Since the reintroduction of dengue viruses in 1987, Sao Paulo State (SP), Brazil,
has experienced recurrent epidemics in a growing number of municipalities, each
time with more cases and deaths. In the present study, we investigated the
spatio-temporal dynamics of dengue-related deaths and associated factors in SP.
This was an ecological study with spatial and temporal components, based on
notified dengue-related deaths in the municipalities of SP between 2007 and
2017. A latent Gaussian Bayesian model with Poisson probability distribution was
used to estimate the standardized mortality ratios (SMR) for dengue and relative
risks (RR) for the socioeconomic, demographic, healthcare-related, and
epidemiological factors considered. Epidemiological factors included the annual
information on the number of circulating serotypes. A total of 1,019
dengue-related deaths (0.22 per 100,000 inhabitant-years) between 2007 and 2017
were confirmed in SP by laboratory testing. Mortality increased with age,
peaking at 70 years or older (1.41 deaths per 100,000 inhabitant-years).
Mortality was highest in 2015, and the highest SMR values were found in the
North, Northwest, West, and coastal regions of SP. An increase of one
circulating serotype, one standard deviation in the number of years with cases,
and one standard deviation in the degree of urbanization were associated with
increases of 75, 35, and 45% in the risk of death from dengue, respectively. The
risk of death from dengue increased with age, and the distribution of deaths was
heterogeneous in space and time. The positive relationship found between the
number of dengue serotypes circulating and years with cases at the
municipality/micro-region level indicates that this information can be used to
identify risk areas, intensify surveillance and control measures, and organize
healthcare to better respond to this disease.