Influenza in Brazil: surveillance pathways

Abstract

Influenza is a viral disease of global concern that has demanded the attention of health authorities. Since 1947, as a preventive measure, the World Health Organization monitors viral circulation to define the annual vaccine through a worldwide network of laboratories. This article presents the structuring of influenza surveillance in Brazil and highlights virological surveillance and the role of diagnostic laboratories as well as the expansion of actions to improve detection and expedite responses. The model set corresponds to sentinel surveillance complemented by the universal notification of severe acute respiratory syndrome investigating outbreaks, deaths, and unusual events and monitoring hospitalization and mortality in an expanded surveillance. In this review, we address aspects of influenza surveillance in animals, the need for interagency integration, and the sharing of information in many surveillance systems.

Avaliação do sistema de vigilância da síndrome respiratória aguda grave (SRAG) com ênfase em influenza, no Brasil, 2014 a 2016 *

“…As such, the proportion of individuals with confirmed viral infection in relation to those who only met the SARS case definition was considered to be the PPV of the surveillance system case definition. Given that according to the literature, between 20% and 30% of notified SARS cases relate to viral infections, 1,17 if the value found in this study was greater than 20%, then PPV was considered to be satisfactory. 18…”

“…It is caused by RNA viruses of the Orthomixoviridae family, subdivided into types A, B and C. Type A virus is the most mutagenic and important regarding human infection, and its predominant subtypes in Brazil are A(H1N1)pdm09 and A(H3N2). 1,2 Its main reservoirs are human beings, mammals and birds. 2,3 Susceptibility is general and transmission occurs through contact with respiratory secretions or droplets, principally in the coldest period of the year (autumn and winter), and in the South and Southeast regions of Brazil.…”

“…[7][8][9][10] Over 120 years, from 1889 to 2009, Brazil faced six substantial influenza epidemics, which contributed to the structuring and enhancement of the national epidemiological surveillance system. 1,[12][13][14][15] One of these structured components is universal surveillance of severe acute respiratory syndrome (SARS), which began in 2009, following the World Health Organization (WHO) declaration of a Public Health Emergency of International Concern in view of human cases of influenza A(H1N1) pdm09. The new system aimed to identify the profile of influenza pandemic cases and deaths based on the clinical picture of SARS, this being its most serious manifestation.…”

“…The main diagnosis methods used are real-time polymerase chain reaction (RT-PCR) and the indirect immunofluorescence (IIF) method. [1][2][3] Since its implementation, the system has undergone several adjustments to variables and changes in case definition, but had never been submitted to a process of evaluation of the quality of its attributes and its usefulness. 1,16,17 As such, the objective of this study was to evaluate the attributes of the severe acute respiratory syndrome (SARS) surveillance system for the period 2014-2016.…”

Avaliação da implantação do Sistema de Informação de Agravos de Notificação em Pernambuco, 2014*

“…2,3 Disease control institutions recommend that surveillance systems evaluations be focused on specific diseases, 4 in order to ensure the efficient and effective monitoring of important Public Health problems. 5,6 When evaluations have specific dimensions their usefulness is restricted, 7 with gaps remaining in knowledge about the complete process of information production. There is a scarcity of evaluation research addressing the totality of health surveillance information systems, such as studies that have identified weaknesses in organizational settings and in the data collection, processing, transmission and dissemination stages, 8,9 so as to contribute to the development of strategies favouring better information coverage, regularity and quality.…”