What is Dengue?

Dengue fever (DF) is a viral infection caused by dengue virus which is transmitted by mosquito bite. Dengue fever can be caused by any of four related dengue viruses (DENV-1 to DENV-4). Dengue is transmitted to by the bite of Aedes aegypti mosquito which bites during the day. Dengue infection can vary in severity from mild acute febrile illness or can be even fatal. In some patients the virus can cause damage to the blood vessels that leads to leakage of fluid from the blood vessels (increase in vascular permeability) and bleeding problems known as dengue hemorrhagic fever (DHF).

• Dengue hemorrhagic fever (DHF): DHF is a complication of the disease that can be fatal. It usually occurs if you have dengue infection more than once. The symptoms of DHF are similar to DF but the condition of the patient shows rapid deterioration a few days after the fever starts to decrease (usually 3–7 days after symptom onset). The patient may develop severe symptoms of disease like severe abdominal pain, persistent vomiting, marked change in temperature (from fever to hypothermia), and bleeding (from nose, mouth skin) or change in mental status (irritability, confusion, or obtundation). Most of the patients recover quickly following appropriate medical treatment.
• Dengue Shock Syndrome (DSS): Some patients with DF/DHF can rapidly progress to severe shock, which can lead to death within 12 to 24 hours. Patients with DSS have all the signs and symptoms of DHF and their blood pressure is also low (hypotension). This is the most severe manifestation of dengue fever. Patient with DSS has excessive thirst, pale and cold skin (due to very low blood pressure), is restless and feels very weak or fatigued.

Dengue fever is also referred to as "break-bone" fever because it can cause severe joint and muscle pain in some patients that feels like bones are breaking. Dengue fever occurs in the tropical and subtropical areas regions and is epidemic in more than 100 countries. About 50 million cases of dengue infection occur worldwide every year. Dengue fever occurs frequently during and shortly after the monsoon season in:

• Africa
• Southeast Asia and China
• India
• Middle East
• Caribbean and Central and South America
• Australia and the South and Central Pacific

Dengue fever is common in several parts of India. It has been known to occur in India for a long time. However the first case of dengue hemorrhagic fever was reported from Calcutta in1963. After that outbreaks of dengue fever from India have been reported several times. In 1996 a major outbreak of dengue hemorrhagic fever occurred in Delhi. During this outbreak 10,252 cases and 423 deaths were reported. After this the number of DF/DHF cases and deaths reported were low up till 2002, but has shown a rise since 2003.
The disease causes sudden onset of fever, severe headache, severe pain in muscle and joint pains (myalgias and arthralgias). Consult you doctor if have these symptoms to diagnose the cause of your symptoms.

Dengue fever facts

• Dengue fever (DF) is a viral infection caused by any of four related dengue viruses (DENV-1 to DENV-4).
• Dengue is not contagious that is it does not spread from person to person.
• Dengue is transmitted to by the bite of Aedes aegypti mosquito. It is a day biting mosquito.
• Dengue infection can vary in severity from mild acute febrile illness or can be even fatal.
• Incubation period of dengue fever is generally 5 – 6 days (can vary from 3 to 10 days).
• People of all age and sex living or travelling to dengue endemic areas can be affected by dengue fever