San Francisco Marin Medical Society Blog

HEALTH ADVISORY: Hepatitis A Outbreaks in California; Prevention Recommendations for San Francisco Providers

SITUATION: Two California counties are reporting outbreaks of hepatitis A virus (HAV) among individuals who are homeless and/or using illicit drugs. As of August 29, San Diego County has identified 378 cases and 15 deaths since November 2016; Santa Cruz County has reported 62 cases since April 2017. Related cases have been identified in other California counties, as well as in Arizona and Utah. To date, no related cases have been identified in San Francisco; this presents an opportunity to prevent an outbreak locally.

HAV is a highly infectious enteric virus that is transmitted person-to-person and via contaminated food, water, or surfaces. Persons in San Francisco are considered to be at risk of HAV infection at this time if they are (a) homeless or (b) using or may be using illicit drugs of any type (injection or non-injection), and if they are not already immune by means of completed vaccination (2 doses of monovalent HAV vaccine or 3 doses of combined hepatitis A/B vaccine) or serology (total hepatitis A antibody positive).


1.      Routinely identify and immediately vaccinate your non-HAV-immune patients who are homeless or who are, or may be, using illicit drugs. Serologic testing for HAV immunity is NOT recommended as screening before vaccination; instead, vaccinate those for whom you lack a record of serologic immunity or completed immunization. Use either monovalent HAV vaccine or combined hepatitis A/B vaccine. The first dose of monovalent HAV vaccine appears to provide fuller protection than the first dose of combined hepatitis A/B vaccine, and is preferred for outbreak prevention if follow up is uncertain.

2.      Suspect acute hepatitis A in homeless and/or drug-using individuals who present with consistent symptoms (abdominal pain, nausea, vomiting, fever, jaundice and significant elevation in LFTs). Confirm via serum hepatitis A IgM testing.

3.      Report cases of symptomatic, lab-confirmed hepatitis A infection by phone to SFDPH Communicable Disease Control Unit at (415) 554-2830. After hours, follow instructions to contact the On Call Physician. Prompt reporting may allow patient interviews to be conducted while the patient is still at the treatment facility so individuals are not lost to follow up.

Health care workers who may have contact with suspected hepatitis A cases, and who lack HAV immunity or vaccination, should consider obtaining HAV immunization through their employer or health plan.

Post-exposure prophylaxis with HAV vaccine (or in some cases, IM immune globulin) is effective in non-HAV-immune persons who have been exposed to HAV in the prior 2 weeks.



SFDPH: Hepatitis A Information – HAV Drop-In Vaccination Locations in SF –

CDPH: HAV Information for Health Professionals –

CDC: 2017 Adult Immunization Schedule – Hepatitis A Q&A for Health Professionals –

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