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1.
Weekly Epidemiological Monitor. 2019; 12 (3): 1
in English | IMEMR | ID: emr-199687

ABSTRACT

The Ministry of Health, Sultanate of Oman reported an outbreak of dengue fever, which started during second week of December 2018, and till 12th January 2019, a total of 48 dengue fever cases were reported and these cases are proba-bly the first locally-acquired dengue fever cases ever reported from Oman


Subject(s)
Humans , Travel-Related Illness , Neglected Diseases , Densovirinae/virology
2.
Weekly Epidemiological Monitor. 2017; 10 (03): 1
in English | IMEMR | ID: emr-187404

ABSTRACT

In response to the threat of introduction of Zika Virus [ZIKAV], the WHO Eastern Mediterranean Regional Office has produced risk map for the Region as well as for each of the twenty-two countries that integrates the information about two zika vectors- Aedes aegypti and Ae. Albopictus taking into account the current and future habitat suitability of these vectors in these countries


Subject(s)
Zika Virus , Middle East Respiratory Syndrome Coronavirus , Densovirinae , Maps as Topic
3.
Weekly Epidemiological Monitor. 2017; 10 (19): 1
in English | IMEMR | ID: emr-187411

ABSTRACT

The Chikungunya outbreak reported from Pakistan [Please see weekly epidemiological monitor-issue no 01; volume-10; 01 January 2017] showed a slight peak in recent time with additional cases reported. A total of 2,267 cases were notified to WHO from 19 December 2016 to 05 May 2017. All the cases have been reported from Karachi, Sindh Province


Subject(s)
Humans , Female , Male , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Young Adult , Adult , Middle Aged , Aged , Aged, 80 and over , Chikungunya virus/pathogenicity , Togaviridae , Densovirinae , Age Distribution
4.
Med. interna (Caracas) ; 31(1): 8-15, 2015. ilus, mapas
Article in Spanish | LILACS | ID: lil-772203

ABSTRACT

Una nueva enfermedad amenaza a las Américas, se trata de la infección por el virus Zika (VZIK), perteneciente a la familia Flaviviridae, genero flavivirus, trasmitida por mosquitos del género Aedes. El VZIK fue aislado en abril de 1947 en Uganda en el bosque Zika. La primera infección en un ser humano fue en Nigeria en 1954. Se trasmite fundamentalmente por vectores del género Aedes, también vía vertical, y un solo caso por relación sexual. Es considerada una enfermedad emergente; previo al año 2007, los casos reportados eran esporádicos, y luego se han descrito dos brotes de importancia, uno en 2012 en Yap, Micronesia y los años 2013, 2014, 2015, se han producido epidemias en la Polinesia francesa, Isla de Pascua, las Islas Cook y Nueva Caledonia. Con excepción del brote en la isla de Pascua el año 2014, la enfermedad en las Américas era totalmente desconocida; recientemente se ha descrito un brote en el norte de Brasil, dado que los vectores trasmisores de la enfermedad se encuentran ampliamente distribuidos en la región y se proveen epidemias de mayor magnitud en un periodo de tiempo cercano. Clínicamente es similar al dengue y la chikungunya, se caracteriza por mialgias, cefalea, artralgias principalmente de manos y pies, conjuntivitis no purulenta, las complicaciones hemorrágicas y neurológicas son raras. La mayoría de las infecciones son asintomáticas, y no se han reportado fallecimientos. El método recomendado para su diagnóstico es el PCR en tiempo real, durante los primeros 3-5 días durante la viremia, la serología IgM y IgG puede dar reacción cruzada con otros flavivirus como el dengue. Los Ministerios de Salud deben activar sus “Sistemas devigilancia” para detectar precozmente la introducción del virus, sensibilizar a los profesionales de la salud, el control de los vectores es fundamental


A new disease threatens the Americas, it is an infection caused by the Zika (VZIK) virus, which belongs to the Flaviviridae family, genus flavivirus. The VZIK was isolated in April 1947 in Uganda in the Zika forest and the the first infected human was in Nigeria in 1954. It is primarily transmitted by vectors of the genus Aedes, by vertical transmission, potentially through blood and only one case of sexual intercourse. It is considered an emerging disease; before 2007 reported cases were sporadic, two major outbreaks have been reported, one in 2012 in Yap, Micronesia and in the years 2013, 2014 and 2015 outbreaks had occurred in French Polynesia, Pascua Island (Chile), the Cook Islands and New Caledonia. Except for the VZIK outbreak at the Pascua Island in 2014, this disease was completely unknown in the Americas. Recently an outbreak has been reported in northern Brazil, because transmitters vectors, Aedes aegypti and A. albopictus, are widely distributed in the region, and outbreaks of greater magnitude are expected in a short period of time. The disease is similar to Dengue and Chikungunya, is characterized by myalgia, headache and hands and feet arthralgiae, non purulent, hemorrhagic and neurological complications are rare. It is believed that most of the cases are asymptomatic and until now no deaths have been reported. The recommended method for diagnosis is the real-time PCR of the first 3–5 days during viremia; the IgM and IgG serology have crossed reaction with other flaviviruses as dengue. Ministries of Health must activate their "monitoring systems" for early detection of virus introducion and alert health professionals and general population about this emerging disease. The Americas could be affected by three diseases with similar clinical spectrum of dengue, chikungunya and now VZIK infection, which are transmitted by the Aedes mosquito, hence the vector control is essential in the fight against these diseases


Subject(s)
Humans , Male , Female , Disease Outbreaks/prevention & control , Densovirinae , Virus Diseases/diagnosis , Virus Diseases/pathology , Central America , Latin America , North America , South America
5.
Chinese Journal of Virology ; (6): 537-541, 2015.
Article in Chinese | WPRIM | ID: wpr-296251

ABSTRACT

Several virus families have been shown to encode microRNAs (miRNAs), which have roles in the infection and replication of viruses in host cells. These virus-encoded miRNAs are identified in double-stranded DNA virus (dsDNA virus) and in several RNA virus families, but not in single-stranded DNA virus (ssDNA virus). We used a bioinformatics approach based on VMir, miRNAFold and MaturePred software to predict virus-encoded miRNA-like small RNAs from the genome of a ssDNA virus: Aedes aegypti densovirus (AaeDV). Northern blotting and stem-loop reverse transcription-polymerase chain reaction (RT-PCR) were used to detect predicted small RNAs. A miRNA-like small RNA termed "AaeDVMD" was identified by stem-loop RT-PCR from predicted candidates. This is the first report demonstrating that a ssDNA virus can encode miRNA-like small RNAs. These data will aid further exploration of the interaction between the AaeDV and its mosquito host.


Subject(s)
Animals , Aedes , Virology , Base Sequence , Computational Biology , Densovirinae , Chemistry , Genetics , Metabolism , MicroRNAs , Chemistry , Genetics , Metabolism , Molecular Sequence Data , RNA, Viral , Chemistry , Genetics , Metabolism
6.
Rev. cuba. med. trop ; 66(2): 252-262, Mayo.-ago. 2014.
Article in Spanish | LILACS, CUMED | ID: lil-731977

ABSTRACT

INTRODUCCIÓN: Aedes albopictus es un mosquito originario de las selvas del sudeste de Asia, que en las últimas décadas está extendiéndose a todos los continentes. Ésta especie se registró por primera vez en Cuba en la provincia La Habana en 1995. OBJETIVO: determinar la distribución espacial y temporal de los sitios de cría de Ae. albopictus en los municipios de la provincia de La Habana durante el 2011 y 2012. MÉTODOS: se realizó el muestreo de todos los depósitos conteniendo agua en los bloques o manzanas, así como, en los terrenos baldíos presentes en las áreas urbanas y peri urbanos del universo de cada municipio que compone la provinciaLa Habana. RESULTADOS: Ae. albopictus se registró en 13 de los 15 municipios del área estudiada, lo que evidencia además de su introducción su dispersión en el área. Se encontró una mayor presencia de Ae. albopictus en los municipios periféricos tales como Playa, La Lisa, Boyeros, Arroyo Naranjo, Cotorro, Guanabacoa y Habana del Este.Se encontró un incremento en el total de muestras en el 2012 con respecto al 2011notándose en ambos años un incremento a partir de junio hasta octubre. La mayor cantidad de muestras de Ae. albopictus con más de una especie de culícido correspondieron en ambos años a los meses de lluvia (mayo-septiembre). CONCLUSIONES: se constató la presencia y distribución de Ae. albopictus en La Habana favorecido por las condiciones ecológicas existentes y la disponibilidad de sitios de cría(AU)


INTRODUCTION: Aedes albopictus is a mosquito native to the forests of Southeast Asia which has spread to all continents in recent decades. The species was first reported in Cuba in the province of Havana in 1995. OBJECTIVE: determine the spatial and temporal distribution of breeding sites of Ae. albopictus in the municipalities of the province of Havana in 2011 and 2012. METHODS: sampling was conducted of all containers with water in residential areas and vacant lots of urban and suburban zones of all municipalities in the province of Havana. RESULTS: presence of Ae. albopictus was reported in 13 of the 15 municipalities in the study area, revealing not only its introduction but also its spread in the area. The greatest presence of Ae. albopictus was found in peripheral municipalities like Playa, La Lisa, Boyeros, Arroyo Naranjo, Cotorro, Guanabacoa and Habana del Este. An increase in the total number of samples was observed in 2012 with respect to 2011. In both years there was an increase from June to October. Again in both years, the greatest number of samples of Ae. albopictus with more than one culicid species was found in the rainy season (May to September). CONCLUSIONS: the presence and distribution of Ae. albopictus in Havana was confirmed. Favorable ecological conditions and the availability of breeding sites play a decisive role in such presence and distribution(AU)


Subject(s)
Humans , Densovirinae/growth & development , Culicidae , Aedes/growth & development , Temporal Distribution
7.
Rev. cuba. med. trop ; 66(1): 71-83, ene.-mar. 2014.
Article in Spanish | LILACS | ID: lil-717209

ABSTRACT

Introducción: el Ministerio de Salud Pública de la ciudad de Guayaquil, Ecuador, ha utilizado, hasta la fecha, temefos (abate) como principal medida química para el control larval de Aedes aegypti, principal vector del dengue en este país.Objetivos: determinar la resistencia a temefos y sus mecanismos bioquímicos en dos cepas Aedes aegypti de Ecuador, así como determinar la eficacia del regulador de crecimiento, pyriproxifeno, como posible alternativa para su control.Métodos: en larvas de Aedes aegypti provenientes de dos localidades (Pascuales y Guayacanes), de la ciudad de Guayaquil, Ecuador, se evaluó la resistencia al insecticida oganofosforado temefos y la eficacia del pyriproxifeno mediante metodologías recomendadas por la Organización Mundial de la Salud. Los mecanismos de resistencia metabólicos se determinaron a través de ensayos bioquímicos y electroforesis en gel de poliacrilamida.Resultados: las larvas de la cepa Pascuales resultaron con moderado nivel de resistencia a temefos y Guayacanes resultó susceptible. A través de ensayos bioquímicos y electroforesis se demostró que el mecanismo de resistencia de acción metabólica, basado en una incrementada actividad de la esterasa-A4, resultó ser responsable de la resistencia detectada a temefos. Las dosis de pyriproxifeno que causaron 50 por ciento de inhibición de la emergencia (IE50) y 95 por ciento (IE95), resultaron muy similares entre las cepas de Ecuador y la cepa de referencia susceptible a insecticidas, Rockefeller.Conclusiones: se demostró que el mecanismo de esterasas, responsable de la resistencia a temefos, está presente en Aedes aegypti de Guayaquil, Ecuador, de ahí la necesidad de monitorear este fenómeno en diferentes regiones del país. El regulador de crecimiento pyriproxifeno resultó muy eficaz, y esto lo convierte en una alternativa a evaluar para el control de poblaciones de Aedes aegypti en Ecuador.


Introduction: the Ministry of Public Health in the city of Guayaquil, Ecuador, has so far used temephos (abate) as the main chemical measure for larval control of Aedes aegypti, the fundamental dengue vector in the country. Objectives: determine temephos resistance and its biochemical mechanisms in two strains of Aedes aegypti in Ecuador, and determine the efficacy of the growth regulator pyriproxyfen as a possible control alternative. Methods: resistance to organophosphorus insecticide temephos and the efficacy of pyriproxyfen were evaluated in Aedes aegypti larvae from two areas (Pascuales and Guayacanes) in the city of Guayaquil, Ecuador, by means of methodologies recommended by the World Health Organization. Metabolic resistance mechanisms were determined by biochemical assays and polyacrylamide gel electrophoresis. Results: larvae from the Pascuales strain showed moderate resistance to temephos, whereas those from the Guayacanes strain were found to be susceptible. Biochemical assays and electrophoresis revealed that the resistance mechanism of metabolic action, based on increased esterase-A4 activity, was responsible for the temephos resistance observed. The doses of pyriproxyfen causing 50 percent emergence inhibition (EI50) and 95 percent (EI95) were very similar between strains from Ecuador and the reference insecticide susceptible strain Rockefeller. Conclusions: it was found that the esterase mechanism, responsible for temephos resistance, is present in Aedes aegypti from Guayaquil, Ecuador. Hence the need to monitor this phenomenon in different regions of the country. The growth regulator pyriproxyfen proved to be very effective, which turns it into an alternative to evaluate for the control of Aedes aegypti populations in Ecuador.


Subject(s)
Aedes/virology , Densovirinae/chemistry , Juvenile Hormones/therapeutic use , Insecticides, Organophosphate/prevention & control , Myiasis/prevention & control , Temefos
8.
Rev. biol. trop ; 61(3): 1175-1188, sep. 2013. ilus, graf, mapas
Article in English | LILACS | ID: lil-688468

ABSTRACT

The development of shrimp aquaculture in Mexican coasts of the Gulf of Mexico began to be explored using the Pacific white shrimp Litopenaeus vannamei in the mid 90´s. Many concerns over the risk of disease transmission to the economically important native penaeids, have been the main deterrent for the aquaculture of L. vannamei in the region. Concurrently, more than 10 years of research experience on the aquaculture suitability of the native Litopenaeus setiferus from the Terminos Lagoon, in the Yucatán Peninsula, have been accumulated. The aim of this study was then to determine the seasonal variations of the naturally acquired diseases and the possible detection of exotic pathogens. For this, random subsamples (n~60) of juveniles L. setiferus were collected from monthly captures. In order to detect the widest range of pathogens, including infectious hypodermal and hematopoietic necrosis (IHHNv) and white spot syndrome (WSSv) viruses, both histopathological and molecular methods were employed. Monthly prevalence (%) was calculated for every finding. We were able to detect a total of 16 distinct histological anomalies, most of which the presump- tive aetiological agent was readily identified. PCR results for viruses were negative. For some pathogens and symbionts, the prevalence was significantly different between the adult and juvenile populations. Prevalence of diseases tended to be higher in juvenile shrimp than in adults. The results of this study indicated that L. setiferus carry a wide variety of pathogens and symbionts that seem to be endemic to penaeids of the Gulf of Mexico, and those juveniles were more conspicuous to acquire pathogens and symbionts than adults.


Durante la década de los 90´s se introdujo el camarón blanco del Pacífico Litopenaeus vannamei a los Estados costeros mexicanos del Golfo de México con fines acuícolas, por lo que desde entonces existe preocupación por la posible introducción de enfermedades que puedan afectar a las poblaciones de camarones nativos. La investigación sobre la domesticación de especies nativas para una acuacultura sustentable se ha realizado por más de 10 años, sin embargo, aún existe escasa información sobre las enfermedades que se presentan de manera natural en estas poblaciones y posible trasfaunación. El presente estudio aborda el problema de las enfermedades encontradas en subpoblaciones de jóvenes y adultos de Litopenaeus setiferus del Área natural protegida Laguna de Términos, estado de Campeche, México. Técnicas de histología y biología molecular fueron utilizadas como herramientas de diagnóstico. Se encontró que L. setiferus es portador de patógenos y simbiontes endémicos del Golfo de México, y comparativamente, los jóvenes son más susceptibles en adquirir estas infecciones que los adultos, como probable respuesta al ambiente lacustre que ocupan. No se encontró evidencia de los virus IHHNv y WSSv, aunque en trabajos más recientes en algunos Estados del Norte ya se han detectado en poblaciones silvestres.


Subject(s)
Animals , Aquaculture , DNA Virus Infections/veterinary , Penaeidae/virology , DNA Virus Infections/epidemiology , Densovirinae/genetics , Gulf of Mexico/epidemiology , Polymerase Chain Reaction , Population Surveillance , Seasons , White spot syndrome virus 1/genetics
9.
Rev. cuba. med. trop ; 65(3): 339-349, jul.-sep. 2013.
Article in Spanish | LILACS, CUMED | ID: lil-692259

ABSTRACT

Introducción: el uso intensivo del larvicida químico temefos (abate) en Cuba, ha generado el desarrollo de mecanismos de resistencia en Aedes (Stegomyia) aegypti (Linnaeus, 1762). Por esta razón, apremia la necesidad de evaluar otras alternativas de control, como el pyriproxyfeno, inhibidor de crecimiento. Objetivos: determinar la eficacia de pyriproxyfeno como larvicida, pupicida y adulticida en cepas de referencia de Aedes aegypti y establecer su efecto sobre la reproducción. Métodos: para el estudio se utilizó una cepa de Aedes aegypti de referencia susceptible (Rockefeller) y otra resistente (SANtemF13) a temefos. La evaluación de pyriproxyfeno se realizó a través de bioensayos recomendados por la Organización Mundial de la Salud. Se determinó el efecto en la reproducción, midiendo la fecundidad y viabilidad de los huevos (fertilidad) en larvas de la cepa Rockefeller, sobrevivientes a dosis subletales de pyriproxyfeno. Resultados: en Rockefeller, pyriproxyfeno manifestó actividad larvicida en 32 por ciento, pupicida en 21 por ciento y adulticida solo 1 por ciento. En SANtem F13, resultó larvicida en 31 por ciento, pupicida 12 por ciento y adulticida 1 por ciento. El análisis de varianza entre rangos de dosis letales para larvas, pupas y adultos de las cepas referenciales, Rockefeller y SANtem F13, no mostró diferencias significativas (p= 0,000001). El pyriproxyfeno resultó ser un excelente inhibidor de la emergencia de adultos en las cepas de Aedes aegypti estudiadas a concentraciones bajas, inferiores a las recomendadas por la Organización Mundial de la Salud en mosquitos del género Aedes. También tuvo fuerte efecto subletal y afectó la fertilidad de los adultos, en condiciones de laboratorio. Conclusión: el inhibidor de crecimiento pyriproxyfeno representa una buena alternativa a incluir dentro de las estrategias de control integrado de Aedes aegypti en Cuba, sin afectarse su eficacia por la resistencia que esta especie ha...


Introduction: intensive use of chemical larvicide temephos (abate) in Cuba has resulted in the development of resistance mechanisms in Aedes (Stegomyia) aegypti (Linnaeus, 1762). Therefore, there is an urgent need to consider other control alternatives, such as pyriproxyfen, a growth inhibitor. Objectives: determine the efficacy of pyriproxyfen as larvicide, pupicide and adulticide in reference strains of Aedes aegypti and establish its effect on reproduction. Methods: the study was based on a strain of reference Aedes aegypti susceptible to temephos (Rockefeller) and a strain resistant to temephos (SANtemF13). Pyriproxyfen was evaluated with bioassays recommended by the World Health Organization. Determination was made of the effect of pyriproxyfen on reproduction by measuring fecundity and egg viability (fertility) in larvae of the Rockefeller strain surviving sublethal doses of pyriproxyfen. Results: in the Rockefeller strain, pyriproxyfen was larvicidal in 32 percent, pupicidal in 21 percent and adulticidal in a mere 1 percent. In the SANtem F13 strain, it was larvicidal in 31 percent, pupicidal in 12 percent and adulticidal in 1 percent. Analysis of variance between ranges of lethal doses for larvae, pupas and adults of the reference strains Rockefeller and SANtem F13 did not show any significant differences (p= 0.000001). Pyriproxyfen was found to be an excellent inhibitor of adult emergence in the strains of Aedes aegypti studied when used at low concentrations, below those recommended by the World Health Organization for mosquitoes of the genus Aedes. It also showed a strong sublethal effect and affected the fertility of adults in laboratory conditions. Conclusion: growth inhibitor pyriproxyfen is a good alternative to be included among integrated control strategies against Aedes aegypti in Cuba without affecting its efficacy, due to the resistance that this species has developed to larvicide temephos


Subject(s)
Mosquito Control/methods , Densovirinae , Insecticide Resistance/immunology
10.
Bol. malariol. salud ambient ; 51(2): 107-116, dez. 2011.
Article in Portuguese | LILACS | ID: lil-630459

ABSTRACT

A dengue é causada por um Flavivirus que apresenta elevada diversidade genética, com quatro sorotipos e vários genótipos. A enfermidade é endêmica na maioria dos países das Américas, e as fêmeas de Aedes (Stegomyia) aegypti (Linnaeus, 1762) são as únicas transmissoras, com importância epidemiológica. Um único mosquito infectado permanece assim pelo resto de sua vida, podendo infectar múltiplos hospedeiros humanos. Com a detecção do vírus da dengue em mosquitos, podemos revelar o sorotipo circulante ou a entrada de um novo sorotipo em uma determinada região, sem quaisquer implicações éticas, além de apresentar reprodutibilidade dos resultados. Esta revisão aborda as técnicas para detecção viral em mosquitos, suas vantagens e limitações, bem como as pesquisas já realizadas com populações naturais de Aedes aegypti.


Dengue is caused by Flavivirus which exhibits high genetic diversity, with four serotypes and various genotypes. The disease is endemic in most countries in the Americas, and the female Aedes (Stegomyia) aegypti (Linnaeus, 1762) are the only transmitters of epidemiological importance. A single infected mosquito remains so for the rest of his life and can infect multiple human hosts. For dengue virus detection in mosquitoes, the circulating serotype can be revealed or detect an entry of a new serotype in the region, without any ethical implications, and reproducible results. This review covers the techniques for detecting virus in mosquitoes, their advantages and limitations, as well as previous studies with natural populations of Aedes aegypti.


El dengue es causado por un Flavivirus que presenta una alta diversidad genética, cuatro serotipos y varios genotipos. Esta enfermedad es endémica en la mayoría de los países del continente Americano y sólo las hembras de Aedes (Stegomyia) aegypti (Linnaeus, 1762) son las transmisoras de esta enfermedad de importancia epidemiológica. Un único mosquito infectado permanece así por el resto de su vida pudiendo infectar múltiples hospederos humanos. El detectar el serotipo de virus de dengue presente en los mosquitos permite conocer, ya sea, el serotipo circulante o el ingreso de un nuevo serotipo a una determinada región sin ningún tipo de implicaciones éticas presentando así resultados reproducibles. Ésta revisión aborda las técnicas de detección viral en mosquitos, sus ventajas y limitaciones, así como estudios previos con poblaciones naturales de Aedes aegypti.


Subject(s)
Humans , Animals , Aedes , Dengue , Densovirinae , Flavivirus , Endemic Diseases , Flavivirus Infections , Dengue Virus/pathogenicity
11.
Bol. malariol. salud ambient ; 51(2): 145-158, dez. 2011. ilus
Article in Spanish | LILACS | ID: lil-630462

ABSTRACT

Se realizó un estudio retrospectivo y longitudinal en el área metropolitana de Maracay para el período 1997-2005, a fin de determinar si las variables climáticas y entomológicas influyen sobre la casuística de dengue. Se obtuvieron los datos climatológicos diarios y mensuales de la Estación Climatológica de la Universidad Central de Venezuela y los datos epidemiológicos basados en casos confirmados y muy sugestivos reportados por el Laboratorio Regional de Diagnóstico e Investigación del Dengue y otras Enfermedades Virales (LARDIDEV). Los datos entomológicos se obtuvieron de colectas de adultos de Aedes aegypti (L.) realizadas durante el período Noviembre 2000-Diciembre 2001. La abundancia del vector varió de 3,6 Aedes/casa durante el mes de Abril (período de sequía) a 14,7 Aedes/casa durante el mes de Agosto (período de lluvia). El análisis de correlación de Pearson mostró correlación positiva entre el número de casos reportados con la precipitación (r= 0,7183, P = 0,0038) y la abundancia de Ae. aegypti (r= 0,677, P = 0,0078), pero no con la temperatura ni la humedad relativa para el período Noviembre 2000-Diciembre 2001. El análisis de regresión mostró que para dos meses de rezago existe una regresión lineal altamente significativa (P < 0,0001) con un ajuste de R2= 88,7%, indicando que en promedio, la mayor casuística de dengue ocurre dos meses después de ocurrido el pico de precipitación. Los resultados obtenidos podrían ser utilizados para diseñar e implementar programas para la vigilancia epidemiológica y entomológica del dengue, así como establecer un sistema de alerta temprana para la prevención de brotes y/o epidemias de la enfermedad.


In order to determine the influence of climatic and entomological variables on the number of dengue cases, a retrospective and longitudinal study was conducted in the metropolitan area of Maracay during the period 1997-2005. Daily and monthly climatological data was obtained from the Climatological Station at the Universidad Central de Venezuela and epidemiological data based on confirmed and highly suggestive cases reported by the Regional Laboratory for Diagnosis and Research on Dengue and other Viral Infections (LARDIDEV). Aedes aegypti (L.) adults were collected monthly between November 2000 and December 2001. Vector abundance varied from 3,6 Aedes/house during April (dry season) to 14,7 Aedes/house (rainy season). Pearson correlation analysis showed a positive correlation between the number of dengue cases and rainfall (r= 0,7182, P =0,0038) and abundance of Ae. aegypti (r= 0,667, P =0,0078), but no correlation was found with temperature or relative humidity. Regression analysis showed that there was a highly significant relation (R2 = 88,7%, P< 0,0001) between rainfall and dengue cases at a lag of 2 months. The present results might be used to design and implement programs for the epidemiological and entomological dengue surveillance as well as to establish an early warning system to prevent epidemics.


Subject(s)
Humans , Aedes , Culicidae , Dengue , Densovirinae , Entomology , Chemical Precipitation , Climatic Zones , Diptera , Virus Diseases
12.
salvador; s.n; 2011. 73 p. ilus.
Thesis in Portuguese | LILACS | ID: lil-618639

ABSTRACT

Apesar do combate recorrente ao mosquito vetor da dengue, o Aedes aegypti, mais de 80% dos estratos da cidade de Salvador-BA apresentam condição de alerta ou risco de surto de dengue. Visto que as abordagens tradicionais para controle do mosquito vetor da dengue não têm produzido os efeitos esperados, o presente estudo avaliou parâmetros moleculares para vigilância entomológica do A. aegypti utilizando ferramentas de geotecnologia e de genética de populações como forma de apoiar o trabalho de campo e ações integradas das instâncias responsáveis pelo controle da dengue. O desenho do estudo apresentou um componente transversal, descrevendo dados sobre a genética de população de larvas de A. aegypti coletadas em Salvador e amostras controle coletadas no ano de 2009 em Jacobina e Vitória da Conquista, além da cepa Rockfeller, e um longitudinal, sobre amostras de quatro áreas (Plataforma, Itapagipe, Tancredo Neves e Itapuã) durante quatro ciclos do LIRAa Salvador entre 2007 a 2009. O DNA de cada larva foi isolado pelo método DNAzol® e genotipado por 5 marcadores SSR através da técnica de PCR e eletroforese capilar. A distribuição espacial dos criadouros foi realizada utilizando-se ortofotos pelo programa Arcview v. 9.3. Para a análise da diferenciação populacional e teste de hipótese foram utilizados os programas GenePop, GenAlEx e Spade, e para inferência populacional utilizamos o programa structure. Os marcadores encontraram-se, em geral, em equilíbrio de H-W e comportaram-se como independentes. Quando utilizamos a estatística Φpt e RST foi possível discriminar significantemente (p<0,05) populações geneticamente diferenciadas de A. aegypti a nível de município, áreas do município de Salvador e estratos pertencentes a estas áreas. O programa structure indicou K igual a 2 populações como ideal para representar os dados, considerando a população de Salvador uma miscigenação de populações de A. aegypti de outras regiões do estado. Os resultados do estudo longitudinal mostraram uma diferenciação entre os ciclos de 2008.3 e 2009.4. As medidas de Ne variaram consideravelmente por área e ciclo evidenciando o efeito de gargalo de garrafa em diferentes períodos em cada área, apesar de não haver correlação com o IIP. A partir dos resultados obtidos, concluímos que o controle vetorial produz alterações sobre a estrutura populacional do A. aegypti, mas que não são efetivas. O uso do georreferenciamento e de informações genéticas do vetor poderiam contribuir para a definição das áreas de abrangência das populações do A. aegypti e para a tomada de decisões a respeito do manejo do tratamento.


Subject(s)
Rabbits , Aedes/microbiology , Densovirinae/immunology , Entomology/methods , Genetic Markers/genetics
13.
Rio de Janeiro; s.n; 2011. ix, 103 p
Thesis in Portuguese | LILACS | ID: lil-638438

ABSTRACT

Aedes aegypti é uma espécie sinantrópica que utiliza essencialmente criadouros artificiais como locais de desenvolvimento das formas imaturas, localizados dentro e ao redor das casas. Sabe-se que a produtividade dos criadouros, assim como o tamanho dos mosquitos adultos neles gerados dependem de uma série de fatores bióticos e abióticos, como disponibilidade de alimentos, competição larval inter e intraespecífica, temperatura, características físico-químicas da água, entre outras. Mosquitos de diferentes tamanhos podem ter capacidade vetorial diferente: podem se dispersar, sobreviver, alimentar-se e se infectar diferentemente. No presente estudo buscamos avaliar o potencial papel dos nutrientes (encontrados na água e no sedimento do criadouro), assim como de parâmetros físico-químicos na determinação do peso corporal e do tamanho das asas de A. aegypti. Também procuramos avaliar os efeitos da competição interespecífica entre A. aegypti e A. albopictus sobre o peso e tamanho das asas dessas duas espécies de mosquitos quando as mesmas foram encontradas simultaneamente no mesmo criadouro. Para tal, de abril a agosto de 2010, foram examinados 240 criadouros em quatro bairros da área metropolitana do Rio de Janeiro com características sócio-econômicas e ambientais distintas, sendo 50 criadouros positivos e 10 negativos em cada bairro. Avaliamos características físico-químicas da água (nitratos, fosfatos, carbono dissolvido, carbono no sedimento, O2 dissolvido, pH, condutividade, temperatura e volume de água), além da temperatura ambiente, velocidade do vento, exposição ao sol, área do criadouro, presença de predadores e de outros mosquitos co-ocorrendo com A. aegypti. As caixas d’água e outros recipientes usados para armazenamento de água foram os mais freqüentemente positivos para mosquitos nas localidades onde as condições sócio-econômicas e ambientais são mais precárias (Prainha e Tubiacanga), ao passo que, nas localidades com melhores condições socioeconômicas, os focos mais freqüentes foram vasos de plantas (Curicica), ralos e bromélias (Vila Valqueire). Observou-se um menor tamanho das asas e peso corporal em A. aegypti quando encontrados co-ocorrendo nos mesmos que A. albopictus, apesar de não significativo estatisticamente, sugere que uma espécie interfere no desenvolvimento da outra, produzindo mosquitos menores. O volume de água e a área do criadouro se mostraram como fatores importantes para a colonização por A. aegypti e parecem ser limitantes para o número de formas imaturas. A temperatura ambiente mostrou-se associada ao número de imaturos. O teor per capita de carbono orgânico no sedimento per capita não se mostrou associado ao número de imaturos presentes no criadouro, mas, tal como o oxigênio dissolvido, condutividade e incidência de luz, parece influenciar positivamente o tamanho das asas e o peso dos A. aegypti adultos emergidos.


Subject(s)
Humans , Water/analysis , Dengue , Densovirinae , Diptera
14.
Journal of the Egyptian Society of Parasitology. 2011; 41 (2): 289-306
in English | IMEMR | ID: emr-154403

ABSTRACT

Dengue [DF] and dengue hemorrhagic fevers [DHF] are present in urban and suburban areas in the Americas, South-East Asia, the Eastern Mediterranean and the Western Pacific, but dengue fever is present mainly in the rural areas of Africa. Several factors have combined to produce epidemiological conditions in developing countries in thejropics and subtropics that favour viral transmission by the main mosquito vector, Aedes aegypti as the rapid population growth, rural-urban migration, inadequate basic urban infrastructure [eg. the unreliable water supply leading householders to store water in containers close to homes] and the increase in volume of solid waste, such as discarded plastic containers and other abandoned items which provide larval habitats in urban areas. Geographical expansion of the mosquito has been aided by the international commercial trade particularly in used car-tyres which easily accumulate rainwater. Increased air travel and the breakdown of vector control measures have also contributed greatly to the global burden of dengue and DH fevers. The presence of Ae. aegypti and endemicity of DF and DHF in the neighboring regional countries must be in mind of the Public Health Authorities


Subject(s)
/etiology , Urban Population , Rural Population , Aedes , Densovirinae
15.
Bol. malariol. salud ambient ; 50(2): 219-232, dic. 2010. ilus, tab
Article in Spanish | LILACS | ID: lil-630439

ABSTRACT

El dengue es uno de los mayores problemas de salud pública en el estado Aragua. La situación se ha deteriorado en los últimos años, reportándose la mayor epidemia durante el año 2001. En los años 2002 y 2003 las tasas de exposición y riesgos relativos en municipios que conforman al estado Aragua, muestran que el área metropolitana de Maracay concentra riesgos importantes. Los municipios Girardot (capital), Francisco Linares Alcántara y Santiago Mariño, son los que concentraron los mayores riesgos. Durante ese período el número de nuevos casos de dengue aumentó especialmente durante la época de lluvias, evidenciándose la existencia de un patrón estacional. Este trabajo propone Modelos Bayesianos Jerárquicos con estructura espacio temporal que incluye variables climáticas y socio-demográficas con las cuales se identificaron factores de mayor influencia en la incidencia del dengue y se determinaron las parroquias con mayores riesgos.Los ajustes de los modelos resultantes se obtuvieron mediante técnicas con cadenas Markov Monte Carlo (MCMC) y se compararon con el criterio de información de deviancia (DIC). Estos modelos constituyen una herramienta importante que expertos en epidemiología y miembros del sector de salud pública deben considerar para el control del vector Aedes aegypti Linnaeus en el estado Aragua.


Dengue fever is a major public health problem in Aragua State, Venezuela. The situation has worsened in recent years, with a major epidemic during 2001. During 2002 and 2003 the exposition rates and relative risks of the municipalities that encompass Aragua State showed the highest relative risk of infection in the metropolitan area of Maracay. The municipalities of Girardot (capital), Francisco Linares Alcántara and Santiago Mariño concentrated the highest risk. During 2002 and 2003 the number of new dengue cases increased especially during the rainy season, showing the existence of a seasonal pattern. The present work presents Bayesian Hierarchical Models with spatio-temporal structure that included climatic and socioeconomic explanatory variables used to identify factors of major influence on dengue incidence and determined the municipalities with higher risks. Models were fitted using Markov Chain Monte Carlo (MCMC) methods and selected using the deviance information criteria (DIC), respectively. These models constitute an important tool that epidemiologists and public health officers in Aragua State have to consider for the control of the vector Aedes aegypti Linnaeus.


Subject(s)
Humans , Animals , Aedes , Dengue , Markov Chains , Public Health , Densovirinae , Mosquito Control , Vector Control of Diseases
17.
Medisan ; 14(3)mar.-abr. 2010. tab
Article in Spanish | LILACS | ID: lil-576587

ABSTRACT

Se realizó una investigación evaluativa en 566 habitantes pertenecientes al área de salud del Policlínico Docente 28 de Septiembre del Consejo Popular Altamira, de Santiago de Cuba, desde septiembre del 2007 hasta enero del 2008, con el objetivo de evaluar la calidad del servicio de vectores, teniendo en cuenta la satisfacción de los moradores por la lucha contra el Aedes aegypti. Se halló que la labor efectuada al respecto no logró el estándar establecido de más de 70 por ciento en la zona y quedó demostrada la insatisfacción de los vecinos con la actividad ejecutada por los trabajadores de la campaña antivectorial.


An evaluative investigation in 566 inhabitants belonging to the health area of the 28 de septiembre Teaching Polyclinic of Altamira people's council was conducted in Santiago de Cuba, from September, 2007 to January, 2008, aiming at evaluating the vector service quality, taking into account the satisfaction of the inhabitants for the control against Aedes aegypti. It was found that the work done in this regard did not achieve the standard established of more than 70 per cent in the zone and the neighbor's insatisfaction was demonstrated with the activity conducted by the workers of the antivectorial campaign.


Subject(s)
Humans , Male , Female , Aedes , Densovirinae , Patient Satisfaction , Pest Control, Biological , Quality Assurance, Health Care , Quality Control , Evaluation Studies as Topic
18.
Chinese Journal of Virology ; (6): 490-495, 2010.
Article in Chinese | WPRIM | ID: wpr-286088

ABSTRACT

Loop-mediated isothermal amplification (LAMP) assay is a novel method of gene amplification with high specificity, sensitivity and rapidity, which can be applied for disease diagnosis in shrimp aquaculture. The method is performed under isothermal conditions with a set of four specially designed primers that recognize six distinct sequences of the target. In the present study, according to the conservative regions of non-structural protein gene NS1, a set of four specific primers were designed, and a rapid detection of IHHNV was established by LAMP assay. The parameters of reaction time and temperature were optimized, and its specificity and sensitivity were assessed. The reactions were carried out at 60 degrees C, 62 degrees C, 63 degrees C, 64 degrees C, 65 degrees C, 66 degrees C, 67 degrees C, 68 degrees C for different time (0 min; 15 min; 30 min; 45 min; 60 min; 75 min). A plasmid pMDIHHNV carrying target sequence of LAMP detection was constructed. Ten-fold serially diluted pMDIHHNV (10(7)-10(0)copies/microL) was used as template for LAMP assay to investigate the detection limit. To determine the specificity, LAMP assays were carried out with DNA templates from other pathogens (White spot syndrome virus; WSSV, Taura Syndrome Virus; TSV, Aeromonas. hydrophila, V. alginolyticus, Vibrio. parahaemolytious, Escherichia. coli). The results showed the optimized LAMP assay for the rapid detection of IHHNV was performed at 65 degrees C for 60 min. The LAMP assay had an unequivocal detection limit of 100 copies/microL, and it was 1,000 times lower than that of PCR. The nucleic acids of other pathogens were not amplified by this LAMP system with the specific primers, which showed a good specificity. The resulting amplicons were detected using visual observation after the addition of SYBR Green I and gel electrophoresis. We investigated the efficacy of UNG (uracil-N-glycosylase) and dUTP in avoiding carry-over contamination in the LAMP assay procedure and explored its effect on the amplification efficiency. Products of LAMP with dUTP adding could be lysed by UNG to avoid LAMP products carry-over contamination effectively. The LAMP assay could be finished within an hour, requiring only a regular laboratory water bath or heat block for reaction and the result could easily be detected using visual observation. Clinically suspected IHHNV-infected shrimp samples were detected by both LAMP and PCR assay, and the result indicated that IHHNV was detected rapidly by LAMP instead of by PCR.


Subject(s)
Animals , DNA Primers , Genetics , Densovirinae , Genetics , Nucleic Acid Amplification Techniques , Methods , Penaeidae , Virology , Viral Proteins , Genetics
19.
Chinese Journal of Preventive Medicine ; (12): 385-389, 2009.
Article in Chinese | WPRIM | ID: wpr-242645

ABSTRACT

<p><b>OBJECTIVE</b>To probe the primary characteristic of 0507JS11 virus isolated from Culex sp. and determine the classification of 0507JS11 virus in taxonomy.</p><p><b>METHODS</b>0507JS11 virus was cultured in Aedes albopictus C6/36 cells and cytopathic effects (CPEs) were recorded. Electro-microscopic morphology of 0507JS11 virus was observed. Total DNA extract of 0507JS11 virus was detected by 1% Agarose Gel Electrophoresis. Complete genomic sequence of 0507JS11 virus was sequenced and then made phylogenetic analysis.</p><p><b>RESULTS</b>0507JS11 virus could cause CPEs in Aedes albopictus C6/36 cells. Viral particles have no envelope and appear icosahedron symmetry with diameter of 20 nm. The genome of 0507JS11 virus was positive single strand DNA (ssDNA) with full length of 3977 nt. However, a DNA band about 4 kbp was observed in the electrophoresis of total DNA extract of 0507JS11 virus. The coding region of the genome included three ORFs, ORF1 and ORF2 code NSP1 and NSP2, ORF3 codes VP. Phylogenetic analysis of the complete genomic sequence of 0507JS11 virus indicated an independent linear in Brevidensovirus.</p><p><b>CONCLUSION</b>0507JS11 virus is a new member in Brevidensovirus.</p>


Subject(s)
Animals , Culex , Virology , DNA, Viral , Genetics , Densovirinae , Classification , Genetics , Genome, Viral , Sequence Analysis, DNA
20.
Med. infant ; 15(3): 278-281, sept. 2008. ilus
Article in Spanish | LILACS, BINACIS, UNISALUD | ID: lil-544707
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