Browsing by Autor "Rosario Rivera"

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Cost-effectiveness of rotavirus vaccination in Bolivia from the state perspective
(Elsevier BV, 2011) Emily R. Smith; Emily Rowlinson; Volga Iñiguez; Kizee A. Etienne; Rosario Rivera; Nataniel Mamani; Richard Rheingans; Maritza Patzi; Percy Halkyer; Juan S. León
Effectiveness of monovalent rotavirus vaccine in Bolivia: case-control study
(2013) Manish M. Patel; Maritza Patzi; Darwin Pastor; AL Nina; Yelin Roca; Luisa Álvarez; Volga Iñiguez; Rosario Rivera; Ka Ian Tam; Osbourne Quaye
The monovalent rotavirus vaccine conferred high protection against hospital admission for diarrhea due to rotavirus in Bolivian children. Protection was sustained through two years of life against diverse serotypes different from the vaccine strain.
Estimation of influenza and respiratory syncytial virus hospitalizations using sentinel surveillance data—La Paz, Bolivia. 2012–2017
(Wiley, 2019) Dabeyva Chavez; Vicente Gonzales‐Armayo; E Perla Mendoza; Rakhee Palekar; Rosario Rivera; Angel Rodríguez; Claudia Salazar; Ángel Veizaga; Arletta Añez
Influenza and RSV represent major causes of hospitalization in La Paz, Bolivia-with the highest burden among children under one year of age. Our estimates support current prevention strategies in this age group.
Evidence of reproductive isolation among closely related sympatric species of <i>Serrasalmus</i> (Ostariophysii, Characidae) from the Upper Madeira River, Amazon, Bolivia
(Wiley, 2006) Nicolas Hubert; Fabrice Duponchelle; J. N. Rodrìguez; Rosario Rivera; Jean‐François Renno
The delimitation of the Serrasalmus species (Characiformes, Serrasalminae) from the Bolivian Amazon (Amazonas, Madeira) was examined using intron length polymorphism assessed by EPIC‐PCR. The six pairs of primers provided 16 polymorphic loci across the species of the region and the allelic diversity ranged between two and 10 alleles per locus. For each locus, the lack of departure from Hardy‐Weinberg expectations in a large number of the populations analysed and the homogenous distribution of linkage disequilibrium between paralogous loci and loci belonging to different intronic systems provided strong lines of evidence that the 16 amplified loci constituted independent neutral markers. Furthermore, allelic diversity was size‐dependent, thereby indicating that insertion‐deletions occurred frequently but randomly in introns, and that intron length polymorphism was a valid marker for investigating the systematics of piranhas. EPIC‐PCR demonstrated that eight of the nine nominal species of piranha of the Upper Madeira were reproductively isolated and identified a new species that differed from its closest morphological and genetic relatives by seven diagnostic or semi‐diagnostic loci. By contrast, no diagnostic or semi‐diagnostic locus was found between S. spilopleura and S. eigenmanni , nor were their allelic frequencies different, thereby questioning the validity of their biological species status, at least in the Upper Madeira. This study, which was one of the first applications of EPIC‐PCR to a large‐scale molecular systematic purpose, demonstrates that it is a rapid, reliable and cost‐effective tool for elucidating issues pertaining to fish systematics.
Isolation by distance and Pleistocene expansion of the lowland populations of the white piranha <i> Serrasalmus rhombeus</i>
(Wiley, 2007) Nicolas Hubert; Fabrice Duponchelle; J. N. Rodrìguez; Rosario Rivera; François Bonhomme; Jean‐François Renno
The genetic variability and distribution of Amazonian fish species have likely been influenced by major disturbance events in recent geological times. Alternatively, the great diversity of aquatic habitat in the Amazon is likely to shape ongoing gene flow and genetic diversity. In this context, complex patterns of genetic structure originating from a joint influence of historical and contemporary gene flow are to be expected. We explored the relative influence of Pleistocene climatic fluctuations and current water chemistry on the genetic structure of a piranha, Serrasalmus rhombeus, in the Upper Amazon by the simultaneous analysis of intron length polymorphism and mitochondrial DNA sequences. The Madeira river is well suited for that purpose as it is characterized by a great diversity of water types, the presence of one of the largest floodplain of the Amazon and the potential occurrence of two Pleistocene refuges. We found evidence of genetic structure even at a small geographical scale (less than 10 km), indicating that the floodplain is not a homogenizing factor promoting interdrainage dispersal in S. rhombeus. Likewise, the hierarchical genetic structure inferred was correlated to geographical distance instead of habitat characteristic. Our results also support the hypothesis that the area underwent population expansion during the last 800,000 years. In addition, a higher level of genetic diversity was found in the samples from the putative Aripuanã refuge. The present findings suggest that Pleistocene refuges contributed significantly to the colonization of the lowlands in the Upper Amazon valley during the Pleistocene.
Prevalence, seasonality and severity of disease caused by pathogenic Escherichia coli in children with diarrhoea in Bolivia
(Microbiology Society, 2013) Lucia Gonzales‐Siles; Enrique Joffré; Rosario Rivera; Åsa Sjöling; Ann‐Mari Svennerholm; Volga Iñiguez
The prevalence of infection caused by different categories of diarrhoeagenic E. coli (DEC) strains, including enteroaggregative (EAEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), enteroinvasive (EIEC) and enterohaemorrhagic (EHEC) E. coli, in children who suffered from diarrhoea (n = 3943) or did not have diarrhoea (n = 1026) were analysed in two areas in Bolivia over a period of 4 years. We also analysed the seasonality of DEC infections and severity of diarrhoea in children with DEC infection and compared antibiotic resistance in DEC strains isolated from children with and without diarrhoea. Stool samples were analysed for the presence of DEC by culturing followed by PCR. The most prevalent DEC categories in samples from the children were: EAEC (11.2 %); ETEC (6.6 %); EPEC (5.8 %); and EIEC and EHEC (<1 %). DEC strains were isolated significantly more often from diarrhoea cases (21.6 %) than from controls (17.6 %; P = 0.002). The number of children with diarrhoea associated with EAEC, EPEC and ETEC infections peaked in the Bolivian winter (April-September), although the proportion of DEC-positive stool samples was higher during the warm rainy season (October-March). High levels of antibiotic resistance were detected among the DEC strains. In particular, resistance to tetracycline and sulfamethoxazole-trimethoprim was significantly higher in strains isolated from individuals with diarrhoea than in samples from controls. The severity of disease in children infected with EAEC, EPEC and ETEC varied from mild to severe diarrhoea, although disease severity did not differ significantly between the different DEC categories. ETEC, EPEC and EAEC are commonly found in Bolivia and may cause severe disease in children.
Rotavirus genotype distribution during the pre-vaccine period in Bolivia: 2007–2008
(Elsevier BV, 2013) Rosario Rivera; Kristen Forney; Maria René Castro; Paulina A. Rebolledo; Nataniel Mamani; Maritza Patzi; Percy Halkyer; Juan S. León; Volga Iñiguez