Clinical Evaluation & Disease
Diagnosis & Reporting
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.
The differential diagnosis of chikungunya virus infection varies based on place of residence, travel history, and exposures. Dengue, Zika, and chikungunya viruses are transmitted by the same mosquitoes and have similar clinical features. The viruses can circulate in the same area and can cause occasional co-infections in the same patient. Chikungunya virus infection is more likely to cause high fever, severe arthralgia, arthritis, rash, and lymphopenia, while dengue virus infection is more likely to cause neutropenia, thrombocytopenia, hemorrhage, shock, and death. In general, the signs and symptoms of Zika virus are mild, though infections can cause congenital infections. It is important to rule out dengue virus infection because proper clinical management of dengue can improve outcome. Click for the WHO dengue clinical management guidelines [PDF – 160 pages].
In addition to dengue and Zika, other diagnostic considerations include leptospirosis, malaria, rickettsia, group A streptococcus, rubella, measles, parvovirus, enteroviruses, adenovirus, other alphavirus infections (Mayaro, Ross River, Barmah Forest, o’nyong-nyong, and Sindbis viruses), post-infections arthritis, and rheumatologic conditions.
Laboratory diagnosis is generally accomplished by testing serum or plasma to detect virus, viral nucleic acid, or virus-specific immunoglobulin M and neutralizing antibodies. Click for more information about diagnostic testing..
Chikungunya virus disease is a nationally notifiable condition. Health care providers are encouraged to report suspected chikungunya cases to their state or local health department to facilitate diagnosis and mitigate the risk of local transmission.
Clinical Signs & Symptoms
The majority of people infected with chikungunya virus become symptomatic. The incubation period is typically 3–7 days (range, 1–12 days). The disease is most often characterized by acute onset of fever (typically >39°C [102°F]) and polyarthralgia. Joint symptoms are usually bilateral and symmetric and can be severe and debilitating. Other symptoms may include headache, myalgia, arthritis, conjunctivitis, nausea/vomiting, or maculopapular rash. Rare complications include uveitis, retinitis, myocarditis, hepatitis, nephritis, bullous skin lesions, hemorrhage, meningoencephalitis, myelitis, Guillain-Barré syndrome, and cranial nerve palsies.
Persons at risk for severe disease include neonates exposed intrapartum, older adults (> 65 years), and persons with underlying medical conditions (hypertension, diabetes, or cardiovascular disease).
Clinical laboratory findings can include lymphopenia, thrombocytopenia, and elevated creatinine. Elevated hepatic transaminases can be seen with acute infection but are not specific and do not occur frequently enough to be diagnostic.
Acute symptoms typically resolve within 7–10 days. Some patients may have persistence or relapse of rheumatologic symptoms (polyarthralgia, polyarthritis, tenosynovitis) in the months following acute illness. Studies report variable proportions of patients with persistent joint pains for months to years. Mortality is rare and occurs mostly in older adults.