San Diego County officials are banking on a four-week run with no new confirmed cases as a signal that a deadly hepatitis A outbreak is coming to an end. The county board voted unanimously Tuesday to end the emergency status that has been in place since Sept. 1.

Public health officials updated the San Diego County Board of Supervisors at the board’s weekly meeting Tuesday. They reported only four cases of hepatitis A remain under investigation and no new cases have been confirmed for four weeks.

Through Jan. 17, public health officials confirmed 577 cases of hepatitis A infection in the county. Twenty of the sick people died. Of the outbreak victims, 395 had symptoms so sever they required hospitalization.

The county spent about $9.6 million responding to the outbreak between April and December 2017. The bulk of that went toward a vaccination program that treated almost 120,000 people and the installation of 160 hand-washing stations and 13 portable toilets.

Most of the outbreak victims in San Diego County — as well as the rest of California and several other states where hundreds of cases have been confirmed — have been homeless or substance abusers, or both. However, depending on the locality, between 20 percent and 30 percent of the victims have been neither homeless nor substance abusers.

California’s Department of Public Health (CDPH) has been tracking the outbreak, posting infection numbers from the hardest hit areas. As of Jan. 12, the date of the most recent numbers available from the state, 688 people have been confirmed with the outbreak strain of the hepatitis A virus. Of those, 21 have died and 449 have required hospitalization.

For several months, state health officials have been describing the outbreak as the largest person-to-person hepatitis A outbreak in the United States since the hepatitis A vaccine became available in 1996.

However, increasingly municipalities in the main outbreak states of Michigan, Nevada, Utah and Kentucky have been confirming cases among restaurant workers.

Those infected foodservice employees have spurred tens of thousands of people across the country to seek post-exposure treatment to avoid infection. In many cases, the infected workers were not confirmed as hepatitis A cases soon enough for restaurant patrons to seek the post-exposure vaccine, which is only effective if given within two weeks of exposure.

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