HOW DO I?
Current Situation: December 10, 2017
Since early 2017, the San Diego County Health and Human Services Agency has been investigating a local hepatitis A outbreak. The outbreak investigation is ongoing. 567 cases and 20 deaths have been reported to date. 67% of cases were hospitalized. It has been challenging because of the long incubation period of the disease (15 to 50 days) and the difficulty experienced to contact many individuals sickened with the illness who are homeless and/or illicit drug users. To date, no common source of food, beverage, or other cause has been identified; as a result, the source of the outbreak remains undetermined. Santa Cruz County Health and Human Services Agency has also recently reported 76 hepatitis A cases, one of which was fatal.
Hepatitis A has been identified in 4 homeless individuals in Monterey County. These individuals did not travel outside of Monterey County so are assumed to have become ill due to transmission within the homeless community in Monterey County. The Health Department has confirmed the virus strain in 2 of the 4 Monterey County cases among homeless individuals is the same as the outbreak strain in California.
At this time, the Monterey County Health Department recommends that providers serving the homeless, injection drug users, incarcerated individuals, international travelers, and men who have sex with men actively seek opportunities to vaccinate their patients in these high risk groups. Individuals who work closely with homeless people and illicit drug users on a frequent and ongoing basis, such as those who work or volunteer at homeless service agencies and syringe exchange programs, as well as health care workers who provide ongoing direct medical care to these populations, should also consider vaccination against HAV at this time. This action is critical to preventing the spread of hepatitis A in these at risk and often difficult to reach populations.
Due to the high rate of false positive test results, IgM anti-HAV testing should be limited to individuals with evidence of clinical hepatitis. It should not be used as a screening tool for asymptomatic individuals.
All confirmed or suspected hepatitis A cases, including all positive laboratory tests for IgM anti-HAV antibody, must be immediately reported to the Communicable Disease Unit while the patient is still in the facility (phone 831-755-4521 or fax 831-754-6682; after hours call 831-755-5100 and ask for the Hazardous Materials Team, who will connect you with the on-call Health Officer). It may be difficult to locate the individual once he/she is released. Also, all positive IgM anti-HAV antibody tests must be sent to the Monterey County Public Health Lab for additional testing. Once a case of confirmed or suspect hepatitis A has been reported, the Health Department will make recommendations for postexposure prophylaxis as needed for close contacts, day care situations, common-source exposures, schools, hospitals and work settings.
Post-exposure Prophylaxsis (PEP) for Hepatitis A
On July 7, 2017, Grifols Therapeutics increased the recommended dosages of its product (GamaSTAN S/D) for pre- and post-exposure prophylaxis of hepatitis A virus infection. Susceptible people exposed to hepatitis A should receive a single dose of sign-antigen hepatitis vaccine or intramuscular IG (0.1 mL/kg) or both as soon as possible within 2 weeks of last exposure. The newly recommended dose for HAV post-exposure prophylaxsis (0.1 mL/kg) is 5 times greater than the previously recommended dose. The efficacy of Twinrix for PEP has not been evaluated, so it is not recommended for PEP.
HAV vaccine is preferred over IG for PEP in patients 1-40 years of age because the effectiveness of vaccine for PEP has been studies only in this age group. Data on vaccine efficacy at older ages are limited. However, other countries recommend vaccine for PEP in people >40 years of age and there is evidence that HAV vaccine is immunogenicity in older people. Therefore, the California Department of Public Health (CDPH) suggests consideration of HAV vaccine for PEP in people 41-59 years of age because it confers long-term immunity.
|Age in Years||<1||1-40||41-59||60-74||75+|
|Healthy||IG||Vaccine Preferred||Vaccine and/or IG||IG; vaccine if IG is in short supply||IG|
*Consider vaccine + IG for posisible longer-term protection. Individuals with chronic liver disease or who are immunocompromised, regardless of age, should always receive at least IG PEP because they are at increased risk of severe HAV infection or may have a decreased immune response to vaccine.