Nineteen people have now died in California’s hepatitis A outbreak, a week after a state of emergency was declared, according to the BBC.
Over 500 people in California have contracted the disease since November—the second-largest U.S. outbreak of hepatitis A in the last 20 years.
Many of the diagnoses are of homeless people, with the disease being spread by touching contaminated food or objects, or through sex.
The disease attacks the liver and is often spread through faecal matter.
Because it is transmitted from hand to mouth, it is most likely to spread in unsanitary places.
In San Diego, officials have been disinfecting streets with bleach and encouraging people to use hand-washing stations.
Cases have also emerged in Los Angeles, San Francisco, and Santa Cruz.
According to officials, usually only one out of 100 patients die from hepatitis A, but it has killed more in California because of the vulnerable people it has affected.
Officials say it may take months or years before the outbreak is over.