Virus or Arthritis? Diagnosis Not Always Clear

Chikungunya virus may be mistaken for rheumatoid arthritis in some patients

(RxWiki News) Despite its name, the chikungunya virus has nothing to do with chickens. It may, however, have something to do with rheumatoid arthritis (RA).

A research team at the Washington University School of Medicine in St. Louis found that blood tests and symptoms of patients with chikungunya virus and RA can be very similar. The similarity could confuse doctors and might lead to problems with treatment.

The authors of this study stressed the need for doctors to obtain a good travel history on all patients.

“For now, good travel histories of patients are among the best diagnostic tools for physicians," said study author Wayne M. Yokoyama, MD, in a press release. "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. In addition, the disease typically starts with high fever and abrupt onset of severe pain in the joints, which are not usually seen with rheumatoid arthritis.”

The chikungunya virus originated in Africa and was first identified about 60 years ago, according to these researchers. It is spread by mosquitoes. Most people develop the disease after traveling to an area where the disease is common.

Chikungunya has recently spread to Central and South America, as well as the Caribbean and other parts of the world.

In 2014, cases began to appear among people who lived in Florida but had not traveled outside the US. This suggests that some mosquitoes in that state may now spread the virus.

The current study, led by Jonathan J. Miner, MD, PhD, compared 10 St. Louis residents who had traveled to Haiti in June of 2014 with healthy people and people who were newly diagnosed with RA. Dr. Miner’s team found that lab tests in both people with RA and chikungunya showed similar results.

To identify the virus itself, however, blood samples must be sent to the Centers for Disease Control and Prevention for specialized testing. If a doctor thinks the symptoms are from RA, further tests like these may be less likely.

Chikungunya virus usually starts abruptly with a high fever and severe joint pain. It can also cause a rash. Although the fever and rash typically go away within about 10 days, the joint pain can, in some cases, persist for years. These joint pain symptoms are very similar to the symptoms of RA.

The problem with a misdiagnosis is that patients may not receive the treatment they need.

A strong immune system helps protect people against all kinds of infections. RA, however, is an autoimmune disease, in which the body attacks itself instead of a germ or virus.

Doctors usually treat RA with medications to suppress the immune system. Since chikungunya is an infection, suppressing the immune system might be the wrong thing to do.

Dr. Miner and team noted that their study was small but expressed concern that, in areas where chikungunya virus is often found, it could cloud the diagnostic picture of RA. People who actually have chikungunya might be misdiagnosed with RA.

A careful travel history is an important factor in the diagnostic process, Dr. Miner and team noted. Patients who have traveled outside the US should inform their doctors.

This study was published online Jan. 29 in the journal Arthritis and Rheumatology.

The Foundation for Barnes-Jewish Hospital and the Howard Hughes Medical Institute funded this research. Dr. Miner and team disclosed no conflicts of interest.

Review Date: 
February 2, 2015