A hepatitis A outbreak has sickened at least 50 people in Virginia, with one person dying and another requiring a liver transplant. The cases have been linked to a restaurant employee who worked at a local chain’s various locations. Though the outbreak’s spread is now thought to be largely contained, health officials have warned that more cases may emerge.

The outbreak was first reported in late September, when officials from the Roanoke City and Alleghany Health Districts announced that ten people had become ill with the viral illness. All of these cases were linked to the Famous Anthony’s restaurant chain. Their investigation eventually led them to the most likely source: an employee who had recently worked at three different locations where cases had been discovered and tested positive for the virus.

Officials announced the first death in connection with the outbreak about two weeks ago, a 75-year-old man with underlying health conditions who frequented the restaurant. Another victim was said to require a liver transplant. This week, health officials confirmed to local media outlets that 50 cases have been discovered so far, with 31 people hospitalized as a result.

Hepatitis is defined by doctors as liver inflammation, with viruses being the most common cause. Despite the name, none of the five main causes of viral hepatitis (A through E) are related, but they do cause similar acute symptoms. Fever, headache, nausea, abdominal pain, discolored urine, and jaundice are some of the symptoms. Hepatitis B and C can develop into chronic infections that cause long-term liver damage, whereas A and E usually cause self-limiting, albeit unpleasant, bouts of illness (hepatitis D is weird even among viruses, since it only can survive as a co-infection with hepatitis B). Hepatitis A, like B and C, can be transmitted through bodily fluid contact, but it’s also a foodborne infection.

The initial infection happened in August, and subsequent victims were exposed until August 27. Because the virus has a 50-day incubation period and no new cases have been identified as of October 15, officials are confident that the chain of transmission has been broken. However, because a small percentage of people can remain symptomatic for up to six months, it’s possible that more cases linked to the original outbreak will be reported in the future. It is also possible that additional secondary infections will be discovered. Forty-nine of the fifty cases have been linked to Famous Anthony’s, but one was most likely caught from a person who became ill at the restaurant.

Hepatitis A isn’t a concern for some, but not all, Americans because a childhood vaccine has been available since the 1990s. Every child should be vaccinated beginning at the age of one, and protection has been shown to last at least 20 years and may be lifelong. However, it is only required for students in about half of the country. Restaurant employees, who may come from countries where vaccination is not available, may be especially vulnerable to outbreaks. In addition, due to large-scale outbreaks, cases of hepatitis A in the United States have been on the rise in recent years.

Virginia health officials have been holding vaccination clinics in response to this outbreak. Even after exposure, the vaccine can prevent illness if administered soon enough.