Case Presentation: A 17-year-old previously healthy female presents with abrupt-onset fever and rash after returning from Thailand. The rash started the day of admission on her thighs bilaterally, and rapidly progressed cephalad to her trunk and face. She also complained of headache, back pain, neck pain, and left wrist pain. The patient was hemodynamically stable and physical exam revealed diffuse erythematous, blanching maculopapular rash, sparing the palms and soles. She had bilateral conjunctivitis but no joint effusion or synovitis. She was empirically treated with Rocephin and subsequently Doxycycline for coverage of rickettsia species. During the admission she developed worsening thrombocytopenia (platelets 85) and leukopenia with an absolute neutrophil count of 420. Influenza PCR, Malarial smear, and Rickettsia antibodies were negative. Given travel history, endemic arboviruses were also on the differential. Zika, Dengue, and Chikungunya PCR testing were performed. Her fever and rash resolved with supportive care, however she continued to complain of wrist and jaw pain. She was deemed stable for discharge home with outpatient follow up. PCR testing for Chikungunya virus came back positive, and the health department was notified. She still has residual arthralgia of the wrists on follow up visits requiring NSAIDS as needed, however her neutropenia and thrombocytopenia have resolved.
Discussion: The arboviruses were first identified in Africa and Asia, however they have since spread to include many other regions closer to the United States. 2014 marked the start of cases reported in US travelers returning from affected areas, with local transmission identified in Florida, Puerto Rico, and the US Virgin Islands. Per current CDC reports, there have been three documented cases of Chikungunya in Florida in 2019, which were all travel associated.Chikungunya virus is marked by acute onset high fever and polyarthralgia, especially involving the small joints. Rash is also present about 50% of the time. Laboratory abnormalities often include lymphopenia, thrombocytopenia, and elevated transaminases. Chikungunya, Dengue, and Zika viruses share many symptoms, along with the same disease vector. This makes it imperative to test for all three if you suspect one, as co-infection is a possibility. This is especially important due to the documented teratogenic effects of Zika and higher morbidity/mortality with Dengue. Chikungunya often stands out due to the leukopenia and persistent arthralgias, and is more likely to cause a rash. The virus typically has an incubation period of 3-7 days, with viremia then lasting 4-6 days. Arthralgias however may persist for months, and can be severe and disabling. Some patients require anti-inflammatories or steroids for the arthralgias.
Conclusions: Though Chikungunya remains rare in the United States, there have been increasing cases in the last 10 years related to international travel. Providers should have a higher index of suspicion when the international traveler presents with classic symptoms such as fever and polyarthralgia, especially if travel was to endemic areas. Early diagnosis reduces unnecessary antibiotic use and allows for testing for co-infection of other pathogens.