Essential Information on the Hepatitis A Outbreak in LA County

Los Angeles County public health officials have reported an outbreak of hepatitis A. This highly contagious liver infection is caused by a virus that can, in rare instances, lead to serious illness.

Typically, there are fewer than 50 cases annually in LA County, but at least 138 individuals were infected in 2024, with cases continuing to rise significantly in 2025. These numbers are incomplete.

Here’s what you should know.

How is hepatitis A transmitted?

The hepatitis A virus is spread via the oral-fecal route, meaning it can be ingested through food and beverages contaminated with microscopic stool from infected individuals. The virus can also be transmitted through close contact with someone harboring it, even if they show no symptoms.

Certain individuals face a higher risk of contracting hepatitis A due to inadequate access to clean toilets and handwashing facilities. It is more prevalent among travelers, in settings with poor hygiene, among men who have sex with men, and among drug users.

Officials note that many recent cases have appeared in individuals lacking these risk factors. The reasons remain unclear, but Dr. Timothy Brewer, an infectious disease specialist and epidemiologist at UCLA, is increasingly concerned about two issues: food contamination and community transmission.

“In a community with good hygiene and access to drinking water, we shouldn’t see high numbers of infections,” he remarked. “Something is happening, but we aren’t sure what it is.”

What are the symptoms of hepatitis A infection?

Initial symptoms include fever, fatigue, nausea, and loss of appetite, followed by vomiting and diarrhea. Infected individuals may subsequently develop jaundice, dark urine, and pale stools.

One significant challenge in controlling the spread of hepatitis A is that contact tracing can be quite challenging. The virus can incubate for up to seven weeks before symptoms appear, and carriers can transmit it for up to two weeks before they feel ill.

Moreover, many infected individuals do not exhibit severe symptoms, according to Dr. Edward Jones Lopez, an infectious disease specialist at Keck Medicine at the University of Southern California, which means they might not seek medical evaluation, undergo blood tests, or report their cases.

Severe symptoms are predominantly observed in the elderly, those with chronic liver diseases, and individuals with compromised immune systems or HIV. While fatalities from hepatitis A are rare, at least seven deaths have been linked to the outbreak. Officials suspect that the true number of infections is significantly higher than reported, as many individuals likely remain asymptomatic or have mild symptoms that go unrecognized.

What is the treatment for hepatitis A?

There are no specific antiviral treatments for hepatitis A, as the infection typically resolves on its own within weeks without causing permanent liver damage. However, hospitalization might be necessary for some patients.

In rare instances, hepatitis A can lead to acute liver failure, known as fulminant hepatitis, which may necessitate a transplant, stated Dr. Jones Lopez. “It can escalate rapidly. It’s a serious condition.”

If you believe you may be infected, consult your doctor, stay hydrated, and rest adequately.

How can I prevent it?

Vaccination is the most effective way to prevent hepatitis A. The vaccination schedule consists of two doses given at least six months apart, which provides substantial protection. While children have routinely received this vaccine for the past two decades, many adults over the age of 25 do not get vaccinated unless they belong to a high-risk group.

“Infection can occur anywhere,” warns Dr. Anne Limoyne, a professor of epidemiology at UCLA.

If you have been exposed to someone with the virus but haven’t been vaccinated, a prompt vaccination can prevent infection. Experts suggest that individuals with compromised immune systems may also benefit from receiving immunoglobulins. Practicing good hygiene, such as thorough handwashing with soap and water after using the restroom and before preparing food, is essential for everyone.