Circulation of Different Lineages of Dengue Virus Type 2 in Central America, Their Evolutionary Time-Scale and Selection Pressure Analysis

Dengue is caused by any of the four serotypes of dengue virus (DENV-1 to 4). Each serotype is genetically distant from the others, and each has been subdivided into different genotypes based on phylogenetic analysis. The study of dengue evolution in endemic regions is important since the diagnosis is often made by nucleic acid amplification tests, which depends upon recognition of the viral genome target, and natural occurring mutations can affect the performance of these assays. Here we report for the first time a detailed study of the phylogenetic relationships of DENV-2 from Central America, and report the first fully sequenced DENV-2 strain from Guatemala. Our analysis of the envelope (E) protein and of the open reading frame of strains from Central American countries, between 1999 and 2009, revealed that at least two lineages of the American/Asian genotype of DENV-2 have recently circulated in that region. In occasions the co-circulation of these lineages may have occurred and that has been suggested to play a role in the observed increased severity of clinical cases. Our time-scale analysis indicated that the most recent common ancestor for Central American DENV-2 of the American/Asian genotype existed about 19 years ago. Finally, we report positive selection in DENV-2 from Central America in codons of the genes encoding for C, E, NS2A, NS3, and NS5 proteins. Some of these identified codons are novel findings, described for the first time for any of the DENV-2 genotypes

Gestión del conocimiento. Perspectiva multidisciplinaria. Volumen 10

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 10, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada de acceso abierto a todas las áreas del conocimiento, que cuenta con el esfuerzo de investigadores de varios países del mundo, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico que consoliden la transformación del conocimiento en diferentes escenarios, tanto organizacionales como universitarios, para el desarrollo de habilidades cognitivas del quehacer diario. La gestión del conocimiento es un camino para consolidar una plataforma en las empresas públicas o privadas, entidades educativas, organizaciones no gubernamentales, ya sea generando políticas para todas las jerarquías o un modelo de gestión para la administración, donde es fundamental articular el conocimiento, los trabajadores, directivos, el espacio de trabajo, hacia la creación de ambientes propicios para el desarrollo integral de las instituciones

Impacto económico del dengue y del dengue hemorrágico en el Estado de Zulia, Venezuela, 1997-2003 Economic impact of dengue and dengue hemorrhagic fever in the State of Zulia, Venezuela, 1997-2003

OBJETIVOS: Determinar los costos directos e indirectos asociados con la atención de los casos de dengue y de dengue hemorrágico o síndrome de choque por dengue (DH/SCD) entre los años 1997 y 2003 en el Estado de Zulia, Venezuela. MÉTODOS: El número total de pacientes con dengue y DH/SCD se obtuvo de los registros de la Dirección Regional de Epidemiología del Estado de Zulia y de los informes de casos confirmados en la Sección de Virología del Instituto de Investigaciones Clínicas Dr. Américo Negrette, de la Facultad de Medicina, Universidad del Zulia, Maracaibo, entre el 1.° de enero de 1997 y el 31 de diciembre de 2003. Como costos directos se consideraron el costo de la atención médica de urgencia de todos los casos y los costos de hospitalización de los casos con DH/SCD (costo por día-cama y costos de laboratorio). Los costos asociados con la ausencia laboral de los enfermos mayores de 15 años y de las madres acompañantes de los enfermos menores de 15 años conformaron los costos indirectos, ajustados según la proporción de hombres y mujeres en la fuerza laboral activa del país. Para el cálculo se utilizó el salario mínimo anual y los resultados se expresaron en dólares estadounidenses, según la tasa de cambio promedio de cada año. RESULTADOS: En el período estudiado se atendieron 33 857 casos de dengue y de DH/SCD; de ellos, 30 251 (89,35%) fueron de dengue y 3 606 (10,65%) de DH/SCD. Seis de estos fallecieron (letalidad 0,2 por 100 casos de DH/SCD). Los costos directos fueron US$474 251,70; de esa suma, US$ 132 042,30 correspondieron a la atención en los servicios de urgencia y US$342 209,40 a los gastos de hospitalización de los casos con DH/SCD. Los costos indirectos ascendieron a US$ 873 825,84 y representaron 64,8% del gasto total (US$1 348 077,54) relacionado con esta enfermedad en los años estudiados. CONCLUSIONES: Este es el primer estudio acerca del impacto económico del dengue en el Estado de Zulia y en Venezuela. A pesar de que el estudio tuvo algunas limitaciones, los resultados demuestran que el dengue constituye un importante problema de salud pública que ocasiona grandes gastos por ausentismo laboral temporal y que afecta considerablemente al desarrollo de la economía regional y nacional.OBJECTIVES: To determine the direct and indirect costs of medical care provided to cases of dengue and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) between 1997 and 2003 in Zulia State, Venezuela. METHODS: The total number of patients with dengue and DHF/DSS was obtained from records belonging to the Regional Epidemiology Office of the state of Zulia and from reports of cases that were confirmed in the Virology Section of Dr. Americo Negrette’s Clinical Research Institute, Zulia University, Maracaibo, Venezuela, between 1 January 1997 and 31 December 2003. Direct costs included the cost of emergency medical care for all cases and hospital costs for cases with DHF/DSS (cost per bed-day and laboratory expenses). The costs connected to absence from work among patients over 15 years of age and mothers who accompanied their children under 15 years of age comprised the indirect costs, which were adjusted for the proportion of men and women in the labor force. Calculations were based on the minimum yearly wage, and results were given in United States dollars, converted according to each year’s average exchange rate. RESULTS: During the study period, 33 857 cases of dengue and DHF/DSS were seen. Of them, 30 251 (89.35$ 474 251.70; of these costs, US$132 042.30 were spent on emergency medical care and US$ 342 209.40 on the hospital costs of DHF/DSS cases. Indirect costs were US$873 825.84 and comprised 64.8$ 1 348 077.54) connected to this disease during the study years. CONCLUSIONS: This is the first study on the economic impact of dengue in the state of Zulia and in Venezuela. In spite of some limitations, results show that dengue is an important public health problem that causes great expense because of temporary absenteeism from work and that undermines regional and national economic development

Passage of Dengue Virus Type 4 Vaccine Candidates in Fetal Rhesus Lung Cells Selects Heparin-Sensitive Variants That Result in Loss of Infectivity and Immunogenicity in Rhesus Macaques▿

Three dengue virus type 4 (DENV-4) vaccine candidates containing deletions in the 3′ noncoding region were prepared by passage in DBS-FRhL-2 (FRhL) cells. Unexpectedly, these vaccine candidates and parental DENV-4 similarly passaged in the same cells failed to elicit either viremia or a virus-neutralizing antibody response. Consensus sequence analysis revealed that each of the three viruses, as well as the parental DENV-4 when passaged in FRhL cells, rapidly acquired a single Glu327-Gly substitution in domain III (DIII) of the envelope protein (E). These variants appear to have accumulated in response to growth adaptation to FRhL cells as shown by growth analysis, and the mutation was not detected in the virus following passage in C6/36 cells, primary African green monkey kidney cells, or Vero cells. The Glu327-Gly substitution was predicted by molecular modeling to increase the net positive charge on the surface of E. The Glu327-Gly variant of the full-length DENV-4 selected after three passages in FRhL cells showed increased affinity for heparan sulfate compared to the unpassaged DENV-4, as measured by heparin binding and infectivity inhibition assays. Evidence indicates that the Glu327-Gly mutation in DIII of the DENV-4 E protein was responsible for reduced infectivity and immunogenicity in rhesus monkeys. Our results point out the importance of cell substrates for vaccine preparation since the virus may change during passages in certain cells through adaptive selection, and such mutations may affect cell tropism, virulence, and vaccine efficacy

Efecto de la Dosis de eCG sobre las Características Foliculares y Luteales, Momento y Tasa de Ovulación de Novillas Mestizas Cebú Sincronizadas con Progestágeno Intravaginal

Para evaluar el efecto de una dosis reducida de la gonadotropina coriónica equina (eCG) sobre el crecimiento folicular, las características luteales, el momento de la ovulación y la tasa de ovulación en novillas mestizas cebú sincronizadas con unprogestágeno intravaginal, se seleccionaron 41 novillas cíclicas. Para la sincronización se utilizó una esponja intravaginal (EI) impregnada con 250 mg de medroxi-acetato-progesterona (MAP), bajo el protocolo siguiente: Día 0: Inserción de la EI más 2 mg de benzoato de estradiol (BE) im y 25 mg de PGF2α im; Día 6: 12,5 mg de PGF2α, 21 novillas recibieron 400 UI de eCG im (T1; n=21) y 20 recibieron 200 UI (T2; n=20); Día 8: retiro de EI; Día 9: 0,5 mg de BE im. La evaluación ultrasonográfica se realizó entre los días 6 y 8, cada 24 h, para determinar la tasa de crecimiento folicular (TCF). A partir del día 8 hasta la ovulación, se evaluaron cada 8 h para determinar el diámetro del folículo ovulatorio (DFO), el momento de la ovulación (MO), el diámetro y área del cuerpo lúteo (DCL y ACL), así como la tasa de ovulación (TO). Las variables TCF, DFO, DCL y ACL se analizaron con el PROC GLM, mientras que el MO mediante el procedimiento NPAR1WAY y la TO mediante χ2, utilizando el PROC FREQ del SAS. No hubo diferencias en las variables TCF, DFO y ACL (1,44±0,27 vs.1,72±0,27 mm/d; 12,61±0,47 vs.13,85±0,47 mm y 33,9±2,1 vs. 30,3±2,4 mm2 para T1 y T2, respectivamente). Las ovulaciones ocurrieron en promedio 61,67±1,8 y 62,73±1,92 h, respectivamente después de retirado el dispositivo para T1 y T2. El DCL fue mayor (P<0,05) en T1 que en T2 (21,7±1,44 vs.16,9±1,56 mm). Se encontraron mayores porcentajes para la TO (P=0,06) en el grupo T1 que en T2 (95,25 vs. 75%). En conclusión, la dosis de 200 UI de eCG fue suficiente para inducir un adecuado crecimiento folicular y no afectar el momento de la ovulación y la dosis de 400 UI de eCG mejoró las características del cuerpo lúteo y permitió obtener un mayor número de ovulaciones en novillas mestizas cebú sincronizadas con un progestágeno intravaginal.AbstractThe effect of a reduced dose of eCG on follicular growth, luteal characteristics, ovulation time (OT) and ovulation rate (OR) was evaluated in crossbred Zebu heifers synchronized with an intravaginal progestagen device. A total of 41 cyclic heiferswas selected and synchronized with an intravaginal sponge (IE) impregnated with 250 mg of medroxyprogesterone-acetate (MPA), using the following protocol. Day 0: insertion of IE plus 2 mg of estradiol benzoate (EB) im and 25 mg of PGF2α im . Day 6: 12.5 mg de PGF2α, 21 heifers received 400 IU eCG im (T1; n = 21) and 20 received 200 IU (T2; n = 20). Day 8: IE withdrawal. Day 9: 0.5 mg of BE im . Heifers were timed-artificial inseminated (TAI) between 52 and 56 h after IE withdrawal. Ultrasound evaluation was performed between d 6 until d 8, every 24 h, to determine the rate of follicular growth (FGR). Then, from d 8 until ovulation, heifers were evaluated every 8 h to determine diameter of the ovulatory follicle (DOF), OT, and diameter (CLD) and area (CLA) of the corpus luteum. The OR was also assessed. The variables FGR, DOF, CLD and CLA were analyzed using PROC GLM, while OT was analyzed using the NPAR1WAY procedure and OR using Chi-square with PROC FREQ from SAS. No differences were found in FGR, DOF, and CLA (1.44±0.27 vs. 1.72±0.27 mm/d; 12.61±0.47 vs. 13.85±0.47 mm and 33.9±2.1 vs. 30.3±2.4 mm2 for T1 and T2, respectively). Ovulations occurred at 61.67±1.8 h and 62.73±1.92 h, respectively, after IE withdrawal for T1 y T2, respectively. The CLD in T1 was higher (P<0.05) than T2 (21.7±1.44 vs. 16.9±1.56 mm). Higher OR (P=0.06) were found in T1 than in T2 (95.25 vs. 75.0%). In conclusion, the dose of 200 IU of eCG was sufficient to induce an suitable follicular growth without affecting OT and dosing with 400 IU of eCG improved the corpus luteum characteristics and allowed to obtain a greater number of ovulations in crossbred Zebu heifers synchronized with an intravaginal progestagen

Epidemiological Scenario of Dengue in Brazil

Dengue is the most important reemerging mosquito-borne viral disease worldwide. It is caused by any of four Dengue virus types or serotypes (DENV-1 to DENV-4) and is transmitted by mosquitoes from the genus Aedes. Ecological changes have favored the geographic expansion of the vector and, since the dengue pandemic in the Asian and Pacific regions, the infection became widely distributed worldwide, reaching Brazil in 1845. The incidence of dengue in Brazil has been frequently high, and the number of cases in the country has at some point in time represented up to 60% of the dengue reported cases worldwide. This review addresses vector distribution, dengue outbreaks, circulating serotypes and genotypes, and prevention approaches being utilized in Brazil

Differential Oxidative Stress Induced by Dengue Virus in Monocytes from Human Neonates, Adult and Elderly Individuals

<div><p>Changes in immune response during lifespan of man are well known. These changes involve decreased neonatal and elderly immune response. In addition, it has been shown a relationship between immune and oxidative mechanisms, suggesting that altered immune response could be associated to altered oxidative response. Increased expression of nitric oxide (NO) has been documented in dengue and in monocyte cultures infected with different types of dengue virus. However, there is no information about the age-dependent NO oxidative response in humans infected by dengue virus. In this study, monocyte cultures from neonatal, elderly and adult individuals (n = 10 each group) were infected with different dengue virus types (DENV- 1 to 4) and oxidative/antioxidative responses and apoptosis were measured at days 1 and 3 of culture. Increased production of NO, lipid peroxidation and enzymatic and nonenzymatic anti-oxidative responses in dengue infected monocyte cultures were observed. However, neonatal and elderly monocytes had lower values of studied parameters when compared to those in adult-derived cultures. Apoptosis was present in infected monocytes with higher values at day 3 of culture. This reduced oxidant/antioxidant response of neonatal and elderly monocytes could be relevant in the pathogenesis of dengue disease.</p></div

Genetic Analysis of West Nile Virus Isolates from an Outbreak in Idaho, United States, 2006–2007

West Nile virus (WNV) appeared in the U.S. in 1999 and has since become endemic, with yearly summer epidemics causing tens of thousands of cases of serious disease over the past 14 years. Analysis of WNV strains isolated during the 2006–2007 epidemic seasons demonstrates that a new genetic variant had emerged coincidentally with an intense outbreak in Idaho during 2006. The isolates belonging to the new variant carry a 13 nt deletion, termed ID-Δ13, located at the variable region of the 3′UTR, and are genetically related. The analysis of deletions and insertions in the 3′UTR of two major lineages of WNV revealed the presence of conserved repeats and two indel motifs in the variable region of the 3′UTR. One human and two bird isolates from the Idaho 2006–2007 outbreaks were sequenced using Illumina technology and within-host variability was analyzed. Continued monitoring of new genetic variants is important for public health as WNV continues to evolve