South America Faces Historic Dengue Outbreak with Record Cases in 2023

South America has become the epicenter of a historic dengue outbreak, with record-breaking case numbers reported in 2023. The Pan American Health Organization (PAHO) has joined forces with Argentine authorities to tackle the crisis, which is characterized by a greater magnitude than previous epidemic seasons.

In the first 15 weeks of 2023, the accumulated dengue cases in South America were 3.17 times more than the same period in the previous season and 9.1 times more than the same period in 2019/2020. Argentina alone has confirmed over 315,000 cases, while regionally, cases have increased to 5.2 million, with around 1,800 deaths reported.

Experts warn that the dengue mosquito, Aedes Aegypti, has become resistant to insecticides, and that large-scale use of insecticides is not the proper way to control the outbreak. Instead, they recommend focusing on attacking the immature stages of the mosquito and avoiding potential breeding sites.

Why this matters: The historic dengue outbreak in South America highlights the growing global threat of mosquito-borne diseases, exacerbated by climate change and urbanization. As the world continues to warm, the risk of these diseases spreading to new areas and affecting more people will likely increase, necessitating enhanced disease surveillance, early warning systems, and targeted resource allocation to control and prevent future outbreaks.

Driven by global warming and urbanization, mosquito-borne diseases like dengue are spreading rapidly, with outbreaks now occurring in areas where people are immunologically naive and public health systems are unprepared. The number of dengue cases reported to the World Health Organization has increased eightfold in the last two decades, from 500,000 in 2000 to over 5 million in 2019.

Experts warn that longer hot seasons and climate extremes like droughts and floods are fueling the spread of dengue, with projections suggesting that an additional 2.4-4.7 billion people could be at risk of malaria and dengue by 2100 if global warming continues unchecked. Mosquitoes that carry dengue have invaded 13 European countries since 2000, with local spread of the disease seen in France, Italy, and Spain in 2023 due to the climate crisis.

Researchers are developing ways to predict and intervene in these outbreaks using disease surveillance and climate change data, but they emphasize that the most effective solution is to dramatically curb greenhouse gas emissions to reduce the risk of these diseases spreading to new areas where over half the world's population could be at risk. Efforts to enhance disease surveillance, develop early warning systems, and target resources to the most at-risk areas are crucial to mitigate the growing threat of vector-borne diseases like dengue in South America and globally.

Key Takeaways

• South America faces historic dengue outbreak with record-breaking cases in 2023.
• Dengue cases in South America 3.17x higher in 2023 vs 2022, 9.1x higher vs 2019/2020.
• Dengue mosquito has become resistant to insecticides, requiring focus on immature stages.
• Climate change and urbanization fuel global spread of mosquito-borne diseases like dengue.
• Curbing greenhouse gas emissions is crucial to mitigate risk of dengue spreading to new areas.