CDC Warns U.S. Travelers of Rising Dengue Threat

The Centers for Disease Control and Prevention (CDC) has issued a stark warning regarding the alarming rise in dengue fever cases among U.S. travelers. With 3,484 reported cases in 2024, representing an 84% increase compared to the previous year, the agency expects numbers to continue rising in the coming months.

Dengue fever, commonly known as “breakbone fever,” is a mosquito-borne disease that has seen a significant resurgence globally over the past few years. With record-breaking cases in Latin America, the Caribbean, and parts of Asia, the spread of dengue has become an urgent public health concern.

Dengue Cases Surge Among U.S. Travelers

According to the CDC, travel-related dengue infections have spiked dramatically in 2024. The highest number of imported cases has been reported in the states of Florida, California, and New York—all of which serve as major travel hubs for destinations where dengue is endemic.

The situation is especially concerning in Puerto Rico and the U.S. Virgin Islands, where outbreaks have led to public health emergencies being declared. Puerto Rico, in particular, has been grappling with a sustained outbreak since early 2024, crossing the outbreak threshold in February and prompting officials to issue a public health emergency in March.

By the end of 2024, Puerto Rico reported 6,291 dengue cases, with more than half of the infected requiring hospitalization. Tragically, 13 fatalities were confirmed. Similarly, the U.S. Virgin Islands saw a spike in cases, recording 208 cases in 2024 and an additional 30 cases in early 2025.

Why is Dengue Becoming a Growing Threat?

Dengue is not new, but the frequency and intensity of outbreaks have escalated. Several factors contribute to this alarming trend:

1. Climate Change and Rising Temperatures

Warmer temperatures create ideal breeding conditions for mosquitoes. The Aedes aegypti mosquito, which transmits dengue, thrives in humid and warm climates. With global temperatures rising, mosquito populations are expanding, allowing dengue to spread to new regions.

2. Increased Global Travel

The rise in international travel has made it easier for the virus to move across borders. Tourists unknowingly carry the virus back to their home countries, contributing to a rise in travel-related infections.

3. Urbanization and Poor Sanitation

Rapid urbanization has increased the mosquito population in densely populated areas with poor drainage and sanitation. Stagnant water—found in construction sites, garbage dumps, and open drains—becomes a breeding ground for mosquitoes.

4. Lack of Effective Vaccination Coverage

Although dengue vaccines exist, widespread access is limited. The Dengvaxia vaccine is only recommended for individuals who have had a prior dengue infection, while newer vaccines are still in the early stages of distribution.

What is Dengue Fever? Symptoms and Risks

Dengue fever is caused by the dengue virus (DENV), which is transmitted to humans through mosquito bites. The disease can range from mild flu-like symptoms to severe, life-threatening complications.

Common Symptoms of Dengue

• High fever (104°F or higher)

• Severe headaches

• Joint and muscle pain (“breakbone fever”)

• Pain behind the eyes

• Skin rash

• Mild bleeding (nosebleeds, gum bleeding, easy bruising)

Severe Dengue Symptoms (Dengue Hemorrhagic Fever & Dengue Shock Syndrome)

• Severe abdominal pain

• Persistent vomiting

• Internal bleeding (black stools, vomiting blood)

• Difficulty breathing

• Organ failure

Severe cases can lead to Dengue Hemorrhagic Fever (DHF) or Dengue Shock Syndrome (DSS), both of which are life-threatening without immediate medical attention.

How to Protect Yourself from Dengue While Traveling

With dengue cases on the rise, travelers need to take proactive measures to protect themselves from mosquito bites and infection.

1. Use Mosquito Repellents

Apply EPA-approved repellents containing DEET, Picaridin, or Oil of Lemon Eucalyptus on exposed skin and clothing.

2. Wear Protective Clothing

Opt for long-sleeved shirts, long pants, socks, and closed-toe shoes to minimize skin exposure.

3. Choose Accommodations with Mosquito Protection

Stay in air-conditioned rooms or accommodations with window screens and mosquito nets to reduce mosquito exposure.

4. Avoid Peak Mosquito Hours

Aedes mosquitoes are most active during early morning and late afternoon. Limit outdoor activities during these times.

5. Eliminate Standing Water

Mosquitoes breed in stagnant water. If staying in a rental property, ensure there are no water-filled containers, birdbaths, or clogged drains around.

Treatment and Management of Dengue

There is no specific antiviral treatment for dengue. If infected, supportive care is essential.

At-Home Care

• Stay hydrated with plenty of fluids (water, electrolyte drinks, coconut water).

• Take pain relievers like acetaminophen (Tylenol) for fever. Avoid ibuprofen and aspirin, as they increase bleeding risks.

• Rest and monitor symptoms closely.

Hospitalization May Be Required If:

• There is severe dehydration.

• The patient experiences internal bleeding.

• Blood pressure drops (Dengue Shock Syndrome).

The Global Burden of Dengue: A Growing Crisis

According to the World Health Organization (WHO), dengue has become one of the fastest-spreading mosquito-borne diseases globally. The Americas, Southeast Asia, and the Western Pacific have been hit hardest.

Dengue Statistics (2024 WHO Data)

• 7.6 million cases reported worldwide

• 3.4 million confirmed infections

• 16,000+ severe cases

• 3,000+ deaths

Dengue is no longer confined to tropical and subtropical regions. With climate change, urbanization, and increased travel, the disease is spreading to new territories.

Will the U.S. See Local Dengue Transmission?

While most dengue cases in the U.S. are travel-related, experts warn that localized outbreaks could become more frequent.

Factors Increasing the Risk in the U.S.:

✅ Warmer climates, especially in Florida, Texas, and the Gulf Coast
✅ Presence of Aedes mosquitoes in southern states
✅ Increased travel to endemic areas
✅ Lack of mosquito control measures in urban centers

The CDC urges state health departments to monitor mosquito populations and conduct awareness campaigns to prevent local outbreaks.

What’s Next? The Future of Dengue Prevention

Efforts are underway to develop better vaccines, mosquito control programs, and antiviral treatments. Scientists are also exploring genetically modified mosquitoes to reduce transmission rates.

Current Initiatives:

🔹 Dengue Vaccination Programs – Expanding vaccine access in endemic regions
🔹 Wolbachia Bacteria Research – Using bacteria to make mosquitoes less infectious
🔹 Gene-Editing Mosquitoes – Releasing modified mosquitoes that cannot spread dengue

The CDC’s warning about rising dengue cases among U.S. travelers is a wake-up call. With record-breaking global outbreaks, travelers must take precautionary measures to protect themselves from the disease.

By following preventive guidelines, staying informed about affected regions, and advocating for stronger mosquito control measures, we can reduce the impact of dengue fever and prevent future outbreaks.

Stay safe, stay informed, and take proactive steps to protect yourself while traveling to dengue-prone region.