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 Guarujá, 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 Guarujá prioritized vector control on specific places with clusters of georeferenced viremic patients, which appear to have diminished the epidemic impact.
Highlights
The dengue viruses exist as four antigenically distinct serotypes named DENV-1, DENV-2, DENV-3 and Dengue virus serotype 4 (DENV-4)
Sampling The year 2013 coincided with a steep rise in the confirmed cases of dengue fever in the State of Sao Paulo (Fig. 1B)
DENV-4 was relatively new to the country and outbreaks had been reported throughout the country since it was first detected in Brazil in 2011
Summary
The dengue viruses exist as four antigenically distinct serotypes named DENV-1, DENV-2, DENV-3 and DENV-4. How to cite this article Villabona-Arenas et al (2016), Epidemiological dynamics of an urban Dengue 4 outbreak in Sao Paulo, Brazil. This means that the disease occurs every year, usually during the wet season when Aedes mosquitoes’ population sizes are high and the rainfall is optimal for breeding. People provide the mosquitoes with blood meals and water-holding containers where the mosquitoes lay their eggs This country is at periodic risk for epidemic dengue (i.e., when large numbers of people become infected during a short period), which requires a coincidence of large numbers of vector mosquitoes and large numbers of people with no immunity to one or more of the four serotypes (CDC, 2015). We studied the dynamics of a dengue epidemic in a single city. Health authorities in Guarujaprioritized vector control on specific places with clusters of georeferenced viremic patients, which appear to have diminished the epidemic impact
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
