Will the Dengue Fever Epidemic Extend to the U.S.? A Closer Look

Key Takeaways:

• Dengue fever, a tropical disease spread by mosquitoes, has seen a few sporadic cases in Florida and Texas but it’s currently unclear whether the disease is establishing its presence in the U.S.
• Dengue fever results in around 100 million infections and kills 25,000 people each year globally, thriving in tropical climate zones like Central and South America, the Caribbean and parts of Australia.
• While Dengue fever isn’t contagious, an infected person can indirectly transmit the disease if they’re bitten by another mosquito, which then bites and infects another person.
• There are four known strains of Dengue, with prior exposure to one strain increasing the risk of developing a more severe form of the disease if bitten by a mosquito infected with a different strain.
• Prevention is key, with travelers to high-risk areas advised to take precautions like using effective mosquito repellants and wearing long-sleeved clothing and long pants whenever possible.

Recent health announcements have highlighted two new cases of Dengue Fever in Florida this week, bringing the count up to 46 confirmed instances since the previous Fall. However, senior health officials have stated that it’s premature to conclude whether this tropical disease transmitted by mosquitoes is establishing its presence in the U.S.

Harold Margolis, the head official of the dengue division of the U.S. Centers for Disease Control and Prevention, stationed in San Juan, P.R., commented, “The origins of how dengue arrived in Key West and its presence as an endemic disease aren’t clear.”

“The pattern of the disease will only become evident as we observe the outcomes during this warm and wet period, which serves as a peak time for dengue,” Margolis further stated.

The Challenging Conundrum of Controllable Diseases

Margolis pointed out the fundamental issue with diseases such as Dengue Fever, “You need to monitor the disease while also implementing control measures.“

As the most common virus spread by mosquitoes, dengue results in around 100 million infections and kills 25,000 people each year globally. This disease thrives mainly in tropical climate zones, with many regions like Central and South America and the Caribbean currently experiencing epidemics. In Puerto Rico alone, there have been a minimum of five fatalities and over 6,000 suspected dengue cases this year.

Could the Outbreak in Florida be an Isolated Incident?

Margolis suggests that the Florida outbreak might be an isolated event. “We’ve noticed this trend in other parts of the world, like northern Australia. Travellers have brought back the infection, initiating its spread for some time, and then it subsides,” he mentioned.

In the U.S., a few locally acquired cases in Texas have been reported since 1980, aligning with significant outbreaks in neighbouring Mexican cities. The last recorded dengue outbreak in Florida was 75 years ago, as per the CDC.

The Symptoms and Consequences of Dengue

The disease typically manifests as flu-like symptoms such as high temperature, headache, and pains in muscles, bones, and joints. Symptoms generally appear two to seven days after the mosquito bite. “The disease is often referred to as ‘breakbone fever’ due to the severe pains it causes in bones and joints,” explained Dr. Bert Lopansri, head of the Loyola University Health System International Medicine and Traveler’s Immunization Clinic. No conclusive cure or vaccine has been identified yet, with most cases resolving on their own within a few weeks.

The disease might present mild symptoms in some individuals, leading them to overlook a potential exposure, as per the CDC. A study in Key West found that 5 percent of the local residents had dengue active in their systems or showed antibodies to the virus, indicating a recent infection within three months.

How Does Dengue Spread?

While dengue fever is not contagious, an infected person can act as a carrier, indirectly transmitting the disease to another person if they get bitten by another mosquito, which then bites and infects another individual.

The Risks of Multiple Strains

There are four known strains of dengue, and prior exposure to one strain increases the risk of developing a severe form of the disease if bitten by a mosquito infected with a different strain.

Preventative Measures

Margolis urged travellers to stay informed about Dengue and the most effective methods to prevent it. “There’s a lot of dengue in many parts of the world right now, like Mexico, Guatemala, and Colombia, where massive epidemics are being reported. If you’re travelling to these places, you must ensure that you protect yourself.” This includes using mosquito repellants and wearing full-sleeved clothing and long pants as much as possible

As per Dr. Lopansri, mosquito repellents that contain either DEET or picaridin are the most effective ones. Products made of citronella or other plant-based components are not as efficient at repelling mosquitoes.

“If you develop a fever, headache, and body aches after travelling to an area known for dengue, make sure you inform your doctor,” advised Lopansri.

Further Information

For more detailed information on dengue fever, you can visit the U.S. National Library of Medicine.