SAN JUAN, Puerto Rico - Dengue fever is spreading across the Western Hemisphere at an unprecedented rate, with soaring temperatures and rapid urbanization serving as contributing factors to the surge in infections. Experts warn that this year's dengue outbreak has surpassed all records, with more than 4 million cases reported in the Americas and Caribbean, exceeding the previous record set in 2019. Furthermore, over 2,000 deaths have been reported in the region.

The Pan American Health Organization (PAHO), the regional office of the World Health Organization (WHO), describes this year as the worst in recorded history for dengue. Thais dos Santos, an adviser on surveillance and control of arboviral diseases at PAHO, emphasized that vector-borne diseases, especially those transmitted by mosquitoes, serve as an important indicator of climate change impacts.

Dr. Gabriela Paz-Bailey, from the U.S. Centers for Disease Control and Prevention (CDC) in Puerto Rico, highlighted the role of higher temperatures in extending the habitat of mosquitoes and accelerating the development of the dengue virus within their bodies. This results in higher viral loads and increased probabilities of transmission.

Dr. Jeremy Farrar, the chief scientist of the WHO, cautioned that dengue is just one among many diseases that are becoming more frequent and difficult to manage due to climate change and rapid urbanization.

Dengue is not only a concern for the Americas but has become a global phenomenon. Bangladesh has witnessed a record number of cases and deaths, with the majority of fatalities occurring shortly after hospitalization. Additionally, the mosquito responsible for transmitting dengue has been detected in 22 European countries, and local outbreaks have been reported in France, Italy, and Spain. Even Chad, in central Africa, experienced its first-ever dengue outbreak.

The impact of dengue is staggering, given that roughly half of the world's population is at risk in approximately 129 countries, according to the WHO. The virus, mainly transmitted by infected female Aedes aegypti mosquitoes, can cause severe symptoms such as crushing headaches, fever, vomiting, and a rash. In advanced cases, plasma leakage can occur, leading to potentially fatal outcomes.

Reinfections pose an increased risk of severe dengue, while the mosquito responsible for dengue can also spread chikungunya and Zika virus, although past immunity has limited the circulation of these diseases.

Despite the global threat posed by dengue, there are currently no specific treatments available once a person is infected. Vaccines and innovative approaches, such as releasing specially bred mosquitoes containing Wolbachia bacteria, are being explored. Countries are considering vaccine options, with the Pan American Health Organization's immunization technical advisory group currently discussing recommendations.

The impact of the dengue outbreak is particularly pronounced in the Americas. Brazil, Argentina, Paraguay, and Peru have reported the highest number of cases worldwide. Peru has declared a state of emergency due to a historic number of dengue cases, while the Caribbean is also battling a surge in infections, with a 15% increase in confirmed cases compared to the previous year.

The French Caribbean islands of Guadeloupe and Martinique are still facing an ongoing epidemic, with Martinique experiencing an average of 800 cases per week. Countries such as Jamaica, the Bahamas, and Barbados have declared dengue outbreaks in recent months.

The Caribbean Public Health Agency underlines that dengue outbreaks pose substantial threats to health, tourism, and socioeconomic development. Impoverished countries face the greatest challenges, as poor sanitation provides breeding grounds for infected mosquitoes, lack of air conditioning and screened windows allow easy access for insects, and healthcare systems struggle to cope with the growing caseload.

Experts stress the urgency of addressing this global health crisis. Caring for dengue patients is complex due to the rapid progression of the virus, and ensuring proper fluid management is time-consuming. Healthcare systems must be equipped to handle a large number of severe cases.

Dr. Georgiana Gordon-Strachan, director of the Tropical Metabolism Research Unit at the University of the West Indies in Jamaica, attributes the island's recent outbreak to favorable conditions during the summer of 2023, as heat is known to exacerbate dengue transmission. Additionally, the dominant strain circulating in Jamaica is the most severe of the four known strains.

As dengue continues to spread across borders, international collaboration and concerted efforts are necessary to mitigate the impact of this deadly disease.