Dengue fever is a viral infection spread by mosquitoes. It is a common disease in tropical and subtropical regions of the world, affecting millions of people each year.
There are four types of dengue viruses (DENV), belonging to the flavivirus family, that cause dengue fever. An infected female Aedes mosquito bites during the day to spread the virus. By biting a person with dengue fever, the mosquito can infect and transmit the virus to another individual. DENV has at least four strains, and any of them can infect a person. A second infection with a different strain can increase the risk of severe complications, but infection with one strain does not provide immunity to the others.
The symptoms of dengue fever usually appear 4 to 10 days after the mosquito bite. The symptoms may vary depending on the severity of the infection, but they typically include:
High fever (104 F or 40 C)
Headache
Pain behind the eyes
Muscle, joint, or bone pain
Nausea or vomiting
Rash
Swollen glands
Some people may have mild or no symptoms at all, while others may develop severe dengue, also known as dengue hemorrhagic fever or dengue shock syndrome. Severe dengue is a medical emergency that can cause:
Bleeding from the nose, gums, or skin
Blood in the urine, stool, or vomit
Severe abdominal pain
Persistent vomiting
Difficulty breathing
Low blood pressure or shock
Organ failure
Death
The warning signs of severe dengue usually occur after the fever subsides, and they require immediate medical attention.
Blood tests can identify dengue fever by detecting the virus or its antibodies. They should be performed as soon as possible after onset of symptoms, as the virus may not be detectable after a week. The blood test can also help determine the type of DENV and the level of platelets, which are blood cells that help with clotting. A low platelet count can indicate severe dengue and an increased risk of bleeding.
There is no specific treatment for dengue fever, and the main goal is to relieve the symptoms and prevent complications. The treatment may include:
Resting and drinking plenty of fluids to prevent dehydration
Taking acetaminophen or paracetamol to reduce fever and pain
Avoiding aspirin, ibuprofen, or other nonsteroidal anti-inflammatory drugs (NSAIDs), as they can increase the risk of bleeding
Seeking medical care if the symptoms worsen or the warning signs of severe dengue appear
Severe dengue requires hospitalization and intensive care, which may involve:
Intravenous fluids and electrolytes to restore hydration and blood pressure
Blood transfusion to replace lost blood and platelets
Oxygen therapy to support breathing
Antibiotics to treat any secondary bacterial infections
The best way to prevent dengue fever is to avoid mosquito bites, especially in areas where the disease is endemic or epidemic. Some of the preventive measures include:
Wearing long-sleeved shirts, pants, and socks to cover the skin
Applying insect repellents that contain DEET, picaridin, IR3535, or oil of lemon eucalyptus on the exposed skin
Using mosquito nets, screens, or coils to keep mosquitoes away from the sleeping area
Eliminating or reducing mosquito breeding sites, such as stagnant water, containers, tires, or trash
Reporting any suspected cases of dengue fever to the local health authorities
Vaccines for dengue fever are also available in some countries. Vaccines are recommended for people aged 9 to 45 who have been infected with the dengue virus in the past. The vaccine is administered in three doses, with a six-month interval between each dose. The vaccine reduces the risk of severe dengue by about 80%, but it is not effective against all strains of the disease. People who have never had dengue fever should not get the vaccine, as it may increase their risk of severe dengue disease.
Viruses transmitted by mosquitoes cause dengue fever, a serious and potentially fatal disease. In addition to fever, headache, rash, pain, bleeding, and shock, dengue fever can be diagnosed by a blood test and treated by supportive care. In order to prevent dengue fever from developing, avoid mosquito bites and get vaccinated if you are eligible. More research, surveillance, and control efforts are needed to combat dengue fever, which is a global health problem.
