The Centers for Disease Control and Prevention (CDC) has just issued a warning that people in 19 states may have been exposed to a drug-resistant bacteria if they drank raw, unpasteurized milk from a farm in Pennsylvania.

Health officials said that they are “investigating potential exposures to Brucella strain RB51” in the following states: Alabama, California, Connecticut, Florida, Georgia, Iowa, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina and Virginia.

“This type of Brucella is resistant to first-line drugs and can be difficult to diagnose because of limited testing options and the fact that early brucellosis symptoms are similar to those of more common illnesses like flu,” the CDC explained.

The contaminated milk came from Miller’s Biodiversity Farm in Quarryville, and at least one case of someone getting sick from the milk has already been confirmed in New York. The farm’s website describes itself as a “private food club” that  “allows its members access to buying food directly from farms and other vendors, bypassing the supermarket.”

The CDC also said that the cow who tested positive for RB51 has since been “removed from the milking herd” on the farm.

Drinking this kind of raw milk can lead to someone getting brucellosis, the symptoms of which include fever, sweats, weight loss, fatigue, joint pain and headache, among other things.

“People who last drank raw milk from this dairy more than six months ago and have had symptoms of brucellosis – but not been treated – should see their doctor immediately for testing that can determine if they are infected and need antibiotics to prevent long-term health problems caused by brucellosis,” the CDC said.