Abstract

AIDS cases in Brazil: a method to identify sub-notifications

A.I.A. de Sousa, A.V. de Lima

Ministry of Health, STD, AIDS and Viral Hepatitis Department, Brasília, Brazil

Background: In Brazil information on AIDS cases is obtained from the Notifiable Diseases Information System (SINAN). Since 2004 the Brazilian Ministry of Health has been implementing a strategy based on linking the various official sources of health information to identify the occurrence of sub-notification and adjust the diagnosis of the temporal tendencies of the epidemic as a way of responding to the complexity of the disease.
Methods: To identify cases that were sub-notified to the SINAN, probabilistic procedures using the Reclink^® software application were adopted to identify cases of AIDS registered in the Laboratory Test Control System (SISCEL) classified on the basis of the official definition of AIDS cases for epidemiological purposes in Brazil namely: a) individuals with T CD4⁺ lymphocyte counts lower than recommended level for the age group and with 01 detectable viral load for adults and 02 viral loads with over 10,000 copies for children; b) individuals with T CD4⁺ lymphocyte counts lower than recommended level for the age group and use of medicines registered in the System for Logistic Control of Drugs (SICLOM); and c) individuals with AIDS registered as cause of death in the Mortality Information System (SIM); that were not registered in the SINAN.
Results: From June 1980 to June 2009, 462,237 AIDS cases were notified to the SINAN, which is 85% of the number identified using probabilistic linkage methodology. In 2008, 34,480 cases of AIDS were identified but only 19,022 were actually notified.
Conclusions: This study is primarily aimed at knowing and developing surveillance models that are not exclusively based on mandatory notification of cases in order to delineate epidemic dynamics more accurately and provide support for disease control and prevention actions.