The Centers for Disease Control and Prevention (CDC) is closely monitoring flights across the U.S. after all the measles outbreaks in the early months of 2019 were linked to travelers who carried the disease from other countries with lower vaccination rates.

In February, an adult from Asia infected two U.S. citizens in San Francisco during their flight. The incident was just among numerous reports of travel related measles outbreaks in the country. 

In 2018, 82 of the 349 people diagnosed with measles in the U.S. contracted the disease from other countries, the New York Times reported Thursday. The CDC warned that such “imported cases” could easily affect people in areas of the U.S. where residents were not vaccinated.

The public health institute said measles may spread across the country when those infected fliers will transport the disease to other areas, even those with high rates of vaccinations.  

“Suddenly the single introduction of a case can have explosive consequences,” Martin Cetron, director of the Division of Global Migration and Quarantine at the CDC, said. To date, the institute has 17 countries under its travel watch, including England, France and Italy. 

Measles is considered among the most contagious diseases in the world. Due to the vast number of people traveling from across the globe, it’s hard to avoid the spread of infection. But how can a person determine when someone has been infected? 

According to Mayo Clinic, measles infection occurs in stages over a period of 10 to 14 days after exposure to the virus. No clear signs or symptoms of measles commonly occur during the first two to three weeks of infection. However, there are a number of symptoms to watch out for in case of possible exposure. They are listed below.

  • Koplik's spots or tiny white spots with bluish-white centers on a red background inside the mouth
  • A skin rash made up of large, flat blotches
  • Conjunctivitis
  • Fever
  • Dry cough
  • Runny nose
  • Sore throat

If one or a combination of the symptoms occur, it is important to visit a doctor to confirm the infection of measles. Early detection of the infection could help save lives of those affected by the highly contagious, serious disease. 

The World Health Organization said that measles already caused millions of deaths worldwide and nearly 110,000 people died of the infection in 2017.