Dengue Fever
Dengue fever is another mosquito borne disease that costs lives. Where malaria is caused by a parasite that is injected when a female anopheles mosquito bites; Dengue fever, or the more serious form Dengue Hemorrhage Fever (DHF) is a virus that is spread through the bite of the female Aedes Aegypti mosquito who has previously bitten someone who has the Dengue virus in their blood. (The Aedes Aegypti mosquito is identifiable by the stripes that appear on its body.)
There are four distinct, but closely related, viruses that cause Dengue fever. Like the virus that causes influenza these mutate so it is hard to treat the virus as such. This means that treatment for dengue is really treating the symptoms and the disease must run it course in the human body.
Recovery from infection by one type of Dengue virus provides lifelong immunity against that serotype but confers only partial and transient protection against subsequent infection by the other three. Therefore it is possible to get dengue fever multiple times.
Dengue fever is also known as Breakbone fever. The virus is not contagious and cannot be spread directly from person to person. There must be a person-to-mosquito-to-another-person pathway.
Like all other mosquitoes the Aedes aegypti mosquito can breed in small quantities of water; such as flower pots, tin cans, plastic bags etc. The Aedes aegypti mosquito breeds all year round. Managing mosquito populations is a major key in the reduction of Dengue infections.
Dengue fever is transmitted by the Aedes mosquito.
It generally bites during the day.
Symptoms
Dengue fever is an acute illness of sudden onset; symptoms include headache, fever, exhaustion, severe joint and muscle pain, swollen glands and a rash. The presence (the “dengue triad”) of fever, rash, and headache (and other pains) is particularly characteristic of dengue.
Symptoms appear 3-14 days after the infective bite. Dengue fever is a febrile illness that affects infants, young children and adults.
Dengue hemorrhagic fever (DHF)
Dengue hemorrhagic fever (DHF) is a more severe form of the viral illness. Manifestations include headache, fever, rash, and evidence of hemorrhage in the body. Petechiae (small red or purple blisters under the skin), bleeding in the nose or gums, black stools, or easy bruising are all possible signs of hemorrhage. This form of dengue fever can be life threatening or even fatal.
Affected Areas
Dengue is prevalent throughout the tropics and subtropics. Outbreaks have occurred in the Caribbean, including Puerto Rico, the U.S. Virgin Islands, Cuba, and Central America. Cases have also been imported via tourists returning from areas with widespread dengue, including Tahiti, the South Pacific, Southeast Asia, the West Indies, India, and the Middle East.
Dengue fever is common and may be increasing in Southeast Asia. Thailand, Vietnam, Singapore and Malaysia have all reported an increase in cases. According to the World Health Organization, there were 188,684 cases of dengue reported in 2006, with Indonesia having 57% of the reported cases.
According to the World Health Organization (WHO), on a global scale there are approximately 80-100 million cases of Dengue fever reported each year which results in 150,000 deaths. Some 2500 million people, (two fifths of the world’s population) are at risk from Dengue fever.
Vaccine
Vaccine development for dengue and DHF is difficult because any of four different viruses may cause disease, and because protection against only one or two dengue viruses could actually increase the risk of more serious disease. Nonetheless, progress is being made in the development of vaccines that may protect against all four dengue viruses. Such products may become available for public health use within several years.