San Diego's homeless population has been hit hardest by the highly contagious hepatitis A virus.

The outbreak, which began in November, has spread after vaccination and educational programs in the city failed to reduce the infection rate. The virus attacks the liver.

The public health declaration bolsters the county Health and Human Services Agency's ability to request state assistance to fund new sanitation measures. Areas with high concentrations of homeless people will receive dozens of portable hand-washing stations. Health workers will also use bleached-spiked water for power-washing contaminated surfaces.

Dr. Wilma Wooten, the San Diego Public Health Officer who signed the declaration into law on Friday, says the sanitation precautions are modeled after similar programs in other Southern California cities - including Los Angeles.

"We know that L.A. has had no local cases of hepatitis A related to the strain that we're seeing here in San Diego," she said. "It makes sense that, if they're doing it there and they haven't had any cases, it could be beneficial here as well."

The first cases linked to the outbreak were first reported in November. As of Friday, more than 15 people in the area have died from hepatitis infections and more than 350 others have been sickened.

According to the World Health Organizationmost hepatitis A outbreaks are primarily spread when an uninfected person ingests food or water that is contaminated with the feces of an infected person. The disease is closely associated with unsafe water or food, inadequate sanitation and poor personal hygiene.

Hepatitis A infections are common among the homeless population due to the lack of access to sanitary facilities. San Diego's efforts to combat the illness began earlier this summer. Health workers promoted hand washing practices and stepped-up street cleanings - but an article published by Voice of San Diegohighlighted bureaucratic obstacles that have delayed sanitation improvements in the city.

Concerns have also been raised over the city's ability to handle the outbreak. Employees of the Service Employees International Union say the county doesn't employee enough public health professionals to meet the demand of the growing epidemic.

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