Utah’s largest hepatitis A outbreak in years has now sickened at least 75 people since the first case was discovered in May.

The state usually sees three or four cases annually. Now, at least that many cases are reported each week.

Health officials have scrambled to keep up, launching an outreach and vaccination campaign around Salt Lake County, where the majority of cases are centered. The rapid spread of the virus has occurred among the homeless population, due to poor hygiene and unsanitary conditions.

“Our greatest concern with the outbreak is that it will leap into another population, or into the general population, and the outbreak will grow exponentially,” said Nicholas Rupp, a spokesman for the Salt Lake County Health Department.

Utah is one of three national hepatitis A hot spots along with California and Michigan, according to the federal Centers for Disease Control and Prevention (CDC). Those other two states have reported more than 1,000 cases combined since last year, along with more than 800 hospitalizations and 40 deaths. In Utah, more than half the cases have required hospitalization and no one has died — but the outbreak here is also more recent.

“If we look at the examples that have occurred in other jurisdictions, we can expect this to be a long-term response,” said Jeff Eason, a viral hepatitis epidemiologist with the Utah Department of Health.

Hepatitis A is a viral disease that inflames the liver. It typically spreads when traces of infected feces get into the mouth — often via contaminated food, water or unclean hands. Symptoms can include fever, diarrhea, vomiting and jaundice, or yellowing of the skin. “Most people who are healthy recover within a few weeks,” Rupp said.

But the homeless are especially vulnerable, he said, because they frequently lack access to restrooms and sinks. They also often face underlying medical conditions or drug addictions that exacerbate symptoms and increase the likelihood of hospitalization or death.

The first outbreak-related case — which Eason said came from California — surfaced in early May. The next case didn’t arise for another month, he said, but that’s not surprising, considering the disease has a long “incubation period.”

Salt Lake County began its response in August, Rupp said, after several cases trickled in. The county had confirmed 60 cases related to the outbreak as of last week. Another 11 had been reported in Utah County. The majority of people coming down with the illness are men, and 17 people got sick while in jail, according to state Health Department data.

The Salt Lake County Health Department has deployed teams of nurses and other employees every day into areas where homeless people stay. They have done more than 3,400 vaccinations since the outbreak began. Meanwhile, they have posted flyers in public areas like libraries and sent several thousand letters to restaurant owners with cleaning and hand-washing reminders, Rupp said.

Patrick Rezac, executive director of One Voice Recovery, has helped county health workers track down some of the more isolated homeless camps to provide vaccination shots and hand wipes.

“These [people] are in survival mode,” Rezac said. ”The last thing they’re thinking about right now is washing their hands.”

On Thursday afternoon, two county health employees hovered near a sidewalk folding table that held medical forms, hepatitis A vaccinations and candy. Nearby, three more worked the crowd of homeless people gathered outside The Road Home shelter downtown.

The candy helps persuade people to come over to the table and get the vaccine, said nurse Steven Beach. Still, many require extra coaxing. Sometimes it takes several days of returning to the same spot to persuade them, Beach said, due to skepticism of vaccines or the government in general.

Demetria Thomas, 46, has been homeless on and off recently and heard about the outbreak, which concerns her. She’s also seeking housekeeping work at a nursing home, which she said often requires a hep A vaccination. So, she got her shot Thursday.

“This situation is not helping [the outbreak], being homeless,” she said. “You have nowhere to go to heal, rest. You get run-down.”

Blanca Miranda-Piñuelas, 23, also got the vaccine Thursday. She said some are skeptical — especially if they’re high — about the intent of vaccines. But she said she appreciates the Health Department seeking her out.

“A lot of homeless people are scared to ask for help,” she said.