Molecular Detection and Species Determination of Malaria Parasites, Venezuela.

In southeastern Venezuela, malaria cases have increased since 2013. We found that 46% of 352 blood samples from symptomatic patients in 1 municipality tested positive for Plasmodium spp. In addition, the number of cases increased by 10 times in 4 years (2014-2017) and by 3 times in 1 year (2016-2017).

A high number of pfmdr1 gene copies in P. falciparum from Venezuela.

Multidrug resistance in Plasmodium falciparum has been associated with gene amplification of pfmdr1. We studied the corresponding gene amplification in P. falciparum from blood samples of malaria patients in the Sifontes Municipality, Bolívar State, Venezuela, known as the highest region of incidence of malaria. Fifty-five P. falciparum DNA samples were extracted from different hosts and used for qPCR assessment of the copy number of pfmdr1. The assay detected four copies of the multidrug-resistant line P. falciparum Dd2 in comparison with the P. falciparum 3D7 that had only one copy. In the patients' samples, the copy number of pfmdr1 was a single copy in 80% and 20% left distributed in different copy numbers up to seven.

Inhibition of defensin A and cecropin A responses to dengue virus 1 infection in Aedes aegypti. / Inhibición de las respuestas de defensina A y cecropina A contra la infección del virus dengue 1 en Aedes aegypti

INTRODUCTION: It is essential to determine the interactions between viruses and mosquitoes to diminish dengue viral transmission. These interactions constitute a very complex system of highly regulated pathways known as the innate immune system of the mosquito, which produces antimicrobial peptides that act as effector molecules against bacterial and fungal infections. There is less information about such effects on virus infections. OBJECTIVE: To determine the expression of two antimicrobial peptide genes, defensin A and cecropin A, in Aedes aegypti mosquitoes infected with DENV-1. MATERIALS AND METHODS: We used the F1 generation of mosquitoes orally infected with DENV-1 and real-time PCR analysis to determine whether the defensin A and cecropin A genes played a role in controlling DENV-1 replication in Ae. aegypti. As a reference, we conducted similar experiments with the bacteria Escherichia coli. RESULTS: Basal levels of defensin A and cecropin A mRNA were expressed in uninfected mosquitoes at different times post-blood feeding. The infected mosquitoes experienced reduced expression of these mRNA by at least eightfold when compared to uninfected control mosquitoes at all times post-infection. In contrast with the behavior of DENV-1, results showed that bacterial infection produced up-regulation of defensin and cecropin genes; however, the induction of transcripts occurred at later times (15 days). CONCLUSION: DENV-1 virus inhibited the expression of defensin A and cecropin A genes in a wild Ae. aegypti population from Venezuela.

Introducción. Es esencial determinar las interacciones entre los virus y los mosquitos para disminuir la transmisión viral. Estas interacciones constituyen un sistema muy complejo y muy regulado conocido como sistema inmunitario innato del mosquito, el cual produce péptidos antimicrobianos, moléculas efectoras que funcionan contra las infecciones bacterianas y fúngicas; se tiene poca información de su acción sobre los virus. Objetivo. Determinar la expresión de dos genes AMP (defensina A y cecropina A) en mosquitos Aedes aegypti infectados con el virus DENV-1. Materiales y métodos. Se infectaron oralmente mosquitos de generación F1 con DENV-1 y mediante el análisis con PCR en tiempo real se determinó el potencial papel de los genes defensina A y cecropina A en el control de la replicación del DENV-1 en Ae. aegypti. Como referencia, se infectaron mosquitos con Escherichia coli. Resultados: Los mosquitos no infectados expresaron niveles basales de los ARNm de los genes defensina A y cecropina A en diversos momentos después de la alimentación. Los mosquitos infectados experimentaron una reducción, por lo menos, de ocho veces en la expresión de estos ARNm con respecto a los mosquitos de control en todo el periodo posterior a la alimentación. En contraste con el comportamiento del virus DENV-1, los resultados mostraron que la infección bacteriana produjo una regulación positiva de los genes defensina y cecropina; sin embargo, la inducción de los transcritos ocurrió tardíamente (15 días). Conclusión. El virus DENV-1 inhibió la expresión de los genes defensina A y cecropina A en una población silvestre de Ae. aegypti en Venezuela.

Prior interaction of ATP with yeast mRNAs enhances protein synthesis at the initiation step.

ATP hydrolysis is important for different stages of the protein synthesis process. A novel effect of this nucleotide was detected using mRNAs isolated from S. cerevisiae after phenol extraction of polysomes. When polysomal mRNA (pmRNA) or poly(A)(+) RNA were preincubated with ATP (approximately 3 mM, near physiological concentration), their translational activity in a cell-free system from yeast was stimulated 2-3 fold. This increased translational activity is specific for the poly(A)(+) RNA fraction, correlates with facilitated assembly of 80S initiation complexes, and is associated to increased synthesis of high molecular weight polypeptides. TCA precipitation assays of RNA incubated with [(14)C]ATP suggested an association of the nucleotide with the nucleic acid. The amount of [(14)C]ATP co-precipitated was dependent on magnesium (optimum at 5-6 mM), was partially inhibited by monovalent ions, and was maximal with poli(A)(+) RNA. Existence of RNA-associated kinases or ATPases appear unlikely since neither phosphorylation nor nucleotide hydrolysis were observed during preincubation of pmRNA with ATP. Another evidence of ATP-RNA interaction was an increased absorbance at 260 nm after incubation suggesting unwinding of the RNA secondary structure. Therefore, preincubation with ATP may affect the conformation of mRNAs and thereby facilitate the initiation of protein synthesis. This event could be part of an in vivo energy-dependent mechanism for translational control.

Genetic relationships among Aedes aegypti collections in Venezuela as determined by mitochondrial DNA variation and nuclear single nucleotide polymorphisms.

A population genetic analysis of gene flow was conducted among 619 Aedes aegypti from nine collections distributed among six geographic regions of Venezuela. Genetic markers included a 387-basepair region of the mitochondrial NADH dehydrogenase 4 (ND4) gene and single nucleotide polymorphisms (SNPs) at 11 nuclear loci. Genotypes at SNP loci were identified using melting curve analysis. Six different ND4 haplotypes were detected and patterns of variation suggested that collections were isolated by distance. The variance in SNP allele frequencies was much less than the variance in haplotype frequencies and a pattern of isolation by distance was not detected. Aedes aegypti from eight collections were orally challenged with dengue 2 virus. Disseminated infection rates ranged from 77% to 95%. The percentage of mosquitoes exhibiting a midgut infection barrier ranged from 2% to 15%, and those exhibiting a midgut escape barrier ranged from 2% to 18%. Venezuelan Ae. aegypti appear to be susceptible to dengue virus infection.

Inhibition of defensin A and cecropin A responses to dengue virus 1 infection in Aedes aegypti / Inhibición de las respuestas de defensina A y cecropina A contra la infección del virus dengue 1 en Aedes aegypti

Abstract | Introduction: It is essential to determine the interactions between viruses and mosquitoes to diminish dengue viral transmission. These interactions constitute a very complex system of highly regulated pathways known as the innate immune system of the mosquito, which produces antimicrobial peptides that act as effector molecules against bacterial and fungal infections. There is less information about such effects on virus infections. Objective: To determine the expression of two antimicrobial peptide genes, defensin A and cecropin A, in Aedes aegypti mosquitoes infected with DENV-1. Materials and methods: We used the F1 generation of mosquitoes orally infected with DENV-1 and real-time PCR analysis to determine whether the defensin A and cecropin A genes played a role in controlling DENV-1 replication in Ae. aegypti. As a reference, we conducted similar experiments with the bacteria Escherichia coli. Results: Basal levels of defensin A and cecropin A mRNA were expressed in uninfected mosquitoes at different times post-blood feeding. The infected mosquitoes experienced reduced expression of these mRNA by at least eightfold when compared to uninfected control mosquitoes at all times post-infection. In contrast with the behavior of DENV-1, results showed that bacterial infection produced up-regulation of defensin and cecropin genes; however, the induction of transcripts occurred at later times (15 days). Conclusion: DENV-1 virus inhibited the expression of defensin A and cecropin A genes in a wild Ae. aegypti population from Venezuela.

Resumen | Introducción. Es esencial determinar las interacciones entre los virus y los mosquitos para disminuir la transmisión viral. Estas interacciones constituyen un sistema muy complejo y muy regulado conocido como sistema inmunitario innato del mosquito, el cual produce péptidos antimicrobianos, moléculas efectoras que funcionan contra las infecciones bacterianas y fúngicas; se tiene poca información de su acción sobre los virus. Objetivo. Determinar la expresión de dos genes AMP (defensina A y cecropina A) en mosquitos Aedes aegypti infectados con el virus DENV-1. Materiales y métodos. Se infectaron oralmente mosquitos de generación F1 con DENV-1 y mediante el análisis con PCR en tiempo real se determinó el potencial papel de los genes defensina A y cecropina A en el control de la replicación del DENV-1 en Ae. aegypti. Como referencia, se infectaron mosquitos con Escherichia coli. Resultados: Los mosquitos no infectados expresaron niveles basales de los ARNm de los genes defensina A y cecropina A en diversos momentos después de la alimentación. Los mosquitos infectados experimentaron una reducción, por lo menos, de ocho veces en la expresión de estos ARNm con respecto a los mosquitos de control en todo el periodo posterior a la alimentación. En contraste con el comportamiento del virus DENV-1, los resultados mostraron que la infección bacteriana produjo una regulación positiva de los genes defensina y cecropina; sin embargo, la inducción de los transcritos ocurrió tardíamente (15 días). Conclusión. El virus DENV-1 inhibió la expresión de los genes defensina A y cecropina A en una población silvestre de Ae. aegypti en Venezuela.

Volatile chemical composition of Piper sancti-felicis Trel essential oil and its biocidal action against Tribolium castaneum (Herbst)

This research assessed the fumigant activity of the essential oil from Piper sancti-felicis Trel and five of its components on the Tribolium castaneum (Herbst) biological model. Hydrodistillation was used for extraction of the essential oil, with separation and identification of the compounds through gas chromatography coupled to mass spectrometry (GC-MS). The fumigant was evaluated through gas dispersion on the T. castaneum. The majority compounds found in the EO were b-nerolidol (15.4%), 3-carene (14.9%), p-cymene (9.1%), spathulenol (8.2%), a-cubebene (6.2%) and calamenene (5.2%). Piper sancti-felicis displayed fumigant activity with a LC50 = 108.5 & 956;g L-1 air, and other individual monoterpenes tested such as & 945;-terpinolene (LC50 = 110.1 & 956;g L-1 air), p-cymene (LC50 = 120.3 & 956;g L-1 air), 3-carene (LC50 = 130.6 & 956;g L-1 air), (R) -limonene (CL50 = 189.6 & 956;g L-1 air), and a-pinene (LC50 = 213.1 & 956;g L-1 air), were significantly less toxic than methyl pyrimiphos used as a positive control, CL50 = 87.4 & 956;g L-1 air. The essential oil of P. sancti-felicis can be considered as a natural source of biocides.

Detection of dengue viruses in field-caught Aedes aegypti (Diptera: Culicidae) in Maracay, Aragua state, Venezuela by type-specific polymerase chain reaction.

Virological surveillance of dengue viruses in Aedes aegypti populations constitutes a powerful tool for early prediction of dengue outbreaks. We have standardized a protocol for viral RNA extraction from individual and pools of mosquitoes that permits a sensitive detection of dengue virus without RNA degradation or PCR inhibition when we apply a semi-nested RT-PCR. The limit of detection for each dengue serotype was 0.1 PFU. In a prospective field study conducted from November 2000 to December 2001, adult female A. aegypti mosquitoes from several municipalities with high dengue transmission in Maracay, Aragua State, Venezuela were collected and screened for dengue viruses using RT-PCR. We analyzed a total of 296 A. aegypti pools (1,632 mosquitoes); of these, 154 pools (469 mosquitoes) were collected from houses with persons with clinical diagnosis of dengue (dengue houses), and 142 pools (1,163 mosquitoes) from adjacent residences (neighbour houses). From the dengue houses, eight mosquito pools (5.2%) were positive for DENV-1 (0.7%), DENV-3 (3.2%) and DENV-4 (1.3%) viruses. From the neighbour houses, 18 mosquito pools (12.7%) were positive for DENV-3 (12%) and DENV-4 (0.7%) viruses. From these 26 RT-PCR positive mosquito pools (containing 1-25 mosquitoes each), 22 pools (84.6%) were positive for DENV-3. The most prevalent serotype in the 2001 dengue outbreak was also DENV-3. The minimum infection rate in both A. aegypti collections, from dengue houses and neighbour houses was 17 and 15 per 1,000, respectively. The relevance of these results for dengue surveillance is discussed.

Co-circulación viral de Dengue y Chikungunya en mosquitos Aedes aegypti infectados naturalmente en Venezuela / Dengue and Chikungunya viral co-circulation in naturally infected Aedes aegypti mosquitoes in Venezuela

Para detectar los arbovirus Dengue (DENV), Zika (ZIKV) y Chikungunya (CHIKV) en mosquitos Aedes aegypti (Ae. aegypti), se evaluaron dos municipios del estado Aragua, Francisco Linares Alcántara (FLA) y Mario Briceño Iragorry (MBI). Se capturaron 163 mosquitos en MBI y 105 en FLA con aspirador de espalda. Estos se agruparon (2-9 mosquitos) para la extracción de ARN y análisis mediante RT-PCR específica para cada virus. Se calcularon, Tasa Mínima de Infección (TMI) y Estimación de Máxima Verosimilitud (EMV). Los resultados evidenciaron co-infección de mosquitos por DENV-3 y CHIKV en FLA, y solo por CHIKV en MBI. Las TMI en MBI fueron para DENV (0%), CHIKV (0,61%), en FLA los valores para DENV y CHIKV, fueron 1,90% y 2,86%; respectivamente. Las EMV fueron en MBI igual a 0% para DENV y 0,63% para CHIKV, en FLA DENV (0,19%) y CHIKV (1,53%). Se comprobó la infección natural de Ae. aegypti con DENV y CHIKV, específicamente la co-circulación viral de DENV-3 y CHIKV en FLA, en MBI solo fue detectado CHIKV. La ausencia de detección de ZIKV probablemente se debió a interferencia viral. Los resultados indican la relevancia de incorporar a las prácticas convencionales de control vectorial, la detección específica de virus en zonas endemo-epidémicas durante todo el año, lo que favorecería las intervenciones y puesta en marcha de estrategias de control y prevención efectivas para limitar la permanente transmisión viral(AU)

To detect Dengue (DENV), Zika (ZIKV) and Chikungunya (CHIKV) in mosquitoes (Ae. aegypti) we evaluated two municipalities in Aragua State, Francisco Linares Alcántara (FLA) and Mario BriceñoIragorry (MBI). We captured 163 mosquitoes in MBI and 105 in FLA using Back Aspirator. The mosquitoes were grouped (2-9 mosquitoes per tube) for RNA extraction and typification by RT-PCR. We calculated Minimal Infection Rate (MIR) and Maximum Likelihood Estimation (MLE). The results showed co-infection by DENV-3 and CHIKV in FLA, and CHIKV in MBI. The MIR was to DENV 0% and 0.61% to CHIKV in MBI, whiles in FLA the values were 1.90% and 2.86% to DENV y CHIKV, respectively. The EMV were in MBI to DENV 0% and 0.63% to CHIKV, in the case of FLA DENV value was 0.19% and CHIKV 1.53%. We showed the natural infection of Ae. aegypti mosquitoes with DENV-3 and CHIKV in FLA and CHIKV in MBI. The absent of detection to ZIKV was probably due to viral interference. The results showed the relevance of incorporation of these techniques to conventional practices about vectorial control, specifically detection of viruses in endemic and epidemic regions during all year, because these practices could contribute to the effective interventions to control and prevention the viral transmission(AU)

Antioxidant and biological activities of essential oil from Colombian Swinglea glutinosa(Blanco) Merr fruit

The objectives of this work were the study of the volatile chemical composition of essential oils (EO’s) from Swinglea glutinosa, as well as to evaluate their antioxidant, repellent and fumigant properties. The EO was obtained by hydrodistillation from the peel of the fruit, gathered in the city of Cartagena, Bolívar (Colombia). The volatile composition was analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The major compounds found in S. glutinosaweregermacrene D (4.8%), limonene (5.2%),-terpineol (6.5%), -pinene (8.5%), nerolidyl acetate (9.8%), and trans-nerolidol (34.6%). S. glutinosashowed antioxidant potential (85.8%) (IC50=142.49 μg mL-1). The EO deployedrepellent activity against the Tribolium castaneumweevil at a concentration of 15.73 nL cm-1at 2 hours of exposure (72%), while the result for the commercial repellent was 50% at the same concentration. EO from S. glutinosadisplayed the best fumigant activity withLC50of 153.4 μg mL-1air. The essential oil from S. glutinosacan be considerated as a natural source of biocides and antioxidants.

Acción larvicida de extractos alcohólicos de semilla de Annona Muricata (guanábana) sobre Aedes Aegypti y Aedes Albopictus / Larvicidal action of alcoholic extracts of the seed of Annona Muricata (soursop) on Aedes Aegypti y Aedes Albopictus

Cada vez es más frecuente el reporte de resistencia de diferentes especies de vectores a los insecticidas usados en los programas de control; por ello existe un interés creciente en el desarrollo de productos eficaces, económicos y más amigables con el medio ambiente que permitan el control de los vectores de enfermedades como el dengue. Los extractos crudos obtenidos a partir de diferentes plantas han demostrado poseer actividades larvicidas. El objetivo de esta investigación fue evaluar la actividad larvicida de dos extractos alcohólicos (etanólico y metanólico) obtenidos a partir de las semillas de Annona muricata (guanábana) sobre Ae. aegypti (cepa Rockefeller) y Ae. albopictus exponiéndolas durante 24 h a diferentes diluciones de cada extracto. Las concentraciones letales (CL50) fueron las siguientes: a) para Ae. aegypti 41,8 mg L-1 (LC0,95=34,5-49,2 mg L-1) con el extracto etanólico y 32,8 mg L-1 (LC0,95=27,4-38,4 mg L-1) con el extracto metanólico; y b) para Ae. albopictus 299,6 mg L-1 (LC0,95=224,9-377,3 mg L-1) con el extracto etanólico y 326,1 mg L-1 (LC0,95=209,5-442,4 mg L-1) con extracto metanólico. El análisis de los resultados demostró que el efecto tóxico de ambos extractos sobre las larvas de Aedes fue similar y depende de la especie y de la concentración utilizada. Los resultados apuntan a que los extractos alcohólicos obtenidos a partir de A. muricata son una alternativa para el control de las especies de Aedes presentes en Venezuela.

Reports of resistance of different species of vectors to insecticides used in control programs are every time more frequent. Therefore, there is a growing interest to control harmful vectors (that transmit diseases such as dengue) by developing products that are effective, economical and environment friendly. Crude extracts obtained from different plants have demonstrated larvicidal activities. The objective of this research was to evaluate the larvicidal activity of two alcoholic extracts (ethanol and methanol) obtained from the seeds of Annona muricata (soursop) on Ae. aegypti (strain Rockefeller) and Ae. albopictus, exposed for 24 h to different dilutions of each extract. Lethal concentrations (LC50) were as follows: a) For Ae. aegypti 41.8 mg L-1 (LC0.95 =34.5 to 49.2 mg L-1) with ethanolic extract and 32.8 mg L-1 (LC0.95 =27.4 to 38.4 mg L-1) with methanolic extract; and b) For Ae. albopictus 299.6 mg L-1 (LC0.95=224.9 to 377.3 mg L-1) with ethanolic extract and =326.1 mg L-1 (LC0.95=209.5 to 442.4 mg L-1) with methanolic extract. The analysis of the results showed that the toxic effect of both alcoholic extracts on Aedes was similar and depends on the species and the concentration used. The results suggest that the alcoholic extracts obtained from A. muricata are an alternative for control of Aedes species present in Venezuela.

Genetic structure of Latin American Aedes aegypti / Estructura genética de Aedes aegypti latinoamericano

The mosquito Aedes aegypti is the main Dengue vector in Latin America. This study investigated the genetic structure of this vector using samples collected in Venezuela, Colombia, Peru, Mexico, Argentina, Puerto Rico, and French Guiana. We examined the distribution of a 246-basepair region of the NADH dehydrogenase subunit 4 mitochondrial gene among a total of 369 Ae. aegypti from all the populations. This gene was amplified by the polymerase chain reaction and tested for variation using single strand conformation polymorphism analysis. Twelve haplotypes were detected among all the countries sampled and grouped into two clades. Significant differentiation was detected among the populations studied and these were not genetically isolated by distance.

El mosquito Aedes aegypti es el principal vector del Dengue en los países latinoamericanos. En este estudio se investigó la estructura genética de este vector en muestras colectadas en Venezuela, Colombia, Perú, Mexico, Argentina, Puerto Rico y Guyana Francesa. Nosotros examinamos la distribución de una región de 246 pares de bases del gen mitochondrial de la subunidad 4 de la NADH deshidrogenasa entre un total de 369 Ae. aegypti de todas las poblaciones. Este gen fue amplificado por la reacción en cadena de la polimerasa y la variación se determinó usando el análisis de polimorfismos de conformación de cadena simple. Doce haplotipos se detectaron entre todos los países y se repartieron en dos clados. Una diferenciación significativa se detectó entre las poblaciones y estas no se encontraron genéticamente aisladas por distancia.

Persistencia en la competencia vectorial de Aedes albopictus de Venezuela a una cepa asiática dengue 2 / Vector competence persistance of Venezuelan Aedes albopictus for an Asian dengue-2 strain

En Venezuela, existen poblaciones de Aedes aegypti (Ae. aegypti) de diferente origen geográfico y estructura genética que difieren en la competencia vectorial para el virus dengue. Debido a que, recientemente, se reportó la presencia de Aedes albopictus (Ae. albopictus), es importante también conocer la competencia vectorial de esta especie para prever el riesgo epidemiológico el cual conlleva a su propagación. Se determinó la persistencia en la competencia vectorial de Ae. albopictus de Maracay, Venezuela a una cepa asiática dengue 2. Las especies de mosquitos Ae. albopictus y Ae. aegypti fueron alimentadas con una suspensión sangre-virus dengue 2 y luego de 20 días post-exposición viral se determinó la presencia del virus por el ensayo de la reacción en cadena de la polimerasa (PCR) en las diferentes partes de los insectos: abdomen (infección), patas/alas (diseminación) y cabeza (transmisión). Los resultados muestran que la cepa Ae. aegypti es más susceptible a la infección del abdomen (60 %) que la cepa de Ae. albopictus (37,5%); sin embargo, sólo en Ae. albopictus se encontró el virus presente en las patas/alas (100%) y cabezas (33%). La cepa de Ae. albopictus estudiada podría ser más competente para la transmisión del virus dengue asiático que la de Ae. aegypti. Este hallazgo es de gran importancia epidemiológica, ya que se demuestra que este vector aún no estando en su continente de origen, puede seguir siendo un vector eficiente y con el tiempo adecuarse a las cepas virales propias.

In Venezuela, there are populations of Aedes aegypti (Ae. aegypti) with different geographic origins and genetic structure that differ in vector competence for dengue virus. Since recently, the presence of Aedes albopictus (Ae. albopictus) was reported, it is also important to know the vector competence of this species to predict the epidemiological risk which would bring its spread. The objective was to determine the vector competence persistance of Ae. albopictus from Maracay, Venezuela for an Asian dengue-2 strain. The two species of mosquitoes were fed with a blood-dengue 2 virus suspension and after 20 days post-exposure to virus, the presence of the virus was determined by the polymerase chain reaction assay in different parts of the insect: abdomen (infection), legs/wings (spread) and head (transmission).The results show that the strain Ae. aegypti is more susceptible to infection in the abdomen (60 %) that the strain of Ae. albopictus (37.5%); however, only in Ae. albopictus this virus was found in the legs /wings (100%) and heads (33%). The studied strain of Ae. albopictus may be more competent vector in the transmission of the dengue 2 virus than Ae. aegypti. This finding is of great epidemiological importance as this shows that even this mosquito not being in its continent of origin, it can still be an efficient vector and eventually become adapted to the native viral strains.

Conocimientos, Actitudes y Prácticas sobre dengue y su relación con hábitats del vector en Aragua-Venezuela / Knowlegde, attitudes and practices regarding dengue and their relationships with vector breeding sites in Aragua-Venezuela

Con el objetivo de determinar los conocimientos, actitudes y prácticas sobre dengue en dos localidades del estado Aragua, Venezuela y su relación con la presencia de hábitats larvales de Aedes aegypti, se realizó un estudio epidemiológico transversal de campo, a través de una encuesta aplicada a los jefes de familia de 500 viviendas y una evaluación entomológica. La mayoría, 80,8%, reportó que la enfermedad se transmite por la picadura del vector. Los síntomas más reconocidos fueron: fiebre 86,8%, cefalea 59,4% y malestar general 51%. Las medidas de prevención más conocidas fueron: mantener tapados los recipientes con agua 89,8%, limpiar alrededor de las viviendas 70,6% y evitar agua estancada 68%. Las prácticas de prevención predominantes fueron: tapar los contenedores de agua 77%, limpiar alrededor de las viviendas 39,4% y usar insecticidas 35,8%. La actitud fue buena: un 95% de los entrevistados reconoce que el dengue puede prevenirse y 85,6% acude al médico cuando enferma. El conocimiento adecuado de la clínica, de las medidas de prevención y la práctica adecuada de prevención fue 9%, 20,6% y 5,4% respectivamente. La televisión fue la mayor fuente de información. Los índices entomológicos más conocidos (Índice de vivienda, Índice de recipiente, Índice de Breteau, entre otros) fueron elevados. Se encontraron asociados significativamente a la presencia de hábitats: almacenamiento de agua (OR= 7,43), conocimiento adecuado de las medidas preventivas (OR= 0,42), realizar actividades colectivas de prevención anti-dengue (OR= 0,51) y revisión de patio y casa por instituciones oficiales (OR= 1,78). Las personas en ambas comunidades tienen poco conocimiento adecuado sobre el dengue y poca práctica adecuada de prevención, lo cual se traduce en presencia de hábitats.

To determine the knowledge, attitudes and practices about dengue in two localities of Aragua state, Venezuela and its relationship to the presence of Aedes aegypti breeding sites. A cross-sectional study was conducted through a survey to the heads of the families of 500 homes. Also an entomological evaluation was performed. The majority 80.8%, reported that the disease is transmitted by vector bite. The most recognizable symptoms were: 86.8% fever, 59.4% headache and 51% malaise. The best known prevention measures were: to keep containers covered with water 89.8%, to clean around the house 70.6% and to avoid standing water 68%. The predominant prevention practices were: to cover water containers 77%, to clean around the house 39.4% and to use insecticides 35.8%. The attitude was good: 95% recognize that dengue can be prevented and 85.6% go to the doctor when they are sick. The adequate knowledge of clinical, prevention measures and good prevention practices was 9%, 20.6% and 5.4% respectively. The television was the main source of information. The best-known entomological indices were high. They were significantly associated with the presence of breeding sites: water storage (OR = 7.43), adequate knowledge of preventive measures (OR = 0.42), fullfilling collective activities of anti-dengue prevention (OR = 0.51) and monitoring the backyard and the house by the official institutions (OR = 1.78).People in both communities have poor adequate knowledge about dengue and poor adequate preventive practices which results in the presence of breeding sites.

Asociación entre presencia del virus del papiloma humano y hallazgos anatomo-patológicos / Association between the presence of human papilloma virus and pathological findings

OBJETIVO: Determinar por reacción en cadena de la polimerasa la presencia del virus del papiloma humano en pacientes femeninas, quienes acudieron a un tamizaje de lesiones en cuello uterino en la red ambulatoria del Municipio Francisco Linares Alcántara (Edo. Aragua) y asociar la presencia de virus del papiloma humano con hallazgos anatomo-patológicos. MÉTODOS: Luego de obtener el consentimiento informado se tomó una muestra de hisopado vaginal a 301 pacientes, a quienes se les realizó citología y colposcopia. Se aisló ADN para la genotipificación mediante ensayos de reacción en cadena de la polimerasa acoplados a digestión con enzimas de restricción. Se efectuaron pruebas estadísticas para analizar la relación entre la presencia de virus del papiloma humano y las variables: edad, inicio de relaciones sexuales, número de parejas sexuales y hallazgos citológicos y colposcópicos. RESULTADOS: Se obtuvieron 43 muestras positivas para virus del papiloma humano 17 fueron 16 (39,53.%), 3 virus del papiloma humano 18 (6,98 %), 1 virus del papiloma humano 33 (2,33 %), 14 muestras presentaron coinfección (32,56 %) y en 8 muestras (18,60 %) no ocurrió digestión con las enzimas utilizadas. Existen relaciones estadísticas significativas entre la presencia de virus del papiloma humano y las variables analizadas. CONCLUSIÓN: La presencia de genotipos de alto riesgo en el 48,84 % de las pacientes con virus del papiloma humano, es una situación preocupante, dada la vinculación de dichos genotipos al desarrollo de cáncer de cuello uterino

OBJECTIVE: To determine by Polymerase Chain Reaction the presence of the human papillomavirus in female patients attending a screening for lesions of uterine neck in the outpatient network of Francisco Linares Alcantara Municipality and to relate the results to anatomopathological findings. METHODS: After obtaining informed consent from patients, samples of vaginal swabs were taken from 301 women that were used for cytology and colposcopy studies. Also, DNAs were isolated and they were used for Polymerase Chain Reaction test coupled to restriction enzyme digestion. Statistical tests were performed to analyze the relationship between the human papillomavirus positivity and the variables: stratus age, the onset of sexual activity, number of sexual couple, cytology and colposcopy findings. RESULTS: Out of 43 human papillomavirus positive samples, 17 (39.53 %) were genotype 16, 3 (6.98 %) genotype 18 and 1 (12.33.%) genotype 33; 14 (32.56 %) samples showed coinfection and 8 (18.60 %), samples were not digested with the restriction enzymes used. The relationship between the presence of human papillomavirus and the others studied variables (stratus age, the onset of sexual activity, number of sexual couple and cytological results) was statistically significant. CONCLUSIONS: The presence of human papillomavirus genotypes, of so-called high risk in the 48.84 % of the women with a positive HPV test is a particular concern, because they are associated with the development of cervical cancer.

Efecto larvicida de extractos metanólicos obtenidos de semillas y hojas de Persea americana (Laurales: Lauraceae) (aguacate) sobre Aedes aegypti (Diptera: Culicidae) / Larvicide effect of methanolic extracts from seeds and leaves Persea americana (Laurales: Lauraceae) (avocado) on Aedes aegypti (Diptera: Culicidae)

Aedes aegypti es el principal vector del dengue en el continente americano, una de las arbovirosis de mayor impacto en Venezuela, debido a su alta morbilidad y mortalidad. La ausencia de una vacuna contra este virus ha llevado al uso indiscriminado de insecticidas provocando la resistencia del vector, daños al medio ambiente y reacciones adversas en personas susceptibles. En un esfuerzo por encontrar formas eficaces y asequibles para el control, surge como una alternativa el uso de extractos vegetales que proporcionen menos riesgo ambiental y bajo costo. El objetivo de esta investigación fue evaluar el efecto larvicida de extractos metanólicos obtenidos a partir de semillas y hojas de Persea americana (aguacate) sobre Ae. aegypti [cepas Rockefeller y Mario Briceño Iragorry (MBI)]. El mayor efecto tóxico se observó con el extracto metanólico obtenido a partir de las semillas con 100% de mortalidad a 25 mg/L para la cepa Rockefeller y 50 mg/L para la cepa MBI, 24 horas post-exposición. Las concentraciones letales (CL50) fueron las siguientes: a) extracto metanólico preparado a partir de las semillas CL50= 5,7mg/L para Rockefeller y CL50=9,9 mg/L para MBI; b) extracto metanólico de las hojas CL50= 22,8mg/L para Rockefeller y para MBI CL50= 26,2 mg/L. Los resultados muestran el efecto tóxico de los extractos metanólicos preparados a partir de la semilla y de la hoja del aguacate, sobre Ae. aegypti y sugieren la potencialidad de estos productos como agentes de control químico.

Aedes aegypti is the main vector of dengue in the Americas. This disease is one of the most important arboviruses in Venezuela due to the high morbidity and mortality it produces. The absence of a vaccine against this virus has led to the indiscriminate use of insecticides causing vector resistance, environmental damage and adverse reactions in susceptible individuals. The search for effective and inexpensive ways to control dengue has led to the evaluation of plant extracts as a low environmental risk, economical alternative. The aim of this study was to assess the larvicidal effect of methanol extracts obtained from the seeds and leaves of Persea americana (avocado) on Ae. aegypti [Rockefeller and Mario Briceño Iragorry (MBI) strains]. The methanol extract obtained from the seeds proved to be the most toxic for Ae. aegypti, producing 100% mortality 24 hours post-exposure, at concentrations of 25 mg/L (Rockefeller strain) and 50 mg/L (MBI strain). The lethal concentrations (LC50) were: a) methanol seed extract LC50 = 5.7 mg/L (Rockefeller strain) and 9.9 mg/L (MBI strain), b) methanol leaf extract LC50 = 22.8 mg/L (Rockefeller strain) and 26.2 mg/L (MBI strain). These results demonstrate the toxicity of methanol extracts from avocado seeds and leaves for Ae. aegypti and suggest that these products have potential as chemical controls of this vector.

Infección Congénita por Citomegalovirus en neonatos pretérmino: Hospital Central de Maracay; marzo-julio, 2012 / Congenital Citomegalovirus Infection in preterm infants: Hospital Central de Maracay. March-july 2012

Citomegalovirus, virus ADN bicatenario, de la familia Hepesviridae es capaz de ocasionar infecciones agudas o crónicas en el ser humano, invade a sus víctimas, aprovechándose principalmente de los menos inmunocompetentes quienes sufren mayor daño, especialmente los neonatos. Es de vital importancia su diagnóstico en la mujer de edad fértil, por su prevalencia y riesgo de transmisión vertical durante el embarazo, causando infección congénita que varía de 0.2 a 2.2% de todos los nacidos vivos, pudiendo ocasionar secuelas graves. El objetivo de esta investigación fue conocer la incidencia de infección congénita por Citomegalovirus en neonatos pretérmino y/o de bajo peso en el Hospital Central de Maracay en el período Marzo-Julio 2012, amplificando y detectando el ADN viral por reacción en cadena de polimerasa en muestras sanguíneas. Se estudiaron 106 neonatos menores de 1 semana de edad, siguiendo las normas bioéticas, se registraron sus antecedentes y se les tomó una muestra de sangre completa (1 mL) con anticoagulante. De las muestras procesadas se obtuvo 1 muestra positiva, mostrando incidencia de 0.9%. El neonato infectado, presentó sintomatología respiratoria producto de prematuréz, obtenido por cesárea a causa de ruptura prematura de membranas y procidencia de cordón. La incidencia de infección por Citomegalovirus en neonatos en el Hospital Central de Maracay, está dentro del rango encontrado en otros países, el paciente positivo se considera asintomático para Citomegalovirus tal como lo demuestra la literatura, un 90% de los casos nacen sin clínica evidente.

Citomegalovirus, double-stranded DNA virus, from the Herpesviridae family, can cause acute or chronic infections in humans, it invades his victims, mainly taking advantage of the less immunocompetent ones, suffering most damage, especially the newborn. It is vital to the diagnosis in women of childbearing age, because of its prevalence and the risk of vertical transmission during pregnancy, causing congenital infection ranging from 0.2 to 2.2% of all live births and can cause serious sequelae. The objective of this investigation was to know the incidence of citomegalovirus congenital infection in preterm newborns and / or low weight at the Maracay Central Hospital in the period March-July 2012, amplifying and detecting the viral DNA by polymerase chain reaction in blood. 106 newborns being less than one week old were studied, following bioethical standards, their background were registrated, and was taken a blood sample from them (1 mL). from the processed samples, one tested positive, showing an incidence of 0.9%. The infected newborn presented respiratory symptoms caused by the premature state, it was carried out by cesarean section caused by the rupture of the membranes and the prolapsed corde. The incidence of citomegalovirus infection in newborn at the Maracay Central Hospital, is within the range found in other countries, the positive case is considerate asymptomatic for citomegalovirus. as evidenced on text books, 90% of cases are born without clinical evidence.

Análisis filogenético de cepas Venezolanas del virus de la encefalitis equina del este / Phylogenetic Analysis of Venezuelan Strains of the Eastern Equine Encephalitis Virus

Se realizó un estudio molecular de cinco cepas de virus de encefalitis equina del este (VEEE) mediante secuenciación de productos obtenidos en el ensayo de transcriptasa reversa acoplada a la reacción en cadena de la polimerasa (RT-PCR, por sus siglas en inglés). Secuencias de ~ 500 pb de la región 3’ no traducible del genoma se compararon con secuencias homólogas variantes Sur Americana (SA) y Norte Americana (NA) del complejo VEEE. La cepa EE VE02 EL PAO, con la cual se desarrolló una vacuna inactivada oleosa tuvo más similitud con la cepa EE VE76 EL DELIRIO, seguida por EE VE75 CATATUMBO,  EE VE96 MLLANO y EE VE84 TUCACAS respectivamente. La alineación de secuencias entre las cepas típicas reveló diferencias de 2,82 a 8,48 %. En tanto que, la cepa EE VE02 EL PAO difirió en un 8,86 % de la de Perú (EE PE-0,0155 del linaje III) y en un 38,08 % de la de EEUU (EE-PE-6 del linaje I, usada en vacunas comerciales). Los resultados indican que las cepas autóctonas tuvieron más similitud con la cepa SA, que con la NA. Se han identificado cuatro principales linajes en el complejo de VEEE (I-IV). El árbol filogenético evidenció dos clado: uno que agrupa los linajes I-III y el otro, el linaje IV. La mayoría de las secuencias están contenidas en el primer clado que, a su vez, se separa en dos grupos que contienen secuencias del linaje I y secuencias de los linajes  II-III y, debido al valor bootstrap alto (99%), los grupos se consideran completamente distintos. Sin embargo, éste no es el caso del grupo que contiene a los linajes II-III porque éstos se separan sólo el 53% de las veces, pero se asume que las cepas venezolanas pertenecen al linaje III dividido en dos subclados: IIIA y IIIB.

A molecular study of five strains of the eastern equine encephalitis virus (EEEV) was conducted by sequencing of products generated using the reverse transcriptase assay, coupled to the polymerase chain reaction (RT-PCR). Sequences of approximately 500 pair of bases from the non-translated 3’ region of the genome were compared with homologous sequences of the South American (SA) and North American (NA) variants of the EEEV complex. The EE VE02 EL PAO strain, used to develop an inactivated oil vaccine had most resemblance with the EE VE76 EL DELIRIO strain, followed by the EE VE75 CATATUMBO, the EE VE96 MLLANO and the EE VE84 TUCACAS strains, respectively. The alignment of sequences among typical strains revealed differences of 2.82 and 8.48%, respectively, while the EE VE02 EL PAO strain differed in 8.86% from the Perú strain (EE PE-0.0155, from lineage III) and in 38.08% from the NA strain (EE-PE-6, from lineage I, used in commercial vaccines). The results of the present investigation indicate that the autochthonous strains have more similarly with the SA strain than with the NA strain. Four major lineages (I-IV) in the EEEV complex have been identified. The phylogenetic tree evidenced two clades, one which groups lineages I-III and another, lineage IV. Most of the sequences are contained in the first clade, which at the same time, separates into two groups containing sequences of lineage I and lineages II-III; and, due to the high bootstrap value (99%) the groups are considered completely different. However, this was not the case of the group which enclosed the lineages II and III; because these only separate 53% of the time, but it is assumed that the Venezuelan strains belong to linage III, which diverges into two subclades: IIIA and IIIB.