AUGUSTA, Maine (AP) The Maine Center for Disease Control says the state has seen four cases of hepatitis A over the past three months.

The agency says the state has seen a total of six cases of hepatitis A so far this year, and the increase in recent months is “unusual.” Hepatitis A is a contagious liver disease caused by a virus that can cause severe sickness that lasts several months.

Symptoms of an infection can include tiredness, low appetite, stomach pain and jaundice. Children who are younger than six often do not have symptoms.

The disease can be spread through contaminated food and water or through sexual contact. The Maine CDC is reminding residents that there is a vaccine to prevent the disease, and that is the best way to prevent it.