Severe polyarthralgia, high-grade fever, diffuse maculopapular rash on trunk and extremities • Dx?

Choice of testing modality depends on when symptoms began

Laboratory diagnosis of chikungunya can be accomplished 3 ways: viral culture, reverse transcriptase-polymerase chain reaction (RT-PCR) viral RNA, and serology.¹ The choice of which modality to use depends on the time between the onset of symptoms and the date on which a serum sample is drawn.

• If the patient presents within the first 3 days of illness, viral culture can detect chikungunya. Chikungunya virus testing is available through the Centers for Disease Control and Prevention (CDC), some state laboratories, and one commercial lab.⁸ Viral cultures are considered the gold standard for diagnosis, but a requirement for an elevated biosafety level, as well as a longer incubation time, make them less useful in the clinical setting.^1,9
• If symptoms started less than 5 to 8 days prior, serum should be sent for RT-PCR for viral RNA.
• If symptoms occurred more than 8 days prior, serum should be sent for IgM and IgG serologic testing.

If the acute sample was negative (and chikungunya is still suspected), a second serum sample should be drawn 2 to 3 weeks later during the convalescent phase and sent for IgG serologic testing.

There are no specific treatments or vaccines available for chikungunya, but both live and inactivated vaccines are being tested. To prevent chikungunya virus infection, advise patients traveling to endemic areas to reduce mosquito exposure by avoiding outdoor activities during dusk and dawn, wearing long-sleeved shirts and long pants, and using an insect repellent that contains DEET. Recommend that patients who will be sleeping in a high-risk area use bed netting treated with permethrin. The CDC Web site has excellent additional information, available at https://www.cdc.gov/chikungunya.¹⁰

Our patient was briefly hospitalized due to intractable pain. She was discharged after 2 days and given prescriptions for motrin 800 mg and percocet 5/325 mg for breakthrough pain. Her wrist and ankle pain persisted after discharge, but slowly resolved after 2 to 3 months.

THE TAKEAWAY

Chikungunya is becoming more common among travelers returning to the United States from the Caribbean islands, and mosquito vectors found in parts of the United States are enhancing the possibility of local outbreaks. Travel to endemic regions—and the classic symptoms of fever, polyarthralgia, and a maculopapular rash—should lead you to put chikungunya high on the differential. Chikungunya is considered a reportable disease and treatment is largely supportive. Co-infections are possible and should be considered based on the patient’s travel history.