California State University, Los Angeles, says 656 students and staffers possibly exposed to measles are under quarantine.

The number is up sharply Friday from the initial report of 198 employees and students told to stay at home earlier in the week.

The Los Angeles County Department of Public Health says the number of confirmed cases among county residents remains at five.

While the quarantine at Cal State LA has grown, the number of staff members and students quarantined across town at University of California, Los Angeles, has dropped sharply to fewer than 50.

Officials told students and employees stay home and avoid contact with others after determining that infected students were on each campus earlier this month.

UCLA was notified Monday that a student with a confirmed case of measles had been on campus this month. Initially, more than 500 students, staff and faculty were notified they may have been exposed.

Most were cleared, and public health officials quarantined 127 people Wednesday. That number was rapidly reduced as people established proof of immunity.

The orders come as a small outbreak of measles is occurring in Los Angeles County involving five confirmed cases linked to overseas travel.

Just the day before it was announced that U.S. measles cases have climbed to their highest level in 25 years, largely because misinformation is turning parents against vaccines.

New York City health officials on Wednesday reported 61 new cases since late last week. According to an Associated Press count, that pushes this year's national tally past the 667 cases reported for all of 2014. It makes it the worst year for measles since 1994.

The Centers for Disease Control and Prevention updates its national measles count on Mondays. CDC officials on Wednesday said they are reviewing and validating the latest reports.

Roughly three-quarters of this year's illnesses have been in New York, mainly in New York City and nearby Rockland County. Most of those cases have been in unvaccinated people in Orthodox Jewish communities.

The CDC recommends the vaccine for every American over 1 year old.

Twenty-two states, including Nevada, have reported cases, but the vast majority have been in New York - mainly in New York City and in nearby Rockland County. Most of the New York cases have been unvaccinated people in Orthodox Jewish communities.

No fatalities have been reported in the United States from measles this year.

The CDC says states that have reported cases are Arizona, California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Maryland, Massachusetts, Michigan, Missouri, Nevada (Clark County), New Hampshire, New Jersey, New York, Oregon, Tennessee, Texas, and Washington.

The CDC says, in the U.S., the disease killed hundreds of people and hospitalized 48,000 each year, before the first measles vaccine became available in 1963.

Meanwhile, hundreds of opponents of mandatory vaccines are in Sacramento to oppose a California proposal to give state public health officials instead of local doctors the power to decide which children can skip their shots before attending school. Opponents say the measure removes parental rights.

Critics are unlikely to derail the bill, since Sacramento pediatrician Richard Pan is chairman of the health committee considering his legislation Wednesday.

Supporters say unvaccinated students are helping to spread measles outbreaks in California and elsewhere.

Opponents also plan a rally to denounce what they term the "measles frenzy."

(The Associated Press contributed to this report.)