Dengue fever is a viral disease that is spread by mosquitoes. It is a problem in many tropical and subtropical parts of the world, including Africa, Asia, South America and Australia. Estimates suggest that around 100 million cases occur each year.
Dengue fever ranges in severity from a mild flu-like illness through to a severe disease. Dengue fever can develop into the more severe forms of the illness, dengue haemorrhagic fever and dengue shock syndrome.
There is no specific treatment and no vaccine. The best way to protect against dengue fever is to avoid mosquito bites when in affected tropical and subtropical areas.
Seek medical attention immediately if you think you may have contracted dengue fever. Early diagnosis and management of symptoms is critical to reduce the risk of complications and avoid further spread of the virus.
Cause of dengue fever
Dengue fever is caused by infection with one of four different viruses known as DEN-1, DEN-2, DEN-3 and DEN-4. All four viruses are capable of causing the complications of dengue haemorrhagic fever and dengue shock syndrome.
Infection with one type gives you lifelong immunity to that particular dengue virus. However, the infection does not offer immunity to the other three types, so it is possible to contract dengue fever again. A person who has had dengue fever once is at increased risk of dengue haemorrhagic fever or dengue shock syndrome if they get infected again.
Symptoms of dengue fever
The typical signs and symptoms of uncomplicated dengue fever may include:
- high temperature within one week of infection
- severe headache
- pain behind the eyes
- joint and muscle aches
- metallic taste in the mouth
- appetite loss
- abdominal pain
- nausea and vomiting
- generally feeling unwell (malaise)
- skin rash that appears about four days after the onset of fever
In most cases, symptoms resolve within one to two weeks. Some people, however, take longer to recover and may struggle with lethargy and depression for weeks or even months.
Symptoms of dengue haemorrhagic fever
Although rare in Australia, dengue fever can sometimes develop into dengue haemorrhagic fever. Babies and young children are at increased risk of this complication. Signs and symptoms may include:
- all the above symptoms of uncomplicated dengue fever
- bleeding under the skin, which causes purple bruises
- bleeding from the nose or gums
- liver problems
- heart problems.
Symptoms of dengue shock syndrome
A person with dengue haemorrhagic fever may go on to develop dengue shock syndrome. Signs and symptoms may include:
- all the above symptoms of uncomplicated dengue fever and dengue haemorrhagic fever
- severe bleeding
- extremely low blood pressure caused by blood loss (shock)
Most infected areas of the world
Dengue fever is common throughout tropical and subtropical areas of:
- the Caribbean
- Central America
- Central Pacific
- the Middle East
- South America
- Southeast Asia
- the South Pacific.
Dengue fever in Australia
Cases of dengue fever occur in northern Australia from time to time when travellers who have been infected overseas return and introduce the virus to the local mosquito population. To date, it isn’t as common as in other subtropical regions.
How it is spread
Dengue fever is not transmitted (spread) from person to person. Only infected mosquitoes transmit dengue fever. It is thought that the mosquito contracts the virus when it bites an infected person. The mosquito is then infective for the rest of its life and can spread the virus every time it bites someone.
At least three different kinds of mosquito in Australia are suspected to be dengue carriers. They are Ae aegypti
, Ae scutellaris
and Ae katherinensis
. These mosquitoes are found in northern Queensland, the Northern Territory and northern Western Australia.
Diagnosis of dengue fever
See a doctor immediately if you think you may have dengue fever. Early diagnosis is important to reduce the risk of complications and avoid further spread of the virus.
Your doctor will ask about your medical history, including any travel, and will do a physical examination. They may order a blood test.
The two types of blood tests that can be used to diagnose dengue fever are:
- Nucleic acid testing requires one blood test.
- Antibody testing requires two blood tests, three weeks apart.
Treatment for dengue fever
There is no specific treatment for dengue fever. Medical care aims to manage the symptoms and reduce the risk of complications while the person recovers. Most cases of uncomplicated dengue fever resolve within two weeks or so.
During this time, your doctor may advise:
- bed rest
- plenty of fluids
- medication to reduce fever, such as paracetamol (do not take aspirin because of its blood-thinning properties).
Hospital admission is usually required if the person develops dengue haemorrhagic fever or dengue shock syndrome. Treatment for these complications may include intravenous fluids and replacement of lost electrolytes.
Avoid mosquito bites
Protect yourself against mosquito bites when in dengue-prone areas. Suggestions include:
- Avoid outdoor activity, particularly around dusk and dawn when mosquitoes are most active.
- Wear socks, long pants and long-sleeved shirts when outdoors.
- Wear mosquito repellent that contains the active constituents DEET (N,N-Diethyl-m-toluamide) or picaridin. Reapply regularly and make sure you follow directions for safe use on the label.
- Apply a product, such as permethrin, to your clothes or bedding.
- Use a bed net.
- Stay in air-conditioned accommodation with flyscreens on the windows.
Where to get help
- Your doctor
- Department of Foreign Affairs and Trade Travel Advice Tel. 1300 139 281
- Communicable Disease Prevention and Control Unit, Department of Health Victoria Tel. 1300 651 160
- NURSE-ON-CALL Tel. 1300 60 60 24 – for expert health information and advice (24 hours, 7 days)
Things to remember
- Dengue fever is a viral disease spread by mosquitoes in many tropical and subtropical parts of the world including Africa, Asia, South America and Australia.
- Symptoms include high temperature, headache, joint and muscle pains, nausea and malaise.
- There is no specific medical treatment and no vaccine – the best way to protect against dengue fever is to avoid mosquito bites.
- Seek medical attention immediately if you think you may have dengue fever.
This page has been produced in consultation with and approved by:
Department of Health and Human Services - RHP&R - Health Protection - Communicable Disease Prevention and Control Unit
Page content currently being reviewed.
Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.