John-Paul Mutebi, Ph.D., chief of the Mosquito Control Division at Miami-Dade County, was recently invited to speak at the University of Miami Miller School of Medicine by Naresh Kumar, Ph.D., a professor in the Department of Public Health Sciences, Division of Environment & Public Health.
Dr. Mutebi’s presentation focused on the proactive strategies being employed to manage the reemerging threat of vector-borne diseases like Dengue, Zika, and Chikungunya.
Proactive Surveillance: Stopping Outbreaks Before They Start
With extensive experience in vector biology and entomology, Dr. Mutebi emphasized the critical role of surveillance in predicting and preventing outbreaks. “The key to stopping mosquito-borne diseases is proactive surveillance. By monitoring mosquito populations and understanding the environmental factors at play, we can forecast outbreaks and intervene before they become public health crises.”
His team employs cutting-edge techniques, including the use of traps to monitor mosquito density and species distribution across the county. Dr. Mutebi explained, “We have 320 surveillance sites across Miami-Dade, and this helps us know what’s happening on the ground. It’s not just about reacting to an outbreak; it’s about stopping it before it starts.”
Climate Change and Mosquito Proliferation
Climate change, through warmer temperatures and extended transmission seasons, allows mosquitoes like Aedes aegypti to develop faster and expand their geographical range. As these mosquitoes, which carry diseases such as Dengue and Zika, adapt to warmer climates, their extended periods of activity heighten the threat to public health, allowing them more time to breed, spread, and transmit dangerous pathogens.
Heavy rainfall also plays a critical role in mosquito proliferation.
In regions with increased rain, breeding sites multiply, significantly raising the risk of disease transmission. Dr. Mutebi shared examples from East Africa and Massachusetts, where unusually high rainfall consistently precedes outbreaks of vector-borne diseases like Rift Valley Fever and Eastern Equine Encephalitis. “Wherever you have abnormal rainfall, you need to worry about mosquito-borne diseases,” he warned.
Maintaining Critical Mosquito Population Thresholds
To combat these evolving threats, Miami-Dade County employs a multifaceted approach, combining mosquito population surveillance, larviciding, and adulticiding techniques.
The surveillance system tracks mosquito density and species composition in real-time, allowing public health officials to identify high-risk areas, predict potential outbreaks, and respond swiftly. Complementing this, larviciding targets mosquitoes in their early stages by applying biological agents like Bacillus thuringiensis israelensis (BTI), which prevent larvae from developing into adult mosquitoes capable of spreading diseases.
When mosquito populations exceed critical thresholds or there is confirmed disease transmission, adulticiding—focused on reducing adult mosquito numbers through targeted ground and aerial sprays—becomes essential.
“The goal is to keep mosquito numbers below the action threshold, where transmission is likely. If we can do that, we can stop outbreaks before they happen,” said Dr. Mutebi.
Collaborative Efforts to Mitigate Risk
By understanding the environmental and climatic factors driving mosquito-borne diseases, Miami-Dade is better equipped to protect its residents. Dr. Mutebi has been collaborating with John Beier, Sc.D., director of the Environment and Public Health Division, and is exploring collaboration with Dr. Kumar to develop real-time location-specific risk prediction of vector-borne diseases.
Dr. Kumar noted the importance of this real-time surveillance. “By using the local time-space models, that we have tested and validated, we can assess the risk of mosquito-borne diseases at a given for a specific location or community in Miami-Dade. Integrating the county’s mosquito data with ecological, socio-economic, and real-time meteorological data allows us to accurately predict potential outbreaks.”
These collaborative efforts outline the ongoing battle against reemerging mosquito-borne threats and the necessity of proactive public health strategies to mitigate risks before they escalate into a public health crisis.
Written by Deycha Torres Hernández, published on September 24, 2024.
