Underreporting is one of the main challenging epidemiologic AIDS surveillance is faced with. The objective of this study was to estimate the level of underreporting of AIDS in adults in Fortaleza in the 2002-2003 period. In addition, the level of underreporting at two referral hospitals (Hospital São José - HSJ, and Hospital Geral de Fortaleza - HGF) was estimated. The study used the capture-recapture method and relied on three secondary databases: SINAN (national disease surveillance), SISCEL (laboratory test control), and SIM (mortality information). SINAN was compared to SISCEL and to SIM. Cases confirmed by SINAN were considered as reported. Cases from the databases were paired using the RecLink II software. Subsequently cases eligible for the capture-recapture method were selected using the Lincoln-Petersen and Chapman estimators. The levels of underreporting were estimated at 33.1% and 14.1% for SISCEL and SIM, respectively. Underreporting for SISCEL was 5.4% at HSJ and 90.5% at HGF, comparing Siscel to Sinan. The study shows a considerable level of underreporting of AIDS cases in Fortaleza, and suggests that SISCEL is an important source of AIDS reporting considering that it allowed detecting levels of underreporting more than twice the estimates derived from SIM and SINAN databases. Considering the findings of the present study, SINAN-AIDS should be compared periodically with all relevant information systems in order to reduce levels of AIDS underreporting.
Acquired Immunodeficiency Syndrome; Epidemiology; Disease reporting; Epidemiological surveillance; Epidemiological surveillance services; Information systems; Estimation technique
