Ultimately, over 650 confirmed cases, both primary and secondary, were linked to this outbreak. The victims included at least 13 employees of the Chi Chi’s restaurant, and numerous residents of six other states. Four persons died as a consequence of their hepatitis A illnesses. In addition, more than 9,000 persons who had eaten at the restaurant during the period of potential exposure, or who had been exposed to ill persons, obtained immune globulin shots as protection against the hepatitis A virus.
The Pennsylvania Department of Health and the federal Centers for Disease Control and Prevention (CDC), along with the U.S. Food and Drug Administration (FDA), conducted further studies investigating the incident. The FDA issued a statement dated December 9, 2003, reaffirming that this outbreak was associated with eating raw or undercooked green onions.