Dengue in northeastern Brazil: a spatial and temporal perspective.

INTRODUCTION: The state of Ceará (Brazilian Northeast) has a high incidence of dengue. Therefore, we aimed to characterize the temporal patterns and spatial distribution of dengue cases in Ceará during 2001-2019. METHODS: A spatiotemporal ecological study was performed with secondary data. Time-trend analysis was performed using a segmented log-linear regression model to estimate the average annual percentage change (AAPC) and the annual percentage change (APC) in incidence of dengue. We also performed spatiotemporal analysis to identify the place, time, and relative risk (RR) of dengue clusters. RESULTS: There were 539,653 dengue cases. The AAPC reduced over time (-9.5%; 95% confidance interval [CI]: -18.3; -0.3). Three trends were identified-2001-2004: APC=-20.9% (95% CI: -65.1 to 44.8), 2005-2015: APC=7.9% (95% CI: -6.0 to 98.9), and 2016-2019: APC=-48.8% (95% CI: -83.0 to -6.1). During 2001-2007, 10 significant clusters were identified (RR=3.57-14.38: n=4 and RR=0.05-0.39: n=6). During 2008-2013, there was 1 cluster in the western region (RR= 3.40) and four other clusters (RR=0.02-0.15). The last period presented 5 high-RR clusters (RR=2.95-9.24). The low-RR clusters were located in the central-north, central-south, south, and northwest regions. However, the central-west region remained a high-RR cluster region throughout the study period. CONCLUSIONS: Dengue showed a decreasing incidence. During the epidemic years, the southern, eastern, and western regions presented high-risk clusters. Introduction of a new dengue serotype in a low-RR area can cause explosive outbreaks due to population susceptibility.

Dengue in northeastern Brazil: a spatial and temporal perspective

Abstract INTRODUCTION: The state of Ceará (Brazilian Northeast) has a high incidence of dengue. Therefore, we aimed to characterize the temporal patterns and spatial distribution of dengue cases in Ceará during 2001-2019. METHODS: A spatiotemporal ecological study was performed with secondary data. Time-trend analysis was performed using a segmented log-linear regression model to estimate the average annual percentage change (AAPC) and the annual percentage change (APC) in incidence of dengue. We also performed spatiotemporal analysis to identify the place, time, and relative risk (RR) of dengue clusters. RESULTS: There were 539,653 dengue cases. The AAPC reduced over time (-9.5%; 95% confidance interval [CI]: -18.3; -0.3). Three trends were identified-2001-2004: APC=-20.9% (95% CI: -65.1 to 44.8), 2005-2015: APC=7.9% (95% CI: -6.0 to 98.9), and 2016-2019: APC=-48.8% (95% CI: -83.0 to -6.1). During 2001-2007, 10 significant clusters were identified (RR=3.57-14.38: n=4 and RR=0.05-0.39: n=6). During 2008-2013, there was 1 cluster in the western region (RR= 3.40) and four other clusters (RR=0.02-0.15). The last period presented 5 high-RR clusters (RR=2.95-9.24). The low-RR clusters were located in the central-north, central-south, south, and northwest regions. However, the central-west region remained a high-RR cluster region throughout the study period. CONCLUSIONS: Dengue showed a decreasing incidence. During the epidemic years, the southern, eastern, and western regions presented high-risk clusters. Introduction of a new dengue serotype in a low-RR area can cause explosive outbreaks due to population susceptibility.

Involvement of the dopaminergic system in the antidepressant-like effect of the lectin isolated from the red marine alga Solieria filiformis in mice.

This study aimed at evaluating the antidepressant-like action of the marine alga Solieria filiformis lectin (SfL) and to investigate the participation of the monoaminergic system in this action. For this, male Swiss mice (n=10) were pretreated with intravenous injections (i.v.) of SfL (1, 3 or 9mg/kg) and submitted to open field (OFT), tail suspension (TST), forced swimming (FST), elevated plus-maze (EPMT) and hole-board tests (HBT). As controls, mice received sterile saline (i.v.), imipramine (10 or 30mg/kg; intraperitoneally - i.p.) or diazepam (1 mk/kg; i.p.). To assess the involvement of the monoaminergic system in SfL effects, the FST was conducted in mice pretreated with PCPA, an inhibitor of serotonin synthesis, or noradrenergic and dopaminergic receptors specific antagonists. The results showed that SfL has an antidepressant-like effect, with no psychostimulant and anxiolytic-like effects. When denatured or combined with mannan, SfL lost the ability to reduce the immobility time in the FST. In addition, SfL antidepressant-like effect was inhibited by the pretreatment of mice with SCH 23390, a dopamine D1 receptor antagonist, and by sulpiride, a dopamine D2 receptor antagonist. Thus, SfL produced an antidepressant-like effect, which is probably dependent on its interaction with the dopaminergic system.