You may not yet have heard of chikungunya virus, but chances are you will be hearing a lot about it…and soon. It was nonexistent in the Western hemisphere until December 2013, but in just over a year, more than one million cases were reported, mostly in the Caribbean and South and Central America—and now it’s here in the United States. The virus, which is transmitted by mosquitos, can cause symptoms that mimic rheumatoid arthritis—and those symptoms can last for months to years. Plus, treating the infection as if it were rheumatoid arthritis might do more harm than good! Here’s what you need to know about this new viral threat—and how to tell whether your “arthritis” might actually be a case of chikungunya infection…
RHEUMATOID ARTHRITIS OR CHIKUNGUNYA?
First of all, don’t panic. Chikungunya virus, often referred to as “CHIKV,” is not a lethal illness. The most common symptoms are joint pain and fever. Symptoms can also include headache, joint swelling and muscle pain in the first seven to 10 days of infection. In most people, the more severe symptoms, such as flu-like fever and achiness, last for about a week or so and pass. But joint symptoms in particular can persist for 12 to 15 months in up to 60% of those infected and up to three years for some, according to Jonathan Miner, MD, PhD, a fellow in the rheumatology division of Washington University School of Medicine in St. Louis and a key US researcher of CHIKV infection.
As mentioned, some CHIKV symptoms, such as joint achiness and swelling, are similar to those of—and easily confused with—rheumatoid arthritis. But unlike rheumatoid arthritis, with CHIKV, joint pain and inflammation occur very suddenly, in the same way flu symptoms occur, in many joints all at once instead of gradually over months or years, said Dr. Miner.
HOW IT GOT HERE
First described in Tanzania in the 1950s, CHIKV spread from Africa to Asia and Europe before hitting the Caribbean and South America and, ultimately, the United States. Most of the nearly 2,500 reported cases in the United States in 2014 were linked to travel to other affected areas, but 11 cases were reported in nontravelers in Florida. This means that mosquitos in parts of the southern United States are now carrying the virus.
The only factor currently limiting the virus’s spread in the United States, according to Dr. Miner, is the type of mosquito that is, so far, carrying the virus our way—an insect known as the yellow fever mosquito. It is native to the Caribbean, Florida, the Gulf Coast and parts of Texas. If the virus mutates to jump from the Caribbean yellow fever mosquito to the American Asian tiger mosquito, found throughout much of the continental United States, the number of cases might rival that of West Nile virus, which caused a panic about a decade ago. And it is likely to happen eventually, said Dr. Miner…the virus is also spread by the Asian tiger mosquito in the Eastern hemisphere.
Proper diagnosis hinges on giving your doctor appropriate details about your symptoms and travels, said Dr. Miner—such as whether your joint pain and swelling developed slowly over several months…or developed after traveling to places where the virus is actively spreading, such as the Caribbean. If you only visited places such as Canada or most of the United States where CHIKV outbreaks are rare or have not yet occurred, infection is very unlikely, he said.
The problem is that CHIKV, generally speaking, has not necessarily been on an American rheumatologist’s radar, which is why you ought to be well informed about it. A rheumatologist might treat the joint symptoms of CHIKV in the same way as rheumatoid arthritis—with immunosuppressive drugs. This may not be so bad when the residual symptoms of joint pain and swelling persist after the body has otherwise fought off the viral infection, but such treatment will thwart your body’s natural efforts to fight off the virus during the early stages of infection. And your body’s natural efforts are all you’ve got…there is no medical remedy for CHIKV infection. Treatment is similar to that of the flu bug, according to the US Centers for Disease Control and Prevention: Get plenty of rest, drink fluids to prevent dehydration and take aspirin, ibuprofen, naproxen or acetaminophen for pain and fever relief.
“During the first week of infection, levels of the virus are high in the blood. This is when the body’s immune response is extremely important. It has to be allowed to fight off the virus,” said Dr. Miner. “I think it’s fair to say, therefore, that taking immunosuppressive drugs when symptoms first appear is likely to be dangerous.”
In fact, people with weakened immune systems, including infants, people older than 65 and people who have serious medical conditions, such as high blood pressure, heart disease or diabetes, are known to be at greater risk for more severe and prolonged symptoms from CHIKV. And if you already have arthritis, the virus may worsen your condition. On the up side, if you’ve been infected with CHIKV, your body becomes immune to reinfection if you should happen to again be bitten by an infected mosquito.
If you’re traveling to the Caribbean or an area with locally transmitted cases of CHIKV, it goes without saying that you should use mosquito repellent and wear long-sleeved shirts and long pants if the weather permits. Also keep the windows of your lodging closed or screened at night, and use the air conditioner to keep the mosquitos out and the room air temperature and humidity at levels that discourage presence of mosquitos.
In addition, keep abreast of which travel areas are more affected than others, said Dr. Miner. One Caribbean island may be having more of an outbreak than another at any given time. You can find up-to-date information on the number of CHIKV cases by region on the websites of the the Centers for Disease Control and Prevention and the Pan American Health Organization.