Chikungunya Virus

Chikungunya virus is spread to people by the bite of an infected mosquito. The most common symptoms of infection are fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash. Outbreaks have occurred in countries in Africa, Asia, Europe, and the Indian and Pacific Oceans. In late 2013, chikungunya virus was found for the first time in the Americas on islands in the Caribbean. There is a risk that the virus will be imported to new areas by infected travelers. There is no vaccine to prevent or medicine to treat chikungunya virus infection. Travelers can protect themselves by preventing mosquito bites. When traveling to countries with chikungunya virus, use insect repellent, wear long sleeves and pants, and stay in places with air conditioning or that use window and door screens.

Prevention

Chikungunya virus is spread to people through the bite of an infected mosquito. Mosquitoes bite during the day and night. There is no vaccine to prevent chikungunya virus infection. The best way to prevent chikungunya is to protect yourself from mosquito bites. Use insect repellent, wear long-sleeved shirts and pants, treat clothing and gear, and take steps to control mosquitoes indoors and outdoors.

Transmission

Through mosquito bites

Chikungunya virus is transmitted to people through mosquito bites. Mosquitoes become infected when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites.

Chikungunya virus is most often spread to people by Aedes aegypti and Aedes albopictus mosquitoes. These are the same mosquitoes that transmit dengue virus. They bite during the day and at night.

Rarely, from mother to child

Chikungunya virus is transmitted rarely from mother to newborn around the time of birth.

To date, no infants have been found to be infected with chikungunya virus through breastfeeding. Because of the benefits of breastfeeding, mothers are encouraged to breastfeed even in areas where chikungunya virus is circulating.

Rarely, through infected blood

In theory, the virus could be spread through a blood transfusion.  To date, there are no known reports of this happening.

Symptoms

• Most people infected with chikungunya virus will develop some symptoms.
• Symptoms usually begin 3–7 days after an infected mosquito bites you.
• The most common symptoms are fever and joint pain.
• Other symptoms may include headache, muscle pain, joint swelling, or rash.
• Chikungunya disease does not often result in death, but the symptoms can be severe and disabling.
• Most patients feel better within a week. In some people, the joint pain may persist for months.
• People at risk for more severe disease include newborns infected around the time of birth, older adults (≥65 years), and people with medical conditions such as high blood pressure, diabetes, or heart disease.
• Once a person has been infected, he or she is likely protected from future infections.

Diagnosis

• The symptoms of chikungunya are similar to those of dengue and Zika. These diseases are spread by the same mosquitoes that transmit chikungunya.
• See your healthcare provider if you develop the symptoms described above and have visited an area with chikungunya.
• If you have recently traveled, tell your healthcare provider when and where you traveled.
• Your healthcare provider may order blood tests to look for chikungunya or other similar viruses like dengue and Zika.

Treatment

• There is no vaccine to prevent or medicine to treat chikungunya virus.
• Treat the symptoms:
• Get plenty of rest.
• Drink fluids to prevent dehydration.
• Take medicine such as acetaminophen (Tylenol®) or paracetamol to reduce fever and pain.
• Do not take aspirin and other non-steroidal anti-inflammatory drugs (NSAIDS until dengue is ruled out to reduce the risk of bleeding).
• If you are taking medicine for another medical condition, talk to your healthcare provider before taking additional medication.

If you have chikungunya, prevent mosquito bites for the first week of your illness.

• During the first week of infection, chikungunya virus can be found in an infected person’s blood and passed from that person to a mosquito through mosquito bites.
• An infected mosquito can then spread the virus to other people.

Diagnostic Testing

Chikungunya virus infection should be considered in patients with acute onset of fever and polyarthralgia, especially travelers who recently returned from areas with known virus transmission.

Laboratory diagnosis is generally accomplished by testing serum or plasma to detect virus, viral nucleic acid, or virus-specific immunoglobulin (Ig) M and neutralizing antibodies. Viral culture may detect virus in the first 3 days of illness; however, chikungunya virus should be handled under biosafety level (BSL) 3 conditions. During the first 8 days of illness, chikungunya viral RNA can often be identified in serum. Chikungunya virus antibodies normally develop toward the end of the first week of illness. Therefore, to definitively rule out the diagnosis, convalescent-phase samples should be obtained from patients whose acute-phase samples test negative.