BACKGROUND: Dengue viruses (DENV) are the most widespread arthropod-borne viruses, which have shown an unexpected geographic expansion, as well as an increase in number and severity of outbreaks in the last decades. Although the emergence of dengue is considered to be due to a number of complex factors, epidemiological studies have shown that some strains of dengue might be associated with increased severity and higher transmission rates than others. In this context, surveillance and identification of the appearance or introduction of more virulent strains, along with fluctuation of DENV among endemic areas are now considered essential public health activities. METHODS: Samples from travelers returning from the tropics with acute dengue infections were analyzed to obtain up-dated information on circulating dengue strains. A short nucleotide fragment located in the carboxyl terminus of the dengue E gene was used for the characterization of DENV strains and the identification of their sero- and genotype. RESULTS: One hundred eighty-six new dengue strains have been classified into 12 distinct genotype groups within the four dengue serotypes. The identification of the emergence of different sero- and genotypes, the appearance of new clades correlating with outbreaks, and the identification of a dengue-4 genotype not previously reported have been achieved. Interestingly, African strains characterized in this study have provided valuable data on dengue circulation on the continent. CONCLUSIONS: This work demonstrates the convenience of routine application of molecular epidemiology analyses in dengue diagnosis laboratories. The use of molecular epidemiology tools on the analysis of imported dengue infections strengthens data acquisition on dengue strain movements correlating with epidemiological changes. The importance of surveillance of imported diseases contributing data for the epidemiological knowledge of infectious diseases in endemic areas has been once more demonstrated.
BACKGROUND:Dengue viruses (DENV) are the most widespread arthropod-borne viruses, which have shown an unexpected geographic expansion, as well as an increase in number and severity of outbreaks in the last decades. Although the emergence of dengue is considered to be due to a number of complex factors, epidemiological studies have shown that some strains of dengue might be associated with increased severity and higher transmission rates than others. In this context, surveillance and identification of the appearance or introduction of more virulent strains, along with fluctuation of DENV among endemic areas are now considered essential public health activities. METHODS: Samples from travelers returning from the tropics with acute dengue infections were analyzed to obtain up-dated information on circulating dengue strains. A short nucleotide fragment located in the carboxyl terminus of the dengue E gene was used for the characterization of DENV strains and the identification of their sero- and genotype. RESULTS: One hundred eighty-six new dengue strains have been classified into 12 distinct genotype groups within the four dengue serotypes. The identification of the emergence of different sero- and genotypes, the appearance of new clades correlating with outbreaks, and the identification of a dengue-4 genotype not previously reported have been achieved. Interestingly, African strains characterized in this study have provided valuable data on dengue circulation on the continent. CONCLUSIONS: This work demonstrates the convenience of routine application of molecular epidemiology analyses in dengue diagnosis laboratories. The use of molecular epidemiology tools on the analysis of imported dengue infections strengthens data acquisition on dengue strain movements correlating with epidemiological changes. The importance of surveillance of imported diseases contributing data for the epidemiological knowledge of infectious diseases in endemic areas has been once more demonstrated.
Authors: Maria Dolores Fernandez-Garcia; Mathieu Bangert; Fernando de Ory; Arantxa Potente; Lourdes Hernandez; Fatima Lasala; Laura Herrero; Francisca Molero; Anabel Negredo; Ana Vázquez; Teodora Minguito; Pilar Balfagón; Jesus de la Fuente; Sabino Puente; Eva Ramírez de Arellano; Mar Lago; Miguel Martinez; Joaquim Gascón; Francesca Norman; Rogelio Lopez-Velez; Elena Sulleiro; Diana Pou; Nuria Serre; Ricardo Fernández Roblas; Antonio Tenorio; Leticia Franco; Maria Paz Sanchez-Seco Journal: Euro Surveill Date: 2016-09-08
Authors: Andreas Neumayr; Jose Muñoz; Mirjam Schunk; Emmanuel Bottieau; Jakob Cramer; Guido Calleri; Rogelio López-Vélez; Andrea Angheben; Thomas Zoller; Leo Visser; Núria Serre-Delcor; Blaise Genton; Francesco Castelli; Marjan Van Esbroeck; Alberto Matteelli; Laurence Rochat; Elena Sulleiro; Florian Kurth; Federico Gobbi; Francesca Norman; Ilaria Torta; Jan Clerinx; David Poluda; Miguel Martinez; Antonia Calvo-Cano; Maria Paz Sanchez-Seco; Annelies Wilder-Smith; Christoph Hatz; Leticia Franco Journal: Euro Surveill Date: 2017-01-05