•  Orange County providers should offer HAV vaccine to persons who are homeless or might be using illicit injection or noninjection drugs. Any person one year or older with either of these risk factors should receive two doses of HAV vaccine separated by 6 months. The first dose should protect most healthy persons. OCHCA is conducting outreach to offer HAV vaccination to these populations throughout the County.

• CDPH recommends considering HAV vaccination for persons working with the homeless in counties such as San Diego that have active local outbreaks. Orange County does not have local HAV spread; persons working with the homeless in Orange County are currently at minimal risk.

• Providers should report any suspect or confirmed HAV-infected patients promptly to Orange County Public Health Epidemiology by phone at 714-834-8180 or by fax at 714-564-4050.

• Consider HAV infection in persons with signs and/or symptoms of hepatitis, particularly in those who report a history of homelessness and/or illicit drug use. HAV infection signs and symptoms include jaundice, dark urine, fever, malaise, anorexia, nausea, diarrhea, and abdominal discomfort, and increased transaminases (AST/ALT). The incubation period for HAV infection ranges from 15–50 days.

• Providers should contact OCHCA immediately with any homeless persons who are suspected to have hepatitis A. Follow up on potentially exposed persons should begin immediately, prior to the patient’s clinical discharge.

• Send serum for HAV IgM testing for all suspect hepatitis A patients.

• All patients with confirmed HAV infection should have serum forwarded to OCHCA laboratory to arrange for genotypic testing. The current statewide outbreak has been caused by genotype 1B. Genotyping testing enhances public health surveillance and allows identification of cases that are related to the statewide outbreak.

• HAV vaccination continues to be recommended for all children at one year of age, as well as persons with high risk conditions or behaviors including: 
• Persons with chronic liver disease, including those with hepatitis B or C virus (HBV or HCV) infection
• Users of injection and noninjection illicit drugs
• Men who have sex with men
• Persons traveling to or working in countries that have high or intermediate levels of HAV transmission
• Persons who have been exposed to HAV in the prior 2 weeks and are not known to be immune (immune globulin is an alternative to vaccine or given in addition to vaccine in some instances).

• The first dose of single-antigen HAV vaccine appears to provide protection to more people than the first dose of the combined HAV/HBV (Twinrix®) vaccine. This apparent advantage disappears when the respective series are completed. The California Department of Public Health recommends that providers consider the short-term risks of exposure to HAV, the likelihood of follow-up to complete multidose immunization and the need for protection from HBV when selecting vaccines for those at risk. Immunization against HAV with existing supplies should not be delayed to obtain a different formulation of vaccine.