Thursday, 24 December 2015

Dengue Fever Spreads Around the World

Dengue fever, the world's fastest growing mosquito-borne disease, has spread its wings from being a tropical disease, endemic in just nine countries, to a worldwide threat. Globalisation, urbanisation, climate change and jet travel have enabled it to move into more temperate zones.

Following are some basic facts:

What is dengue fever?

Dengue fever is a flu-like infection, caused by the flavivirus in the same family as yellow fever.
Dengue fever has four separate strains -- DEN-1, DEN-2, DEN-3 and DEN-4. Once cured, the patient is protected for life but only against the strain he was stricken by.

How is the virus transmitted? 

Dengue is transmitted by several species of mosquito within the Aedes aegypti, which originate in Africa but which are now present in all tropical and subtropical areas.

The symptoms

Dengue can trigger a crippling fever along with headache, nausea, vomiting, muscle and joint pain, and skin rashes similar to measles.

The most severe form

The most severe form of the disease, dengue haemorrhagic fever, accounts for one percent of cases, killing 22,000 people a year, the World Health Organisation (WHO) says. It results in bleeding and blood plasma leakage. It can be fatal, in particular among children.

How many cases?

The number of cases in the world has risen 30-fold over the last 50 years, according to the WHO, making it the world's fastest growing mosquito-borne disease and leaving more than half of the world's population potentially at risk.

The WHO says that half a million people are hospitalised by the illness every year, many of them children of which around 2.5 percent die.

Treatment and vaccination

There is currently no specific treatment for dengue fever. The world's first-ever dengue vaccine, Dengvaxia, manufactured by French pharmaceutical giant Sanofi, secured its first regulatory approval in Mexico on December 9. The Philippines became the first Asian country on Tuesday to approve the sale of the vaccine. Other pharmaceutical companies are developing dengue vaccines, including US firm Merck, Japan's Takeda and Britain's GlaxoSmithKline.