It’s common knowledge that mosquitoes can carry pathogens that may cause disease. One of these diseases is dengue fever. And while you’re probably familiar with its name, you might not know much about this disease’s causes and symptoms.
What is dengue fever and how is it spread? What should you do if you think you’re infected? Read on to learn more about this illness.
What is Dengue Fever?
According to the World Health Organization (WHO), dengue fever is a mosquito-borne viral infection. It is caused by any one of four closely related strains of the dengue virus: DEN-1, DEN-2, DEN-3 and DEN-4.
Dengue fever first emerged as a health concern in the 1950s. Today, it is a leading cause of illness and death in tropical and subtropical climates, including areas of Africa, the Americas, the eastern Mediterranean, southeast Asia and the western Pacific. While the disease is rare in the United States, small, isolated outbreaks have occurred in Florida (2013) and Hawaii (2015), according to the World Health Organization. Most outbreaks in the United States are caused by infected travelers returning from areas where the disease is prevalent.
The Centers for Disease Control and Prevention (CDC) estimates that nearly one third of the world’s population is at risk of the disease and that nearly 400 million people are infected with the illness each year. Again though, there is a low risk associated with this disease in the U.S.
Mosquitoes Associated With Dengue
Dengue fever is primarily spread by the Aedes aegypti mosquito, commonly referred to as the “yellow fever mosquito.” These mosquitoes live in tropical and urban areas throughout the world. According to the University of Florida, the species originated in Africa and made its way to North America on ships used for colonization and exploration.
The Centers for Disease Control and Prevention notes that aegypti mosquitoes commonly live in close proximity to humans, making them more likely to spread disease than other species of the insect. Yellow fever mosquitoes commonly feed during the day, usually in the morning and right before dusk.
These mosquitoes typically breed in containers and areas with standing water, such as spare tires, unmaintained swimming pools and flower pots.
To a lesser extent, dengue fever may also be spread by Aedes albopictus, a species of mosquito found in Asia, Europe and North America. These mosquitoes can survive in cooler temperatures than the yellow fever mosquito can.
Dengue fever is spread through the bites of infected female mosquitoes. The mosquitoes acquire the virus by biting infected humans and spreading it to other hosts when they acquire blood meals. The virus will incubate inside the mosquito for 4-10 days, and once a mosquito has the virus, it can transmit the disease for the rest of its life.
Infected humans can transmit the disease to mosquitoes for 4-5 days (and in some cases up to 12 days) after initial symptoms appear.
If you are traveling to certain parts of the world where dengue fever is common (mentioned above), then you may want to be aware of the symptoms of the disease.
According to WHO, Dengue symptoms may include high fever, severe headache, pain behind the eyes, joint pain, muscle and bone pain, rash and minor bleeding (gums or nose). A fever of 104 Fahrenheit or higher accompanied by two or more of these symptoms is reason for concern. Dengue fever can affect infants, children and adults, and symptoms may persist for 2-7 days.
Once a person is infected with a particular strain of the disease and recovers, they have lifelong immunity against that strain. However, immunity against the other strains is only partial and temporary.
Dengue Hemorrhagic Fever
In some cases, dengue fever can evolve into dengue hemorrhagic fever, also known as “severe dengue.” This is according to WHO. This is a potentially fatal condition caused by plasma leaking, fluid accumulation, respiratory distress, severe bleeding or organ impairment.
Symptoms of dengue hemorrhagic fever usually appear between 3 and 7 days after the initial symptoms of dengue fever. The patient’s fever will usually drop, but they may experience additional symptoms such as severe abdominal pain, vomiting with blood present, rapid breathing, bleeding gums and fatigue. Typically, for 24-48 hours, patients with dengue hemorrhagic fever are at risk for circulatory system failure, shock and death, so proper medical care is critical.
According to the Centers for Disease Control and Prevention, there is no vaccine for dengue fever, but pain relievers containing acetaminophen can help reduce symptoms. Patients should avoid taking medications that contain aspirin. Rest and fluids may also help. If you have recently traveled to certain parts of the world where dengue fever is common and you think you are experiencing symptoms of dengue fever, consult your doctor.
If you experience any of the symptoms associated with dengue hemorrhagic fever or symptoms worsen 24 hours after they appear, the Centers for Disease Control and Prevention recommends visiting the hospital for evaluation.