Number of people bringing dengue fever into the U.K. doubles

According to the British Health Protection Agency, the number of people entering the U.K. with dengue fever contracted in tropical countries has doubled.

In 2009, there were a total of 166 confirmed cases of dengue in the U.K. In 2010, the number of cases reached 406, according to the BBC.

The disease, which in some cases can be fatal, particularly if the hemorrhagic form of the disease is contracted, generally causes fever, muscle pain, headache and a rash.

Dengue fever is common in tropical areas. The World Health Organization said that there are at least 50 million cases of dengue fever every year. HPA figures point to 21 percent of the cases in the U.K. linked with travel to India and 15 percent with travel to Thailand.

Dr. Jane Jones, the head of the HPA’s travel and migrant health section, warned that dengue fever has no known treatment.

"To minimize the risk of being bitten it is advisable to wear appropriate clothing to cover up - such as long sleeve tops and trousers - and use insect repellents," Jones said, according to the BBC.

Unlike mosquitoes that carry malaria, insects that carry dengue are active during the day. For those traveling or living where both illnesses are endemic, it is important to have some protection against mosquitoes around the clock.