Author:
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Lowe, Rachel; Barcellos, Christovam; Brasil, Patrícia; Cruz, Oswaldo G.; Honorio, Nildimar Alves; Kuper, Hannah; Carvalho, Marilia Sá
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Abstract:
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The first confirmed case of Zika virus infection in the Americas
was reported in Northeast Brazil in May 2015, although
phylogenetic studies indicate virus introduction as early as
2013. Zika rapidly spread across Brazil and to more than 50
other countries and territories on the American continent. The
Aedesaegypti mosquito is thought to be the principal vector
responsible for the widespread transmission of the virus.
However, sexual transmission has also been reported. The
explosively emerging epidemic has had diverse impacts on
population health, coinciding with cases of Guillain-Barre
Syndrome and an unexpected epidemic of newborns with
microcephaly and other neurological impairments. This led to
Brazil declaring a national public health emergency in November
2015, followed by a similar decision by the World Health
Organization three months later. While dengue virus serotypes
took several decades to spread across Brazil, the Zika virus
epidemic diffused within months, extending beyond the area of
permanent dengue transmission, which is bound by a climatic
barrier in the south and low population density areas in the
north. This rapid spread was probably due to a combination of
factors, including a massive susceptible population, climatic
conditions conducive for the mosquito vector, alternative
non-vector transmission, and a highly mobile population. The
epidemic has since subsided, but many unanswered questions
remain. In this article, we provide an overview of the discovery
of Zika virus in Brazil, including its emergence and spread,
epidemiological surveillance, vector and non-vector transmission
routes, clinical complications, and socio-economic impacts. We
discuss gaps in the knowledge and the challenges ahead to
anticipate, prevent, and control emerging and re-emerging
epidemics of arboviruses in Brazil and worldwide. |