What is Dengue Fever?
Dengue Fever (DF) is a mosquito-borne disease affecting
an estimated 50 million people each year. DF occurs in all tropical
and some sub-tropical areas of the world, usually in an urban setting.
Before 1970 only nine countries had experienced DF, by 1995 this
had increased four fold. Today 2,5 billion people worldwide live
in areas that are at risk of infection. Humans contract the disease
when bitten by an infected female Aedes mosquito.
Mosquitoes remain infected all their lives and
can in turn pass on infectivity to their eggs. In some parts of
the world it has been seen that monkeys are also able to pass on
the infection to mosquitoes. Endemic areas increase around the world
due to trade (particularly tyre trade where mosquitoes breed in
pools of water in tyres). After a bite from an infected Aedes mosquito,
the virus circulates in the blood for 2-7 days, causing a feverish
illness with headache and muscle pains similar to flu. Sometimes
presents with a rash.
Who is at risk of Dengue Fever?
Any traveller to an endemic area; that is, an area
where the disease is constantly present with low levels of infection.
Endemicity is high in Central America, as well as in African countries
such as Mauritania around to Nigeria, with patches around the Egypt
and the Sudan border. In Asia DF is endemic in Pakistan, Southern
China and through to the North West area of Australia.
How can I prevent Dengue Fever?
In many countries efforts are made to combat the
vector through control of breeding sites. For the traveller, mosquito
bite prevention is the only method of preventing DF.