Dengue haemorrhagic fever is a potentially fatal dengue infection which is caused when a person gets infected the second, third or fourth time with a different dengue virus than before.
There are four types of Dengue Virus, DEN-1, DEN-2, DEN-3 and DEN-4 carried by the Aedes aegypti mosquito. It is ironical that the immunity that a person develops for one type of dengue virus actually serves to accentuate the problem when the other type of virus infects the patient.
The early symptoms of dengue haemorrhagic fever are the same as dengue but ultimately the situation worsens and the acute phase comes. The early symptoms include:
• High Fever
• Joint Aches
• Muscle Aches
• Decrease in Appetite
These are much the same as dengue but the real problem begins in the next phase, which is more apparent with acute symptoms.
• Ecchymosis - Skin discolouration due to internal rupture of blood vessels
• Generalised Rashes.
• Petechiae – Red spots on the skin caused by breaking of blood capillaries.
• The earlier symptoms are worsened.
Dengue haemorrhagic fever can also get worse and leave the patient in a shock-like state. It is called the dengue shock syndrome. The main symptoms of this are clamminess due to the process of sweating and cooling. The circulatory system is badly affected and it can even turn fatal.
Cases of dengue fever that are reported worldwide every year are more than 100 million. Some of them develop into dengue haemorrhagic fever. Children below 12 years of age, women, Caucasions and those who have been infected with one of the dengue viruses earlier are at risk.
Just like dengue, there is no immunization or specific treatment for dengue haemorrhagic fever. For severe cases of dengue fever, the doctors and experienced medical professionals can help to save lives by maintaining the body fluid of the patient as doing so is a critical aspect of dengue care. Developing a vaccine for the prevention of dengue or protection of an individual from dengue has been a challenging experiment though there has been progress in its development. The WHO gives technical guidance and advice to several countries as well as its private partners to help in evaluation and vaccine research. A lot of candidate vaccines are in different phases of the trials and one is expected to be commercially available by the year 2015.
Read articles and Understand dengue.