Seasonal influenza activity has increased slightly in the United States, according to the Centers for Disease Control and Prevention. The proportion of people seeing a health-care provider for influenza-like illness increased slightly for the week ending Dec. 2, per the latest report from the CDC. In fact, several flu-activity indicators were higher than is typically seen for this time of year.
Among various measures the CDC tracks is the proportion of people who visit a health-care provider for influenza-like illness. In the week ending Dec. 2, three states experienced particularly high levels of such activity: Louisiana, Mississippi and South Carolina.
Other data tracks new cases of influenza by state. Widespread flu activity was reported by seven states for the week: Arkansas, Georgia, Louisiana, Massachusetts, Mississippi, Oklahoma and Virginia.
The single best way to prevent seasonal flu for anyone six months or older is to get a yearly flu vaccine, preferably before flu season begins, the CDC stresses. The following is specific advice for travelers or meeting attendees.
The risk for exposure to influenza during travel depends on the time of year and destination.
• In the Northern Hemisphere, the flu season can begin as early as October and can last as late as April or May.
• In the temperate regions of the Southern Hemisphere, influenza activity typically occurs during April-September.
• In the tropics, influenza activity occurs throughout the year.
• Travelers in the Northern and Southern Hemispheres can be exposed to the flu during months that fall outside of those listed above, especially when traveling as part of large groups (e.g., on cruise ships) that include people from areas of the world where influenza viruses are circulating.
If you have not gotten a flu vaccine this season and are traveling to parts of the world where influenza activity is ongoing, get one before your trip.
• This is particularly important for people at high risk of flu-related complications.
• The flu vaccine used in the Northern Hemisphere usually protects against the main viruses that have been circulating in other parts of the world.
Get vaccinated at least two weeks before travel, because it takes two weeks for vaccine immunity to develop.
• Keep in mind that influenza vaccines manufactured for the upcoming or current season usually expire the following June. After June, flu vaccines are usually not available in the U.S. until the influenza vaccine for the next season is produced and made available in the fall.
• Even if you receive the previous season's vaccine before travel during the summer months, you should still receive the new flu vaccine that coming fall or winter.
If you are sick with symptoms of influenza-like illness, you should not travel.
• Flu symptoms include fever, cough, sore throat, runny or stuffy nose, muscle or body aches, headache and fatigue. Some people may experience vomiting and diarrhea, though this is more common in children than adults.
• It is important to note that not everyone with flu will have a fever.
• If you are sick, stay home until at least 24 hours after you no longer have a fever or signs of a fever without the use of a fever-reducing medicine.
Research risks before you go.
• Investigate current flu activity in your region of travel. The Centers for Disease Control and Prevention provides frequently updated information on seasonal flu activity throughout the world.
• For additional travel resources, visit the CDC's Travelers' Health Website (General) and its Traveler Information Center.