Chikungunya

Chikungunya is a viral disease transmitted to humans by infected mosquitoes. It is caused by the chikungunya virus and is characterized by sudden fever and joint pain that can be severe and debilitating.

Symptoms #

• Sudden onset of high fever (typically above 102 degrees F)

• Joint pains

• Headache

• Myalgia

• Arthritis

• Conjunctivitis

• Nausea

• Vomiting

• Maculopapular rash (characterized by a flat red area on the skin covered with elevated bumps)

Causes #

• Chikungunya is a viral disease transmitted to humans by infected mosquitoes. It is caused by the chikungunya virus (CHIKV).

• An infected person cannot directly transmit the virus to another person. The disease is spread when a mosquito feeds on a person with the virus circulating in their blood. The mosquito can pick up the virus and spread it to another person through its bite.

• According to the CDC, no infants have been found to have been infected with chikungunya virus through breastfeeding.

• Chikungunya virus is most often spread to people by Aedes aegypti and Aedes albopictus mosquitoes. These are the same mosquitoes that transmit dengue virus.

• CHIKV epidemics in Africa and Asia have been primarily associated with the urban mosquito A. aegypti. But since an outbreak on Réunion in 2005, A. albopictus has been introduced as a second major spreader of CHIKV.

Diagnosis #

• If you have recently returned from an area with known virus transmission and are experiencing high fever and joint pain, your doctor might recommend a series of blood tests to detect the presence of chikungunya virus or antibodies.

• Several methods can be used for diagnosis of chikungunya virus infection.

• Serological tests, such as enzyme-linked immunosorbent assays (ELISA), may confirm the presence of IgM and IgG anti-chikungunya antibodies.

• Chikungunya virus antibodies normally develop toward the end of the first week of illness. IgM antibody levels are highest three to five weeks after the onset of illness and persist for about two months.

• The virus may be directly detected in the blood during the first few days of infection as well. Samples collected during the first week of illness are tested by both serological and virological methods.

• Blood tests can also look for similar viruses like dengue and Zika, which have similar symptoms.

• Test results are normally available 4 to 14 days after a specimen is received by the lab.

Prognosis #

• Most patients recover fully from the infection, but in some cases joint pain may persist for several months, or even years.

• According to the CDC, some patients will have a relapse of rheumatologic symptoms such as polyarthralgia, polyarthritis, tenosynovitis, or Raynaud’s syndrome in the months after acute illness. Studies have reported that anywhere from 5 to 80 percent of patients may experience persistent joint pain, as well as prolonged fatigue, for months or years after their illness.

• Once an individual is recovered, they are likely to be immune from future infections.

• Severe cases and deaths from chikungunya are very rare and are almost always related to other existing health problems.

• People at risk for more severe disease include newborn babies infected around the time of birth, adults over the age of 65, and people with medical conditions such as high blood pressure, diabetes, or heart disease.

Treatment #

There is no specific antiviral drug for chikungunya, so treatment involves relieving the symptoms. Treatment includes:

• Antipyretics to reduce fever

• Analgesics for pain relief and to reduce fever

• Drinking plenty of fluids

• Rest

Given the similarity of symptoms between chikungunya and dengue, in areas where both viruses circulate, suspected chikungunya patients should avoid using aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) until a dengue diagnosis is ruled out (this is because these medicines can increase the risk of bleeding with dengue).

Once a diagnosis is established, patients with persistent joint pain can use nonsteroidal anti-inflammatory drugs and corticosteroids, including topical preparations. Physical therapy may help lessen the symptoms.