2016 Islander of the Year in Health and Medicine: Sarah Park

Tracked down hepatitis A.

March 28, 2017

Michael Keany,

Disease fighter: Dr. Sarah Park oversees the Disease Outbreak Control Division of the state Department of Health.

Photo: Aaron Yoshino

If Hawai‘i state epidemiologist Dr. Sarah Park had her way, you’d never hear about her. “We’re always working on something, but you know, the ideal situation is that we’re just in the background, and not in the news,” she says. “Boring is good.”

In 2016, Sarah Park had a decidedly un-boring year. She and her department hit the ground running, battling the outbreak of dengue fever that had been plaguing Hawai‘i Island since the previous September. Investigators interviewed patients, identified dengue hotspots and worked to eliminate the mosquitos that spread the disease. By late April, the state Department of Health claimed a milestone—30 days since any of the 264 known infected people was contagious.

But Park scarcely had a chance to take a breather. By mid-June, the state Disease Outbreak Control Division had identified four cases of hepatitis A, a contagious, viral liver infection that lasts from a week to several months, and is spread by eating contaminated food or through personal contact.

During a normal year, Hawai‘i will see an average of 10 hepatitis A cases, total. Four cases in two weeks was not normal. “When I realized this was more than just a one-off incident, my stomach dropped,” Park says.

Four cases in two weeks was not normal. “When I realized this was more than just a one-off incident, my stomach dropped.”—Sarah Park

Soon, her 75-strong team of investigators and epidemiologists were maxed out, interviewing hepatitis A patients, running down leads.

Investigating a contagious illness outbreak is a labor- and time-intensive process. “It’s tough,” Park says. “You have these patients who are still feeling the effects of the illness, and now they’re getting asked to list everything they ate for the past few weeks.”

And there’s no guarantee that investigators would be successful at tracking down the source of the virus. Most of the time, in fact, they aren’t, and the outbreak subsides on its own. But as more and more people were hospitalized, Park and her department were under enormous pressure.

They started to see a few fuzzy correlations and overlaps in the data they were collecting, but nothing you could consider a smoking gun. After all, a lot of local people order out at Zippy’s, and shop at Costco, and eat at Genki Sushi. Narrowing that down is tricky.

The real break in the case came in early August, when Park and her team published an online survey polling the eating habits of the general public in Hawai‘i. A “case control study,” to use the technical term.

She says there were initial doubts about going online for clues, but, by that point, 168 patients had been confirmed, 48 of them hospitalized, and Park needed to try something new. “We’ve got all this attention from the media,” she reasoned. “Why not make the most of it?” Over the next week, almost 6,000 people filled out the Survey Monkey questionnaire, enough to establish a rough baseline for comparison. One thing popped out almost immediately: Patients who contracted hepatitis A had eaten at Genki Sushi way more often than the general public: 70 percent compared with just 25 percent.

And then, astonishingly, when U.S. Food and Drug Administration labs tested the dishes at Genki, they actually found the virus. “When we got the call from the lab that the samples tested positive for hepatitis A, I had to double-check,” Park says. “You’re not pulling my leg, right?”

Finally, the culprit they had been looking for. Genki Sushi acted immediately, closing its O‘ahu and Kaua‘i locations for three weeks to fully cooperate with the state DOH and the FDA, and 800 cases of frozen raw bay scallops from Sea Port Products in Washington state were recalled. Because of hepatitis A’s long incubation period (15 to 50 days) Park and her team remained on high alert, but, by mid-October, the outbreak was effectively over.

Park’s investigation cracked the case, but she also credits the high rate of new hepatitis A vaccinations for slowing the outbreak. (By the way, if you got vaccinated in 2016, make sure you’ve gone back for your second shot.)