Dengue fever (UK /ˈdɛŋɡeɪ/ or US /ˈdɛŋɡiː/), also known as breakbone fever, is an infectious tropical diseasecaused by the dengue virus. Symptoms include fever,headache, muscle and joint pains, and a characteristicskin rash that is similar to measles. In a small proportion of cases the disease develops into the life-threateningdengue hemorrhagic fever, resulting in bleeding, low levels of blood platelets and blood plasma leakage, or into dengue shock syndrome, where dangerously low blood pressure occurs. Dengue is transmitted by several species of mosquitowithin the genus Aedes, principally A. aegypti. The virus has four 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 severe complications.
As there is no commercially available vaccine, prevention is sought by reducing the habitat and the number of mosquitoes and limiting exposure to bites. Treatment of acute dengue is supportive, using either oral or intravenous rehydration for mild or moderate disease, and intravenous fluids and blood transfusion for more severe cases. The incidence of dengue fever has increased dramatically since the 1960s, with around 50–100 million people infected yearly. Early descriptions of the condition date from 1779, and its viral cause and the transmission were elucidated in the early 20th century. Dengue has become a global problem since the Second World War and isendemic in more than 110 countries. Apart from eliminating the mosquitoes, work is ongoing on a vaccine, as well as medication targeted directly at the virus.
STATEMENT OF THE PROBLEM
The incidence of dengue has grown dramatically around the world in recent decades. Some 2.5 billion people – two fifths of the world’s population – are now at risk from dengue. WHO currently estimates there may be 50 million dengue infections worldwide every year.
In 2007 alone, there were more than 890 000 reported cases of dengue in the Americas, of which 26 000 cases were DHF.
The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific. South-east Asia and the Western Pacific are the most seriously affected. Before 1970 only nine countries had experienced DHF epidemics, a number that had increased more than four-fold by 1995.
Not only is the number of cases increasing as the disease is spreading to new areas, but explosive outbreaks are occurring.
SCOPE AND DELIMITATION
There is no specific treatment for dengue fever. But we can prevent having dengue fevers.
The best way to prevent dengue virus infection is to take special precautions to avoid being bitten by mosquitoes. Several dengue vaccines are being developed, but none is likely to be licensed by the Food and Drug Administration in the next few years.
When outdoors in an area where dengue fever has been found
*Use a mosquito repellent containing DEET, picaridin, or oil of lemon eucalyptus *Dress in protective clothing—long-sleeved shirts, long pants, socks, and shoes