Browsing by Autor "Roxana Loayza"

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    A clinical, aetiological, and public health perspective on central nervous system infections in Bolivia, 2017–2018
    (Nature Portfolio, 2021) Paola Mariela Saba Villarroel; María del Rosario Castro Soto; Oriana Melendres Flores; Alejandro Peralta Landívar; María E. Calderón; Roxana Loayza; José Boucraut; Laurence Thirion; Audrey Dubot‐Pérès; Läétitia Ninove
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    Epidemiological analysis of the influenza A(H1N1)v outbreak in Bolivia, May-August 2009
    (European Centre for Disease Prevention and Control, 2009) Alberto Gianella; Azibadighi Walter; Roberto Jimmy Revollo; Roxana Loayza; Jorge Vargas; Yelin Roca
    The outbreak of pandemic influenza (H1N1) began in Bolivia on 25 May 2009. Between May and August, the National Center of Tropical Disease (CENETROP) analysed by RT-PCR 7,060 samples of which 12.7% were positive. A preliminary analysis of the 895 confirmed cases identified between May and August 2009 describes epidemiological and clinical characteristics. After the first imported cases from the United States and Peru, the locally acquired infections predominated (90%). The number of cases was highest in the age group of 10 to 29 year-olds, and 89.6% of cases were observed in people under the age of 40 years. Fever, cough, nasal discharge and headache remained the main symptoms.
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    Genome Sequences of Chikungunya Virus Isolates from Bolivia
    (American Society for Microbiology, 2020) Caio M B França; Roxana Loayza; Yelin Roca; Ana Maria Montaño Arias; Freddy Tinajeros; José R. Loaiza; Anshule Takyar; Robert H. Gilman; Matthew J. Miller
    We generated nine coding-complete chikungunya virus genome sequences from blood samples collected during the early 2015 outbreak in Bolivia. Relative to other publicly available chikungunya sequences, the Bolivian samples represent a monophyletic group, suggesting that a single lineage was widely circulating in the country between February and May 2015.
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    Human Antibody Response to Aedes aegypti Saliva in an Urban Population in Bolivia: A New Biomarker of Exposure to Dengue Vector Bites
    (American Society of Tropical Medicine and Hygiene, 2012) Souleymane Doucouré; François Mouchet; Amandine Cournil; Gilbert Le Goff; Sylvie Cornélie; Yelin Roca; Mabel Guerra Giraldez; Z. Barja Simon; Roxana Loayza; Dorothée Missé
    Aedes mosquitoes are important vectors of re-emerging diseases in developing countries, and increasing exposure to Aedes in the developed world is currently a source of concern. Given the limitations of current entomologic methods, there is a need for a new effective way for evaluating Aedes exposure. Our objective was to evaluate specific antibody responses to Aedes aegypti saliva as a biomarker for vector exposure in a dengue-endemic urban area. IgG responses to saliva were strong in young children and steadily waned with age. Specific IgG levels were significantly higher in persons living in sites with higher Ae. aegypti density, as measured by using entomologic parameters. Logistic regression showed a significant correlation between IgG to saliva and exposure level, independently of either age or sex. These results suggest that antibody responses to saliva could be used to monitor human exposure to Aedes bites.
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    Molecular Epidemiological Analysis of Dengue Fever in Bolivia from 1998 to 2008
    (Mary Ann Liebert, Inc., 2009) Yelin Roca; Cécile Baronti; Roberto Jimmy Revollo; Shelley Cook; Roxana Loayza; Läétitia Ninove; Roberto Fernández; Jorge Vargas Flores; Jean-Pierre Hervé; Xavier de Lamballerie
    Dengue fever was first recognized in Bolivia in 1931. However, very limited information was available to date regarding the genetic characterization and epidemiology of Bolivian dengue virus strains. Here, we performed genetic characterization of the full-length envelope gene of 64 Bolivian isolates from 1998 to 2008 and investigated their origin and evolution to determine whether strains circulated simultaneously or alternatively, and whether or not multiple introductions of distinct viral variants had occurred during the period studied. We determined that, during the last decade, closely related viruses circulated during several consecutive years (5, 6, and 6 years for DENV-1, DENV-2, and DENV-3, respectively) and the co-circulation of two or even three serotypes was observed. Emergence of new variants (distinct from those identified during the previous episodes) was identified in the case of DENV-1 (2007 outbreak) and DENV-2 (2001 outbreak). In all cases, it is likely that the viruses originated from neighboring countries.
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    Réponse IgG spécifique à la salive d’Aedes aegypti dans une population urbaine bolivienne : vers un nouveau biomarqueur d’exposition aux piqûres du vecteur de la dengue ?
    (Centre National de la Recherche Scientifique, 2009) François Mouchet; Amandine Cournil; Souliman Doucouré; Gilbert Le Goff; Sylvie Cornélie; Yelin Roca; Mabel Guerra-Giraldez; Norman Valdez-Zamorano; Zaira Barja-Simon; Roxana Loayza
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