SEROTYPE-SPECIFIC DIFFERENCES IN CLINICAL MANIFESTATIONS OF DENGUE

Dengue, the most prevalent arthropod-borne viral disease of humans, is caused by four serotypes of dengue virus (DENV 1-4). Although all four DENV serotypes cause a range of illness, defining precisely which clinical characteristics are associated with the distinct serotypes has been elusive. A cross-sectional study was conducted on 984 and 313 hospitalized children with confirmed DENV infections during two time periods, respectively, in the same hospitals in Nicaragua: a 3-year period (1999-2001) when DENV-2 accounted for 96% of the viruses identified, and the 2003 dengue season when DENV-1 predominated (87% of identified serotypes). When the two periods were compared, more shock (OR 1.91, 95% CI 1.35-2.71) and internal hemorrhage (OR 2.05, CI 1.16-3.78) were observed in the period when DENV-2 predominated, whereas increased vascular permeability was associated to a greater degree with the DENV-1 period (OR 2.36, CI 1.80-3.09). Compared with the DENV-2 period, the DENV-1 season was associated with more hospitalized primary dengue cases (OR 3.86, CI 2.72-5.48) and more primary DENV infections with severe manifestations (OR 2.93, CI 2.00-4.28). These findings provide new data to characterize the pathogenic potential of distinct DENV serotypes in human populations. epidemic, allowed us to address the issue of the association of particular DENV serotypes with specific clinical manifesta- tions. We compared detailed clinical characteristics of chil- dren with laboratory-confirmed DENV infections who were hospitalized in the same hospitals during the period when DENV-2 dominated (1999-2001) with the 2003 dengue sea- son when DENV-1 was the predominant serotype identified. We found significant differences in the association of the DENV-1 and DENV-2 periods with severe clinical manifes- tations of dengue as well as with the number of hospitalized primary DENV infections. These results constitute new find- ings regarding the pathogenic properties of different DENV serotypes in human populations.