The Fight Against Dengue: How Brazil is Using Innovative Methods to Combat This Persistent Public Health Crisis

Sunday - March 17 2024, 02:56 UTC - 8 months ago

As dengue cases continue to rise in Brazil, the country is facing a massive public health crisis. Innovative methods, such as infecting mosquitoes with Wolbachia bacteria, have shown promising results in reducing dengue rates in Niterói, a Brazilian city of 500,000 people.

As the rainy season approaches in Brazil, so does the dreaded rise in dengue cases. With over a million Brazilians infected with the mosquito-borne disease in 2024 alone, the country is facing a significant public health challenge. This year, all four types of dengue virus are in circulation, making it especially difficult for people to build immunity against them all. This, coupled with favorable weather conditions, has led to a surge in the Aedes aegypti mosquito population - the primary carrier of dengue .

To combat this persistent public health crisis, Brazil has turned to innovative methods such as the use of Wolbachia bacteria. Wolbachia is a naturally-occurring bacteria that has been found to inhibit the replication of dengue and other viruses in mosquitoes. By infecting mosquitoes with Wolbachia, Brazil hopes to reduce the spread of dengue in the country.The World Mosquito Program, through its insectaries, breeds and releases Wolbachia-infected mosquitoes into communities .

These mosquitoes mate with wild mosquitoes, passing on the bacteria to their offspring. Over time, this leads to the spread of Wolbachia throughout the mosquito population. Since its start in 2014, the program has successfully covered an area with a population of over 3 million people across five municipalities in Brazil.One of the first places to benefit from this method is Niterói, a coastal community of 500,000 people just across the bay from Rio de Janeiro .

Since the first releases in 2015, the prevalence of Wolbachia in the mosquito population has increased, ranging from 80% in some parts of the city to 40% in others. In comparison to a control zone with no Wolbachia releases, areas with the bacteria experienced a 69% reduction in dengue cases.But what about the ongoing surge in dengue cases in Brazil? While it is too early to see the full impact of Wolbachia on dengue rates, the data from Niterói is promising .

With only 69 confirmed cases per 100,000 people, the incidence of dengue in the city is one of the lowest in the state. In comparison, Rio de Janeiro, a city of nearly 7 million people, has seen over 42,000 cases with an incidence rate of 700 per 100,000.According to the World Mosquito Program, Niterói is the first Brazilian city to be fully protected by the Wolbachia method. With the bacteria now present throughout the mosquito population, the city continues to see low rates of dengue activity .

This innovative approach gives hope to Brazil and other countries battling dengue and other mosquito-borne diseases.