Infectivity and Dissemination of Dengue Virus-1 in Different Aedes aegypti Populations Throughout Brazil

Dengue virus, one of the most prevalent mosquito-borne flaviviruses affecting humans globally, is primarily transmitted by the Aedes aegypti mosquito, which thrives in densely populated urban environments. Dengue incidence has surged in recent decades, becoming a major public health concern in many regions, particularly in Brazil, which has experienced recurrent outbreaks and reported over 6.6 million probable cases in the year of 2024. While the link between the mosquito vector and dengue transmission is well understood, the effects of different DENV types and their interactions with the vector capacity of natural mosquito populations are crucial for understanding disease dynamics. Here we report findings from experiments designed to analyze and compare the infectivity and dissemination of the DENV-1 strain among five Ae. aegypti populations collected from different regions of Brazil. When exposed to DENV-infected AG129 mice for blood feeding, these populations exhibited variations in infection rates and dissemination efficiency. Eight days post-infection, all populations demonstrated high infection rates, underscoring the substantial capacity of Brazilian Ae. aegypti populations to support the locally circulating DENV-1 strain. Our results demonstrate variation in Ae. aegypti vector competence across Brazil, revealing distinct patterns of DENV transmission efficiency. These findings highlight the necessity for geographically tailored control strategies, particularly in high-risk urban areas where outbreak potential is greatest.