Dengue Fever

Where it occurs

It is widespread but mostly occurs during and just after the rainy season in tropical and sub-tropical areas of South-east Asia including China, India, Africa, the Middle East, Central and South America, the Caribbean, Australia and the Central Pacific Islands.

Infection

It is caused by a virus transmitted between people by mosquitoes. Once in the body, the virus travels to various glands where it begins to multiply and will then enter the blood stream where it damages blood vessels and also harms the spleen, lymph nodes and liver. It may also interfere with the blood’s ability to clot.

Symptoms

It normally takes about five days after infection before symptoms start to show. In some cases, symptoms are only mild and much like flu with a raised temperature, chills, headache and sweating. In more serious cases, there is severe pain in the muscles and joints, headache and eye pain, and a bright red or purplish rash appears usually on the lower limbs and chest though it may cover most of the body – the reddened areas indicate where blood vessels have been damaged. This may be accompanied by bleeding from the nose or gums and/or severe stomach pain and vomiting – the vomit is normally a dark-brown colour and indicates bleeding of the stomach.

In the most severe cases, as the blood vessels are more and more severely damaged, the blood supply to major organs is reduced, especially to the heart and kidneys, and death can occur.

Treatment

There is no specific treatment. In mild cases, sufferers should take pain-reducing medicines, rest and drink plenty of fluid – recovery normally takes a couple of weeks. In more serious cases, immediate hospital treatment is necessary. Even after recovery, weakness and fatigue can last for months.