Dengue fever is caused by the dengue virus..There are four different strains of the virus and hence immunity to one strain of the virus will not give rise to immunity to the other strains of the virus.
Dengue fever is transmitted by the bite of the female Aedes mosquitoes.These mosquitoes breed in stagnant waters and can carry other diseases , like yellow fever as well.
Dengue fever has two forms, the fever and the haemorrhagic fever.
Dengue fever is characterized by sudden onset of high fever, weakness,headaches,pain behind the eyes, joint and muscle pain ,nausea and vomiting, and rash. The fever rises rapidly to as high as 40C F. The rash appears 3-4 days after the onset of fever, and usually appears on the trunk first, before spreading throughout the body. The symptoms persist for 7 days, hence the disease is also known as seven-day fever.
Dengue haemorrhagic fever is a complication of dengue fever. It begins with begins with high fever, abdominal pain and vomiting, severe bleeding(haemorrhagic),liver enlargement and febrile convulsions In moderate cases, all symptoms abate after the fever subsides. In severe cases, the patient's condition may suddenly worsen after a few days of fever; the temperature drops, followed by signs of heart failure, and the patient may rapidly go into a state of shock and die within 12-24 hours(dengue shock syndrome).However,he may quickly recover following appropriate volume replacement therapy.
There is no specific treatment for dengue fever.Treatment is supportive, that is treating the symptoms of the disease.However, if haemorrhaging(bleeding) occurs, then infusion of blood plasma to replace lost fluids may be needed.
Since the disease is transmitted by mosquitoes, prevention therefore includes preventing mosquito bites.Wear insect repellant,use mosquito coils and nets to prevent mosquito bites.The Aedes mosquitoes breed in stagnant water, hence it is advisable to replace water regularly in pots and pans and clear bloacked roof gutters.
There are other names for the disease, namely breakbone fever due to the symptoms of aching joints;dandy fever;seven day fever mentioned in symptoms,duengero - from the Spanish duengo.If one gets the disease before, the second time he gets it again, he will have a more severe form.This is due to the immune system's partial reaction against the virus, which does not kill it.