The causative organism for dengue is known as the dengue fever virus (DENV, an RNA-type virus. The virus has five subtypes, and each of these subtypes is capable of causing full-blown symptoms of dengue fever. This means that if you have been infected once with a subtype, it is still possible to get another infection if you get infected with a different subtype of the same virus. The virus is transmitted by the Aedes aegypti mosquito when it bites the skin of an already infected person. The virus completes the rest of its life-cycle within the mosquito and can infect another person once the carrier mosquito bites another healthy person. Therefore the spread of this disease occurs primarily using carrier mosquitoes and not by coming in direct contact with an infected person. Another way is by blood transfusion from an infected to an uninfected person. Once it enters a healthy person’s bloodstream, the virus stays in an incubation period of around three to fourteen days, after which the symptoms start to appear.
Multiple risk factors are involved in developing and spreading the dengue virus. Carrier mosquitoes of this virus require standing water as a part of their development. So people living close to areas with standing or uncovered water reservoirs are at high risk. Traveling to regions with an active outbreak of dengue fever can also increase the risk of getting contaminated with the dengue virus. Newborn babies and children are also at high risk. Contrary to popular belief, well-fed children or children from urban areas are more likely to get infected with this virus. Another major risk factor for developing a serious condition of dengue fever is if you have been previously contaminated with one of the subtypes.
Dengue outbreak is observed more frequently in Southeast Asia, Southern China, India, Pakistan, Taiwan, Mexico, Indonesia, Malaysia, Africa, and other countries. It can spread to other countries via traveling. The virus can affect people of any age and gender, although severe infection is more prevalent among young children due to lower immunity.
Symptoms of dengue fever may vary depending on the person’s age, viral load, and immunity. Some patients may remain asymptomatic or develop a very mild infection. When an active infection begins, commonly experienced symptoms include high-grade fever, severe headache, pain behind eyes, nausea, vomiting, diarrhea, pain in joints and muscles, fatigue, and sluggishness. A characteristic rash is also present in the majority of the cases that may appear on the face, back, or other parts of the body. This phase may lead to a critical stage where blood plasma starts leaking outside the blood capillaries in a few cases. It can cause fluid accumulation in the lungs, abdomen, or GIT. The patient’s immunity keeps decreasing, and organs start dysfunction as the blood volume is lost. This is called dengue shock syndrome, which can even lead to death. Several cases move towards the recovery phase without experiencing any critical symptoms.
Diagnosis of dengue is made based on presenting symptoms and clinical examination. In a region with an active dengue outbreak, it is easier to diagnose patients solely based on presenting symptoms. Clinical examination involves checking for vital signs (pulse, temperature, blood pressure, and breathing rate), skin rashes, and any signs of fluid accumulation. A complete blood count (CBC) may show decreased white blood cells and a low platelet count. This is often used for conformational diagnosis. For a more accurate diagnosis, virology or serology tests are performed in which the virus RNA is isolated within a given sample.
If you experience mild symptoms of dengue fever, no treatment is required in that case except for supportive care at home. It is suggested to drink plenty of water and use oral rehydration fluids or salts to fulfill any volume loss. Fever is reduced by taking an antipyretic such as acetaminophen, and NSAIDs are avoided. The patient is asked to take bed rest and avoid doing any strenuous activities that may increase joint or muscle pain. Severe dengue cases that present with low blood count and blood volume are referred for emergency medical treatment. Intravenous fluids are given until the vital signs are stabilized. If the count of blood cells has gone too low, whole blood or packed RBCs are given to the patient to normalize blood count.
There is no specific medication for dengue. The only medicine prescribed during dengue fever is acetaminophen to reduce fever. NSAIDs are avoided because they may increase the risk of gastrointestinal bleeding.
The prognosis of dengue fever is good in the majority of cases. Only those who had been infected previously with a subtype or those with low systemic immunity may develop serious complications.
Mosquito sprays are used publicly in areas with a high rate of dengue fever to control the infection. Individual prevention methods include mosquito repellants, mosquito nets, wearing full-length clothes covering body parts, and avoiding going to active areas of infection. No commercial vaccine has been developed yet for this virus, so the best way to prevent this disease is by taking precautions on an individual and public level.
Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 16, 2023.
Dengue and severe dengue (who.int)
Dengue - ScienceDirect
https://www.sciencedirect.com/science/article/abs/pii/S0140673618325601
Dengue, also known as dengue fever, is a viral infection caused after being bitten by a specific mosquito that carries the virus. These mosquitoes are frequently found in tropical and sub-tropical areas such as India, Pakistan, Taiwan, Mexico, Africa, etc. Among these regions, the majority of the cases are observed in areas with standing water or poor hygiene maintenance. The majority of dengue cases recover on their own with symptomatic care and do not require any specific medications or treatment options. However, a few cases may develop severe complications which require emergency medical attention.