Epidemiology is the study of how often diseases occur in different groups of people and why. Epidemiological information is used to plan and evaluate strategies to prevent illness and as a guide to the management of patients in whom the disease has already developed. The study of the outbreak can also help in planning, controlling, and monitoring the spread of the disease.
For example, a study by Leandro, André S et al. (2022) study about Citywide Integrated Aedes aegypti Mosquito Surveillance as Early Warning System for Arbovirus Transmission, Brazil. In this study, The Aedes aegypti mosquito is the primary vector of arboviruses. This mosquito species is common in urbanized areas in the tropics because it is highly adapted to live in close association with humans, preferentially feeding on the blood of human hosts and laying eggs in containers located around human dwellings.
They report on a 4-year integrated citywide vector surveillance approach that involved extensive use of adult mosquito traps, molecular diagnostic testing for natural arbovirus infection in live collected mosquito specimens, construction of transmission risk maps, and performance of timely vector control intervention <48 h after mosquito collection. In this scheme, vector control was intensified in areas with a higher risk for transmission instead of maintaining homogeneous vector control efforts over the landscape. In addition, they evaluated the correspondence of larval- and adult-based indices with the epidemiologic trend in the city of Foz do Iguaçu, Brazil, during 2017–2020.
The results show, that comparing the predictive ability of traditional versus adult indices revealed that indices based on adult trapping consistently performed much better than indices based on larval surveys. and one criterion that could be used to prioritize areas is the occurrence of Ae. aegypti female mosquitoes are naturally infected with DENV, ZIKV, or CHIKV. In Foz do Iguaçu, an inspection of the 3,476 Adultraps took 4 days, and real-time qPCR results were available, on average, 36 h after all Adultraps were inspected and live mosquitoes collected.
In conclusion, They conducted a 4-year citywide study to deepen the entomologic and epidemiologic features of dengue transmission in Foz do Iguaçu by focusing on developing indicators based on adult mosquito trapping. They proposed a surveillance system that can predict a dengue outbreak with high accuracy, and indices based on adult trapping are able to predict a dengue outbreak 4 weeks after DENV detection in adult mosquitoes. In addition, the adoption of easily accessible technological resources makes it possible for the model to be replicated in other localities.
Ref: Leandro, A. S., de Castro, W., Lopes, R. D., Delai, R. M., Villela, D., & de-Freitas, R. M. (2022). Citywide Integrated Aedes aegypti Mosquito Surveillance as Early Warning System for Arbovirus Transmission, Brazil. Emerging infectious diseases, 28(4), 701–706. https://doi.org/10.3201/eid2804.211547