Dengue and Dengue Hemorrhagic Fever, Brazil, 1981–2002

Brazil has experienced an increase in dengue disease severity in the past 5 years

Dengue no Brasil: situação epidemiológica e contribuições para uma agenda de pesquisa

The epidemiological situation of dengue in Brazil is presented, showing the introduction and spread of vector and the different virus serotypes in Brazil. At the present time the Aedes aegypti, the vector, and 3 out of 4 existing virus serotypes (DENV-1, DENV-2 and DENV-3) are spread by virtually the entire national territory. The epidemiological picture has been characterized by recurrent epidemics, especially in large urban centers. A new characteristic in this scenario is the growth in the proportion of severe cases, particularly cases of dengue hemorrhagic fever. Existing control actions have been costly and ineffectives. In order to meet the gaps in existing knowledge, some elements for a research agenda are presented. Finally, we must recognize that problems such as dengue have their roots in the explosive form urban populations in countries such as Brazil has grown and in the conditions and lifestyles under which these people live.A situação epidemiológica da dengue no Brasil é apresentada, mostrando-se a introdução e a dispersão do vetor e dos diferentes sorotipos do vírus no Brasil. No presente momento, o Aedes aegypti, o vetor, encontra-se disseminado por praticamente todo o território nacional, bem como três dos quatro sorotipos existentes do vírus (DENV-1, DENV-2 e DENV-3). O quadro epidemiológico tem se caracterizado como epidemias recorrentes, mais visível nos grandes centro urbanos. Um elemento novo no cenário é o crescimento da proporção de casos graves, especialmente casos da febre hemorrágica da dengue. As ações de controle existentes, além de custosas, têm se mostrado inefetivas. Com vistas a preencher as insuficiências existentes no conhecimento, alguns elementos para uma agenda de pesquisa são apresentados. Finalmente, não devemos deixar de reconhecer que problemas como dengue têm suas raízes na forma explosiva como as populações urbanas em países como o Brasil têm crescido, nas condições em que essas populações vivem e nos estilos de vida que adquirem

Vigilancia molecular del dengue en un área remota de la Costa Norte del Ecuador usando muestras de suero y sangre capilar tomada en papel filtro Molecular surveillance of dengue fever in a remote area of the Northern Coast of Ecuador using serum and capillary blood samples on filter paper.

In the last 20 years, dengue has suffered a geographic expansion from urban to rural settings. Currently, the methods for the diagnosis of dengue infections in the field include antibody detections with ELISA rapid test. The objective of this research was to apply a retrotranscriptase polymerase chain reaction (RT-PCR) technique in blood collected from febrile patients for the diagnosis and identification of dengue serotypes circulating in an endemic area in the Northern Coast of Ecuador. Two types of samples were collected and analyzed, serum and capillary blood on filter paper from febrile patients at Hospital Civil de Borbón (HCB) and National Service of Arthropod Borne Diseases Control (SNEM) respectively. A total of 77 samples (36 serum and 41 blood spots samples) were collected from July 2010 to February 2011. Six (17%) serum samples and 7 (17%) blood spots samples were positive for dengue infection by RT-PCR. Nucleotide sequences of the amplicons indicated the presence of DENV-2 and DENV-3 serotypes in these two types of samples. This is the first report of DENV-3 since 2009 in Ecuador. In addition, this is the first time that RNA from blood samples on filter paper has been used successfully to study dengue virus infection in Ecuador.En los últimos 20 años el dengue ha sufrido una expansión geográfica desde zonas urbanas a zonas rurales. Actualmente, los métodos para el diagnóstico de infecciones por el virus del dengue en el campo incluyen pruebas rápidas de ELISA. El objetivo de ésta investigación fue aplicar una técnica de laboratorio por la técnica de Reacción en Cadena de la Polimerasa- Retrotranscriptasa (RT- PCR) en muestras de sangre colectadas de pacientes febriles para el diagnostico e identificación de los serotipos circulantes del dengue en un área endémica en la costa norte del Ecuador. Dos tipos de muestras fueron obtenidas y analizadas, suero y sangre capilar en papel filtro de pacientes febriles del Hospital Civil de Borbón (HCB) y del Servicio Nacional de Control de Enfermedades Transmitidas por Artrópodos (SNEM) respectivamente. Un total de 77 muestras (36 muestras de suero y 41 de sangre capilar) fueron obtenidas entre Julio del 2010 a Febrero del 2011. Seis (17%) muestras de suero y 7 (17%) muestras de sangre capilar fueron positivas para la infección por el virus del dengue por RT-PCR. Las secuencias de nucleótidos de los amplicones indicaron la presencia de DENV-2 y DENV-3 en estos dos tipos de muestras. Este es el primer reporte de DENV-3 desde el 2009 en el Ecuador. Esta es la primera vez que el RNA de muestras de sangre en papel filtro ha sido utilizado exitosamente para estudiar infecciones por el virus del dengue en Ecuador

Dengue in the South-eastern region of Brazil: historical analysis and epidemiology

Objetivou-se fazer análise histórica da atuação dos órgãos de saúde no combate ao Aedes aegypti e realizar estudo soroepidemiológico de pessoas com quadro febril não identificado para avaliar a ocorrência de dengue na população do Estado de Minas Gerais, Brasil. Foram utilizados os testes de Mac-Elisa, Gac-Elisa, inibição da hemaglutinação, isolamento e tipagem. Foram avaliados os níveis de intoxicação de trabalhadores por inseticidas organofosforado, através de dosagem da colinesterase. Foram coletados 1.989 soros de pessoas com quadro febril não identificado em 28 municípios, sendo constatada a ocorrência de dengue em 17 e comprovada autoctonia em 14 municípios. Foi isolado sorotipo 1. A dosagem de colinesterase de 2.391 soros mostrou 53 casos com alterações, sendo comprovados 3 casos de intoxicação. Os resultados mostraram uma epidemia de proporções maiores do que a oficialmente conhecida. A distribuição ampla do vetor traz inquietação quanto à possibilidade de reurbanização da febre amarela silvestre, enquanto a não detecção do A. aegypti em 2 municípios com autoctonia levanta a possibilidade do envolvimento de outros vetores. Como não existe ainda vacina contra o dengue, o combate ao vetor é a medida eficaz na prevenção de surtos. A erradicação do vetor depende de decisão governamental que envolva a organização do sistema de saúde e a participação de todos os meios e formas de repasse de informação, uma vez que o resultado a médio e longo prazo depende especialmente da capacitação popular e sua participação ostensiva.The aim of the study is an historical analysis of the work undertaken by the Public Health organizations dedicated to the combat of the Aedes aegypti, as well as an epidemiolocal study of persons with unexplained fever, with a view to evaluating the ocurrence of dengue within the population. The Mac-Elisa, Gac-Elisa, hemaglutination inhibition, isolation and typage tests were used. Organophosphate intoxication in agricultural workers was also assessed by measuring concentrations of serie cholinesterase. A sera samples of 2,094 were collected in 23 towns, and the type 1 dengue virus was detected in 17 towns and autochthony was confirmed in 12 of them. The cholinesterase was measured in 2,391 sera samples of which 53 cases had abnormal levels. Poisoning was confirmed in 3 cases. Results reveal an epidemic the gravity of which was not officially know. The relationshipe between levels of IgM and IgG antibodies indicates the outbreak tendency. The widespread distribution of the vector is troubling because of the possibility of the urbanization of wild yellow fever, whereas the absence of A. aegypti in 2 towns with autochthony suggests the existence of another vector. Since there is no vaccine against dengue, the combat of the vector is the most efficient measure for preventing outbreaks. The eradication of the vector depends on government decisions which depend, for their execution, on the organization of the Health System and the propagation of information concerning the prevention of the disease using all possible means because short and long term results depend on the education and the active participation of the entire population

Dengue in Venezuela:A study on viral transmission, risk factors and clinical disease presentation

Dengue is wereldwijd de belangrijkste door muggen overgedragen ziekte. In Venezuela komen regelmatig epidemieën van toenemende omvang voor. In het onderzoek beschreven in dit proefschrift werden ongeveer 2000 personen uit drie wijken in Maracay, Venezuela, bestudeerd middels een prospectieve "community-based" cohortstudie. De doelstelling van deze studie was om de dengue-seroprevalentie te bepalen, om risicofactoren voor dengue-infectie te identificeren en om gebieden met een hoge dengue-incidentie in kaart te brengen door middel van ruimtelijke analyse. Ook werd een observationele cohortstudie uitgevoerd op het niveau van gezondheidscentra om klinische en hematologische parameters te identificeren, die dengue van andere met koorts gepaard gaande aandoeningen onderscheiden in een vroeg stadium van de ziekte. Vroege diagnose wordt ook beïnvloed door "health-seeking behaviour” (HSB) en toegang van patiënten tot medische zorg. Patronen van HSB werden onderzocht bij zowel bij denguepatiënten als patiënten met OFI. In de prospectieve cohortstudie werd een hoge dengue-seroprevalentie (77.4%) gevonden, met 10% recente infecties. De combinatie van toenemende bevolkingsdichtheid, precaire leefomstandigheden en wateropslag bleken de meest bepalende factoren voor dengue-transmissie te zijn. De ruimtelijke analyse leverde clusters van hoge dengue-incidentie op voor recente infecties, maar niet voor eerdere infecties. Deze resultaten suggereren dat dengue-transmissie erg lokaal plaatsvindt. Er werd een diagnostisch algoritme opgesteld op basis van (i) aantal witte bloedcellen, (ii) uitslag, (iii) gemiddelde niveau van corpusculair hemoglobine en (iv) hemorrhagische manifestaties, dat de mogelijkheid biedt om dengue te onderscheiden van OFI gedurende de eerste drie dagen van de ziekte. Tenslotte werd vastgesteld dat patienten, bij een verdenking van dengue, sneller medische zorg zoeken dan bij andere met koorts gepaard gaande ziekten

Aedes aegypti and Dengue in the Philippines: Centering History and Critiquing Ecological and Public Health Approaches to Mosquito-borne Disease in the Greater Asian Pacific

The global incidence of dengue has increase 30-fold over the past 50 years in the western or Asian Pacific, this region is also a contemporary epicenter for resource extraction and ecological destabilization. Dengue is addition to yellow fever, chikungunya and most recently zika virus, are transmitted by the mosquito vector Aedes aegypti- a domesticated mosquito adept at breeding in artificial household containers and within homes. The history of the domestication and global distribution of Aedes aegypti is intrinsically linked to European expansion into and among tropical worlds. Contemporary population genetics research suggest the westward expansion of the mosquito vector beginning with trans-Atlantic Slave Trade moving to the Americas and then making a jump across the Pacific, which I argue occurred first within the Philippines and then spread eastward through the greater Indian Ocean. I argue that Spanish and American colonization facilitated the biological invasion of Ae. aegypti and dengue in the Philippines and created the conditions for contemporary epidemics. The discourse within the dominant voices of public health, CDC and WHO, omit this history as well as down play the significance of land use and deforestation while focusing predominantly upon dengue’s prevention and control. This omission is an act of erasure and a means of furthering western imperialism through paternalistic interventions. Mosquito-borne disease epidemics are unintended consequences of past human action and if public health discourse continues to frame epidemics as random and unfortunate events, we risk missing key patterns and continuing to perpetuate the circumstances of disease and adaptation