San Diego California has turned to pressure washing its “fecally contaminated” downtown with bleach-spiked water every other week and installing dozens of hand washing stations to try to curb an aggressive outbreak of hepatitis A infections, the Associated Press reports.

So far, 398 cases have been reported and confirmed in the outbreak, which began in November. Of those infected, 279 were hospitalized and 15 people died. The city’s homeless community has been particularly hard hit by the outbreak.

Earlier this month, the San Diego Board of Supervisors declared a state of emergency.

Hepatitis A is caused by the highly contagious hepatitis A virus, which infects the liver and can lead to death in some cases. The virus easily spreads through contaminated foods, water and objects, as well as person-to-person contact, fecal matter, bodily fluids, and sex.

Health authorities in San Diego have ruled out contaminated food, beverages, and drugs as the source of the outbreak. Instead, they believe the primary drivers of the outbreak are person-to-person contact and “contact with a fecally contaminated environment.”

San Diego’s mayor Kevin Faulconer is now moving forward with a plan to have crews use a bleach and chlorine-solution to pressure wash streets and outdoor surfaces that may be contaminated with feces, bodily fluids, or blood. The sanitary washes started this week and will occur every other week.

Authorities have installed 40 hand-washing stations in areas where homeless people gather. According to the mayor, the county will install more stations next week. Authorities have also expanded access to restrooms and provided vaccinations to 19,000 people.

Craig Gustafson, senior director of communications for Faulconer, told the San Diego Union-Tribune: “We’re taking swift action to eradicate this virus from our streets and keep our most vulnerable residents safe.”