(NBC) -- A developing story; first mumps, now a measles outbreak hits the United States.
Doctors say they are seeing more cases today, than they've seen in decades.
It's a standard question for Dr. Nadia Qureshi.
The Loyola pediatrician says the two dose MMR vaccine has never been more important.
The CDC said a decade ago measles had essentially been eradicated.
Now 15 states report cases, and seven say they've had outright measles outbreaks.
Experts say more parents are opting out of vaccines and international travel has skyrocketed.
Dr. Qureshi had her infant twins vaccinated before a trip to Pakistan.
So all parents can do is wait it out, but the disease does have one tell tale sign
The irony is that so few us doctors have seen an actual case of measles, experts say they may not immediately know what they're looking at.
Which means those infected may not get immediate quarantine.
But for concerned parents, doctors say the answer is simple.
Initial symptoms include cough, fever, runny nose, watery eyes and feeling run-down.
Tiny white spots may appear in the patient's mouth after a few days and a rash may break out on their face that runs down the body.
Patients may also experience an extremely high fever.