A new study by the University of Miami Miller School of Medicine public health scientists, in collaboration with the county’s Mosquito Control Division, suggests that mosquitos that transmit deadly viruses are now a year-round threat to Miami-Dade County.
Scientists examined more than two years of data from Miami-Dade’s mosquito surveillance program following the 2016 Zika virus outbreak. They found 41 species of mosquitoes in abundance, which can transmit viral diseases like Zika, dengue fever, and chikungunya.
These species were present in high numbers year-round, suggesting that there is no longer a summer mosquito season here.
André Wilke, Ph.D., post-doctoral associate in the Division of Environment & Public Health in the Department of Public Health Sciences, said, “Community Composition and Year-Round Abundance of Vector Species of Mosquitoes Make Miami-Dade County, Florida a Receptive Gateway for Arbovirus Entry to the United States.”
Study co-author John C. Beier, Sc.D., professor and chief of the Division of Environment & Public Health, said, “Our results also show that the five mosquito species that may carry these viruses, including Aedes aegypti and Culex quinquefasciatus, are well adapted to urban environments.”
Dr. Beier said the U.S. Centers for Disease Control and Prevention supports the ongoing collaboration between the Miller School and the Miami-Dade County Mosquito Control Division. “Establishing a state-of-the-art surveillance system provides a foundation to inform and guide public health decision-making.”
Study co-author Chalmers Vasquez, director of research for Miami-Dade County Mosquito Control, said a total of 2.7 million mosquitoes were collected from August 2016 to November 2018 in 191 traps. “We covered the entire county with an emphasis on Miami Beach and Wynwood, as well as Little River,” he said. “These communities experienced locally transmitted Zika cases in 2016, and have large numbers of visitors, who may bring in mosquito-borne arborviruses from other countries.”
Vasquez said samples of trapped mosquitoes are sent to state and federal laboratories every week for viral testing and screening. To date, there have been no indications of active local transmission.
But the high volume of international air travel from the Caribbean region and Latin America to Miami substantially increases the risk of introducing arboviruses to the U.S., said the researchers. “Continued surveillance, public education, environmental ordinance, and active control of mosquito populations are critical for the prevention of viral outbreaks,” they concluded.