SAN JUAN, Puerto Rico — The Caribbean and the Americas are currently facing a major outbreak of dengue fever, with health authorities reporting an alarming total of approximately 12.6 million suspected cases of this mosquito-borne illness in 2024. This figure is nearly three times higher than the cases recorded in the previous year, signaling a significant public health crisis.

The surge in dengue cases can be attributed in part to warmer weather patterns linked to climate change, which allows mosquitoes to expand into new territories. The Pan American Health Organization (PAHO), which serves as the regional branch of the World Health Organization in the Americas, has also noted a rise in fatalities related to dengue, with over 7,700 deaths documented thus far in 2024. This marks a steep increase of more than 200% compared to the 2,467 deaths reported in 2023.

This year’s figures represent the highest number of dengue cases recorded in the region since 1980, according to PAHO’s director Jarbas Barbosa. He attributed the increase to climatic factors, including elevated temperatures, drought conditions, and flooding. Moreover, rapid population growth, unplanned urban development, and inadequate sanitation systems have also exacerbated the situation.

Notably, Brazil is at the epicenter of the outbreak, reporting over 10 million cases, followed by Argentina with more than 580,000, and Mexico with approximately half a million cases. In the Caribbean, Guyana leads with over 41,000 cases, followed by French Guiana, the Dominican Republic, and Martinique. Furthermore, local outbreaks of dengue have been confirmed in states such as California, Florida, and Texas this year, as indicated by the U.S. Centers for Disease Control and Prevention.

There are four distinct serotypes of the dengue virus—1, 2, 3, and 4. Contracting one serotype does not confer immunity against the others. For the first time in a decade, serotype 3 has emerged as the dominant strain in Mexico, Central America, and some Caribbean regions during the latter part of this year, according to Thais dos Santos, an advisor on arboviral diseases at PAHO.

While many individuals infected with dengue may not exhibit symptoms, those affected often suffer from headaches, fever, and flu-like signs. Severe cases can lead to serious complications, such as bleeding, shock, and even death, especially with repeated infections.

Dengue infections generally peak during the rainy season; however, Puerto Rico has already declared an epidemic by late March, reporting upwards of 4,900 cases and at least nine fatalities—among them a 17-year-old girl and a 31-year-old woman. The number of reported cases in Puerto Rico has nearly quadrupled compared to the previous year.

Lydia Platón, a 55-year-old English professor from Puerto Rico, shared her personal struggle with the illness, stating, “You have fever all the time. You have horrible chills.” She noted that her neighborhood experienced five cases within six weeks, attributing the outbreak to heavy rains that created stagnant water, a breeding ground for mosquitoes. This included her daughter being one of the affected. In response, Platón has taken preventive measures by lighting incense and applying insect repellent daily.

Officials in Puerto Rico are actively encouraging residents to eliminate stagnant water where mosquitoes can breed. Additionally, the government of Trinidad and Tobago has implemented fines for individuals whose properties contribute to mosquito breeding sites.

This year, over one-third of dengue cases in countries like Costa Rica, Mexico, and Paraguay have involved children under the age of 15, with Guatemala noting a worrying number of child fatalities. Vaccinations against dengue have been rolled out in countries such as Peru, Brazil, and Argentina, with Honduras anticipated to receive doses next year. These vaccines are primarily aimed at children and are reported to be most effective in individuals who have previously contracted dengue.

However, officials note that vaccine supplies are limited, and their availability is not expected to significantly curb the spread of the virus. Emphasizing the importance of preventative measures, experts have reiterated a crucial message: “If there’s no mosquito, there’s no dengue.”