Chikungunya infections can cause severe and disabling pain. Symptoms of the illness are characterized by:

Sudden high feverSevere joint pain or stiffnessRashMuscle painJoint swellingHeadacheNauseaFatigue

Severity of the illness varies from person to person, but for many, the joint pain is debilitating. The great majority of people who have the virus develop symptoms, although in 10 percent to 15 percent of infections, there are no signs of illness. Symptoms generally last for several days to several weeks, after which most people recover fully. However, symptoms may relapse months or years after recovery. In some people, joint pain may become chronic, lingering for months or even several years. Other possible long-term or severe complications include:

Prolonged (months to years) muscle pain and fatigueInflammation of the eyesBrain inflammation and other neurological effectsDepressionLiver, kidney, and heart complicationsStomach and intestinal complaints

Although children and infants often do not develop symptoms, they also have higher risk of more severe disease, especially newborns infected in the days just before or after birth. They are more likely than others to develop inflammation of the brain. If you are over age 65, or if you have arthritis or a chronic medical condition (such as high blood pressure, diabetes, or heart disease), the disease may affect you more seriously. Although infection with chikungunya is rarely fatal, in older people it may contribute to the cause of death.

Chikungunya or Rheumatoid Arthritis?

Chikungunya is sometimes misdiagnosed as rheumatoid arthritis (RA), especially in the elderly. A 2015 report from the journal Arthritis & Rheumatology described a group of 10 people who traveled to Haiti in 2014, eight of whom developed symptoms that pointed to a diagnosis of rheumatoid arthritis. Blood testing, however, revealed that the group had developed antibodies to the chikungunya virus, though their initial blood work and symptoms mimicked RA.

Chikungunya Onset

The chikungunya virus is transmitted to humans by the bites of infected mosquitoes. The onset of illness usually occurs three to seven days after the mosquito bite, but symptoms may start anywhere from 2 to 12 days after the bite. The virus remains in the person’s system for about a week. During that time, any mosquito that feeds on the infected person may spread the infection to other people. After you contract chikungunya, you are likely to be immune to the disease in the future.

Chikungunya Diagnosis

If you have any of the symptoms of chikungunya, it’s especially important to tell your doctor whether you have been in an area that’s had an outbreak and if you were outdoors a lot or had other exposure to mosquitoes. You doctor will need to distinguish your infection from similar illnesses you can get from mosquito bites, such as dengue fever or malaria. Your doctor may also want to rule out bacterial infections, such as leptospirosis (contracted from exposure to animals), or autoimmune conditions that can have similar symptoms, such as rheumatoid arthritis. Diagnosis is based on symptoms and physical signs, such as inflamed joints, as well as the probability of exposure to infected mosquitoes. Blood tests may also be done, but results can take a while, so they are mainly used to track outbreaks. In 2015, the Centers for Disease Control and Prevention (CDC) requested that chikungunya become a nationally notifiable disease, requiring doctors to report cases. Only a limited number of laboratories can test for chikungunya in the United States, including labs at some state health departments and the CDC. Testing options include:

A culture to isolate the virus from the bloodReverse transcriptase-polymerase chain reaction (RT-PCR)A blood test

A culture can be performed during the first few days of infection and takes one to two weeks to complete. RT-PCR can be used to detect chikungunya genes in the blood. The test can be done in the first eight days of illness. Results can be available in one to two days. A blood test may find antibodies to chikungunya, with results in a couple of days. However, the test may not work in the first few days of illness and it may not distinguish between chikungunya and closely related viruses, so a second confirmatory test may be necessary. Even though there is no cure for chikungunya, getting tested for it is important to rule out other diseases and to help public health officials track this infectious disease. The symptoms of chikungunya are similar to those of dengue fever. Dengue fever is more lethal than chikungunya, and prompt recognition and treatment of it can be life saving. It’s possible to have both diseases at the same time.