Technology and public health needed to combat the growing threat of dengue in Brazil and Mexico

With more than 8.1 million cases, dengue is ravaging North and South America, and experts predict that dengue will engulf almost all of Brazil and Mexico by 2039, creating unprecedented public health challenges.

Dengue fever, a mosquito-borne viral infection, is wreaking havoc across America. An alarming prediction is that the disease will affect almost all of Brazil and Mexico by 2039. According to a comprehensive study published in Nature Communications, this rapid spread poses significant challenges for the two largest countries in Latin America.

The study, a collaboration between scientists from Canada, the United Kingdom, Australia, the United States, Brazil and Mexico, offers a bleak forecast. By 2039, 97% of Brazilian and 81% of Mexican municipalities will be affected by dengue. This expansion will be especially pronounced in the central plateau of Mexico and the southern regions of Brazil.

The research points to a dramatic increase in dengue cases in both countries in recent decades. In Mexico, the number of municipalities affected by dengue increased from 16 in 1996 to 1,350 at the end of 2019. Similarly, in Brazil, the number of dengue cases increased from 549 cities in 2001 to 4,299 municipalities in 2019.

Contributing factors: climate change and mobility

The study attributes the accelerated spread of dengue to climate change and increased human mobility. Rising temperatures, higher humidity and increased rainfall create ideal breeding conditions for the Aedes aegypti mosquito, the main vector for dengue. The global climate crisis is exacerbating these environmental conditions, making previously unaffected areas vulnerable to outbreaks.

Vinyas Harish, a researcher from the University of Toronto and one of the authors of the study, highlighted the novel approach of integrating environmental factors with population mobility data using machine learning. “To understand how dengue affects the population, we need to combine environmental data with mobility patterns over time. Machine learning allowed us to integrate these perspectives effectively,” Harish explains.

This innovative methodology provided a more comprehensive understanding of the spread of dengue, highlighting the critical role of human movement in transmitting the virus between regions.

Dengue has a long history in Latin America, dating back to the 18th century. However, in the second half of the 20th century it became a primary public health problem. The first significant dengue outbreak in the Americas occurred in 1981 in Cuba, followed by subsequent epidemics in several countries.

Rapid urbanization and population growth in Latin American cities have further contributed to the spread of dengue. Poor urban planning, inadequate waste management and lack of access to clean water have created environments where mosquitoes thrive, facilitating the spread of the virus.

Current situation: an escalating crisis

The current dengue situation in America is worrying. The Pan American Health Organization (PAHO) reported that there were three times more documented cases in the first half of this year than in the same period in 2023, with deaths reaching 3,600. This increase underlines the urgency of tackling the dengue epidemic.

The expansion of dengue in Mexico is predicted to reach the inland highlands, including Tijuana, by 2027-2030 and Mexico City by 2038-2039. In Brazil, the southern regions will see a significant increase in dengue cases in the coming years.

The implications of this spreading dengue epidemic are profound. Dengue fever can range from mild, flu-like symptoms to serious, life-threatening conditions, including hemorrhagic fever and dengue shock syndrome. For example, in a small town in Brazil, an outbreak of dengue led to the hospitalization of more than 100 people, with several deaths reported. This underlines the seriousness of the disease and the need for immediate action. Since no specific treatment is available, prevention through mosquito control and public awareness is the main strategy for dengue control.

PAHO emphasizes that preventive measures are crucial as there is no specific drug to treat dengue. Public health initiatives should focus on eliminating mosquito breeding grounds, promoting the use of mosquito repellent, and encouraging the use of protective clothing and nets.

The role of technology and research

Using machine learning in research to predict the spread of dengue is not just a breakthrough, it is a game changer in public health research. By analyzing data from more than 8,000 municipalities in Brazil and Mexico over the past 25 years, the researchers identified patterns and trends that could inform future prevention and control strategies. This is a beacon of hope in our fight against dengue.

Harish expressed optimism about the potential impact of the study’s findings. “Our conclusions can help authorities take preventive measures, from simple interventions such as raising public awareness to more complex approaches such as vaccine research or mosquito replacement techniques,” he said.

Effective prevention of dengue requires a multifaceted approach. Public health campaigns should educate communities about the risks of dengue and how to protect themselves from mosquito bites. Simple measures such as using insect repellents, installing window screens and eliminating standing water where mosquitoes breed can significantly reduce the risk of infection.

In addition, governments and health organizations must invest in research and the development of new tools to combat dengue. This includes researching innovative technologies such as genetically modified mosquitoes that are less able to transmit the virus, and advancing the development of vaccines.

The expected expansion of dengue in Brazil and Mexico has broader implications for Latin America. The region’s unique environmental, social and economic conditions make it particularly vulnerable to vector-borne diseases such as dengue. The economic impact of dengue is significant; the cost of treatment and loss of productivity is estimated at billions of dollars per year. Tackling the dengue epidemic in these two countries could not only save lives but also protect the region’s economy. This could provide a model for other Latin American countries facing similar challenges.

Latin America has traditionally been a hotspot for emerging infectious diseases due to its biodiversity and ecological diversity. The region’s response to dengue could serve as a blueprint for controlling other vector-borne diseases, such as Zika and chikungunya, which are also transmitted by the Aedes aegypti mosquito.

International cooperation and support

Fighting the dengue epidemic in Latin America requires international cooperation and support. Organizations such as the World Health Organization (WHO) and PAHO are critical in coordinating efforts, providing technical assistance and mobilizing resources to support affected countries. The global nature of the dengue threat requires a united front, with countries sharing knowledge, resources and best practices to effectively combat the disease. Only through international cooperation can we control and ultimately eradicate dengue.

Collaborative research initiatives, like those that produced the recent dengue study, are not only important, they are our best hope. By sharing knowledge, data and best practices, we can help countries build more resilient healthcare systems and improve their ability to respond to vector-borne diseases. This international cooperation is our strongest tool in the fight against dengue.

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The alarming increase in dengue fever in the Americas, especially in Brazil and Mexico, underscores the urgent need for comprehensive and coordinated public health efforts. The expected spread of the disease poses significant challenges, but with the right strategies and international support, it is possible to mitigate its impact and protect vulnerable populations.

Integrating advanced technologies, such as machine learning, with traditional public health approaches offers new hope for understanding and controlling dengue. By using these tools and promoting international cooperation, Latin America can combat vector-borne diseases and ensure a healthier future for its people.

As the region braces for the predicted increase in dengue cases, it is critical to remain vigilant, proactive and committed to implementing effective prevention and control measures. The fight against dengue is a collective responsibility, and with joint efforts we can overcome this public health challenge.