Molecular testing for dengue virus is used for laboratory documentation of dengue disease.
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Dengue fever is a viral infection caused by the dengue virus, which is primarily transmitted to humans through the bites of infected mosquitoes, particularly the Aedes aegypti mosquito. It is a significant public health concern, especially in tropical and subtropical regions around the world.
The dengue virus belongs to the Flaviviridae family, which includes other viruses like Zika virus, West Nile virus, and yellow fever virus. There are four distinct serotypes of the dengue virus, known as DEN-1, DEN-2, DEN-3, and DEN-4.
Transmission
The primary mode of transmission of the dengue virus is through the bite of infected Aedes mosquitoes, particularly Aedes aegypti. These mosquitoes become infected when they feed on the blood of a person who has dengue fever. The virus can also be transmitted through blood transfusions, organ transplants, or from an infected mother to her newborn during childbirth.
Geographic Distribution
Dengue fever is endemic in many regions of the world, including Southeast Asia, the Pacific Islands, the Caribbean, Central and South America, parts of Africa, and the Mediterranean. It has become an increasing global concern due to urbanization, international travel, and climate change, which have contributed to the expansion of mosquito habitats.
Symptoms
Symptoms of dengue fever typically appear within 4 to 10 days after being bitten by an infected mosquito. They may include high fever, severe headache (often behind the eyes), joint and muscle pain, rash, nausea, vomiting, and mild bleeding (such as nose or gum bleeding). Dengue fever usually follows a biphasic pattern. The initial phase, known as the febrile phase, is characterized by the sudden onset of high fever, severe headache, joint and muscle pain, and rash. This phase lasts for about 2 to 7 days. Following a brief period of improvement, some individuals enter a critical phase, which can progress to severe dengue.
In some cases, dengue fever can progress to a more severe form known as dengue hemorrhagic fever or dengue shock syndrome, which can be life-threatening. It typically occurs when a person who has previously been infected with one dengue serotype is infected with a different serotype. Severe dengue is characterized by bleeding, organ impairment, and in some cases, shock. Prompt medical attention is crucial in these cases.
Diagnosis
Dengue fever is diagnosed through various laboratory tests, including the detection of the virus genetic material (RNA) in blood samples or the detection of antibodies produced by the immune system in response to the infection.
Treatment
There is no specific antiviral treatment for dengue fever. Management involves supportive care to relieve symptoms, such as rest, hydration, and over-the-counter pain relievers (except for aspirin, which should be avoided due to its potential to increase bleeding). Severe cases require hospitalization for close monitoring and intravenous fluid replacement.
Prevention and Control
The most effective way to prevent dengue fever is by controlling the mosquito population and reducing mosquito breeding sites. This includes eliminating standing water, using mosquito repellents, wearing protective clothing, and employing mosquito control measures such as insecticide spraying. Vaccine development efforts are ongoing.