Health officials in Los Angeles County have announced a hepatitis A outbreak, which is known to be a highly contagious liver infection caused by a virus that can occasionally lead to serious health issues.
Typically, fewer than 50 cases are reported in L.A. County each year. However, in 2024, at least 138 individuals contracted the virus, and the numbers have continued to be unusually elevated in 2025. Authorities believe the actual figures might be even higher, as levels of the virus detected in local wastewater indicate an underreporting.
Here’s what you should know.
Transmission of Hepatitis A
The hepatitis A virus spreads through the oral-fecal route, meaning it can be ingested through food or drinks contaminated with tiny amounts of stool from an infected person. It can also be transmitted through close contact with someone who has the virus, even if they aren’t displaying any symptoms.
Those without stable housing are often at a higher risk of hepatitis A due to limited access to sanitation facilities like proper bathrooms and handwashing stations. The virus is also more frequently found among travelers to areas with poor sanitation, men who have sex with men, and drug users.
Interestingly, many recent cases have emerged in individuals without these known risk factors, although the reasons behind this remain unclear. Dr. Timothy Brewer, an infectious disease expert at U.C.L.A., expressed concerns about potential food contamination and the possibility of the virus circulating in the community.
“If good hygiene practices are followed in an area with access to clean water, we shouldn’t see such high numbers,” he mentioned. “Obviously, something unusual is happening, but we haven’t pinpointed what it is yet.”
