Dengue Fever Cases Surge Globally: A Comprehensive Update

Dengue fever, a mosquito-borne viral infection, is experiencing an unprecedented surge in cases worldwide. In 2024, more cases were recorded than in any previous 12-month period, impacting over 100 countries across all continents. Understanding the risks, symptoms, and prevention strategies is crucial as the disease continues to spread.

What is Dengue Fever?

Dengue is caused by the dengue virus (DENV), transmitted to humans through the bite of infected Aedes mosquitoes. There are four distinct serotypes of the virus (DENV-1, DENV-2, DENV-3, and DENV-4). Infection with one serotype provides lifelong immunity to that specific serotype, but only short-term immunity to the others [1]. Subsequent infection with a different serotype increases the risk of developing severe dengue.

Global Impact and Recent Trends

An estimated 100–400 million dengue infections occur each year globally [1]. In 2024, a historic high of over 14.6 million cases and more than 12,000 dengue-related deaths were reported [1]. The disease is most prevalent in tropical and subtropical climates, particularly in urban and semi-urban areas.

Recent outbreaks have been reported in Europe. In 2023, France reported 43 cases, Italy 76, and Spain 3, all occurring between July and October [3].

Symptoms of Dengue Fever

Many dengue infections are asymptomatic or cause only mild illness. When symptoms do occur, they typically begin 4–10 days after infection and last for 2–7 days [1]. Common symptoms include:

• High fever (up to 40°C/104°F)
• Severe headache
• Pain behind the eyes
• Muscle and joint pains
• Nausea
• Vomiting
• Swollen glands
• Rash

Individuals infected for the second time are at a greater risk of developing severe dengue [1].

Severe Dengue

Severe dengue is a potentially life-threatening complication characterized by:

• Bleeding
• Low levels of blood platelets
• Plasma leakage
• Dangerously low blood pressure

Early detection and access to proper medical care are crucial to lowering fatality rates associated with severe dengue [1].

Prevention and Treatment

Currently, there is no specific antiviral treatment for dengue fever. Treatment focuses on managing symptoms, including pain relief and maintaining fluid balance [1]. Intravenous fluids and blood transfusions may be necessary in severe cases.

Prevention primarily relies on controlling the mosquito vector. Key prevention strategies include:

• Avoiding mosquito bites, especially during the day
• Using mosquito repellents
• Wearing protective clothing
• Eliminating mosquito breeding sites (standing water)

A dengue vaccine is available, but its use is recommended only in areas with a high incidence of dengue and for individuals with prior dengue infection [4].

Key Takeaways

• Dengue fever is a growing global health threat.
• Early diagnosis and supportive care are vital for managing the disease.
• Mosquito control is the most effective prevention strategy.
• Individuals with previous dengue infections are at higher risk of severe complications upon subsequent infection.