Dengue fever
Dengue fever is a mosquito-borne tropical disease caused by dengue virus. It is frequently asymptomatic; if symptoms appear they typically begin 3 to 14 days after infection. These may include a high fever, headache, vomiting, muscle and joint pains, and a characteristic skin itching and skin rash. Recovery generally takes two to seven days. In a small proportion of cases, the disease develops into severe dengue (previously known as dengue hemorrhagic fever or dengue shock syndrome) with bleeding, low levels of blood platelets, blood plasma leakage, and dangerously low blood pressure.
| Dengue fever | |
|---|---|
| Other names | Dengue, breakbone fever |
| Typical rash seen in dengue fever | |
| Pronunciation |
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| Specialty | Infectious disease |
| Symptoms | Fever, headache, muscle and joint pain, rash. Can be severe, mild or asymptomatic |
| Complications | Bleeding, low levels of blood platelets, dangerously low blood pressure |
| Usual onset | 3–14 days after exposure |
| Duration | 2–7 days |
| Causes | Dengue virus by Aedes mosquitos |
| Diagnostic method | Detecting antibodies to the virus or its RNA |
| Differential diagnosis | Malaria, yellow fever, viral hepatitis, leptospirosis |
| Prevention | Dengue fever vaccine, decreasing mosquito exposure |
| Treatment | Supportive care, intravenous fluids, blood transfusions |
| Frequency | 5 million per year (2023) |
| Deaths | 5,000 per year (2023) |
Dengue virus has four confirmed serotypes; 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 severe complications. The symptoms of dengue resemble many other diseases including malaria, influenza, and Zika. Blood tests are available to confirm the diagnosis including detecting viral RNA, or antibodies to the virus.
There is no specific treatment for dengue fever. In mild cases, treatment is focused on treating pain symptoms. Severe cases of dengue require hospitalisation; treatment of acute dengue is supportive and includes giving fluid either by mouth or intravenously.
Dengue is spread by several species of female mosquitoes of the Aedes genus, principally Aedes aegypti. Infection can be prevented by mosquito elimination and the prevention of bites. Two types of dengue vaccine have been approved and are commercially available. Dengvaxia became available in 2016 but it is only recommended to prevent re-infection in individuals who have been previously infected. The second vaccine, Qdenga, became available in 2022 and is suitable for adults, adolescents and children from four years of age.
The earliest descriptions of a dengue outbreak date from 1779; its viral cause and spread were understood by the early 20th century. Already endemic in more than one hundred countries, dengue is spreading from tropical and subtropical regions to the Iberian Peninsula and the southern states of the US, partly attributed to climate change. It is classified as a neglected tropical disease. During 2023, more than 5 million infections were reported, with more than 5,000 dengue-related deaths. As most cases are asymptomatic or mild, the actual numbers of dengue cases and deaths are under-reported.