Updated

Almost 200 people could have reportedly been exposed to measles after a child with the disease was treated in the emergency room at the University of California, Davis, (UC Davis) Children’s Hospital last month.

The hospital sent letters to the patients on March 25 and 26 after the 7-year-old girl was diagnosed with measles a few days before, USA Today reported. The girl, from Calaveras County, had not been vaccinated against the disease, according to The Sacramento Bee.

“You will need to notify your primary health care provider(s) and your child’s provider(s) of this possible exposure to discuss your possible risk of infection, vaccination history, and other questions you may have,” the letter warned.

MASSACHUSETTS WARNS OF POSSIBLE MEASLES EXPOSURE AFTER CONFIRMED CASE OUTSIDE BOSTON 

Calaveras County Health Officer Dean Kelaita told The Bee the girl was believed to be infected while on an overseas trip. On her way back, she reportedly traveled through San Francisco International Airport.

There have been no other cases of the measles in Calaveras County, The Bee reported.

“The patient came to the emergency department on March 17 and the patient was suspected of having measles on March 19,” Dr. Dean Blumberg, chief of pediatric infectious diseases at UC Davis, told NBC. “At that time, the patient was placed in appropriate isolation.”

MEASLES COUNT IN US THIS YEAR ALREADY MORE THAN ALL OF 2018

Blumberg also told CBS Sacramento that a 7-year-old terminally ill boy had been examined in the same room as the girl with measles before the girl was diagnosed and the room was closed for cleaning.

Blumberg added that the boy did not have measles 16 days after he was exposed to the disease, which he said typically takes from 8 to 12 days to develop.

“Even vaccinated individuals can get measles because the vaccine is not 100 percent perfect,” Blumberg told NBC. “We need a very high vaccination rate because when measles is introduced to communities that have parents who don’t immunize their children, these clusters of cases can occur.”

According to the Centers for Disease Control and Prevention (CDC), there have been 387 individual cases of the measles in the United States in 2019 so far, which the organization said is the second-highest number of cases in the U.S. since the disease was eliminated in 2000.