( CNN ) -- As many as 5,000 people may have passed recently through a Missouri restaurant where an employee with hepatitis A worked while possibly contagious , health officials said Wednesday . Red Robin said the employee last worked on May 16 and that the restaurant has been deemed safe after an inspection by the Springfield-Greene County Health Department . The New Jersey-based restaurant chain did n't say in what area of the restaurant the employee worked but told diners who ate there between May 8 and 16 to call the health department for information about what to do next . `` It scared me because my husband has been sick , '' Andrea Hall , a Red Robin customer , told CNN affiliate KOLR . `` And a lot of his symptoms of his matched . A red flag just went off and I was like what do I do from here . '' Hepatitis A is usually transmitted via contaminated food or water , or by someone who 's infected , according to the Mayo Clinic . Frequent handwashing is recommended to limit the spread . The highly contagious infection inflames the liver , limiting its ability to function . While mild cases do n't require treatment and the Mayo Clinic says most of those infected recover completely with no permanent liver damage , severe cases can lead to liver failure and death , according to the World Health Organization . Health officials in Springfield said symptoms include fever , nausea , abdominal pain , dark urine and clay-colored bowel movements . Vaccination center set up . All workers at the Red Robin have since been innoculated with a immune globulin prophylaxis shot , the restaurant chain said . The health department will run a two-day vaccination clinic at Remington 's , a venue that hosts concerts and trade shows . On its Facebook page , the entertainment complex said 4,000 doses of a vaccine were being shipped there . According to the Centers for Disease Control and Prevention , the incubation period for hepatitis A is between 15 and 50 days . The CDC says on its website that immune globulin offers protection for about three months for people who get the shot pre- or post-exposure . But the shot needs to be given within two weeks of exposure for maximum protection . Many people already have been given a two-step vaccine , which was introduced in the United States in 1995 . The CDC estimates that 17,000 people contract hepatitis A each year . CNN affiliate KYTV reported that thousands more customers might have been exposed to the virus because the infected employee worked for Red Robin for several months . They should watch for symptoms , the station said . Hepatitis A scare at NYC restaurant prompts 239 to get vaccinated . Stores may have received tainted beef .
A Red Cross worker in Springfield , Illinois , was infected with an infection . The employee last worked on May 16 . Shot that offers protection only effective if taken within two weeks of infection . People who dined before May 8 may have been infected but it 's too late for them to get a shot .