What is dengue fever and how serious is it?

Dengue is a viral infection transmitted by Aedes mosquitoes. Most people experience flu-like symptoms lasting 2-7 days. However, about 1 in 20 people develop severe dengue (previously called dengue hemorrhagic fever), which can cause internal bleeding, organ failure, and death if not treated promptly.

How does dengue spread?

Dengue spreads through bites from infected Aedes aegypti and Aedes albopictus mosquitoes. These mosquitoes bite primarily during the day, particularly in early morning and before dusk. Unlike malaria, dengue cannot spread directly from person to person - it requires mosquitoes as vectors.

What are the warning signs of severe dengue?

Warning signs typically appear 3-7 days after symptoms start and include severe abdominal pain, persistent vomiting, bleeding gums or nose, blood in vomit or stool, fatigue, restlessness, and rapid breathing. Severe dengue is a medical emergency requiring immediate hospitalization.

Can you get dengue more than once?

Yes, there are four dengue virus serotypes (DENV-1, DENV-2, DENV-3, DENV-4). Infection with one provides lifelong immunity to that serotype but only temporary partial immunity to the others. Subsequent infections with different serotypes increase the risk of developing severe dengue.

Is there a dengue vaccine?

Yes, dengue vaccines exist but have specific recommendations. Dengvaxia is approved for people aged 9-45 who live in endemic areas and have had a previous dengue infection. TAK-003 is approved in some countries. The vaccines are not recommended for people who have never had dengue due to increased risk of severe disease.

Where is dengue occurring now?

Dengue is endemic in over 100 countries in tropical and subtropical regions, including Southeast Asia, Latin America, Africa, and Pacific Islands. Climate change is expanding its range. Check the live outbreak data above for current dengue activity worldwide.

Colorado

Dengue Fever in Colorado

Dengue is a mosquito-borne viral infection that causes flu-like illness and can develop into severe dengue, a potentially lethal complication. It is endemic in more than 100 countries, primarily in tropical and subtropical regions. Track Dengue Fever activity and outbreaks specific to Colorado.

Open Web App

iOS Android

What is Dengue Fever?

Dengue fever is one of the fastest-growing mosquito-borne diseases globally. Approximately half of the world's population is now at risk, with an estimated 390 million infections occurring each year. Climate change is expanding the range of Aedes mosquitoes that transmit the disease, bringing dengue to new regions.

Symptoms

High fever (104°F/40°C)
Severe headache
Pain behind the eyes
Severe joint and muscle pain (breakbone fever)
Rash (appears 2-5 days after fever)
Nausea and vomiting
Mild bleeding (nose, gums)

Transmission

Dengue is transmitted through bites from infected Aedes aegypti and Aedes albopictus mosquitoes. These mosquitoes become infected when they bite a person with dengue virus in their blood. The virus cannot spread directly between people.

Contagious Period: Not contagious person-to-person; infectious to mosquitoes from 1 day before fever onset through 5-7 days of illness

Prevention

Use mosquito repellent containing DEET, picaridin, or IR3535
Wear long-sleeved shirts and long pants
Use air conditioning or window/door screens
Remove standing water where mosquitoes breed
Use mosquito nets, especially during the day
Consider dengue vaccine if you live in endemic areas (consult healthcare provider)
Treat clothing and gear with permethrin

Colorado Health Resources

Local health department information and state-specific prevention guidance

We're Monitoring Colorado

Our AI-powered surveillance continuously monitors Dengue Fever activity across Colorado. We track data from state health departments, local hospitals, CDC reports, and 50+ global health sources to provide early warning of emerging threats.

Get instant push notifications when Dengue Fever activity increases in Colorado or your specific county.

Open Web App

iOS Android

Colorado Health Department

For official state health alerts, vaccination locations, and public health guidance specific to Colorado, visit your state health department's website.

→ Colorado Department of Health → Find Dengue Fever Vaccination Near You → CDC Travel Health Notices

Protecting Yourself in Colorado

Whether you live in Colorado, are traveling there, or have family in the state, understanding Dengue Fever prevention is essential. Follow these evidence-based prevention measures:

Prevention Measures

Use mosquito repellent containing DEET, picaridin, or IR3535
Wear long-sleeved shirts and long pants
Use air conditioning or window/door screens
Remove standing water where mosquitoes breed
Use mosquito nets, especially during the day
Consider dengue vaccine if you live in endemic areas (consult healthcare provider)
Treat clothing and gear with permethrin

When to Seek Care

If you experience symptoms of Dengue Fever in Colorado, contact your healthcare provider immediately. Early diagnosis and treatment improve outcomes significantly.

Emergency symptoms: If you experience severe symptoms, difficulty breathing, or signs of dehydration, call 911 or go to your nearest emergency room.

Expert Resources & References

Trusted information from leading health organizations

CDC

Official guidance from the U.S. Centers for Disease Control and Prevention

View CDC Resources →

WHO

Global disease surveillance and guidelines from the World Health Organization

View WHO Resources →

Research

Latest peer-reviewed research and clinical studies

View Research →

Medically Reviewed Content

Disease information on Virus Watcher is reviewed by our Chief Epidemiologist, a former CDC lead analyst for FluSight forecasting. Outbreak data is aggregated from verified sources including BEACON, ProMED, WHO, CDC, and 50+ national health agencies. This information is for educational purposes and should not replace professional medical advice.

Last reviewed: 2026-06-29

Recent Dengue Fever Reports

No confirmed cases reported in Colorado yet. Here are the latest Dengue Fever reports from our global surveillance network.

This event envelope contains reports on Dengue in Vanuatu. *Source: BEACON* - [View Full Report](https://beaconbio.org/en/event/?eventid=8579d91f-76c1-46e4-9d0f-0908880602b7)

Vanuatu · 2026-06-26

Autochthonous transmission of dengue (type 2) has been reported in Taiwan, with 4 cases in Kaohsiung City. Increased mosquito activity related to rain, especially following typhoons, is thought to be increasing risk of transmission. *Source: BEACON* - [View Full Report](https://…

Taiwan · 2026-05-24

In 2025, Colombia reported 123 745 dengue cases and 118 confirmed deaths, corresponding to a national case fatality rate of 0.09% and an incidence of 370.7 cases per 100 000 inhabitants, substantially lower than in 2024 but still above historical baseline levels. Most cases were …

Colombia · 2026-06-27

This event envelope contains reports on Dengue in Viet Nam. *Source: BEACON* - [View Full Report](https://beaconbio.org/en/event/?eventid=3a91e29c-d693-4670-97d3-73e10352519e)

United States · 2026-06-08

This event envelope contains reports on dengue in Yemen. *Source: BEACON* - [View Full Report](https://beaconbio.org/en/event/?eventid=2da917f7-8c72-4975-8823-087f57e306af)

Yemen · 2026-06-15

This event envelope contains reports on dengue in Brazil. *Source: BEACON* - [View Full Report](https://beaconbio.org/en/event/?eventid=4a4130b0-6a6c-4f10-9859-e2297a985d27)

Brazil · 2026-06-08

Georgia has reported up to eight imported dengue cases annually, with no evidence of autochthonous (locally acquired) transmission. *Source: BEACON* - [View Full Report](https://beaconbio.org/en/event/?eventid=ddb4120b-71b0-4d6f-8188-0d31839b3cf9)

Georgia · 2026-06-04

This event envelope contains reports on Dengue in Malaysia. *Source: BEACON* - [View Full Report](https://beaconbio.org/en/event/?eventid=ceb25511-d283-4842-afbf-234fa8a6358f)

Malaysia · 2026-06-15

View all Dengue Fever alerts →

Frequently Asked Questions

Common questions about Dengue Fever answered by our epidemiology team

Related Diseases

Track other diseases with similar symptoms or transmission patterns

zika virus chikungunya yellow fever malaria west nile virus

Get Dengue Fever Alerts for Colorado

Receive instant push notifications when Dengue Fever activity increases in Colorado or your travel destinations. Track 200+ diseases with location-based alerts. Used by healthcare systems, EMS, schools, and travelers worldwide.

Open Web App

iOS Android

Enterprise Solutions