Bruce Bennett/Getty Images(CNN) - The Philadelphia Department of Health has declared a public health emergency due to a surge in Hepatitis A, Dr. Thomas A. Farley, Health Commissioner of the City, said Thursday.
Preliminary information indicates 67% of people who have been diagnosed with Hepatitis A say they have used drugs, while 26% report homelessness, according to health officials.
Southern New Jersey and suburban Pennsylvania counties around Philadelphia are also reporting higher than usual numbers of Hepatitis A among the same at-risk populations, according to the city's health department.
The Hepatitis A vaccine requires two doses given at least six months apart for long-lasting protection, according to the CDC.
Context for the crisisThe 2017 Hepatitis A epidemic in San Diego County, California, included 592 infections, primarily among the homeless and illegal drug users.