State officials have confirmed two more cases of measles in East Tennessee, bringing to three the total for the state.
The new cases are linked to the first reported case in April, according to a news release from the Tennessee Department of Health.
"We expected to have more measles cases linked to the first one, and these new cases occurred in people we had identified and were monitoring as contacts of the first patient," said Dr. Michelle Fiscus, the state's immunization program medical director, said in a statement. "The good news is there are no additional contacts of these new cases that have not already been identified."
The announcement comes less than a week after public health officials in two states warned local residents of possible exposure at a Mapco gas station on Browns Ferry Road in Chattanooga and a Chick-fli-A restaurant on Glenn Boulevard in Fort Payne, Alabama.
Measles is a highly contagious, viral infection that can cause serious illness in unvaccinated children. It's spread through the air when an infected person coughs, sneezes or breathes on another.
Dr. Tim Jones, state epidemiologist for the Tennessee Department of Health, told the Times Free Press last week that the threat is for those who have not been vaccinated, which most Tennesseans are.
"This appearance of measles is a reminder about the importance of vaccines in protecting our population, and we urge everyone who has not been vaccinated to do so now to protect themselves, their families, their coworkers and their communities," he said.
Tennessee's cases are part of the largest measles outbreak in the United States since the disease was eliminated in 2000. There are six known cases in Georgia and none in Alabama.
U.S. health officials on Monday said there are now more than 704 cases reported so far this year in 22 states. That number has already eclipsed the total for any full year since 1994, when 963 cases were reported.
The Centers for Disease Control and Prevention said this year's count includes 44 people who caught the disease while traveling in another country. Some of them triggered U.S. outbreaks, mostly among unvaccinated people. That includes the largest outbreaks, in Orthodox Jewish communities in and around New York City.
Three-quarters of those who caught the extremely contagious disease are children or teenagers.
No deaths have been reported but 66 patients were hospitalized.
Associated Press reporter Mike Strobbe contributed to this story.