Dengue is an acute fever caused by virus. It is of two types: (i) Dengue fever, (ii)
Dengue hemorrhagic fever.
Dengue fever 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?
Dengue 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.
The time between the bite of a mosquito carrying dengue virus and the start of
symptoms averages 4 to 6 days, with a range of 3 to 14 days.
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
Symptoms of Dengue fever
Sudden onset of high fever, generally 104-105 °F (40 °C), which may last 4-
Severe headache mostly in the forehead.
(iii) pain in the joints and muscles, body aches.
(iv) Pain behind the eyes which worsens with eye movement.
Nausea or vomiting.
Symptoms of Dengue hemorrhagic fever
These include symptoms similar to dengue fever, plus other symptoms such as:
Severe and continuous pain in the abdomen.
Rashes on the skin.
(iii) Bleeding from the nose, mouth, or in the internal organs.
(iv) Frequent vomiting with or without blood.
Black stools due to internal bleeding.
(vi) Excessive thirst (dry mouth).
(vii) Pale, cold skin, weakness.
Following steps can be taken to prevent spread of dengue fever:
Avoid water stagnation for more than 72 hours so that the mosquitoes do not
Prevent mosquito breeding in stored water bodies, like ponds, wells etc.
(iii) Destroy discarded objects like old tyres, bottles, etc. as they collect and store
(iv) Use mosquito repellents and wear long sleeved clothes to curtail exposure.
Use mosquito nets, also during daytime.
(vi) Avoid outdoor activities during dawn or dusk when these mosquitoes are most
(vii) Patients suffering from dengue fever must be isolated for at least 5 days.
(viii)Report to the nearest health centre for any suspected case of Dengue fever.
Treatment for dengue and dengue hemorrhagic fever
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