Dengue seropositivity in a randomly selected sample from Yucatan analyzed in the context of dengue cases reported between 1996 and 2006

Abstract

Introduction: Dengue virus (Denv) was first reported in Yucatan in 1979. Since then, Denv has been associated with multiplecases of Dengue Fever (DF) and Dengue Hemorrhagic Fever (DHF), becoming an endemic disease in Yucatan, Mexico. Objectives: To determine the seropositivity to dengue infections in random sample of the Yucatan general population in 1996and 2006 and analyze it along with the reported dengue cases in the state during that ten-year-period. Methods: Samples from the randomly selected participants were tested for IgG dengue antibodies in both serosurveys, whilelaboratory confirmed DF and DHF were obtained from the epidemiologic surveillance system from 1996 to 2006. Results: The overall seropositivity to Denv infection was 59.9% in 1996 and 81.5% in 2006, according to the serosurveys. Theincrease in seropositivity can be at least partially explained by the peak in DF and DHF cases that took place in 1997, as reportedin the surveillance system. Conclussion: Data drawn from the 1996 and 2006 serosurveys showed an increase of seropositivity to Denv infections, which canpartially be explained by the 1997 outbreak in the Yucatan. While seroprevalence studies were useful to identify the proportion ofseropositive population, the case reports from the epidemiologic surveillance system were useful to identify the epidemic year,meaning that both sources of information are complementary to better understand the Denv dynamics during the ten-year-periodelapsed between 1996 and 2006.