In the United States, the arrival of autumn means that residents in most of the country will see fewer mosquitoes and less risk of the diseases they spread. However, the chikungunya outbreak in Caribbean and Central and South American countries continues to spread with no sign of slowing down. Experts at the US Centers for Disease Control and Prevention (CDC) are warning that the painful mosquito-borne disease will likely continue to infect travelers to the region during the rest of this year and beyond.
The current outbreak began in December 2013, and by the end of October 2014 had caused an estimated 795,000 chikungunya fever cases in 37 countries and territories in the Western Hemisphere. As of November 4, 2014, more than 1,600 travelers returning to the United States with chikungunya fever have been reported. Before this outbreak, an average of 28 travelers with chikungunya fever returned to the United States each year.
CDC estimates that about 9 million people travel between the United States and Caribbean nations each year. During fall and winter, people in the United States might not be thinking about mosquitoes as a risk for diseases. So those who will be visiting the Caribbean or Central or South America should be aware of the risk of chikungunya in these areas, and remember their insect repellent and other tips for staying safe.
“The beginning of fall means that mosquito problems in the continental United States will be decreasing. However, travelers to areas where the chikungunya outbreak continues are at risk of becoming infected,” says Roger S. Nasci, PhD, chief of CDC’s arboviral diseases branch. “It is important that travelers understand these risks and take appropriate actions to prevent being bitten by mosquitoes.”
Preventing mosquito bites is the best way to avoid chikungunya and other mosquito-borne illnesses. The mosquitoes that spread chikungunya bite mostly during the daytime. CDC recommends using insect repellent and wearing long-sleeved shirts and long pants during the day and staying in air-conditioned or well-screened rooms at night. Those using sunscreen should apply insect repellent after sunscreen.
Some travelers may be more likely to get chikungunya, depending on where they travel and the length of their trip. Travelers more likely to have severe disease if they are infected (high-risk groups) include people older than 65, and those with arthritis or serious underlying medical conditions such as high blood pressure, heart disease, or diabetes. CDC advises travelers in high-risk groups to discuss their travel plans with their healthcare provider before leaving.
People infected with chikungunya virus typically develop fever and joint pain. Other symptoms can include muscle aches, headaches, joint swelling, or rash. Travelers who return from areas with chikungunya activity and have symptoms of the disease should seek medical care and tell their healthcare provider about their recent travel.
Infection with chikungunya virus is rarely fatal, but the joint pain seen with chikungunya can often be severe and debilitating. The virus is not spread between people. There is no vaccine and no specific treatment for the infection. Patients recover in about a week, although some people have long-term joint pain. Infection is thought to provide lifelong immunity.
Before taking a trip, travelers can check the latest CDC recommendations on the agency’s website (under travel notices) and learn about ongoing chikungunya activity. For more information on preventing mosquito bites, visit CDC’s advisory on chikungunya prevention.