Dengue is an acute fever caused by virus. It is of two types: (i) Dengue fever, (ii) Dengue hemorrhagic fever.This is characterized by an onset of sudden high fever, severe headache, pain behind the eyes and in the muscles and joints.

Dengue hemorrhagic fever is an acute infectious viral disease. It is an advanced stage of dengue fever. It is characterized by fever during the initial phase and other symptoms like headache, pain in the eye, joint pain and muscle pain, followed by signs of bleeding, red tiny spots on the skin, and bleeding from nose and gums.

How does Dengue spread?

Spreads through the bite of an infected Aedes aegypti mosquito. The transmission of the disease occurs when a mosquito bites an infected person and subsequently bites a healthy person. In doing so, it transmits blood containing the virus to the healthy person and the person becomes infected with dengue. The first symptoms of the disease occur about 5 to 7 days after the infected bite.

Aedes mosquito rests indoors, in closets and other dark places, and is active during day time. Outside, it rests where it is cool and shaded. The female mosquito lays her eggs in stagnant water containers such as coolers, tyres, empty buckets etc., in and around homes, and other areas in towns or villages. These eggs become adults in about 10 days.

Incubation period

The time between the bite of a mosquito carrying the causative virus and the start of symptoms averages 4 to 6 days, with a range of 3 to 14 days.

Diagnosis

Diagnosis is made through blood tests by scanning for antibodies against dengue viruses. In addition the blood platelets counts also drastically reduce in the infected person.

Symptoms

Symptoms of Denguefever

          (i)         Sudden onset of high fever, generally 104-105 °F (40                    °C), which may last 4- 5 days.

 (ii)         Severe headache mostlyin the forehead.

(iii)       pain in the jointsand muscles, body aches.

(iv)       Pain behind the eyes which worsenswith eye movement.

Symptoms :

These include symptoms similarto dengue fever, plus othersymptoms such as

1. Severe and continuous pain in the abdomen.
2. Rashes on the skin.
3. Bleeding from the nose, mouth, or in the internal organs.
4. Frequent vomitingwith or withoutblood.
5. Black stools due to internalbleeding.
6. Excessive thirst(dry mouth).
7. Pale, cold skin, weakness.
8. Nausea or vomiting.

Prevention

Following steps can be taken to prevent spreadof dengue fever:      

1. Avoid water stagnation for more than 72 hours so that the           mosquitoes do not breed there.

2. Prevent mosquito breeding in stored water bodies, like                   ponds, wells etc.

3. Destroy discarded objects like old tyres, bottles, etc. as they          collect and store rain water.

4. Use mosquito repellents and wear long sleeved clothes to               curtail exposure.

5. Use mosquito nets, also during daytime.

6. Avoid outdoor activities during dawn or dusk when these              mosquitoes are most active.

7. Patients suffering from dengue fever must be isolated for              atleast 5 days.

8. Report to the nearest health centre for any suspected case of        Dengue fever.

Treatment:

There is no specific treatment for dengue fever. Persons with dengue fever should rest and drink plenty of fluids. Dengue hemorrhagic fever is treated by replacing lost fluids. Some patients need blood transfusions to control bleeding.