Assess the prevalence of arboviral encephalitis seasonal not in the city of São Paulo

• Grant number: 13/03188-0
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): May 01, 2013
• Effective date (End): April 30, 2014
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal researcher: Ester Cerdeira Sabino
• Grantee: Tamiris Zulato Tozetto
• Home Institution: Instituto de Medicina Tropical de São Paulo (IMT). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Arboviruses are zoonoses (diseases of primary animals that can be transmitted to humans, or primary humans that can be transmitted to animals) caused by viruses of the family Togaviridae, Flaviviridae, Bunyaviridae, Reoviridae, and Rhabdoviridae. They are maintained by complex natural cycles involving hematophagous arthropod vectors, mosquitoes, and ticks more often. Once infected, these vectors transmit the organisms by biting other animals. The cycle is completed when a new arthropod becomes infected by eating with the blood of an animal in viremia. In Brazil, the risk of the emergence of new arboviruses is also related to the fact that the country has large cities with high population density, infested by mosquitoes of the Culex and Aedes genera, which, in addition to being vectors of arboviruses, are highly anthropophilic. In our country, most of the arboviruses that cause diseases in humans belong to the families Togaviridae (Alphavirus genus) and Flaviviridae (genus Flavivirus). Clinical manifestations of arbovirus diseases caused by these range from a common framework to severe viral encephalitis. The viral encephalitis arboviruses that have an etiologic agent of the cases are predominantly in rural areas or the appearance of epidemic outbreaks. The clinical differential diagnosis of arboviruses is very difficult, especially in the acute phase of infection when no symptoms of viral diseases, in general, are very similar. The diagnosis of an arbovirus is done by virus isolation or by serological tests. False-negative serological results in the first days of illness and cross-reactivity of antibodies with antigens of other viruses belonging to the same genus are common. To solve such problems of diagnosis, tests based on polymerase chain reaction (PCR) using species-specific primers have been described for some viruses of the genus Alphavirus and Flavivirus. As the main objective of this study is to assess the prevalence of sporadic viral encephalitis (non-seasonal) from infection by an arbovirus of the family Togaviridae, Flaviviridae, and Picornaviridae, patients in the city of São Paulo. (AU)