"California is now experiencing the largest person-to-person hepatitis A virus outbreak in the United States since the hepatitis A vaccine became available 22 years ago", the governor said in his proclamation.
On Friday afternoon, California Governor Jerry Brown declared a state of emergency regarding a hepatitis A outbreak that has thus far killed at least 18 people in the state.
Vaccines from a federal immunization program have been distributed to homeless people, drug users and other at-risk populations, but more vaccine is needed, according to the governor's proclamation. The state can now purchase vaccines directly from manufacturers and distribute them.
The adult hepatitis A vaccine is different than the one given to children, of which there is ample supply. The Los Angeles County Department of Public Health declared a local outbreak of hepatitis A in September.
The San Diego Board of Supervisors voted Tuesday to extend the county's emergency health declaration over the outbreak, which will need to be reviewed and voted on every 14 days.
This is the largest outbreak of hepatitis A since a vaccine became available over two decades ago. California's outbreak, however, has largely been spread person-to-person, primarily within the state's homeless population.
The virus is also transmitted through contact with feces, so unsanitary conditions make it more likely to spread.
Hepatitis A infection typically causes fever, a general ill feeling with lack of appetite and nausea, and, later in the course of the infection, yellowness of the skin and eyes. Severe hepatitis A infection is rare but does occur in people with underlying liver disease and can cause the liver to fail, potentially leading to death.