A serious hepatitis A outbreak started in San Diego, which has had a surge in its unsheltered homeless population. It has now spread to Los Angeles.

A deadly hepatitis A outbreak in Southern California has now spread to Los Angeles despite health officials’ efforts to curb infections.

The outbreak has infected at least 454 people and left 16 dead.

It’s been particularly devastating in the homeless population, which has been on the rise amid a statewide housing crisis.

In Los Angeles, health officials announced the spread of a hepatitis A outbreak after 10 people were confirmed to have had the virus as of Wednesday.

They made the announcement just one day after cases in nearby San Diego County hit a new high of 444.

Health officials in San Diego reported that the outbreak started last November and has been concentrated in the homeless population which lacks access to clean restroom facilities.

The outbreak comes as concerns about homelessness and rising housing costs in California have made headlines.

Currently multiple bills have either passed, or are making their way through the state Legislature, to address the state’s lack of affordable housing.

Housing prices are so high that a recent poll found 56 percent of registered California voters have considered moving due to housing costs.

Dr. Wilma Wooten, MPH and the public health officer and director of public health services in San Diego County, said since the outbreak is concentrated in the homeless population, those infected are more vulnerable to complications.

“It’s in a population that is very transient and does not have healthcare and does not have a place to live and live in an unclean environment,” she told Healthline.

In this outbreak, nearly 70 percent of those diagnosed have ended up in the hospital.

Wooten said 25 percent of those diagnosed with hepatitis A in this outbreak also had hepatitis B or C as well.

Almost all of those who died from the disease also had underlying illnesses.

To fight the outbreak, county health teams have vaccinated more than 19,000 county residents, including more than 7,000 in the at-risk population.

Health officials are also working with homeless outreach centers to educate the public and those at high risk of infections.

They’re also educating businesses on how to properly disinfect restrooms.

Epidemiologists from the U.S. Centers for Disease Control and Prevention (CDC) flew to San Diego to help local health officials fight back against the outbreak as well as to test samples.

Officials are setting up hygiene stations. Pop-up shelters are also expected to be erected so that people can have better access to shelter and restrooms.

However, the cases are still increasing.

In general, Wooten said, hepatitis A cases have vastly diminished since the vaccine that’s been given to children since 1995. The number of cases nationwide dropped from more than 200,000 a year, to around 2,000.

Many of these infections were confined to isolated foodborne outbreaks, where someone preparing a meal infected a large number of people.

This outbreak is different since it has been spread from person to person.

“This outbreak is an outbreak of unprecedented proportions,” Wooten said.

Hepatitis A is a viral infection that leads to inflammation of the liver. This type of viral hepatitis isn’t just spread through sexual contact or intravenous drug use, but often is related to poor hygiene.

The virus is transmitted through the “fecal-oral” route, often when food or drink has been contaminated — even on a microscopic level — with feces from an infected person.

In San Diego, a lack of access to public restrooms may have exacerbated this type of outbreak.

The city has repeatedly been warned they don’t have enough public restrooms, according to a report in The San Diego Union-Tribune. A grand jury that operates as a civil watchdog panel had warned city officials four different times that there weren’t enough restrooms in the city and that human waste could lead to an outbreak, according to the report.

A person infected with hepatitis A usually doesn’t develop a chronic infection unlike other forms of viral hepatitis. However, the liver infection can last for months or even cause death in rare cases.

Complications are more likely if a person has underlying health conditions or another form of hepatitis.

Public health experts point out that this outbreak has occurred in a state with some of the highest housing prices nationwide, as well as amid rising rates of homelessness.

“Homelessness was a crisis already in San Diego and this situation is now occurring on top of that,” Wooten said.

Homelessness in San Diego has been rising, up 5 percent since 2016. The population of unsheltered homeless people has risen even more quickly with a 14 percent bump in that population this year.

Even before the outbreak made headlines, the San Diego mayor had declared a “state of emergency on homelessness” over the past two years so that the city could turn public buildings into shelters.

There are an estimated 9,116 homeless people in San Diego County alone, according to a point-in-time count from January.

Amy Gonyeau, chief operating officer of the homeless outreach program Alpha Project, said the true number is likely far higher.

“In my opinion it’s double that,” Gonyeau said of the tally from the federally mandated count. “That’s a four-hour count once a year.”

Gonyeau said San Diego has the fourth highest rate of homelessness in the nation. She said housing isn’t only expensive in the city, but in short supply with a 2 percent vacancy rate at any given time.

“Our rents are not affordable, it’s hard for my staff to rent a place,” she told Healthline. “The average rent is almost $2,000 (per month).”

In San Diego, she said, high rents have left many people on the verge of homelessness and in danger of being evicted. She said they get calls every day from people asking for help to stay in their homes, but that there just isn’t enough affordable housing.

“We used to have a lot of single room occupancy housing. They’ve torn down 10,000 of those units and it never got rebuilt,” she said.

Gonyeau said that the people they work with who either live on the street or in a shelter were mostly unaware of the outbreak.

“They’re fearful of it and they understand they are the most vulnerable population,” she said of their reaction.

The housing crisis isn’t just a problem in San Diego. It’s become an issue statewide.

A 2015 Legislative Analyst’s Office report found that home prices in California were two-and-a-half times the average national home price and rent is 50 percent higher than the rest of the country.

“All cities in our state need to create housing if we are going to meaningfully address California’s housing shortage,” said State Senator Scott Wiener. “We need to be producing 180,000 units of housing a year in California, but we are producing less than half that, which is inflicting real damage. Our housing shortage is harming our environment, economy, health, and quality of life.”

Robert Watts, the chief executive officer of the National Health Care for the Homeless Council, told Healthline that a lack of affordable housing puts people at direct risk for outbreaks of diseases like hepatitis A.

He said a “lack of housing, lack of place of washing and bathing, and taking care of going to the bathroom in a responsible way” all likely contributed to this outbreak.

Barbara DiPietro, senior director of policy at the National Health Care for the Homeless Council, said a lack of safe and clean housing can mean more outbreaks of other diseases.

She said tuberculosis outbreaks have been a problem at other shelters in the country.

“When you have a lot of people who are living in close proximity and have diminished immunity, shelters can unfortunately be breeding grounds for disease,” she said. “Shelters are not a substitute for housing.”