Context:

Los Angeles County is experiencing a significant outbreak of hepatitis A, a highly contagious liver infection that has led to at least seven deaths. The infection, usually rare in the area, has seen a surge with at least 138 cases in 2024 and continued high numbers in 2025, likely underreported due to unrecognized symptoms. The virus spreads via the oral-fecal route and close contact, often affecting unhoused individuals, travelers to areas with poor sanitation, and certain other groups, though recent cases involve individuals outside these traditional risk categories. Symptoms can resemble a stomach bug initially, but severe cases can lead to liver failure, emphasizing the importance of vaccination and proper hygiene as preventive measures. Health officials are concerned about unknown factors contributing to the outbreak, highlighting the need for reassessment of prevention strategies and increased public awareness.

Dive Deeper:

• Hepatitis A in Los Angeles County has surpassed typical infection rates, with 138 cases reported in 2024 and high numbers continuing into 2025, suggesting underreporting due to asymptomatic cases or mild symptoms.

• The virus is primarily transmitted through the oral-fecal route, involving ingestion of contaminated food or drinks, and can also spread through close contact with infected individuals, even when they are asymptomatic.

• While traditionally affecting unhoused people, travelers, certain sexual practices, and drug use, the current outbreak includes cases in populations without these risk factors, raising concerns about food contamination and community spread.

• Symptoms of hepatitis A start with fever, fatigue, nausea, and appetite loss, progressing to jaundice, dark urine, and pale stools; severe cases can result in acute liver failure, requiring hospitalization or transplantation.

• Vaccination remains the most effective prevention method, consisting of two doses six months apart, and has been part of children's routine immunization, though many adults over 25 may not have received it unless at high risk.

• The outbreak's unusual spread underscores the need to reassess prevention efforts, with experts advocating for increased vaccination coverage and improved hygiene practices to curb transmission.

• Health officials emphasize the importance of recognizing potential exposure to the virus and recommend prompt vaccination and immune globulin for those at high risk, along with maintaining good hygiene practices.