• Los Angeles County declared a Hepatitis A outbreak due to a significant rise in cases and elevated virus levels in local wastewater.
• In 2024, the county reported a tripling of Hepatitis A cases compared to 2023, with a concerning number of cases in 2025 among individuals without traditional risk factors.
• Health officials are urging all residents to get vaccinated against Hepatitis A, emphasizing it is safe and effective, and highlighting the importance of preventative measures like regular handwashing.

Los Angeles County is grappling with a community-wide Hepatitis A outbreak, characterized by a surge in cases and elevated virus concentrations in wastewater. This outbreak, declared by the Los Angeles County Department of Public Health, is raising concerns as the number of infections significantly increased in 2024 compared to the previous year, and early 2025 data suggests a continued upward trend. The situation is further complicated by the emergence of cases among individuals without typical risk factors, prompting health officials to emphasize the importance of vaccination and preventative measures for all residents.

• What: A community-wide outbreak of Hepatitis A has been declared in Los Angeles County, characterized by increased cases and elevated virus levels in wastewater.
• Who: The Los Angeles County Department of Public Health, Dr. Muntu Davis (Los Angeles County Health Officer), Dr. Sharon Balter (Director of Communicable Disease Control and Prevention), Dr. Prabhu Gounder (medical director of the L.A. County Department of Public Health’s viral hepatitis unit), Los Angeles County residents, healthcare providers, and organizations serving the homeless.
• When: The outbreak was declared in May 2025, following a tripling of cases in 2024 compared to 2023. The current increase started 13 months prior to May 2025. The incubation period for Hepatitis A is seven weeks.
• Where: Los Angeles County, with cases also confirmed in Orange and San Bernardino counties.

The Hepatitis A outbreak in Los Angeles County presents a significant public health challenge. The surge in cases, particularly among individuals without traditional risk factors, highlights the need for widespread vaccination efforts and heightened awareness. Wastewater surveillance provides valuable insights into the true scope of the outbreak, as many infections may go undiagnosed. Federal budget cutbacks pose a threat to the county's ability to effectively track and respond to the outbreak. The genetic analysis tracing the strain to LA County underscores the importance of local prevention and control measures.

The ongoing increase in hepatitis A cases signals that quick action is needed to protect public health. The hepatitis A vaccine is safe, effective, and offers long-term protection.

We definitely think that the outbreak is bigger than the numbers imply.

Los Angeles County is actively combating a Hepatitis A outbreak through increased monitoring, vaccination campaigns, and public awareness initiatives. The rising number of cases, coupled with the detection of the virus in wastewater, underscores the urgency of the situation. While vaccination is the most effective preventive measure, challenges remain in reaching all segments of the population and ensuring adequate resources for public health programs. The county is urging all residents to get vaccinated and practice good hygiene to curb the spread of the disease. The situation remains dynamic, with ongoing investigations and monitoring of the outbreak's progression.