NEW YORK (AP) — A Virginia health official says a second person has tested positive for norovirus after eating at a Chipotle before it was temporarily closed last week following reports of illnesses.

David Goodfriend, director of the Loudoun County Health Department, says two people now have tested positive for norovirus. Goodfriend had previously said a second confirmed case would give a strong indication norovirus was behind the reported illnesses. He said more information would be released later Monday.

Chipotle reopened the suburban Washington, D.C., location Wednesday after a "complete sanitization." It noted its procedures to deal with the issue quickly and said its food was safe to eat. Its stock nevertheless fell, underscoring its vulnerability following past food scares. The shares were down again Monday.

The company has been working on winning back customers since an E. coli outbreak in the fall of 2015, which was followed by a norovirus outbreak at a single restaurant later that same year.

Norovirus is a leading cause of illnesses from contaminated food, and infected employees are a frequent source of outbreaks, according to the Centers for Disease Control and Prevention. The agency says one out of six Americans get sick each year by consuming contaminated food or drinks more broadly.

Goodfriend says some of those sickened were Chipotle employees.