The tropical disease is affecting more and more Swedes year on year. In 2010 151 cases of the disease were reported by those returning from foreign trips, up from 100 the previous year.
In most cases, those infected discover the symptoms on their return, with about half of all cases picked up from trips to Thailand, according to the Swedish Institute for Infectious Disease Control (Smittskyddsinstitutet).
The disease is carried by the mosquito Aedes aegypti. The most common symptoms are high fever, headaches and pains in the joints.
There is currently no available vaccine for dengue fever, but measures to reduce number of mosquitoes, and limiting exposure to bites, are being used to stem the growing number of reported cases.
Dengue fever is not life threatening but in the most severe cases a blood transfusion is sometimes necessary. Normally treamtent is done by rehydrating the person infected, either orally or with an intravenous drip.
The rate of infection has increased rapidly over the last 50 years, with around 50–100 million people catching the disease annually.