An outbreak of hepatitis A has infected at least 461 people and killed 17 in San Diego County since last November, largely affecting the homeless and illicit drug-using population. The city has been making efforts to stop the spread of the disease, which was first detected in the county in early March and later declared a local public health emergency on Sept. 1.

Hepatitis A is a virus that causes inflammation of the liver. Though it is not normally fatal, it can be if the infected have other diseases, including hepatitis B or C. According to the Centers for Disease Control and Prevention (CDC), “Hepatitis A is usually spread when a person ingests fecal matter—even in microscopic amounts—from contact with objects, food or drinks contaminated by feces or stool from an infected person.”

The county health department reported that most of those infected are either homeless or illicit drug users, and a large portion of the sickened population falls into both categories. Homeless people often do not have access to public bathrooms and instead have to defecate outside, thus contributing to the spread of the disease. Recreational drug users, especially those who use intravenous drugs, are at risk of contracting hepatitis A through exposure to drugs contaminated with fecal matter from an infected person.

A city-contracted crew started spraying and pressure-washing downtown sidewalks with a diluted sodium hypochlorite, or bleach, solution on Sept. 11 and have since expanded those efforts to include other regions of San Diego. The procedure, set to be repeated every two weeks, is executed in two phases. Contractors first spray down hazardous substances, such as human waste or needles, with a solution of one part bleach to nine parts water. They remove the contaminated items 10 minutes later and respray the area with another solution made by further diluting the first bleach solution with water in a one-to-nine ratio. The crew then ends the procedure by power washing the area with water.

The city has also been installing portable restrooms and hand-washing stations downtown as well as administering vaccinations. Over 42,000 people have been vaccinated as of Sept. 23.

The county has long been battling homelessness, and the outbreak of hepatitis A has incited a ramp up of efforts. San Diego police have been clearing large homeless encampments that, if exposed, could facilitate the spread of the virus.

City workers have been removing roughly three tons of trash and other debris from sidewalks each week. A court order has mandated a 72-hour notice of the cleanup operation to give the approximately 1,000 homeless downtown residents time to pack up their belongings and make way for the cleanup crews.

Some locals, such as Jesi Quinn, find fault with the city’s approach to the issue.

“They are throwing [people’s tents] into this dump truck, and when people come back to their essential “home” that they have, it’s gone,” Quinn said. “I think that it’s their idea of cleaning up the streets of San Diego, which I think is a lazy way of doing it. A lot of the homeless I have encountered either have mental health issues or substance abuse issues or both. I think that [with] the money they already use to summon out the dump trucks, they should use that money to put [the homeless] into a treatment facility or some place where they can go—a shelter with resources so people have places to go–so that they don’t have to be on the street.”

Some homeless advocates say that the homeless run the risk of losing their belongings during the clean-ups even with a settlement that orders that the city keep possessions of value for them until they can retrieve them.

The last time San Diego experienced an outbreak of this scale was in 1996, where the number of cases in the region rose to 645.