What is chikungunya virus?

Chikungunya virus is transmitted when someone is bitten by an infected female Aedes mosquito, the same mosquito that spreads other viruses, including dengue, yellow fever and Zika virus. The virus is found in Africa and Asia and the Western Pacific, so if you are travelling to these areas it is important to take steps to avoid being bitten by mosquitoes.

The mosquito becomes infected when it bites someone who is ill with chikungunya. It can then pass it on to other people a few days later.

Outbreaks of chikungunya virus infection have become more frequent in many regions, including some Indian Ocean and Pacific Island nations, including Papua New Guinea. There have also been cases in other areas, such as Italy and the Caribbean.

Mosquitoes in Australia are not thought to be infected with chikungunya virus, though Aedes mosquitoes are found in north Queensland, the Torres Strait and some locations in central and southern Queensland.

The most likely way for Australians to become infected with the chikungunya virus is if they travel overseas. Australians who get infected have often been bitten in Indonesia, particularly Bali.

Who is at risk?

Most people who are infected with the chikungunya virus feel unwell for a couple of weeks and then get better without treatment.

The disease can be more serious in newborn babies if they are infected around the time of birth; older adults aged over 65 years; and people with medical conditions such as high blood pressure, diabetes and heart disease.

What are the symptoms of chikungunya?

Symptoms usually appear 2 to 4 days after the person is bitten by an infected mosquito. Sometimes, however, symptoms can take as long as 12 days to develop.

The most common symptoms are joint pain and fever. Other symptoms may include:

• muscle pain
• headache
• a rash on your trunk (torso) and limbs, which can last for a week or more
• nausea
• fatigue

Sometimes the symptoms are mild and you might not notice them. In other people, the symptoms can be severe.

Most people start to feel better within 1 to 2 weeks, but the joint pain and inflammation can last for months or even years.

How is chikungunya diagnosed and treated?

If you become unwell and have a high fever after travelling to a tropical destination, see your doctor. They will examine you and order a blood test to confirm whether you have chikungunya.

Sometimes people with chikungunya are misdiagnosed as having another mosquito-borne illness, such as dengue, Ross River or Barmah Forest virus infection.

There is no specific treatment for chikungunya. You can take pain relief to help with joint pain, but avoid aspirin and other non-steroidal anti-inflammatory medicines until dengue fever, which can appear similar, has been excluded. (These medicines increase the risk of bleeding in the case of dengue).

If you have chikungunya virus, it is important to avoid mosquito bites for the first week of your illness. This is because you could infect the mosquito, which will then spread the virus to other people. The best way to do this is to use an insect repellent.

How is chikungunya prevented?

There is no vaccine to prevent chikungunya. The only way to prevent infection is to avoid being bitten by mosquitoes. You can prevent infection by:

• closing windows and using insecticide sprays indoors
• wearing light-coloured, long sleeved shirts and long trousers
• using an insect repellent containing DEET (diethyl toluamide) or picaridin (ask your pharmacist for advice)
• using mosquito nets or screens
• if possible, making sure there is no stagnant water around (such as in discarded containers, fallen palm fronds or gutters)

If someone in your community gets chikungunya, the mosquitoes around you could also be infected. Make sure you remove anything in which stagnant water could gather, such as tins or other containers since mosquitoes could breed there. Also, ensure everyone in your house uses insect repellent regularly.