The Long Beach Post reports that health officials in Long Beach notified recipients of Meals on Wheels that they may have been exposed to hepatitis A, a highly contagious liver infection, in late May and June.

The nonprofit delivers meals five times a week to about 400 people in Long Beach who can’t shop for themselves and live alone, most of them elderly. The Long Beach Health Department sent letters to those who consumed food delivered by the agency on May 23, May 31, June 6 and June 13, warning them of the possible exposure.

The individuals “were notified as standard public health practice, but the risk of developing Hepatitis A infection is low,” the Health Department said in a statement Thursday. “Meals on Wheels has cooperated fully and there is no ongoing risk to eating Meals on Wheels food.”

Meals on Wheels Executive Director Bill Cruikshank said the incident stemmed from a volunteer who was helping package food, but couldn’t provide further details due to privacy laws.

“This was a very low-risk exposure,” he said.

The Health Department advised those who were notified to get vaccinated for hepatitis A if they haven’t already, and to monitor any symptoms of the illness, which include diarrhea, stomach pain, dark-colored urine, fever, jaundice, nausea, vomiting, loss of appetite and muscle pain.

There is no treatment for the virus, which typically goes away on its own.

The virus is spread through contact with someone who is positive, or by ingesting food or water that has been contaminated with feces from an infected person.