Epidemiological dynamics of an urban Dengue 4 outbreak in Sao Paulo, Brazil

Author(s)

Villabona-Arenas, Christian Julian ^[1] ; de Oliveira, Jessica Luana ^{[1, 2]} ; de Sousa-Capra, Carla ^[3] ; Balarini, Karime ^[4] ; Theoto Pereira da Fonseca, Celso Ricardo ^[4] ; de Andrade Zanotto, Paolo Marinho ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Microbiol, Inst Biomed Sci, Lab Mol Evolut & Bioinformat, Sao Paulo - Brazil

^[2] Univ Mogi das Cruzes, Dept Biomed, Sao Paulo - Brazil

^[3] Dept Hlth Guaruja, Off Epidemiol Surveillance, Sao Paulo - Brazil

^[4] ITAPEMA, Clin Lab Anal Ctr, Guaruja - Brazil

• Document type: Journal article
• Source: PeerJ; v. 4, APR 5 2016.
• Web of Science Citations: 4

Abstract

Background: Dengue studies at the urban scale are scarce and required for guiding control efforts. In Brazil, the burden of dengue is high and challenges city public health administrations with limited resources. Here we studied the dynamics of a dengue epidemic in a single city. Methods: Serum samples from dengue suspected cases were collected and tested, from December 2012 and July 2013 in Guaruja, Brazil. We use incidence series analysis to provide a detailed view of the reproduction number dynamics and a Bayesian analysis to infer the spread of the serotype using geographic and temporal data. Results: We obtained nucleotide sequences from 354 envelope genes and georeferenced 286 samples during the course of the outbreak. Serotype 4 was responsible for the epidemic. We identified at least two major lineages that overlapped in distribution. We observed high reproduction numbers and high cladogenesis prior to the escalation of clinical case notifications. Three densely populated non-adjacent neighborhoods played a pivotal role during the onset and/or course of the epidemic. Discussion: Our findings point to high dengue virus transmission with a substantial proportion of unapparent cases that led to a late recognition of an outbreak. Usually source reductions initiatives tend to be insufficient once an epidemic has been established. Nevertheless, health authorities in Guaruja prioritized vector control on specific places with clusters of georeferenced viremic patients, which appear to have diminished the epidemic impact. (AU)

• FAPESP's process: 11/17071-2 - Phylogeography of urban outbreaks of dengue virus in Jundiaí and Guarujá in the State of São Paulo
• Grantee: Christian Julián Villabona Arenas
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 10/19059-7 - Phylogeography of urban outbreaks of dengue virus in Jundiaí and Guarujá in the State of São Paulo
• Grantee: Paolo Marinho de Andrade Zanotto
• Support Opportunities: Regular Research Grants