This summer, students living in Los Angeles can anticipate plenty of sunshine, outdoor movie screenings and, according to Chief Campus Health Officer Dr. Sarah Van Orman, the spread of vaccine-preventable illnesses. 

In a briefing with campus media Monday, Van Orman said while the campus’ spring outbreaks of norovirus, whooping cough, COVID-19 and influenza have subsided, L.A. is currently experiencing an outbreak of Hepatitis A and its first measles cases of the year. 

Hepatitis A — a vaccine-preventable virus that causes liver inflammation — spreads through contaminated food and drinks or close contact with an infected person. Symptoms such as vomiting, joint pain and yellowing of the skin or eyes can last for months. 

So far this year, the Centers for Disease Control and Prevention has also reported 1,168 confirmed measles cases in the United States — a number that calls into question the disease’s eradication. The CDC only recorded 85 cases in 2000, the year it declared measles “eliminated” in the US. 

There have been at least two cases of measles in L.A. County this year and 13 total confirmed cases in California so far. The virus is spreading throughout the Southwest, with over 700 reported cases in Texas and over 1,300 cases in the Mexican state of Chihuahua. 

The severely infectious disease, which Van Orman said used to be a “significant source of childhood illness,” kills one in 1,000 infected children and leaves many more with encephalitis — a condition that causes serious brain inflammation and permanent damage.

“[Some may] think, ‘One in 1,000, that’s not too high,’ but if you think about a disease that, at one point, most children were getting, those are staggering numbers,” Van Orman said.

Measles is so contagious that she considers anyone who shares a room with an infected person — even two hours after that person has left — as having been exposed, Van Orman said. The rash caused by measles, which starts at the hairline and spreads downward, doesn’t typically appear until a few days after a person is already contagious.

“At USC they might be walking into the gym, Tutor Campus Center [and] class over a couple of days before someone recognizes it’s measles,” Van Orman said. “A single measles case can literally expose thousands of people.”

Van Orman said she has never personally seen a case of measles in her three decades practicing medicine and she strongly recommends getting vaccinated.

“If we have strong vaccine programs, we can actually prevent it,” Van Orman said. “It’s a safe vaccine, it is not associated with very many side effects — much, much fewer than other vaccines we give commonly — [and] is certainly not associated with the development of autism.” 

She attributed the rise in measles cases to declining vaccination rates and the rise of vaccine misinformation over the past decade. 

“It is tragic,” Van Orman said. “In 2025 no child should die or have permanent disability from measles because this is a disease we know how to prevent.”  

For measles, 95% of a population needs to be immune to reach the herd-immunity threshold — when enough of a population are immune to a disease that its ability to spread is seriously hindered.  

In the 2023-24 school year, 16 of California’s 58 counties failed to meet that threshold among their kindergartners. In those counties, fewer than 95% of kindergartners had received two or more doses of the measles, mumps and rubella vaccine.

“We’ve done a lot of work here at USC. We’re spending the summer really updating our vaccine records,” Van Orman said. “We’re reaching out to everybody who has an [vaccine] exemption, letting them know the best thing to do is make sure you’re fully vaccinated.” 

Students who have paid the summer health fee — which is $300 — have access to all the services regularly provided during the school year. Students may also opt to pay for either one of the summer sessions individually. The first session runs from May 19 to July 5 and the second session from June 30 to August 17.