General Abstract Submission
Disease/Vector Studies
We monitored the population dynamics of gravid females of Aedes aegypti in two managed (area-wide mass-trapping) and two unmanaged communities in southern Puerto Rico for several years (2013-2019) to understand how inter-annual climate variability influenced local weather and its effects on mosquito and arbovirus populations. During this study we observed drought periods associated with the emergence of El Niño Southern Oscillation events (ENSO), and wetter conditions during La Niña events. Also, during that period, we observed outbreaks of dengue, chikungunya, and Zika viruses. Mosquito populations were more abundant during the warmer and wetter part of the seasonal cycle, corresponding with periods of maximum transmission of arboviruses. Other than these weather factors, the main factor explaining differences in Ae. aegypti abundance among study sites was mass-trapping. Populations of Ae. aegypti were not directly affected by a severe drought that coincided with a strong El Niño event. Since there is a lag between the occurrence of climatic conditions promoting transmission and the subsequent outbreak, we analyzed lagged values of El Niño Index and arbovirus cases and found they were positively correlated. Arbovirus cases were positively correlated with lagged values (5-12 months) of El Niño Index, droughts, and abundance of Ae. aegypti. The results suggest that the onset of strong ENSO conditions in Puerto Rico could potentially be used as an early warning signal for arbovirus outbreaks in areas where Ae. aegypti populations exceed the density threshold value.