Los Angeles County health officials have declared a community-wide hepatitis A outbreak following a dramatic surge in cases that has already claimed seven lives, with wastewater surveillance data indicating the virus is circulating more widely than individual case counts suggest, prompting calls for widespread vaccination among adults who may lack immunity.
The Los Angeles County Department of Public Health confirmed 165 hepatitis A cases since 2024, more than triple the number reported in 2023, with 29 cases already confirmed in the first three months of 2025—a concerning acceleration compared to the 14 cases reported during the same period last year.
Wastewater Data Reveals Greater Community Spread
Public health officials made the outbreak declaration after elevated levels of the hepatitis A virus were detected in county wastewater systems, indicating transmission extends beyond diagnosed cases. “In the first three months of 2025, we’ve had 29 cases of Hep A. This compares to 14 cases in the first three months of 2024,” explained Dr. Sharon Balter, Director of Communicable Disease Control and Prevention for the L.A. County Department of Public Health, as reported by ABC7 Los Angeles.
The county began monitoring wastewater for hepatitis A in September 2023, collecting samples from two major treatment plants that process sewage from approximately 75% of L.A. County residents. This surveillance method has become an increasingly valuable tool for detecting community-wide disease spread since the COVID-19 pandemic…