Dengue fever is a tropical disease transmitted by mosquitoes caused by the dengue virus. Symptoms usually begin three to fourteen days after infection. This may include high fever, headache, vomiting, muscle and joint pain, and a characteristic rash. Recovery usually takes two to seven days. In a small proportion of cases, the disease progresses to dengue hemorrhagic fever, which causes hemorrhage, low levels of blood platelets and loss of blood plasma, or dengue shock syndrome, where blood pressure is dangerously low.
Dengue is spread by several species of mosquitoes of the Aedes type, mainly A. aegypti. The virus has five different types; infection with one type usually gives lifelong immunity to that type, but only short-term immunity to the others. Subsequent infection with a different type increases the risk of serious complications. There are several tests available to confirm the diagnosis, including the detection of antibodies against the virus or its RNA.
A new vaccine for dengue has been approved and is commercially available in several countries. Other methods of prevention are the reduction of mosquito habitat and the limitation of exposure to bites. This can be done by freeing or covering stagnant water and wearing clothes that cover a large part of the body. The treatment of acute dengue is supportive and includes administering liquid orally or intravenously for mild or moderate illness. For more severe cases, a blood transfusion may be required. Nearly half a million people require hospital admission per year. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen should not be used.
Dengue fever has become a global problem since World War II and is common in more than 110 countries. Each year, between 50 and 528 million people are infected and die between 10,000 and 20,000. The first descriptions of an outbreak date from 1779. Its cause and viral spread were understood at the beginning of the 20th century. In addition to eliminating mosquitoes, work is being done on drugs directly targeted to the virus. It is classified as an unattended tropical disease.