and only 3 patients were positive to IgM antibodies. Finally, only one had a weak result for IgG avidity. The polymerase chain reaction detected DNA from Toxoplasma gondii in 15 out of 47 patients for a sensitivity of 31.9 %. Conclusions: this paper reports the detection of anti-Toxoplasma antibodies in all toxoplasmic retinochoroiditis cases by serological methods; but the most sensible method was immunofluorescence assay. The molecular detection of Toxoplasma gondii`s DNA in patients with ocular toxoplasmosis was employed for the first time in Cuba. The results suggest that serological and molecular techniques can be applied to confirm the diagnosis of Toxoplasma infection in patients with toxoplasmic retinochoroiditis.

Actividad antiplasmodial in vivo de las esponjas Mycale laxissima y Clathria echinata / In vivo antiplasmodial activity of Mycale laxissima and Clathria echinata sponges

Introducción: la búsqueda de nuevas sustancias antimaláricas incluye entre sus retos el desarrollo de alternativas para el tratamiento de la malaria cerebral, debido a la alta mortalidad y las deficiencias neurológicas persistentes después del tratamiento con los medicamentos recomendados actualmente. Objetivos: evaluar la actividad de fracciones orgánicas de Mycale laxissima y Clathria echinata en el modelo de malaria cerebral producida por la infección de ratones C57BL/6 con Plasmodium berghei ANKA. Métodos: se evaluaron fracciones orgánicas obtenidas mediante cromatografía flash en fase inversa a partir de los extractos crudos de las dos especies. Se realizó un análisis químico cualitativo para detectar la presencia de saponinas, triterpenos/esteroides y alcaloides en estas fracciones. El efecto esquizonticida de las fracciones se determinó mediante la prueba de supresión de la parasitemia al inicio de la infección. Se evaluaron la supervivencia, los síntomas neurológicos y la reducción del peso corporal en los días subsiguientes. Resultados: las fracciones orgánicas de Mycale laxissima a dosis de 200 mg/kg y Clathria echinata a100 mg/kg no mostraron una disminución sustancial del peso de los animales o muertes hasta el día 4; para las cuales se obtuvieron reducciones significativas de las medianas de la parasitemia de 45 % y 53 %, respectivamente. La fracción de Mycale laxissima a 200 mg/kg produjo un incremento significativo en el tiempo de supervivencia hasta 20 d, mientras los animales tratados con Clathria echinata a 100 mg/kg presentaron una mediana de tiempo de supervivencia de 16 d. Ambos incrementos fueron superiores a 7 d. En este período, los animales tratados con las fracciones orgánicas de Clathria echinata y Mycale laxissima no presentaron los síntomas neurológicos observados en los controles. Esta prolongación de la supervivencia fue similar a la observada en presencia de dosis de 7,5 mg/kg de cloroquina. Conclusiones: las fracciones orgánicas de Mycale laxissima y Clathria echinata mostraron actividades antimaláricas, promisorias en el modelo de infección de ratones C57BL/6 con Plasmodium berghei ANKA, que sugieren el estudio de sus constituyentes químicos activos.

Introduction: the search of new antimalarial compounds comprises, among its challenges, the development of therapeutic alternatives for cerebral malaria; due to the high mortality and neurological deficiencies that persist after treatment with recommended drugs. Objectives: to evaluate the activity of organic fractions of Mycale laxissima and Clathria echinata in the cerebral malaria model of infection of C57BL/6 mice with Plasmodium berghei ANKA. Methods: preparative fractions of both species were obtained by reverse-phase flash chromatography. In order to detect the presence of saponins, triterpenods/steroids and alkaloids, a qualitative chemical analysis was performed. The schyzontocidal effect of the extracts was determined by the suppression test at the beginning of the infection. Survival, neurological symptoms and body weight changes were evaluated in subsequent days. Results: the organic fractions of Mycale laxissima at 200 mg/kg and Clathria echinata at 100 mg/kg showed neither substantial reductions of body weights, nor deaths of animals until day 4; but caused significant reductions of median parasitemia of 45 % and 53 % respectively. The fraction of Mycale laxissima at 200 mg/kg caused a significant increase in the median survival time up to day 20, whereas animals treated with Clathria echinata at 100 mg/kg presented a survival of 16 days. Both increases the survival time 7 days. Neurological alterations were not observed in the groups treated with organic fractions when compared to the control group. This survival extension was similar to the effect of administration of 7.5 mg/kg of chloroquine. Conclusions: the organic fractions of Mycale laxissima and Clathria echinata exhibited promising antimalarial activities in the infection model of C57BL/6 mice with Plasmodium berghei ANKA. This indicates that their active chemical constituents should be studied.

Associations between atopic markers in asthma and intestinal helminth infections in Cuban schoolchildren.

Total serum IgE (tIgE), allergen-specific IgE (sIgE), and skin prick test (SPT) are commonly used markers for atopy and atopic disease. The association between these measures and their relationship to clinical symptoms differs in affluent and non-affluent countries. We investigated the role of intestinal helminth infections in observed variations in atopic markers and asthma, and possible diagnostic and epidemiological consequences. A cross-sectional study was conducted in Cuban schoolchildren (n = 1285; 4-14 yrs). Atopy was determined by SPT, sIgE, and tIgE; asthma by International Study of Asthma and Allergies in Childhood questionnaire; and intestinal helminth infections by stool examination. Percentages of tIgE, sIgE, and SPT positives were 88.9%, 25.5%, and 16.5%, respectively. Asthma was found in 20.8%, and helminth infections in 20.9% of the children. All three atopic markers were significantly associated with each other and with asthma. Median tIgE levels were higher in helminth-infected than in uninfected children, irrespective of their status of atopy/asthma. Discordant results between SPT and sIgE were observed in 22.6% of the children. Among SPT positives, 41% were sIgE negative. The proportion of SPT negatives among sIgE positives was 74% in helminth-infected and 58.4% in uninfected children (p < 0.05). Helminth infections affected tIgE levels, reconfirming the limited value of tIgE for diagnosis of atopy and asthma in tropical areas. Higher frequencies of sIgE than positive SPTs were observed, especially in helminth-infected children. This corresponds with current hypothesis on the role of helminths in atopy. However, the observed proportion of sIgE negatives among children with positive SPT suggests that other mechanisms may also be involved.

Estudio de la susceptibilidad al metronidazol en aislamientos cubanos de Trichomonas vaginalis / Study on metronidazole susceptibility in Cuban isolates of Trichomonas vaginalis

La trichomonosis es una infección muy frecuente a nivel mundial con importantes implicaciones médicas y sociales. El metronidazol constituye el fármaco de elección para el tratamiento de esta infección. Sin embargo, se ha demostrado la existencia de cepas del parásito resistentes a este medicamento en varios países. En el nuestro, la mayoría de los fallos de tratamiento parecen deberse al incumplimiento con la terapia indicada o a reinfecciones. No obstante, algunos quedan sin explicación aparente y pudieran estar circulando aislamientos resistentes. El objetivo es determinar la susceptibilidad al metronidazol de aislamientos cubanos de Trichomonas vaginalis. Se estudiaron 40 aislamientos del parásito, procedentes de exudados vaginales de adolescentes, atendidas en hospitales ginecoobstétricos de Ciudad de La Habana. Los aislamientos fueron sometidos a ensayos in vitro, tanto en condiciones anaeróbicas como aeróbicas, para conocer su susceptibilidad o resistencia al metronidazol. Se utilizaron diluciones dobles seriadas de metronidazol entre 400 Ág/mL y 0,2 Ág/mL y el dimetilsulfóxido como solvente. Mediante los ensayos realizados en condiciones aeróbicas se detectaron dos aislamientos resistentes al metronidazol (Tv-352, CLM: 50 Ág/mL y Tv-240, CLM: 200 Ág/mL). Este hallazgo nos alerta acerca de la necesidad de profundizar en las causas de los fallos de tratamiento para hacer una correcta evaluación e imponer el tratamiento adecuado

The trichomoniasis is a very frequent infection at world level with significant medical and social implications. The metronidazole is the choice drug to treat this infection. However, it was demonstrated the existence of parasite strains resistant to this drug in some countries. In Cuba, most of treatment failures seem to be due to the non-fulfillment of prescribed therapy or to reinfections. Nevertheless, some of them remain without an apparent explanation and could be circulating resistant isolates. The objective of the present paper is to determine the susceptibility to metronidazole of the Cuban isolates of Trichomonas vaginalis. Forty isolates of this parasite were studied, from the vaginal exudates of adolescents attended at the gynecobstetrics hospitals of Havana. The isolates underwent in vitro trials under anaerobic and aerobic conditions, to know their susceptibility or resistance to metronidazole. Serial double dilutions of metronidazole between 400 Ág/mL and 0.2 Ág/mL and the dimethylsulfoxide as solvent were used. According to the trials carried out under aerobic conditions, two resistant isolates to metronidazole (Tv-352, CLM: 50 Ág/mL and Tv-240, CLM: 200 Ág/mL) were detected. This finding alerts us about the need to deepen in causes of treatment failures to make an appropriate assessment in order to apply the suitable treatment