How Dangerous Is Dengue Fever?

A friend of mine is planning to study abroad in Singapore for a year, and his mom is worried about him because of the recent outbreaks of dengue fever. Can dengue kill you?

For the large majority of people infected with dengue fever viruses, the prognosis is excellent with complete recovery, although they are likely to feel very ill during the first one or two weeks of the acute illness and weak for about one month. Patients with underlying illness or immune suppression have a fair to good prognosis because they are more likely to get complications. Also, people who have been infected by one dengue virus type are still able to be infected by the remaining three types; a second infection increases the possibility that complications will develop, so patients with second-time dengue fever have a less optimal prognosis.

Patients who develop dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) have a range of outcomes from good to poor, depending on their underlying medical problems and how quickly supportive measures are given. For example, DHF and DSS have about 50% fatality rate if untreated but only about a 3% rate if treated with supportive measures. Overall, the fatality rate is about 1% for all dengue fever infections. While this rate may seem low, worldwide it means that about 500,000 to 1 million people die each year from dengue fever. This is a concern since the worldwide case numbers and outbreaks are increasing.

The complications of dengue fever are usually associated with the more severe forms of dengue fever: hemorrhagic and shock syndrome. The most serious complications, although infrequent, are as follows:

• Dehydration
• Bleeding (hemorrhage)
• Low platelets
• Low blood pressure (hypotension)
• Slow heart rate (bradycardia)
• Liver damage
• Neurological damage (seizures, encephalitis)
• Death

For more information, read our full medical article on dengue fever.