Phylogenetic, epidemiological and clinical studies on dengue and dengue virus in Vitória, Espírito Santo state, Brazil

Vicente, Creuza Rachel (2016): Phylogenetic, epidemiological and clinical studies on dengue and dengue virus in Vitória, Espírito Santo state, Brazil. Dissertation, LMU München: Faculty of Medicine

Abstract

Background: Vitória is an endemic area in Brazil for dengue. This thesis presents the phylogeny of dengue virus serotype 4, the evaluation of dengue dispersion and the influence of serotypes and demographics to severe dengue outcomes in Vitória. Methods: Sequences of envelope (n = 8) and NS1 (n = 4) gene of dengue virus serotype 4 were used to construct phylogenetic trees (2013). Spatial variation in temporal trends was analyzed (2012-2013). Cross-sectional studies were performed to assess associations of serotypes (2009-2013) and demographics (2007-2013) with severe outcomes. Results: Dengue virus serotype 4 genotype I (n = 2) related to a strain from Bahia, and genotype II (n = 8) related to strains from Roraima, Mato Grosso and São Paulo were detected. Five space-time clusters with lower Time Trend Increase presented higher risk for dengue transmission and lower income than the six space-time clusters with higher Time Trend Increase. In 6,703 dengue cases, 11.3% presented severe dengue, which was significantly higher among males (13.0%) than females (10.0%), and among elderlies (15.5%) than children (8.8%), adolescents (12.5%), and adults (10.5%). Children with severe dengue presented hemorrhage (68.8%-86.4%) and plasma leakage (52.4%-62.5%) in a higher proportion than other age groups. Serotype was determined for 485 cases and severe dengue affected 6.6% of them. Severe dengue occurred at a significantly higher frequency in infections caused by dengue virus serotype 2 (32.3%) than in those caused by dengue virus serotype 4 (6.4%) or by dengue virus serotype 1 (4.5%). Conclusion: Apparently, Vitória is not an international route for dengue introduction in Brazil. Living in low-income areas increased the chance of dengue infection. Dengue virus serotype 2 was associated with an elevated occurrence of severe dengue, which also affected more males and elderlies. Manifestations of severe dengue were worse in children than in other age group.

• Item Type: Theses (Dissertation, LMU Munich)
• Keywords: Dengue, dengue virus, Aedes, phylogeny, epidemic, social class, severe dengue, signs and symptoms, age groups, gender and health
• Subjects: 600 Technology, Medicine; 600 Technology, Medicine > 610 Medical sciences and medicine
• Faculties: Faculty of Medicine
• Language: English
• Date of oral examination: 23. November 2016
• 1. Referee: Herbinger, Karl-Heinz
• Signature of the printed copy: 0700/UMD 17158