Chikungunya virus is spread through mosquito bites and can cause crippling symptoms. Photo by jg/aj/Jack Leonard/New Orleans Mosquito Control Board/UPI | License Photo

ST. LOUIS, Jan. 30 (UPI) -- A lot of viruses share common symptoms -- headache, nausea, fever, chills, aches, sinus pressure, soar throat -- making diagnosis a difficult task. This is especially true for relatively rare viral diseases like Chikungunya, a tropical disease carried by mosquitoes in Africa and India, as well as the Caribbean and Central and South America.

But more than just symptoms, scientific testing can even be confused by maladies with similar symptoms. According to new research by scientists at the Washington University School of Medicine in St. Louis, blood tests of patients infected with the Chikungunya virus and of those diagnosed with rheumatoid arthritis can reveal similar results.


This confusion can lead to some patients with Chikungunya being misdiagnosed and treated for rheumatoid arthritis. As the virus encroaches upon the Caribbean and the southern United States, health officials are concerned about an uptick in infections among Americans.

As researchers showed in their study, the immune system responds to the Chikungunya virus in ways that suggests chronic joint inflammation. In studying patients who had recently acquired Chikungunya in Haiti, researchers were able to see firsthand how both symptoms and blood tests can be confused.

"All eight patients with Chikungunya-related arthritis met the American College of Rheumatology's criteria for a diagnosis of rheumatoid arthritis," lead author Jonathan Miner, a rheumatology fellow, explained in a press release. "Their recent travel to Haiti led us to suspect they had Chikungunya virus infections."

While Chikungunya typically results in a variety of early symptoms, like a rash and fever, these typically subside after several days. The severe joint point, however, can last several months, sometimes longer than a year. But the early symptoms are not always pronounced enough to differentiate Chikungunya from rheumatoid arthritis, researchers say.

"For now, good travel histories of patients are among the best diagnostic tools for physicians," said senior author Wayne Yokoyama. "Recent travel to the Caribbean, Central and South America, Africa, India or other areas where the virus is prevalent should raise suspicions of Chikungunya infection."