Brazilian City Fights Back Against Record Dengue Outbreak wiht Innovative Mosquito Control
As Brazil grappled with its worst-ever dengue fever outbreak in 2024, the city of Niterói bucked the trend, experiencing only a minor increase in cases. This success story is attributed to a pioneering program utilizing Wolbachia-infected mosquitoes, a strategy detailed in a new study presented at the American Society of Tropical Medicine and Hygiene (ASTMH) Annual Meeting.
The initiative, a collaboration between the World Mosquito Program and Brazil’s Ministry of Health, involved releasing Aedes aegypti mosquitoes carrying the naturally occurring bacterium Wolbachia. This bacterium has been proven to significantly hinder the mosquito’s ability to transmit dengue and other viruses.
The program, launched five years prior, initially covered three-quarters of Niterói. Deployment to the remaining areas was completed in May 2023. Lead researcher Katie Anders explained the remarkable results: “we already saw infections essentially flatline in Niterói after the Wolbachia deployment, and while there was a small increase in 2024, the caseload was still 90 percent lower than before the deployment — and nothing like what was happening in the rest of Brazil.”
Anders further emphasized the long-term effectiveness of the program: “The fact that Wolbachia has sustained itself in the mosquito population for years now and remained effective during a record year for dengue outbreaks shows that Wolbachia can provide long-term protection for communities against the increasingly frequent surges in dengue that we’re seeing globally.”
The data speaks volumes. Since the Wolbachia rollout, dengue incidence in Niterói has plummeted to an average of 84 cases per 100,000 people annually, a dramatic decrease from the pre-Wolbachia average of 913 cases per 100,000 people per year.
While similar prosperous trials using Wolbachia have been conducted in Colombia and Indonesia, Anders highlights the significance of Niterói’s success amidst a record-breaking dengue outbreak. She notes that establishing a local production facility in Brazil is a crucial step forward, addressing the challenge of large-scale Wolbachia deployment which requires releasing ample numbers of infected mosquitoes.
This innovative approach offers a beacon of hope in the fight against dengue fever, a disease exacerbated by climate change. The success in Niterói demonstrates the potential of Wolbachia as a enduring and effective tool in combating this growing global health threat, notably relevant as climate change intensifies the spread of mosquito-borne illnesses in the United States and worldwide.
Niterói’s Innovative Approach: Combating Dengue with Wolbachia
Brazil faced its most severe dengue fever outbreak in 2024, yet amidst this crisis, the city of Niterói experienced only a minor rise in cases. This remarkable success can be attributed to a pioneering program utilizing Wolbachia-infected mosquitoes, an innovative strategy detailed in a recent study presented at the American Society of Tropical Medicine and Hygiene (ASTMH) Annual Meeting.
The Wolbachia Effect: reducing Dengue Transmission
Michael O’Connell (Senior Editor, world-today-news.com): Dr. Evelyn Rodriguez, thank you for joining us today. Could you explain what makes Wolbachia so effective in controlling dengue?
Dr. Evelyn Rodriguez (Entomologist & Tropical Disease Specialist): It’s a pleasure to be here. Wolbachia is a naturally occurring bacterium found in many insect species, but not originally in Aedes aegypti mosquitoes, which are the primary vectors for dengue.When introduced, Wolbachia lives inside the mosquito and interferes with its ability to transmit dengue virus.it essentially blocks the virus from replicating within the mosquito, preventing it from spreading to humans.
Niterói’s Success Story: A Model for the Future?
Michael O’Connell: Niterói’s success in bucking the national trend is fascinating. Can you elaborate on how this program was implemented?
Dr. Rodriguez: the World Mosquito Program, in collaboration with Brazil’s Ministry of Health, released Wolbachia-infected aedes aegypti mosquitoes across Niterói over several years. They started coverage in three-quarters of the city and completed the rollout to the remaining areas in May 2023.The results have been astounding. Since the program’s inception, dengue incidence in Niterói has plummeted by over 90%, even during brazil’s record outbreak in 2024.
Long-Term Impact and Global Implications
Michael O’Connell: These results are certainly encouraging. What are the long-term implications of this approach, and can it be replicated in other areas?
Dr. Rodriguez: That’s the beauty of Wolbachia. It’s self-sustaining within the mosquito population. Studies have shown that Wolbachia has persisted in Niterói for years and remains effective. This means it offers long-term protection against dengue surges, which are becoming increasingly frequent due to climate change. Triumphant trials have also been conducted in Colombia and Indonesia, demonstrating its potential for broader application.
Michael O’Connell: dr. Rodriguez, this is truly groundbreaking work.Thank you for sharing your expertise with us and shedding light on this potentially game-changing solution to the global dengue crisis.
Dr. Rodriguez: My pleasure. It’s vital to raise awareness about this innovative approach and work towards making it accessible to more communities worldwide.
