Abstract
Background: Since the 2016 Zika virus (ZIKV) outbreak in Miami-Dade County, dengue virus (DENV) activity has intensified, highlighting the need to evaluate Aedes aegypti patterns between both outbreaks.
Methods: Suspected disease case requisitions (N=4,831) and weekly mosquito surveillance data (N=49,865) were obtained from the Miami-Dade Mosquito Control Division. Spatial clustering of DENV was assessed using Global and Local Moran’s I, while a Space Time Cube Emerging Hot Spot Analysis (EHSA) evaluated recurring temporal activity. Spearman correlations evaluated county-level associations between entomological indicators and then were compared between high-high (HH) and low-low (LL) ZIP codes using Wilcoxon rank-sum tests. Lastly, a negative binomial model estimated female Ae. aegypti counts.
Results: Mean Ae. aegypti per trap collection was higher during the 2016 ZIKV outbreak than during the 2022–2024 DENV years. DENV activity was spatially clustered (Global Moran’s I = 0.490, p < 0.001), with 15 HH and 27 LL ZIP codes identified. 2022-2024 female Ae. aegypti densities were lower in HH than LL ZIP codes with 3.4 vs. 4.6 (p = 0.0335), respectively. Furthermore, female Ae. aegypti counts were 22% lower in HH ZIP codes. The EHSA identified recurring DENV activity in Miami-Dade County with oscillating and sporadic hot spot patterns.
Conclusions: 2022-2024 DENV activity was clustered however did not align with higher Ae. aegypti indicators. These findings suggest that DENV risk in Miami-Dade County is shaped by more than mosquito population dynamics and support prioritizing identified hotspot ZIP codes for further investigation, surveillance and vector control.