National Geographic News
A photo of a worker from Haiti's Ministry of Public Health spraying chemicals to exterminate mosquitos to prevent the Chikungunya virus.

A worker from Haiti's Ministry of Public Health and Population sprays chemicals to exterminate mosquitoes in Port-au-Prince last May.

Photograph by Hector Retamal, AFP/Getty

Karen Weintraub

for National Geographic

Published July 1, 2014

The patient showed up at the University of Miami Jackson Memorial Hospital feverish and hobbled by joint pain, a rash spreading across her face, and was presumed to be suffering from lupus or severe rheumatoid arthritis.

But in talking to the middle-aged woman last week, doctors realized that her symptoms and recent history of travel to the Dominican Republic added up to a different diagnosis: chikungunya, an infectious disease carried by the same mosquitoes that spread dengue fever.

Chikungunya (pronounced chick-un-GOON-ya) has plagued other parts of the world—particularly Asia and Africa—for decades, becoming more prevalent in recent years. But it arrived in the Caribbean only in December and has already infected as many as 250,000 people there.

The virus is generally not lethal and can't pass from person to person. But the pain it brings can be horrible—some who have weathered its wrath have said they wished the virus had killed them. In rare cases, the agony can last for months or even years.

Public health officials in the Caribbean are struggling to contain the outbreak, in part because of the difficulty of limiting mosquito breeding grounds and because the disease is so new to the area.

Paola Lichtenberger, director of the Tropical Medicine Program at the University of Miami, says she is sure the epidemic is more widespread than official numbers suggest simply because making the diagnosis is so difficult.

Public health officials in the U.S. and around the world, meanwhile, are tracking cases carefully and encouraging people in affected areas to take precautions to avoid infections and to clean up areas of standing water. Airports in ten major American East Coast cities with Caribbean-bound flights have posted warnings to passengers about chikungunya.

Table showing countries with higher incidence cases of chikungunya

So far, 73 American travelers have brought the disease home from abroad and another 15 have been infected by mosquitoes in Puerto Rico and the U.S. Virgin Islands, though it hasn't yet reached mosquitoes in the continental United States.

But it's only a matter of time before that happens, according to Lichtenberger, who has helped treat three chikungunya patients since the outbreak began.

"I'm pretty sure we're going to have cases here, if we already haven't had them," she says.

Coming to America

So far, the Dominican Republic has been hardest hit, with 135,000 suspected cases; Guadeloupe comes next with 40,000, followed by Haiti with 39,000 and Martinique with 35,000.

"The whole Caribbean is just full of it," Lichtenberger says.

Doctors who had never seen the disease until six months ago struggle with proper diagnosis, she says, especially because chikungunya can look a lot like influenza or dengue—and can even occur together with dengue.

Lichtenberger expects more cases in the continental United States soon.

Someone from the Caribbean who has long planned a vacation or family visit to the U.S. isn't going to cancel just because mom, dad, or junior feels lousy, Lichtenberger says. If the sick person gets bitten by a mosquito in the U.S., the virus can easily get transmitted.

That's why it's important for sick people to take precautions to protect themselves from further mosquito bites, she says: not for their sake, but for others'.

But Mark Heise, who studies the genetics of disease susceptibility at the University of North Carolina in Chapel Hill, says chikungunya probably won't spread too far in the United States.

"It's something we should be concerned about, but I don't think people need to panic about it either," he says.

Heise looks at the transmission of dengue as an indicator for how chikungunya is likely to spread. Dengue fever is a major problem in the Caribbean and South and Central America, and there are sporadic cases on U.S. soil, "but it isn't a major public health threat."

The type of mosquito that has most often spread chikungunya, Aedes aegypti, does not live in the United States, says Stephen Morse, a virologist and professor of epidemiology at the Mailman School of Public Health at Columbia University in New York.

But its cousin Aedes albopictus, also known as the Asian tiger mosquito, lives as far north as Chicago and is also believed to be able to transmit chikungunya.

The virus tends to burn itself out in a particular community because it strikes so many people so quickly, Morse says. It leaves them with immunity that can last years or even a lifetime.

A photo of a health worker examining a patient for the Chikungunya virus in El Salvador.
A health worker examines a patient during a medical brigade last month to detect cases of chikungunya at a school in El Salvador.
Photograph by Jose Cabezas, AFP/Getty

No Vaccine, No Meds

Chikungunya got its name from the phrase "which bends up" in the local dialect in Tanzania where it was first identified in the early 1950s. The term described the posture of someone with the disease, bent over with pain.

Most victims suffer extreme joint pain for 5-12 days, making it hard for them to grasp things with their hands or put weight on their legs. The pain usually subsides by the two-week mark, but a small number of patients "continue to have sporadic bouts of joint pain, and we really don't understand why that is," Heise says.

People middle-aged and older and those with preexisting medical conditions tend to suffer more than children and young adults, says Heise, whose research focuses on why the virus replicates in joints and why it causes an overreaction of the immune system.

There is no vaccine or medication that can change the course of the disease, though patients are given painkillers and told to drink a lot of fluids, Morse says.

To avoid getting chikungunya while staying in affected areas, take the usual precautions against mosquitoes: Wear long sleeves, use repellents, and keep outside areas free of standing water where mosquitoes can breed.

"Take it very, very seriously," Lichtenberger says. "Especially where you see a lot of people with the disease and lots of mosquitoes."

Carl Fisher
Carl Fisher

I just returned from 2 weeks in Haiti with my 13 y.o. daughter. We both got it and so did almost everyone we talked to in the small village where we stayed in northern Haiti. It was very painful but it only lasted for 2 days in my case. My daughter had only mild symptoms and got over it quickly. Other local people who may not have been in good health to begin with were much worse off and were bedridden for weeks. We were asymptomatic for over one week before our return through Miami so I believe we were not in any danger of spreading the disease in the US. The silver lining for us may be that we will hopefully never have to suffer it again if we have some kind of immunity now though I would not take any chances of being infected again. It is nearly impossible not to get bitten by mosquitoes in a country like Haiti with very little public health resources.

Wendy Wetherell
Wendy Wetherell

I went to a Caribbean Island a few years ago, and the people who reside there made sure I was sprayed head to foot with repellant before I visited their ancient ruins. Needless to say I appreciate their taking of such precautions.

Alex Laraga
Alex Laraga

We have to be careful to this specially the chiildren and ALWAYS use mosquito net at night.

Vikki Mend
Vikki Mend

i had it and doctors didn't know it's chikungunya.  All my lymph nodes swelled. I had about 8 swollen node on my head, about 5 on my armpit, on my inner thighs..all my joints were painful. can barely walk. I suffered for more than a month and yet not one doctor who i visited said it's  chikungunya.  Most of them told me it's ordinary fever that might have triggered my arthritis, or maybe my diet was not good.  It's not lethal though, but super painful.

Song Quan Ong
Song Quan Ong

I though certain Caribbean area was introduced GM Aedes aegypti by Oxitec, a private biotechnology company. Heard that the result is extraordinary in eliminate the mosquito population.

Paul Heitmeyer
Paul Heitmeyer

So chikungunya can be transmitted by mosquitoes, but AIDS, which is also a virus, cannot?  

thecutecat Cat
thecutecat Cat

@Vikki Mend May be because Chikungunya is not a common disease in your country.  
In my country (Indonesia), government has a special program to eradicate this, so  all doctors and paramedic should know well on it.  

Peter Nedyalkov
Peter Nedyalkov

@Paul Heitmeyer When the mosquito bites, it doesn't inject blood in you, it injects saliva to ease the feeding. The saliva cannot carry HIV but it does carry malaria or yellow fever. Additionally it actually digests the virus and there aren't enough particles to cause HIV in another person by contamination. You already know that you don't get infected when you are around a HIV-positive person, unless you have an unprotected intercourse or share needles and other more rare way not worth mentioning. But you do get infected by many other viruses just by being around because they are classified as "airborne". Just research your own question and see for yourself.

Andrew Bell
Andrew Bell

@Paul Heitmeyer "When a mosquito bites someone, it does not inject its own blood or the blood of an animal or person it has bitten into the next person it bites. The mosquito does inject saliva, which acts as a lubricant so that it can feed more effectively. Yellow fever and malaria can be transmitted through the saliva, but HIV does not reproduce in insects, so the virus doesn't survive in the mosquito long enough to be transmitted in the saliva."

So, no.


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