AILSA CHANG, HOST:
Health officials in Los Angeles County have declared an outbreak of hepatitis A. The number of cases tripled from 2023 to 2024, and as NPR's Will Stone reports, there are some concerning trends.
WILL STONE, BYLINE: Hepatitis A is a viral infection of the liver, often spread through person-to-person contact or contaminated food and water due to poor hygiene and sanitation. People shed the virus in their stool and inadvertently pass it on if they don't wash their hands.
SHARON BALTER: Often seen in travelers, in people who are experiencing homelessness or people who are substance abusers.
STONE: That's Dr. Sharon Balter at the LA County Department of Public Health. She says, altogether, there have been 165 cases reported since the start of last year.
BALTER: When the outbreak started, we were mostly seeing it in people who had those risk factors.
STONE: And the infections tended to be geographically concentrated, many of them in downtown LA. But that's changed recently.
BALTER: We're seeing less of that and more of it in places where we're not entirely sure where people got the virus.
STONE: And they're finding it in people with no obvious risk factors. Because it has a long incubation period, Balter says it can be tricky to track chains of transmission. The symptoms can include fever, tiredness, stomach pain, nausea, vomiting and jaundice. Dr. Timothy Brewer at UCLA says, generally in the U.S., which has good sanitation systems and public water supplies, the chance of catching hepatitis A is low. The CDC estimates there were about 3,300 infections nationwide during 2023.
TIMOTHY BREWER: Most people have self-limited disease, so you can feel pretty miserable for several months. But pretty much everybody gets better.
STONE: In rare instances, though, the illness can be fatal, in particular for the elderly, those who are immunocompromised or already have liver disease. And seven people have died during the LA outbreak. While it's not clear what's behind these new cases...
BREWER: If I had to guess, it's more likely due to a contaminated food source than contaminated surfaces.
STONE: Brewer says the good news here is that a vaccine exists.
BREWER: With about 100% effectiveness and essentially gives you lifelong immunity.
STONE: It didn't become standard of care till about 25 years ago, so many adults have never been vaccinated, which is why LA health officials are recommending people consider getting the shots, especially if they're at high risk.
Will Stone, NPR News.
(SOUNDBITE OF APHEX TWIN'S "AVRIL 14TH") Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.